en mogpr wrt m /. a 111°? P7 Fay 25” a : 72 4'.:—'/~ Af CAL . J f Nd [ Petrography of Some (= of Paleozorc Age EARTH SCIENCES LIBRARY From Borings in Florida hw GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-A Petrography of Some Sandstones and Shales of Paleozoic Age From Borings in Florida By DOROTHY CARROLL SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 4+54+-A A description of thin sections of the rocks and of their heavy minerals UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 EARTH SCIENCES UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. 4S4 FARM SCIENCES LIBRARY CONTENTS Page Page 22 enne eee. coon e ene on e ade awa iaa aut . Ar | Heavy 00.0 A9 cc u 1 individual minerals..:... L......" _i} ;o ___I, 10 "...lol... 4 Mineral assemblages. . .l _o cnl "UC 12 Stratigraphy of Paleozoic rocks, by Jean M. Berdan_____ 4a l {.f 12 Methods .}. ti _ c_} 0 Ruoff 15 Sandstones nso _n... ce nen nen .e 4 References .cn ln col DL 15 ec. ss 8 ILLUSTRATIONS Page 1. Map of Southeastern United States showing known areal distribution of subsurface rocks of Paleozoic age in andladjacent n. all coal tunic aut tenia tto ae A2 2. Index map showing locations of wells in Florida, Georgia, and Alabama from which rocks were examined.. ___ __ 3 8. Orthoguartsites and worm boring in silty cl [O_O 5 4. Fine-grained micaceous and clayey sandstones; red and biack ___ {/_ 6 o. Heavy minerals sepatated from sandstones and shale.... _.. ..... __ _...}! l_ [_ 1} [Ql _ O00} 10 6. Heavy-mineral assemblages in sandstones from wells in an approximate north-south traverse of the Peninsular reh (line A, fig. 2)-- cl alma ian al nlc ct tp t rt oc 12 7. Heavy-mineral assemblages in sandstones from wells in an approximate west-east traverse of the Peninsular arch (ne PB fis. L coe. moo denen thn c (O saran rin te ae tne ence ases 13 8. Details of the heavy-mineral assemblages in the sandstones in well 41 (Foremost Properties Corp. 1) ._________ 14 TABLES Page Tastes 1. List of wells in Florida and adjacent states from which rocks were examined.-...__...._._.. ~ /l." .}}. A1 P of thin sections e" nfonacecus rocks... _.... __ 10 [_ [[ 00 CCI, [[. 7. 8. Petrographic and mineralogic data on samples from wells penetrating Paleozoic sedimentary rocks in Florida gnd.adjncont states (well- data from Applin, 4081 _._... ~...... 0100... 0. C04 Ior el {tc 9 4. Distribution of tourmaline shapes in heavy-mineral assemblages from sandstones in the Paleozoic rocks of Nde err e ien cloe corect o ine agi at inc liane ee he oat oad 11 IH SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY PETROGRAPHY OF SOME SANDSTONES AND SHALES OF PALEOZOIC AGE FROM BORINGS IN FLORIDA ' By Dorotry Carrount ABSTRACT Sandstones, orthoquartzites, and other arenaceous sediments and black and red shales occur in the basement rocks of Florida and adjacent parts of Georgia and Alabama. Most of the sand- stones are Early Ordovician in age. The shales range in age from Middle Ordovician to Middle Devonian. The quartzites range in mineralogic complexity from sub- mature to mature. Feldspars are scarce. Micaceous and clayey sandstones can be classed as subgraywackes. Many of the quartzites grade into siltstones that are intercalated with shaly and micaceous layers. Such beds show disturbed bedding and penetration by worm borings. Many beds contain calcite and siderite. All the arenaceous sediments contain small amounts of heavy minerals. Three characteristic heavy- mineral assemblages were recognized. The kinds of minerals present indicate that these rocks are of granitic and metamorphic provenance, although rounding of the grains suggests that most of the rocks were derived finally from second- or third-cycle sediments. The black shales contain abundant organic matter, pyrite, and, commonly, interlaminations of siderite and calcite. The color of the red shales is due to minute blebs of hematite in the micaceous matrix. INTRODUCTION Core samples and thin sections of sandstones and other arenaceous rocks in the Paleozoic strata in Florida and adjacent parts of Georgia and Alabama and of overlying red and black shales were made available for examination by Jean M. Berdan, U.S. Geological Survey. These rocks were penetrated by test wells for oil. The cores are largely from the pre-Mesozoic sedimentary rocks that are sparsely fossiliferous or nonfossiliferous. The fossils found indicate that the beds range in age from Early Ordovician to Middle Devonian. The lithology of the sediments penetrated by the wells was described by Applin (1951), and a brief description of the mineralogy of a few samples was given by Carroll (19592). Applin (1951) summarized the records of 78 wells drilled into the pre-Mesozoic rocks. Since then addi- tional wells have been drilled. Some of the earlier wells penetrated igneous rocks such as rhyolite and tuff. The dominant subsurface structural feature of north-central. Florida and southeastern Georgia is a large anticlinal fold, or arch, about 275 miles long. Applin (1951) named this feature the Peninsular arch. Paleozoic rocks occupy an area of about 25,000 square miles in the Peninsular arch (Applin, 1951, p. 13). The distribution of these rocks is shown in figure 1. Preliminary correlations of the sandstones and shales penetrated by the wells listed in table 1 were made by Bridge and Berdan (1952). The purpose of this paper is to give petrographic descriptions and information on the heavy minerals in sandstones and shales penetrated by the wells. The work was started in 1954 at the request of Jean M. Berdan, U.S. Geological Survey. No correlations of beds have been made as a result of this work, although the heavy minerals present suggest that correlation may be possible if extensive examinations of the rocks are undertaken. The wells, however, do not penetrate very far into rocks of Paleozoic age. The wells from which samples were examined are shown on figure 2. Taste 1.-List of wells in Florida and adjacent States from which rocks were examined [Core sample: X indicates cores examined. Thin sections: An asterisk indicates slides described in table 3. The numbers following the initials of the wells are the core numbers used by the companies drilling the wells, except for well 70, where the depth is given in feet below the land surface] Core Thin sections sample Well Name and location 23 | Sun Oil Co. Henry N. Camp 1, see. 16, T. X 16 S., R. 23 E., Marion County, Fla. 30 | Union Producing Co, E. P. Kirkland 1, X see. 20, T. 7 N., R. 11 W., Houston County, Ala. 36 | Tidewater-Associated Oil Co. R. H. Cato X 1, sec. 23, T. 8 S., R. 18 E., Alachua County, Fla. 37 | Tidewater-Associated Oil Co. Josie Parker X 1, see. 33, T. 7 S., R. 19 E., Alachua County, Fla. *Cp-21, *Cp-22, Cp-28 *K-38, *K-39, *K-41, *K-46 *Ca-14 *JP-31, *JP-37, *JP-38 38 | Tidewater-Associated Oil Co. _J. A. Phifer xX *P-20 1, sec. 24, T. 9 S., R. 21 E., Alachua County, Fla. A 39 | Hunt Oil Co, H. L. Hunt 1, see, 21, T. 1 |..__._.. Hu-15 N., R. 20 E., Baker County, Fla. & 40 | Tidewater-Associated Oil Co. M. F. |..____-. *Wwg-4 Wiggins 1, see. 15, T. 6 S., R. 20 E., Brad- ford County, Fla. 41 | Humble Oil & Refining Co. Foremost X Properties Corp. 1, see. 4, T. 6 S., R 25 E., Clay County, Fla. **F-43, FM-71, FM- 78, *FPM-169 Al SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY EXPLANATION Sedimentary rocks of Triassic age I Sedimentary rocks of Paleozoic age F7 & Metamorphosed vol rocks of possi O ® 3 ic and sedimentary Paleozoic age & ® I i I i \ _- Subsurface sedimentary rocks of Paleozoic age in Florida and adjacent areas Metamorphic and plutonic rocks of Precambrian age and Paleozoic age S 290 MILES Geology by Marcia Newell and Jean M. Berdan, 1960 Geology of Piedmont area generalized from the Tectonic Map of the United States, 1961 FicurE 1.-Map of Southeastern United States showing known areal distribution of subsurface rocks of Paleozoic age in Florida and adjacent areas. PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA A3 TaBus 1.-List of wells in Florida and adjacent States from | Tamum: 1.-List of wells in Florida and adjacent States from which rocks were examined-Continued which rocks were examined-Continued Well Name and location Core Thin sections Well Name and location Thin sections sample 42 | Humble Oil & Refining Co. J. P. Cone 1, X C-122, C-132, C-141, 63 Hunt 011 Co. J. W. Gibson 4, see. 5, T. 2 S., *G4-7 see. 22, T. 1 N., R. 17 E., Columbia C-150, C-153, C-160 R. 11, E., Madison County, Fla, County, Fla. 66 | Sun 011 Co. H. T. Parker 1, see. 24, T. 14 S., *HP-17 43 | Sun Oil Co. Ruth M. Bishop 1, see. 10, x *Bi-1 R. 22 E., Marion County, Fla, T. 4 S., R. 17 E., Columbia County, Fla. 68 | Sun Oil Co. and Seaboard 'Oil Co. Q I *Ro-1 44 | Sun Oil Co. W. F. Johnson 1, see. 27, T. |...... *J-29 Roberts 1A, see. 19, T. 9 S., R. 4 S., R. 16 E., Columbia County, Fla. Putnam County, Fla. 45 | Sun Oil Co. Clarence Loyd 1, see. 11, T. *Lo-23 69 | Sun Oil Co. Earl Odom 1, see. 31, T. 5 S., 0-8, 0-9 5 8., R. 17 E., Columbla County, Fla. R. 15 E., Suwannee County, Fla. 46 | Sun Oil Co. M. W. Sapp 1A, see. 24, T. xX 70 | Sun Oil Co. A. B. Russell 1, see. 8, T. 5 8. , *Ru-3139 2 8., R. 16 E., Columbia County, Fla. R. 15 E., Suwannee County, Fla. 47 | Stanolind Oil & Gas Co. and Sun Oil Co. | _ X | *PF-69, *PF-75 71 | Sun Oil Co. J. H. Tillis 1, see. 28 T.i8.R. T-44 Perpetual Forest, Inc. 1, see. 5, T. 11 S., 15 E., Suwannee County, Fla. R. 11 E., Dixie Countv Fla. 73 | Mont Warren et al. A. C. Chandlerl Lot Ch-5 49 | Sun Oil Co. Hazel Langston 1, sec. 8, T. x *L-14 406, Land District 26, Early County, Ga. R 8 S., R. 14 E., Dixie County, Fla. 74 | Humble Oil & Refining Co. Bennett and BL-44 52 | Ohio Oil Co. Hernasco Corp. 1, see. 19, % *H-166, *H-167 giggly-12:19 1, Lot 146, Land District 12, T. 23 S., R. 18 E., Hernando County, chols County, Ga. Fila 75 Hunt Oil Co. Superior Pine Products Co. 57 | Humble Oil & Refining Co. R. L. Hen- |___... *He-152, *He-157, *He- E 031053}? Land District 13, Echols m * a a gsg'btfifgf‘ii‘g 4. S,, R. 11 E., Lafay 162, *He-185 76 | Hunt 011,00 Superior Pine Products Co. *SPP2-5 58 | Sun Oil Co. P. C. Crapps 1, see. 25, T. | X | Cr-155 (Lower Creta- 330151” 317 Land District 13, Echols * - ~- : HE, Lafeyette County, Pis. O* 004109 |. ao1 | Gulf Oil Co. Brooks-Seanlon, Inc., Block *Bs3r 59 | Coastal Petroleum Co. J. B. and J. P. | % 1g lAtiecmlS T. 6 S., R. 9 E., Taylor Ragland 1, see. 16, T. 15 S., R. 13 E., a £131“ 3K Lely Coghiy Pio io | out oi fop th T as. *R- ! R 60 Hfifggfgsog‘} doe. {lgflfllmfis irony, | o ote hoe 103 | National Turpentine & Pulpwood Corp. NT-24, *NT-25 | Levy County, Fla. Fee 1, see. 7, T. 4 S., R. 19 E., Baker 62 | Hunt Oil Co.J. W. Gibson 2,see.6, T.18., | x | G22 County, Fla R. 10 E., Madison County, Fla. 85° 84° 83° 82° 81° 73 ALABAMA (\ ( m mM mao _ ._ 31° v as I 074 ae, - % \ 76 "t Pm | 6° 9 f &C FLORIDA NT he Moma int te nomics ay §_-7 \] t> Tallahassee 42 39° % % f 9 62 t 5 3 sl € ( \ T ~-o41 |---j30° G C 068 9 ¥ br A 6 U L p 0 I Daytona Ir Beach» & | 23 E \29° 10 0 10 20 30 40 50 MILES .Orla.ndo FrGurRE 2.-Index map showing locations of wells in Florida, Georgia, and Alabama from which rocks were examined. A4 ACKNOWLEDGMENT I am indebted to Jean M. Berdan, U.S. Geological Survey, for supplying the core samples used in this investigation, for many helpful discussions as the work progressed, and for many checks of the well data. STRATIGRAPHY OF THE PALEOZOIC ROCKS By Jran M. BErDAN The Paleozoic rocks underlying Florida and adjacent parts of Georgia and Alabama range in age from Early Ordovician to Middle Devonian. As none of the wells have penetrated strata with a succession of faunas, dating by means of direct superposition is not possible; nevertheless, an approximate sequence of beds can be inferred from the fossils. On this basis, the oldest unit is a series of quartzite and quartzitic sandstone inter- bedded with micaceous shales which commonly contain Scolithus burrows. This unit is about 1,800 feet thick and is dated as Early Ordovician on the basis of the graptolites present in one of the wells (No. 30). It is overlain by about 300 feet of white, tan, and pale-pinkish-red unfossiliferous quartzitic sandstone, which is also assumed to be Early Ordovician in age because of its stratigraphic position. About 1,200 feet of dark-gray to black shales, with minor thin sandstone beds, of Middle Ordovician to Late Silurian age pre- sumably overlies the quartzite, although none of these shales have yet been found in contact with the quartzite. In one well (No. 74) about 65 feet of fine-grained sand- stone and interbedded dark shale dated as Late Silurian by James M. Schopf (written communication, 1959) suggest a return to arenaceous sedimentation in Late Silurian times. The unit of sandstone and interbedded shale repre- sents the youngest Paleozoic rock yet found on the Peninsular arch. In western Florida and Georgia, however, near the junction of the boundaries of Georgia, Florida, and Alabama, two wells penetrated strata which are as young as Middle Devonian. One of these (well 53) penetrated 805 feet of gray and pale pinkish- red siltstones and fine-grained sandstones containing plant fragments, the other (well 73) penetrated 720 feet of dark-gray and brownish-red shale and gray fine- grained sandstone with a fauna of ostracodes and small pelecypods. Whether these two wells represent con- temporaneous facies or whether one is slightly older than the other has not yet been determined. All samples of arenaceous rocks described in this report are from Lower Ordovician units, except one sample (well 74) that is from an Upper Silurian unit. The shales, on the other hand, range in age from Middle Ordovician to Middle Devonian. Four wells pene- trated red or brownish-red shales below which black SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY shales were cored. Except at the site of one well (No. 3), where Middle Devonian strata were cored, the red shales of differing ages lie just below the pre-Meso- zoic unconformity and are not interbedded with the underlying black shales. This has led some geologists to consider that the red color might be the result of weathering of the top of the Paleozoic rocks. METHODS OF EXAMINATION Many of the sandstones and shales were examined in thin section only, but sufficient sedimentary material was available from some samples to concentrate the heavy minerals. Thin sections were used to identify the minerals, to compute the modal compositions of some sandstones and shales, and to measure grain sizes. For heavy-mineral analysis the core samples were crushed to minus 60 mesh (0.25-mm grain diameter), weighed, and heated in 1+ 1 HCl to remove soluble material. - The loss on acid treatment was recorded as soluble minerals, mostly calcareous. The insoluble residues were dried and weighed and then sieved through standard sieves to obtain a fraction, 0.12-0.06- mm grain diameter, that is suitable for microscopic examination. - The heavy minerals in this fraction were separated by bromoform (sp gr 2.8). The heavy resi- due was weighed and expressed a percentage of the fraction separated. - The minerals were identified opti- cally, and the percentage of each mineral in a residue was estimated by partial grain count. Tourmaline grains, which are very resistant to weathering and abrasion, were examined more closely than other detrital grains, because they are present in nearly all the residues and therefore can yield information about history and possible sources of supply of sedimentary materials better than most other minerals. All the sandstones yielded small quantities of detrital minerals, but the shales yielded only negligible amounts. The clay minerals in the shales, but not in the sandstones, were identified by John C. Hathaway, U.S. Geological Survey, using the X-ray diffraction method. SANDSTONES Macroscopically the arenaceous rocks consist of fine silty sandstone interbedded with thin dark shale layers and laminations and of clean white orthoquartzites. Most of the sandstones are orthoquartzites that are nonfeldspathic or contain only a very small (about 1 percent) amount of feldspar. Some of the sandstone is more properly described as subgraywacke with angular quartz grains in a matrix of micaceous clay. Mica is commonly present on bedding planes; it has probably been reconstituted into larger grains by pressure of overlying sediments. PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA A5 Fraur® 3.-Orthoquartzites and worm boring in silty sandstone. A. Orthoquartzite, well 57 (Henderson 1). Depth below sea level, 4,180.5-4,181 feet. Compact quartzite with some overgrowths and no matrix. Average grain size, 2104. Crossed nicols. B. Orthoquartzite, well 52 (Hernasco Corp. 1). Depth below sea level, 8,183-8,185 feet. Modal composition: quartz grains 95 percent; siliceous matrix, 4 percent; and microcline, 1 percent. - Uneven grained with some rounded grains of quartzite and some large strained quartz grains. - The smaller grains are angular, and there are many sutured contacts. Average diameter of quartz, 8604; average size of matrix, 804. Crossed nicols. C. Orthoquartzite, well 37 (Josie Parker 1). Depth below sea level, 3,143-3,150 feet. - Well-rounded quartz grains set in a cement of chalcedony. Modal composition: quartz, 73 percent; chalcedony, 27 percent. Average grain size of quartz is 2104. - Crossed nicols. D. Cross section of worm boring, well 39 (Hunt 1). Depth below sea level, 3,342-3,343 feet. The tube filling consists of fine quartz and clay. The rock penetrated is fine sandstone with interbedded silty layers. Boring is about 10 mm in diameter. Plane polarized light. ‘ 677-291 O-63-2 A6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY The relation between the component mineral grains of the sandstones, as shown in thin section, is given in table 2. The rocks range from compact angular orthoquartzites to argillaceous sandstones. Quartz is the most abundant constitutent. The appearance in thin section of the different types of quartzite and micaceous sandstones or siltstones is shown in figures 3A-D and 4A, B. The grain size and modal composi- tion are given in the explanations of the figures. FIGURE 4.-Fine-grained micaceous and clayey sandstones; red and black shale. PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA A7 TaBus 2.-Descriptions of thin sections of arenaceous rocks [Criteria for describing sandstones and quartzites after Siever (1959)] Clay: I, irregular filling; C, reconstituted. Detrital contact of quartz grains; O, no interpenetration; +, slight interpenetration; Mica: D, detrital; C, reconstituted. +++, sutured. Carbonate: F, indefinite filling; X, well crystallized. Secondary quartz, O, none; +, 10 percent pores filled; +--, 10-75 percent pores filled; Pebbles: M, metaquartzite; V, vein quartz; Ch, chert. +++, >75 percent; Cy, chalcedony. Detrital outline of quartz grains: O, none; R, rounded and free; +, <10 percent; ++, Authigenic contacts of quartz grains: O, no interpenetration; +, sutured interpene- >10 percent. tration. Components of rock Depth of sample Quartz grains Well | below sea level Rock description (feet) Slide Clay | Mica | Carbon- | Pebbles ate Detrital | Detrital | Second- | Authi- outline | contact ary genic quartz contact 30 7,772 4-4 + + Compact angular quartzite with very little cement. 30 7, 891 O + Compact angular quartzite with sutured contacts. 30 7, 897-7, 907 + Se cito Fifigsgrained calcareous, micaceous quartzite (fig. 30 8, 078 0 0 Fine-grained calcareous silty quartzite. 23 4, 500-4, 510 ++ +, Cy <- Coarse-grained quartzite. f 23 4, 371-4, 378 +++ +, Oy + Ffilfipathic quartzite with microcline and other eldspars. 36 3,140-3,150 | Ca-14......._|._______ DO. { ++ 0 0 Micaceous quartzite with recrystallized mica. 37 2,072-2,082 | ..... F.} s Ce R 0 ++, Oy | 0 Quartzite with well-rounded grains cemented with chalcedony and carbonate (fig. 3C). 37 3, 032-3, 035 + Cy + erleiwéen figined closely packed quartzite, slightly eldspathic. 37 3, 035-3, 042 0 0 0 Fine-grained graywacke. 38 3, 093-3, 095 ++ ++ + Quartzite with well-rounded closely packed grains. 39 3, 212-3, 213 0 O O Fine-grained calcareous shaly sandstone with worm boring (fig. 3D). 40 3, 152-3, 154 + 0 -+ Clayey to micaceous, calcareous quartzite. 41 4/0264, DOLA AE M-45..... . . co 12 2 ee ons Ie ne den {e nie cede |e cede ena daelaee (nena nene a 1s ne'e b o ol ba fas nea on Shale with chert inclusions. 4, 938-4, 041 4 0 0 Quartzite with schistose shaly inclusions. 43 2, 649-2, 654 -+ O 0 Fine-grained quartzite with well-rounded to sub- angular grains. 44 2, 947-2, 048. 5 4-4-4 + + Fine-grained quartzite of second cycle material. 45 2, 928. 5-2, 928 O 0 Quartzite with rounded to subangular small grains. 47 5, 310-5, 317 0 0 Fine-grained feldspathic quartzite; broken quartz at some grain boundaries. 47 6, 242-6, 244 | PF-75(1)..___|..._.___. PRO NAH L 44+ 4+ 0 0 Micaceous, feldspathic quartzite; patchy composi- tion. 47 6, 242-6, 244 | PF-75(2)..... T} s M +-- 4-4 0 0 Clayey feldspathic quartzite. 49 9,008-8,071) | O NUN ese ve J+ ++ + + Uneven grained quartzite, closely packed, with a matrix of chaicedony and mica. 52 8,121-8,125 | H-167........ I C in 4+ ++ +, Oy 0 Comic-grained quartzite with clayey micaceous 1 matrix. 62 8,136-8, 138 | H-166.._..... I 0 es eca M 0 +++ +, Oy 0 Coarse, uneven-grained feldspathic quartzite; strained quartz (fig. 3B). 67 (80.04.4181 | Ho152. 20sec + + J+ 0 Quartzite, closely packed; rounded grains with re- growths (fig. 34). 57 4, 187-4, 189 -} + 0 Fine-grained closely packed quartzite. 57 7 s O O 0 Fine silty sandstone. 67 | 4,213-4,213.5 ++ Spe: (o ice Closely packed quartzite with secondary silica. 58 4, 120-2 4,133 0 0 0 Fine-grained silty quartzite interbedded with shale. 58 3, 926-3, 955 0 0 + Angular to subangular quartzite with shale inclu- sions. See footnotes at end of table. EXPLANATION OF FIGURE 4 A. Fine-grained micaceous, calcareous quartzite, well 30, (Kirkland 1). Depth below sea level, 7,897-7,907 feet. Modal composi- tion: quartz, 50 percent; matrix, 32 percent; and mica, 18 percent. - The quartz is angular and subangular and is surrounded by a micaceous matrix. - Quartz grains average 444, and the matrix patches average 484 across. - The micaceous bands are 1154 wide. A little calcite is present as a packing around the quartz grains. Crossed nicols. B. Clayey micaceous quartzite, well 66 (H. T. Parker 1). Depth below sea level, 3,836-3,845 feet. Modal composition: quartz, 69 percent; matrix, 27 percent; and mica, 4 percent. The matrix is poorly crystallized mica that has apparently formed authi- genically from original clay. Laths of mica have formed under pressure and in some parts of the section laminae of mica occur. Average grain size, quartz, 874, matrix, 764. Plane polarized light. C. Red shale, well 75 (Superior Pine Products 1). Depth below sea level, 3,828-3,833 feet. A somewhat schistose shale with rather coarse, angular quartz and recrystallized mica. The red coloring is due to finely divided iron oxide, probably hematite. Some of this oxide is submicroscopic in size, but larger distinct rounded blebs may be oxidizing pyrite. Crossed nichols. D. Black shale, well 42 (Cone 1). Depth below sea level, 3,562-3,587 feet. Shale consists of very fine grained angular quartz and: carbonaceous matter interlaminated with well-crystallized siderite and minor calcite. The siderite is slightly oxidized in places so that reddish-brown rims occur at the edges of the laminae. The clay material occurs as very fine micaceous laths and as in- definite aggregates that exhibit aggregate polarization. - A little carbonate also occurs as minute irregular patches in the clay matrix. Plane polarized light. AS SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaBu® 2.-Descriptions of thin sections of arenaceous rocks-Continued Components of rock Depth of sample Quartz grains Well | below sea level Rock description (feet) Slide Clay | Mica | Carbon- | Pebbles ate Detrital | Detrital | Second- | Authi- outline | contact ary genic quartz contact 60 4, 439-4, 456 0 + 0 Quartzite with clayey matrix; grades into shale. 63 3, 904-3, 996 ~-} -+ 0 Quartzite with well-rounded closely packed grains. 66 3, 757-3, 766 4+ 0 + Micaceous quartzite (fig. 4B). 66 3, 757-3, 766 O 0 0 Micaceous, feldspathic quartzite. 68 3, 118-3, 120 44 +, Oy + Coarse-grained quartzite, partly recrystallized. 70 3, 043 4+ PLH C Closely packed uneven grained quartzite with iron # oxide films. 74 4, 178-4, 179 Lo 0 0 Quartzite with shale inclusions; quartz grains in a micaceous matrix. 76 3, 845-3, 850 0 0 0 Argillaceous quartzite. 101 4, 780 +++ 0 0 Tightly packed even-grained quartzite. 103 2, 885-2, 800 +++ Cy 0 Quartzite with subangular to rounded grains. 1 Probably chlorite. 2 Bottom. 3 6th 20 feet. The coarser quartzite has quartz grains 2004 to 3604 in diameter. In the finer grained or silty sandstones, the quartz grains range in diameter from 454 to 854. Feldspar, where present, is microcline but is very scarce. Most of the coarser grained quartzites are compact, with the grains packed together tightly. Many typical quartzites contain grains of metaquartzite, as well as those of vein quartz, and quartz of unknown origin. Some quartzites have no matrix (fig. 34), whereas others contain chalcedony and scattered carbonate as cement. - Figure 3C shows chalcedony as a cement in orthoquartzite, in which the chalcedony amounts to nearly 30 percent of the rock by volume. Some quartzites have well-rounded grains, but others, such as that shown in figure 34, have grains with sutured contacts that indicate considerable pressure from overlying beds. Well-rounded quartz grains occur in some of the quartzites (fig. 3C). The finer grained clayey micaceous sandstones are shown in figure 44, B. In the sandstone in figure 4A, the clayey matrix has been somewhat reconstituted to mica, and some degree of orientation is apparent from the alinement of mica flakes into thin layers. A sandstone with angular to subangular quartz grains in a clayey matrix is shown in figure 4B. The matrix has not been reconstituted, although in a few places some rather well crystallized mica laths can be seen. A thin section through a typical worm boring is shown in figure 4D. The material in the tube consists of clay and fine-grained quartz that differ in grain size and appearance from the interlaminated shale and silt beds that were penetrated. The carbonate, where-present, occurs as very fine grains in rims around some quartz grains and in a filling between the grains. The percentage of carbonate present in these rocks is indicated by the figures for loss-on-acid treatment given in table 3. The amount ranges from 0 to more than 40 percent. Most of the sandstones examined contain about 20 percent of calcareous material, probably largely siderite. The oxidation of the siderite accounts for the light-tan to pinkish-brown color of many of the sandstones. SHALES The samples of red and black shales examined are given in table 3, and a thin section of each type is shown in figure 4C, D. The loss-on-acid treatment in the black shales ranges from less than 1 to 13 percent. Some of this loss is due to the presence of siderite and calcite, and some to the solution of iron compounds. In the red shales the loss ranges from 3 to 17 percent and is largely due to the removal of iron oxides. Data are given in table 3. The red shales are seen in thin section (fig. 4C) to consist of a fine micaceous clayey paste in which are embedded silt-sized angular quartz grains. Much of the mica is recrystallized into small laths. The red color is due to finely divided iron oxide, probably hematite. Some of this iron oxide is extremely fine, but elsewhere in the section distinctly rounded blebs may be oxidizing pyrite. The black shale in thin section (fig. 4D) ranges in lithologic character from rather dense black shale with abundant organic matter to black micaceous shale. In many thin sections siderite and calcite occur as well-crystallized layers. The siderite may be oxidized in places at the outside edges of the layers. The or- ganic matter is black and opaque. Clay is present as extremely fine micaceous laths and as indefinite aggre- gates exhibiting aggregate polarization. X-ray exam- ination by John C. Hathaway, U.S. Geological Survey, of material less than 24 in grain diameter from 15 samples of black shale and from 3 samples of red shale showed that both kaolinite and hydrous mica (illite) are present in almost equal proportions. PETROGRAPHY OF SOME SANDSTONES AND A9 SHALES IN FLORIDA TaBu® 3.-Petrographic and mineralogic data on samples from wells penetrating Paleozoic sedimentary rocks in Florida and adjacent States [Well data from Applin, 1951] Heavy minerals in 0.12-0.06 mm grade (approximate percent) Depth Loss-on- o o Surface | to top of Depth of acid Heavy 3 hs 4 g| §) & Well | elevation | Paleozoic} samples (feet) Rock treat- | residue! | ,, 4 " a 3| §| 3 (feet) | rocks ment | (percent) | 8 | , |. § 1 alel & 31 § 31! p (feet) (percent) ggsgggsgozggagggs ERIS RLE | 4&1 4 Slalilk| 8) a) §18 18 0| H| <| 4] o 42 141 3, 482 4,196-4,206 | Black shale............. 5.3 TE LLA IA Leol n EEE Aer rena e [Gece | Bs + lames 4, 281-4, 300 |...... do...< 8.2 Tr. s at - 4, 320-4, 330 |__... do.. 4.3 Tr. <4 - 4, 337-4, 347 |_____ do.. 5.8 Tr. +- a 4, 347-4, 354 |_____ do.. 5.8 T+. - 3, 485-3, 487.5 | Red shale... 3.0 0. 26 - 46 138 3, 303 3,200-8, 811 | Black shale 4222112020008 1.0... ACC # 59 14 5,810 | 5,791.5-5,796.5 | Red shale... 17 2.8 S 5,840-5,850 | Black shale. 15 Tr. - 62 107 4, 626 5, 154-5, 162 |__... 11.2 Tr. 69 73 3, 040 8, , 080 9.3 1.9 3, 152-8, 157 |___. 10.2 1.5 71 162 3, 500 3, 494-3, 502 8.1 71 3, 552-8, 508 |___. 8. 6 .6 73 187 6, 950 6, 636-6, 643 7.0 Tr. 7, 001-7, 042 11.2 Tr. 75 148 3, 782 3, 828-3, 833 8 4 102 117 3, 338 3, 450-3, 470 133.0 Tr. 23 74 4, 240 4, 445-4, 452 * nil 2 30 140 7, 556 7,856-7,897 | Sandstone 16 12 7,948-7,949 | Quartzite. 25 Tr. 7,983-7,995 | Black shal 55 Tr. 8,024-8,046 | Sandstone 33 Ts, 8,069-8, 100 | Sandy shale... 34 Tr. 36 112 3, 135 3, 130-3, 137 | Silty sandstone. 30 A 37 168 3, 170 3, 203-3, 210 | Sandstone... 27 Tr. 38 132 3, 127 3, 223-8, 225 | Quartzite... 4 2 41 115 3, 725 3, 753-3, 754 | Sandstone. 41 % 3, 760-8, 761 |___... do.... 21 (2 4, 076-4, 077 |___... do.... 14 4 4, 528-4, 580 |...... do.. 26 L 4,746-4, 751 | Shale... 22 .5 4, 938-4, 941 |___... do.. 290 A 5,051-5,061 |.... do:... 28 .3 5,242-5,252 | Sandstone. 28 .6 5, 653-5, 663 |__... do.... 26 .9 5,720-5,725 | Shale....._... 82 11 5, 778-5, 183 28 .9 5, 8590-5, 862 |.... d 87 +4 43 174 2, 813 2,824 | Shale..._..... 9 .2 47 33 5, 228 5, 415-5, 420 51 1.0 6,275-6, 282 | Sandstone... 18 2.0 6, 275-6, 382 |...... O2 sist :> 18 2.9 58 70 3, 923 3,996-4,025 | Silty sandstone.. 25 .2 4,127-4, 133 |_.__. O- 28 1 52 47 7, 220 8, 468-8, 472 | Sandstone. 8 .4 60 58 4, 377 4,384-4, 391 | Quartzite_______... 30 Tr. 4,393-4, 401 | Quartzite and shale.. 22 1.0 4,482-4,505 | Quartzite... 33 .2 4,506-4,530 | Silty sandsto: 16 Tr. 4,564-4,575 | Sandstone... 15 {4 76 142 3, 770 3, 845-3, 850 | Fine sandsto 19 «6 101 67 4, 809 4,874-4,876 | Quartzite... 13 Tr. 103 155 2, 884 3, 039-3, 040 | Fine sandstone. * Nil Tr: + + 3, 040-3, 043 |.... OLLI eri Nil Tr. 1 Heavy residue separated in bromoform; Tr., <0.1 percent; +, one or two grains only in the residue; 2 Mica in heavy residue only, most mica is in light fraction. HEAVY MINERALS The amount of heavy residues from sandstones and shales and the minerals identified in them are given in table 3. Most of the shales contain only pyrite and iron oxides in their heavy residues, but the black shale from well 62 (J. W. Gibson 2) contains detrital minerals similar to those in the sandstones. The amounts of heavy residues in the 0.12- to 0.06- mm grade ranged from less than 0.1 to 2.9 percent in the sandstones and quartzites. The minerals identi- fied are: the opaque minerals ilmenite, leucoxene, and pyrite; tourmaline; zircon; rutile; epidote; zoisite; garnet; glaucophane; hypersthene; amphibole; mica; sphene; corundum; chloritoid; anatase; and barite. 3 Loss on acid treatment, heavy residue, and heavy minerals not determined. + Heavy minerals not determined. Mica is very abundant in many of the fine silty sand- stones and on bedding planes, but because of its flaky nature most of it remains in the light fraction. The three following assemblages, or suites, of heavy minerals could be recognized in the residues: (A) Ilmenite, zircon, tourmaline, rutile; (B) garnet, epi- dote, ilmenite; and (C) ilmenite, garnet, tourmaline, glaucophane, chloritoid. Fine- to coarse-grained quartzites and quartzites with little mica or clay contain minerals of assemblage A. Fine silty sandstones and sandy shales contain minerals of assemblage B or C. The mineral grains of assemblage A are well rounded, but those of B and C are subangular. A10 The heavy minerals in these quartzitee and other arenaceous rocks do not in themselves have any very striking characteristics. The most abundant minerals (table 3) are ilmenite, zircon, tourmaline, garnet, and epidote. The remaining minerals are present in very small amounts only. Ilmenite, zircon, and tourmaline grains are well rounded in most of the residues. Both ilmenite and leucoxene grains have a polished appear- ance in reflected light. Figure 5 shows the appearance of typical heavy residues. INDIVIDUAL MINERALS Zircon grains have varietal features that may be of use in tracing their provenance when more is known of the detrital grains in the Paleozoic rocks of the Appalachian region. The zircon in most of the residues SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY is colorless, contains few inclusions, and is well rounded. In some residues, however, the colorless zircon is accompanied by a few grains of purple zircon, in the proportion of about 50 to 1. This proportion is similar to that described for the sandy beds of the Conoco- cheague Limestone (Upper Cambrian) in Virginia (Carroll, 1959b, p. 133). Several different types of tourmaline grains can be distinguished by their shapes and colors. Brown rounded grains are the most common. Brown tour- maline is the granitic type described by Krynine (1946, p. 68). Some blue pegmatitic tourmaline is present in many of the residues. Typical tourmaline grains are shown in figure 54, B. Two of these grains have overgrowths such as are formed authigenically on FIGURE 5.-Heavy minerals separated from sandstones and shale. up eom hm: arre arre re ag ope nme cn ope rosen r comm armies n imo rap nh PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA tourmaline in arenaceous rocks of the Appalachian geosyneline and elsewhere. Such overgrowths are apparently an epigenetic feature caused by leaching and alteration within the rock in which the grains occur (Nicholas, 1956; Carroll, 1959b). The shapes of the tourmaline grains were classified as angular, subangular, and well rounded. The per- centages of each type of grain in each residue were obtained from counts and are given in table 4. Table 4 indicates that the percentage of well-rounded tour- maline ranges from 0 to 60 percent. There does not seem to be any readily recognizable relation between the type of mineral assemblage and the percentage of well-rounded tourmaline that it contains. Table 3 shows that the amount of tourmaline in these residues varies considerably, however, and this is one basis for the distinction of assemblage A. Rutile generally occurs as well-worn dark-reddish- brown grains. It apparently belongs in the same cate- gory as the rounded zircon and tourmaline and was contributed by a source rock or rocks containing all three minerals. Epidote and zoisite (fig. 5D) are found with garnet of assemblage B. Both epidote and zoisite grains show the effects of abrasion. - Their presence indicates a con- tribution from crystalline rocks. Garnet (fig. 5C) occurs as sharp angular grains that have etched surfaces. These surfaces were probably produced by solution within the sediments in which the garnet occurs. - Most of the garnet is colorless, but pale- pink grains are present in some residues. The amount of garnet ranges from 20 to $5 percent in assemblage B and is commonly about 40 percent (table 3). Chloritoid, glaucophane, hypersthene, and amphibole are minor constituents of assemblage C. _ Their searce- ness suggests that much of these minerals were removed during transportation or that their source area is far off. Anatase occurs sparsely as authigenic crystals that have probably formed from the titanium released during the decomposition of ilmenite within the sediments. Sphene and corundum were identified in a few of the heavy residues but do not amount to more than a grain or two in any one of them. All TaBus 4.-Distribution of tourmaline shapes in heavy-mineral assemblages from sandstones in the Paleozoic rocks of Florida Depth of Tourma-| Percent of total tourma- sample Miner- line in line Well below Rock type alogic heavy sea level assem- | residue (feet) blage ! |(percent)| Angu- Sub- Well lar - |angular|rounded Samples from north-south subsurface traverse [Line A, fig. 2) T5 ce. 3,657-3,662 | Fine sand- | B 3 58 97 17 103....| 2, 884-2, 885 A 35 20 30 50 2, 885-2, 888 -| A 35 20 25 55 AB 2, 6. A 55 5 35 60 87.02.. 3, 035-3, 042 | Sandstone...| C R lake 75 25 Shee: 3,018-3,025 | Silty sand- | C 5 21 53 25 stone, 3,091-3,093 | Quartzite__.| A 20 28 42 30 4, 376-4, 383 |_____ dos-. A 4 100 L eco elan 60.....] 4, 326-4, 331 |___. do...... C 9 52 34 14 4,355-4,343 | Quartzite A 3 34 42 24 and shale. a 4,424-4,447 | Quartzite__.| C 4 32 55 13 4, 448-4, 472 | Silty snad- | A 35 44 28 28 stone. 4,506-4, 517 | Sandstone...) A 40 40 37 28 Samples from west-east subsurface traverse [Line B, fig. 2] 101....] 4,807-4,809 | A 40 8 42 50 §8..2:0 3, 955-3, 984 | Silty sand- | C 20 62 30 8 stone. 4,086-4, 092 |__... fo:... C 20 52 26 22 48..:.. 2,650 | Shale........ A 55 5 35 60 103....| 2,884-2,885 | Fine sand- | A 35 20 30 50 stone. 2, 885-2, 888 |___. A 35 20 24 56 A1... 3, 638-3, 639 | Sandstone._.| A 25 42 28 30 3, 645-3, 646 d A 25 25 47 27 3, 961-3, 962 C 20 32 33 35 4, 413-4, 415 C 20 62 30 8 4, 631-4, 643 C 15 59 34 7 4, 823-4, 826 C 20 39 31 30 4, 936-4, 946 C 15 43 35 22 5, 127-5, 137 C 15 56 38 6 5, 538-5, 548 B 5 46 47 7 5, 605-5, 610 B 5 32 43 25 5,663-5, 668 | Shaly sand- | B 5 52 24 24 stone. 5, 744-5, 747 |__... do...... B 5 54 31 15 fre 5,352-5,387 | Sandstone, | B 1 P. shale. 6, 242-6, 249 | Sandstone, | B 1 T. calcareous 6, 242-6, 249 | Sandstone, B 1 P noncal- careous. §2.... 8, 421-8, 425 | Sandstone...| A 15 85 13 2 1 Assemblage A: Ilmenite, zircon, tourmaline, and rutile, Assemblage B: Garnet, epidote, and ilmenite. Assemblage C: IImenite, garnet, tourmaline, glaucophane and chloritoid. Barite was found in the residue of a sandstone from a depth of 4,528 to 4,530 feet in well 41 (Foremost Prop- erties Corp. 1). It apparently was present as a cement in this sandstone. EXPLANATION A. Silty sandstone, well 60 (Robinson 1). and rounded rutile. - Ordinary light. B. Noncalcareous black silty shale, well 43 (Ruth M. Bishop 1). zircon, and leucoxene. - Ordinary light. C. Fine-grained quartzite, well 60 (Robinson 1). and rutile. Ordinary light. D. Shaly, micaceous sandstone with worm borings, well 41 (Foremost Properties 1). Worn epidote, angular garnet, rounded zircon, tourmaline, and rutile. Depth below sea level, 4,448-4,472 feet. Depth below sea level, 4,326-4,8331 feet. OF FIGURE 5 Well-rounded zircon, subangular tourmaline, Depth below sea level, 2,650 feet. _ Well-rounded tourmaline, Etched garnet and well-rounded zircon Depth below sea level, 5,663-5,668 feet. Ordinary light. A12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Mica is present in many of the rocks examined. It occurs as minute flakes in the shales and as a fine- grained matrix in micaceous and clayey sandstones. Apparently some of the mica has formed authigenically from micaceous clay minerals originally present. The mica occurs in flakes larger than those in most of the matrices and seems to be in the first stage of low-grade metamorphism produced by pressure of overlying rocks. In the oldest unit, which consists of a series of quarzites and sandstones interbedded with micaceous shales, mica-commonly occurs as large colorless rather soft and brittle flakes on the bedding planes of the silty and im- mature sandstones. - X-ray examination (Carroll, 1961) shows that these flakes consist of a mechanical mixture of muscovite, hydrous mica, chlorite, and possibly some dioctahedral vermiculite. For the most crystalline mica the index of refraction for Y is 1.59-1.60, and for various flakes 2V=23°%-37°. Probably the mica was originally derived from a granitic or pegmatitic source area and was floated gently in shallow water and then deposited on top of the sandy beds at times when no other detritus was being moved. The large composite flakes have been produced from originally much smaller flakes by compression of overlying rocks. MINERAL ASSEMBLAGES The three types of mineral assemblages-A, B, and C-present in these sediments suggest that it may be possible to use them for the correlation of one bed with Feet below sea level N another in this rather uniform series of arenaceous rocks. The stratigraphic position and distribution of A, B, and C in the various wells were found and related to the known top of the Paleozoic strata. In figure 6 the wells with the heavy-mineral assemblages are arranged in an approximately north-south distribution across the Peninsular arch (line A, fig. 2), and in figure 7 they are arranged in an approximately east-west distribution (line B, fig. 2). The position of the surface of the Paleozoic strata is shown as a dashed line in figures 6 and 7. The samples that have been described nearly all come from within a few feet of this surface. It can be seen that assemblage A is almost always just below the top of the Paleozoic strata. Well 41 (Foremost Properties Corp. 1) in Clay County, Fla., probably penetrated almost all the Lower Ordovician section. The composition of the individual heavy residues of the fraction 0.12 to 0.06 mm and the distribution of assemblages A, B, and C in this well are shown in figure 8. DISCUSSION Potter and Glass (1958) pointed out that siltstone- shale laminations in the Pennsylvanian sedimentary rocks of southern Illinois are very similar to those found on modern tidal flats, such as the Wadden Sea in the Netherlands and the Texas gulf coast. Many of the fine-grained interlaminated micaceous siltstone and shale beds with borings in the Paleozoic rocks of Florida S 9 76 103 43 7 36 38 23 60 1000 - 2000 - sert s be A \\ 3000 - // i FA Mave. n a ¢ C i\ i \ // \ B \\ 4000 - \\ \\ A MINERAL ASSEMBLAGES P y rues C ooc A ¥, h 6 Iimenite, zircon, tourmaline, rutile Top of Paleozoic rocks 5000 - ECZ3B Garnet, epidote, ilmenite cum ¢ limenite, garnet, tourmaline, glaucophane, chloritoid FIGURE 6. -Heavy-mineral assemblages in sandstones from wells in an approximate north-south traverse of the Peninsular arch (line A, fig.2). 2° dk aa PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA Feet below sea level o- 1000 ~- 2000- 3000-7 4000- 5000- 6000- 7000 - 8000- 52 47 IOI 58 43 10 3 FIGURE 7.-Heavy-mineral assemblages in sandstones from wells in an approximate west-east traverse of the Peninsular arch (line B, fig. 2). / Top of Paleozoic rocks Ease tc MINERAL ASSEMBL AGES EOICICH A IImenite, zircon, tourmaline, rutile E3 B Garnet, epidote, ilmenite CHI ¢ Iimenite, garnet, tourmaline, glaucophane, chloritoid A13 A14 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY WELL 41 MINERAL ASSEMBLAGES EXPLANATION b Heavy residue in percent of fraction 0.12-0.06 mm Depth in feet in grain diameter ~ 3753-54 0.16 Opaques r A 3760-61 0.20 Tourmaline € a 4076-77 0.17 Zircon 4528-30 0.16 Rutile 4746-51 0.50 Chloritoid 4938-41 0.13 r C Epidote NN \\ 4941-51 0.30 Garnet MINERAL ASSEMBLAGES 5051-61 0.29 A: ilmenite, zircon, tourmaline, rutile - B: garnet, epidote, ilmenite C: ilmenite, garnet, tourmaline, glaucophane, I<:hor?iltoidg € 3 5242-52 0.67 N 5720-25 \ 1.16 m > B NN 5859-62 \\\\\\\\\‘\\\ 0.76 ; 2 0 HEAVY MINERALS 100 percent FicurRE 8.-Details of the heavy-mineral assemblages in the sandstones in well 41 (Foremost Properties Corp. 1). worry -¥ --v--Y - -¥ -¥ -v -y--T -Y ~-V @ -¥ -¥ @ --- -¥ -W -room ® rape cy PETROGRAPHY OF SOME SANDSTONES AND SHALES IN FLORIDA A15 probably had a similar origin; that is, they are of shallow-water marine origin. The heavy-mineral assemblages in the quartzites and other rocks are very simple, but they are present over rather wide areas. This fact indicates similarity of distributive province (Milner, 1952, p. 432), trans- portation, and deposition. Such features are not uncommon in arenaceous sediments in the United States. Krynine (1946) drew attention to the persist, ence over large areas of the suites of heavy minerals that are characteristic of certain formations, notably the suites of the Gatesburg Formation (Upper Cambrian), the Bellefonte Dolomite (Lower Ordovician), and the Tuscarora Quartzite (Lower Silurian). Nicholas (1956) showed that the heavy minerals in the sandy beds of the Conococheague Limestone (Upper Cambrian) are similar over a wide area. The Ocoee Series (Pre- cambrian) in Tennessee maintains its mineralogical identity for many miles (Carroll and others, 1957). Such heavy-mineral assemblages, or suites, could perhaps be used to correlate certain beds and to deter- mine provenance of the minerals. For example, erosion of the Conococheague Limestone could have provided the rounded zircon and tourmaline in the rocks of Early Ordovician age in Florida, but it is unlikely that the Ocoee Series was a contributor. The question of the similarity or difference of the red shales to the underlying black shales has not been completely resolved. The red shales seem to contain a greater quantity of fine mineral detritus than the black shales which have abundant organic matter and pyrite. Oxidation by weathering of pyrite and siderite in the black shales, however, could produce a reddish brown color. The clay minerals in both types of shale are similar. Grim (1951, p. 231) pointed out that red coloration indicates the absence of appreciable organic matter, and hence, an oxidizing environment. Such sediments retain their original color and mineral- ogy. It is possible that the red shales in this sequence were deposited in a reducing environment that was gradually changing to an oxidizing environment. The presence of siderite in the black shales indicates that the Eh was 0 to -0.2 v at the pH of sea water (7.6-8.3) (Krumbein and Garrels, 1952, p. 15). Pyrite is also present, and for it to remain stable the Eh would have to be -0.2 to -0.4 v. The presence of abundant organic matter maintains this Eh range. Pyrite is not stable in the same environment as hematite (Eh, 0 to +0.2 v). Hence, the depositional environ- ment of the red shales was different from that of the black shales. The red shales probably represent rapid accumulation of sediment in an oxidizing environment with little or no organic matter. SUMMARY Petrographic descriptions are given for 17 black and 3 red shales and for 40 quartzites from the upper part of the Paleozoic strata penetrated by wells in Florida and adjacent parts of Georgia and Alabama. The rocks were selected from the very large number of available core samples and are probably representative of the principal types present. - Many of the rocks are calcareous orthoquartzites, but some could be classed as subgraywackes. They were probably deposited in shallow water. The heavy minerals, separated from the quartzites and other rocks, have been identified. Three distinct mineral assemblages were found that could be used to correlate different beds in the sequence. The minerals indicate sources in sedimentary and metamorphic rocks. REFERENCES CITED Applin, P. L., 1951, Preliminary report on buried pre- Mesozoic rocks in Florida and adjacent States: U.S. Geol. Survey Circ. 91, 28 p. Bridge, Josiah, and Berdan, Jean M., 1952, Preliminary correla- tion of the Paleozoic rocks from test wells in Florida and adjacent parts of Georgia and Alabama, in Florida Geol. Survey Guidebook, Assoc. Am. State Geologists 44th Ann. Mtg., Fieldtrip, April 18-19, 1952, p. 20-38, fig. 6. Carroll, Dorothy, 1959a, Petrography of Paleozoic sandstones and shales from borings in Florida [abs.]: Geol. Soc. America Bull., v. 70, p. 1159. % 1959b, Sedimentary studies in the Middle River drainage basin of the Shenandoah Valley of Virginia: U.S. Geol Survey Prof. Paper 314-F, p. 125-154. 1961, Mineralogy of micaceous laminae in sandstones of Paleozoic age in Florida, in Short papers in the geologic hydrologic sciences: U.S. Geol. Survey Prof. Paper 424-D, art. 400, p. 311-316. Carroll, Dorothy, Neuman, R. B., and Jaffe, H. W., 1957, Heavy minerals in arenaceous beds in parts of the Ocoee series, Great Smoky Mountains, Tennessee: Am. Jour. Sci., v. 255, p. 175-193. Grim, R. E., 1951, The depositional environment of red and green shales: Jour. Sed. Petrology, v. 21, p. 226-282. Krumbein, W. C., and Garrels, R. M., 1952, Origin and classifi- cation of chemical sediments in terms of pH and oxidation- reduction potentials: Jour. Geology, v. 60, p. 1-33. Krynine, P. D., 1946, The tourmaline group in sediments: Jour. geology, v. 54, p. 65-87. Milner, H. B., 1952, Sedimentary petrography, 3d ed.: London, Thomas Murby and Co., 666 p. Nicholas, R. L., 1956, Petrology of the arenaceous beds in the Conococheague formation (late Cambrian) in the northern Appalachian valley of Virginia: Jour. Sed. Petrology, v. 26, p. 83-14. Potter, P. E., and Glass, H. D., 1958, Petrology and sedimenta- tion of the Pennsylvanian sediments in southern Illinois: a vertical profile: Illinois Geol. Survey Rept. Inv. 204, 60 p. Biever, Raymond, 1959, Petrology and geochemistry of silica cementation in some Pennsylvanian sandstones, in Silica in sediments, a symposium with discussions: Soc. Econ. Paleontologists and Mineralogists Spec. Pub. 7, p. 55-79. U.S. GOVERNMENT PRINTING OFFICE; 1963 - O-677291 yee tem- Naar -> w ~*~ ae - a - u -> n | s o o ~ H : * up No s ue -e ag " n ermm o scone a com 10 GEOLOGICAL sURVEY Contact Dashed where approximately located,; short dashed where gradational or inferred z Fault, showing dip. Dashed where approximately located; short dashed where inferred; ques- tioned where probable 90 Vertical fault Zone of cataclastic deformation Rocks slightly to intensely deformed by cataclasis g _-__-{ zzz. Anticline Showing crestline and direction of plunge. Dashed where approximately located; dotted where concealed Base from U.S. Geological Survey Topographic quadrangles a pec. Syncline Showing troughlime and direction of plunge. Dashed where approximately located; dotted where concealed Plunge of minor anticline --6F.62 Plunge of minor syncline /8 Cok. Strike and dip of foliation -#- Strike of vertical foliation 1059; 9000' Crescent ' Mountain UNITED SEATES DEPARIMENT OF THE INTERIOR MAP SYMBOLS §4 f; Strike and dip of foliation and plunge of lineations --g-+57 Strike of vertical foliation and plunge of lineation #2 Strike and dip of axial plane Strike and dip of axial plane and plunge of fold axis $e 1D Strike of vertical axial plane and plunge of fold axis 42 Strike and dflf cataclastic foliation 53—~,50 Strike and dip of cataclastic foliation and plunge of lineation oad Strike and dip of slip cleavage and axial plane of crinkles 90 I l._'- Strike of vertical slip cleavage and axial plane of crinkles --+» /Q Direction and plunge of lineation 41 €". Direction and plunge of axis of minor drag fold TRUE NORTH Ma APPROXIMATE MEAN DECLINATION, 1964 Coal Creek 10517 30" S ® § & 39°55" 39°55" T:f s. it. 25. o O 1D 0 «- & 39°52 30" xa Ss ayes epa d Sasa gS" \ 730" g 0 J p $% 39 °50' 105°20' Geology by J. D. Wells, D. M. Sheridan, A. L. Albee, and C. H. Maxwell, 1953-58 B Blue, 4 3 Mountain 9000' 90007 8000' 80007 Lithologic units; order may not reflect age Ava: PROFESSIONAL PAPER 454-0 PLATE I1 EXPLANATION Qa Alluvial and colluvial deposits Stream deposits, talus, and solifluction debris MPa Sedimentary rocks pa Pegmatite and aplite Dikes and irregular bodies generally less than 500 feet wide that are virtually undeformed Cataclastic gneiss Layers of light-colored fine-grained quartz-feldspar cataclastic gneiss and dark-colored fine-grained biotite-quartz-feldspar cataclastic augen gneiss locally rich in epidote Augen gneiss Fine-grained well-foliated cataclastic pinkish-gray to pink rock charac- terized by small white to pink porphyroclasts a= ‘“ = ~~ Ralston Creek Hornblende diorite and hornblendite Mottled black and pale-gray fine- to coarse-grained rock consisting essentially of hornblende and plagio- clase in irregular discordant bodies am Quartz monzonite Gray, pinkish-gray weathering weakly to strongly foliated discordant igneous rock consisting essentially of quartz, potassic feldspar, plagioclase, muscovite, and biotite with fine- and medium-grained phases, both of which show pervasive mild cataclasis and intense cataclasis in the shear zone Boulder Creek Granite Mottled black and white fine- to medium-grained locally porphyritic weakly to strongly foliated discordant igneous rock that shows widespread mild cataclasis and intense cataclasis in the Idaho Springs-Ralston shear zome; consists essentially of quartz, potassic feldspar, plagioclase, and biotite Schist in quartzite Fine-grained muscovite-biotite schist with locally large amounts of quartz; locally contains porphyroblasts of andalusite, cordierite, and garnet and small amounts of staurolite and sillimanite; well-foliated and commonly highly folded and crinkled, locally cata- clastically deformed; locally contains lenses of calcium-silicate rock Quartzite Fine- to coarse-grained white, red, black, and gray quartzite with conglomeratic lenses; micaceous; locally contains garnet, sillimanite, plagioclase, and andalusite; bedding and foliation are conspicuous; locally cataclastically deformed Biotite-quartz-plagioclase gneiss and mica schist (biotite gneiss and mica schist) White and gray fine- to medium-grained biotite- quartz-plagioclase gneiss and mica schist in grada- tional layers consisting of the name minerals plus locally microcline and sillimanite; locally include thin layers of amphibolite and calcium-silicate gneiss; intense cataclasis, folding, and crinkling are common Mica schist Silvery-gray to dark-gray well-foliated fine- to medium- grained schist; locally gneissic; consists of muscovite, biotite, and quartz with minor plagioclase and porphyroblasts of sillimanite, andalusite, and garnet; locally minor microcline Microcline-quartz-plagioclase-biotite gneiss and horn- blende gneiss (microcline gneiss and hornblende gneiss) Microcline-quartz-plagioclase-biotite gneiss intimately interlayered with varying amounts of hornblende gneiss Hornblende gneiss Predominantly amphibolite with layers of biotite- quartz-plagioclase gneiss, and impure marble; amphi- bolite is dark-gray to black fine- to medium-grained rock consisting of hornblende and plagioclase gm Microcline-quartz-plagioclase-biotite gneiss (microcline gneiss) A gramitic-appearing fine- to medium-grained conspic- uously foliated, layered pinkish-gray to dark-gray rock comsisting essentially of the name minerals; locally includes discontinuous layers of amphibolite and biotite-quartz-plagioclase gneiss x 9000" 8000' - 7000" 6000' CI 9000 s 9000' & 3 o 8000 P 8000' 7000 7000' 6000' 6000' GEOLOGIC MAP AND SECTIONS OF THE COAL CREEK AREA, EAST- CENTRAL FRONT RANGE BOULDER AND JEFFERSON COUNTIES, COLORADO f SCALE 1:24000 i o 1 MILE a r I F I T 3 1 5 o 1 KILOMETER E- - E- <-- ~ ~- penny CONTOUR INTERVAL 50 FEET DATUM IS MEAN SEA LEVEL 3 --y PRECAMBRIAN PALEOZOIC QUATERNARY AND MESOZOIC gaze 25 i= 11 12 13 13 14 15 15 16 16 17 18 18 Page B4 9651051”? fats. Mt SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY PILLOWED LAVAS, I: INTRUSIVE LAYERED LAVA PODS AND PILLOWED LAVAS, UNALASKA ISLAND, ALASKA By Grorcr L Sxyorr and Grorer D. Fraser ABSTRACT Extensive sills of andesite and dacite intrude a thick se- quence of argillites of Miocene age in the eastern Aleutians. The sills contain large volumes of pillowed lavas that grade into massive lava, layered lava, and breccia. Pillows range in diameter from 1 to 40 feet but are generally 5 to 10 feet; peperite, a mixed intrusive breccia of sedimentary and primary igneous debris, commonly fills pillow interstices and locally constitutes the entire thickness of a sill. Concentrically lay- ered lava forms roughly equidimensional pods, as much as 600 ' feet thick, and extensive tubular and tabular sills; these lay- ered lava pods are larger than any reported previously. Con- centric layers in the lava pods are 1 foot or more thick ; alternate layers differ in appearance and composition and generally weather differentially. Most of the rocks are completely albitized, but some glass is unaltered. The sills and all the second-order structures were formed by magma intruding semiconsolidated muds. A modified "emul- sion" theory best explains these and probably other large tracts of pillowed lava common in parts of the world. Tough, elastic chilled pillow skins maintain the droplike form of magma in contact with water or mud and serve the same function as fluid surface tension in a normal emulsion. Pillows were formed as unstable apophyses or immiscible droplike masses during turbulent digital advance of magma fronts and engulf- ment of mud and water in magma. The concentric layers of the lava pods probably result from laminar intrusive flow in tubes and tongues which channeled magma from a central source to the pillow-forming front. Compositional differences in succes- sive layers of the layered lava pods, on the basis of evidence from analyzed samples in one lava pod, may be due to different amounts of included mud or to postsolidification differential alteration. INTRODUCTION AND ACKNOWLEDGMENTS Extensive andesite and dacite sills that are abundant on Unalaska Island (fig. 1) in the Aleutian Islands con- sist of large units of pillowed lava and layered lava pods-larger than previously described in the geologic literature-that grade into thick units of layered and nonlayered igneous rock. The pillowed lavas and lava pods were examined during reconnaissance geologic . mapping of Unalaska Island in 1953 and 1954 (Drewes and others, 1961). Most of these structures, which are well exposed in large sea cliffs from Surveyor Bay to Cape Prominence along the southwest coast, were examined from the Motorship Z#¥der, then of the U.S. Geological Survey ; other field observations were made by landing parties. The pillowed lavas and lava pods are described in detail and their origin is explained. This paper has benefited by many conversations with and suggestions from U.S. Geological Survey colleagues in the Aleutian Islands, Alaska, in Colorado, and, in Hawaii. We are particularly indebted to Harald Drewes and Richard Goldsmith for many critical sug- gestions, including those about the reorganization of parts of this manuscript. Besides Drewes the follow- ing people helped with the original field investigations : V. E,. Ames, H. F. Barnett, Jr., W. B. Bryan, C. E. Chapin, E. H. Meitzner, R. P. Platt, H. B. Smith, and L. D. Taylor. Carl Vevelstad and Charles Best fur- nished logistic support during the Aleutian fieldwork. GEOLOGIC SETTING The rocks of Unalaska Island comprise an older group of sedimentary and shallow intrusive rocks, a group of plutonic rocks intermediate in age, and a younger group of volcanic rocks. The older igneous rocks, with which this paper is chiefly concerned, were emplaced in a submarine environment and were subse- quently altered, whereas the younger volcanic rocks were extruded subaerially and are fresh. The rocks of Unalaska are typical of those of most other Aleutian Islands, although some islands do not contain plutonic rocks. The oldest formation underlies most of the island; the texture of the sedimentary rocks and the structure of the igneous rocks differ from the northern to the southern parts of the island. Coarse conglomerate and tuff breccia are abundant in the northern part of the island and argillite and tuffaceous argillite are rela- B1 Ba SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 168° 176° 180° 176° 172" 168° 164° 160° 156° 62° 152° T \y" SIBERIA ). -7~-C \ Anchorage \ ALASK A \ 100 o 100 300 500 MILES O 5g° L. 1 1 1 1 1 ] 100 0 100 300 500 kILOMETERs \ &2 $8" \ al x S C . 4 B E/, 2A €-R& 1 x ¢ g E A _ 37 \ Kodiak Island RS \ »", \ 54° \I C 54° etL Attu Island ‘ ’ £ A ( T 5 o ALE U T I A N 1s LAND 2 i Unalaska Island Ss ] Umnak a 0°C E A N Kiska Island k Island | ) anaga Island Z? I Pu/ - Andreanof Islands 50° 1 50° 176° 180° 176° 172° 168° 164° 160° 156° Makushin Bay Porta Reap??- ($ MILES Paice 0 10 20 30 4 X L 1 I 1 I N Anderson (I) f 1|0 210 3|O KILOMETERS Bay ~1" f Hive Spray Bay Cape Kayak Cape p Umnak Island $ 3 ( Pumicestone Bay P$ G i $15 A2 ? Usof p ® Alimuda Tey V6 Chernofski \ \(\ P 0 pez Cape Prominence Q Q) Harbor\ p G {yg Fayle Rgve‘n I Bay 0 N $ ¥ Bight Fay C4 Reef Point \~\ Tower Point 0 Buttress Point Riding Cove 6 Lance Point h % 6 * Surveyor Cape ? B Bay Aiak FicuRrE 1.-Index map showing location of Unalaska Island and geographic localities mentioned in the text. tively scarce, whereas argillite is abundant in the south- ern part of the island and rocks coarser than siltstone are relatively scarce. Sedimentary structural features attributable to shallow-water deposition are absent in the southern argillites. Sheets of pillowed lava and lava pods of andesitic and dacitic composition are most abundant in the clastic rocks in the southern part of the island. Some of the sedimentary rocks of the coarse PILLOWED LAVAS, I: northern facies contain lower Miocene fossils, but no fossils were found in the southern facies and these rocks may be older. Granodiorite batholiths intrude the older rocks in the center of the island. Wide halos of mild alteration, dominantly albitization, envelop the batholiths, but one area at each end of the island is relatively unaltered. Andesite and basalt of Quaternary age overlie the older rocks and the plutons in the northern part of the island. The young rocks form thick lenses of subaerial flows and pyroclastic cones along the line of young vol- canoes that extend for hundreds of miles in the Aleutian Islands and the adjacent Alaska Peninsula. Surficial deposits, composed of till, ice, fluvial and beach de- posits, and a blanket of ash and peat, cover much of these and older rocks. DESCRIPTION OF PILLOWED LAVA AND LAVA PODS The igneous rocks in the old sedimentary sequence in- clude pillowed lavas, peperite sheets, large pods, and extensive sheets of structureless, layered, or columnar- jointed lava. These rocks are best exposed in large sea cliffs and wave-cut benches, particularly between Sur- veyor Bay and Cape Prominence on the south coast. The terms "lava," "pillowed lava," and "pod lava" will be used here for rocks intruded into mud, as well as for possible extrusive rocks, because the behavior of the magma during emplacement was lavalike even though it was confined by mud and water. PILLOWED LAVA PILLOWS Pillows are separate or connected ellipsoidal masses of aphanitic igneous rock commonly less than 10 feet in diameter and generally occurring in thick sheets. The term "pillow" carries no genetic connotation but is "simply a morphologic term for ellipsoidal structure" (Stark, 1939, p. 207). The pillows on Unalaska Island generally are larger and more silicic than those from other areas. On Unalaska the pillows congealed in marine muds (Snyder and Fraser, 1958). The Unalaskan pillows are distributed regularly or sporadically throughout sheets of lava as much as 600 feet thick, and they grade upward, downward, or later- ally into structureless nonglobular lava (fig. 19). These relations are consistent with those previously reported by many other authors who note that pillows occur at the top, middle, bottom, or at several zones within flows, or that they constitute entire flows or grade into or are intimately interlayered with structureless lava. The pillows are mostly loaflike or irregularly subel- liptical to amoeboid in shape ; only a few have V-shaped 663374 0O-63--2 LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA _ east shore of Alimuda Bay. B3 bottoms. The matrix between Unalaskan pillows is generally abundant, which causes their commonly ir- regular shapes and the scarcity of mutually impinging contacts. Most pillows are wider than they are high, but the proportions of others are reversed (figs. 13, 19). Some pillows have projections of lava extending into the surrounding matrix or projecting toward other pillows ; and some adjacent pillows are connected by narrow necks of lava (figs. 10, 13, 19). Some necks are so narrow that appreciable relief is required on any exposure to see how the pillows are joined. The necks are smoothly continuous with the pillows, and in some exposures (fig. 13) masses of pillowed lava grade into structureless lava. In one outcrop on the east side of Raven Bay, delicate dendritic andesite(?) spines from a pillow layer penetrate a few inches into overlying argillite. At Open Bay, septa of overlying argillite appear to be dragged into a pillow layer. Most Unalaskan pillows are 5-10 feet wide, but some are as small as 1 foot and others are at least 40 feet wide. Pillows elsewhere in the world are generally only 1-4 feet in diameter (see, for example, Burling, 1916, p. 235 ; Johannsen, 1939, p. 228; Cotton, 1952, p. 290; Hen- derson, 1953, p. 25), and Cotton (1952, p. 290) cites a maximum length of 12 feet. The largest pillows pre- viously described are from New Zealand and, in separate localities, are 30 feet in diameter (Uttley, 1918, p. 113) and 80 feet long (Bartrum, 1930, p. 447-455). The dis- tance separating Unalaskan plllows ranges from a few inches to tens of feet.. Unalaskan pillows do not commonly contain internal structural features, but there are notable exceptions. Radial columnar joints are formed in the pillows on the Rinds, cores, or zones of glass occur in otherwise lithoidal pillows in the Chernot- ski Harbor area. Some pillows at the base of the sea cliff on the east side of Reef Point (see Drewes and others, 1961, fig. 84) and in many other areas have resistant purplish gray rims of albitized andesite sur- rounding cores of nonresistant greenish gray albitized andesite (fig. 2, table 1). The chemical composition of the rims and the cores is almost identical, except that the ferriecferrous oxide ratio is greater in the rims. The dif- ferent resistance to weathering of the rims and the cores is apparently controlled by slightly different mineral- ogy and texture. - The rims probably were chilled glassy skins before alteration. _ Vesicles are scarce; where present they generally have a random distribution and seldom are distributed in zones. Unalaskan pillowed lavas and related rocks range in composition from basalt to dacite but are generally in the andesite range. This suite probably is more silicie than most other pillow assemblages. Chemical anal- B4 £3 lnte_rp.illow peperite Nonresistant Resistant rim 5FEET L_ - FIGURE 2.-Sketch of altered andesitic pillowed lava, Unalaska Island. Chemical analyses and petrographic descriptions of core and rim are given in table 1. TABLE 1.-Chemical analyses and petrographic descriptions of altered andesitic pillow lava, Reef Point, Unalaska Island Analysts: P. L. D. Elmore, S. D. Botts, M. D. Mack and J. Goode. Rapid analyses by U.S. Geological Survey (Shapiro and Brannock, 1956); weight percentages are given to 2 or 3 significant figures, and the totals are omitted] 1 1 2 61. 2 1.8 1.6 17.9 . 80 . 85 8.2 . 30 . 33 2.6 . 21 .12 1.2 1.4 2 1.7 <.05 <.05 8 1. New analysis of albitized andesite from purplish-gray resistant pillow rims (see figure 2) at base of active sea cliff on east side of Reef Point, Unalaska Island; collected within 2 ft of specimen 2. Texture: amygdular, porphyritic, felty. Phenocrysts: euhedral plagioclase, 7 percent; anhedral subspherical titanau- gite(?) with striking pleochroism from grass green or bluish green to medium pink or light violet, 2.5 percent; magnetite, 0.4 percent. Groundmass: very fine grained intermeshed plagioclase, about 60 percent; apatite, 0.1 percent; crypto- crystalline mush, probably largely glass before alteration, about 30 percent. All plagioclase completely altered to albite; titanaugite(?) phenocrysts partially to completely altered chiefly to brassy yellow epidote but also to a yellowish-brown chlorite and albite (only in a thin selvage where the phenocryst is in contact with the matrix). Some completely altered subspherical pyroxenes resemble an albite-epidote-chlorite amygdule. All plagioclase and the glassy or crypto- crystalline groundmass is also intensely altered to kaolin and limonite, which gives the rock its dull purplish tint. Quartz (0.3 percent) fills vesicles. 2. New analysis of albitized andesite from greenish-gray nonresistant pillow cores (see figure 2) at base of active sea cliff on east side of Reef Point, Unalaska Island; collected within 2 ft of specimen 1. Texture: amygdular, porphyritic, spherulitic. Phenocrysts: euhedral plagioclase, 4 percent; titanaugite(?), 1.5 percent; mag- netite, 0.2 percent. Groundmass: plagioclase, mostly spherulitic, some in ir- regular lathes, about 70 percent; apatite, 0.5 percent; microcrystalline aggregate of limonite-stained quartz(?) and penninite (which gives rock greenish tint), about 20 percent. . All plagioclase completely altered to albite; all titanaugite(?) completely replaced by a complex intergrowth of the following minerals: quartz; pink radiating aggregates of kaolin(?); light-green chlorite "a," with abnormal interference colors; olive-green chlorite "b," with first-order interference colors; deep-green chlorite "c," nearly opaque; and leucoxene. Chlorite "c" is inti- mately mixed with the leucoxene and is everywhere surrounded by the kaolin (?); chlorite "a" is associated with chlorite "b." _ An intense kaolin alteration of all original plagioclase is responsible for the earthy appearance of the rock. Quartz .(2 percent) fills vesicles. Several stylolitic seams truncate plagioclase pheno- crysts, and one epidote vein cuts the rock. yses and petrographic descriptions of albitized Un- alaskan andesites are presented in table 1, and chemical analyses and petrographic descriptions of fresh, albi- Reef Point, SHORTER CONTRIBfiTIONS TO GENERAL GEOLOGY tized, and contaminated (?) and albitized dacites are presented in table 2. MATRIX The interpillow matrix is an important part of all pillowed lavas. On Unalaska, pillows are separated from each other by peperite, fragmental igneous rock, argillite, or crustified chalcedony and quartz. Peper- ite (a mixture of sedimentary and igneous rocks) is the most common interpillow matrix, more abundant than purely igneous, sedimentary, or secondary infillings. Peperite is widespread in pillowed lava layers hundreds of feet thick. Structureless or layered lava in many sills or pods is overlain by a layer of pillows and peper- ite (figs. 4, 6, 13, 15). Peperite is a mottled light-gray to pale-green breccia of mixed sedimentary and primary igneous debris. The breccia fragments, composing 30 to 70 percent of the rock, consist of predominant albitized felsite and green or gray argillite. The finely granular matrix is much altered and is probably a mixture of comminuted lava and original mud. Unalaskan peperites general- ly have a large sedimentary component, but they grade into wholly igneous breccias. Fragments of argillite are commonly plastically molded around pillows, and small tabular chunks retain varvelike bedding which is truncated at the edges of some fragments. Most Un- alaskan peperites have been thoroughly chloritized and albitized, but relict structures and textures remain. The Unalaskan peperites locally resemble mottled green to white tuffs, but true tuff fragments lack the character- istic bedding of the marine muds that many peperite fragments contain. Coarse peperite is commonly gneissoid at intrusive contacts and is flow rather than pyroclastic breccia. Peperites, described in the liter- ature from California, Montana, and Europe, have been universally ascribed to intrusion of magmas into incoherent, poorly consolidated or moist sediments. Unalaskan peperite occurs mostly between pillows and only rarely as small sills and irregular masses not associated with pillows. The interpillow peperite, which grades into the selvage of igneous rock at the margin of each pillow, forms a very irregular network, as thin as 1 inch. Commonly the peperite is weaker than the pillows and weathers into pockets or hollows in a wave-cut bench or sea cliff ; it is therefore difficult to sample. Tabular peperite bodies ranging in thick- ness from a few inches to several feet occur as con- cordant lenses and layers without pillows in a thick sequence of contemporaneously deformed laminated ar- gillite and massive sills near Hive Bay. The argillite in these peperites bodies occurs as distinctly alined laminated chips or tabular fragments, some of which are bent plastically. The altered groundmass contains PILLOWED LAVAS, I: LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA B5 feldspar crystals. Several large masses of altered easily eroded peperite occur within the pillow-rich rocks on southwestern Unalaska. Smedes (1956, p. 1783) describes similar peperites from sills in Montana. A sample of typical peperite from between the al- bitized andesite pillows, the analyses of which are given in table 1, is green to very pale green and contains ill- defined fragments of finely layered rock and of unlay- ered rock. Alternate fine layers are composed of chlorite and of fine- or coarse-grained albite plus quartz. The long dimensions of most crystals in these layers are oriented perpendicular to the layering. The layered fragments are probably altered argillite. The unlayered fragments consist of abundant albite spher- ules and a few crystals of quartz set in a chlorite matrix. Irregular masses of calcite replace parts of the unlay- ered fragments, especially the albite spherules. The unlayered fragments are probably altered andesite. Relict crystals of andesine (now largely albite) and unaltered crystals of magnetite and sphene are dispersed with the rock fragments. The rock fragments and crystals are all set in a very fine grained matrix of albite, chlorite, calcite, and quartz. This matrix may have been mud derived from both igneous and sedi- mentary sources, but its origin is obscured by pervasive alteration. Many albite and chlorite veins cut both matrix and fragments. Unaltered peperites have not been found on Unalaska. Igneous breccia, clastic sediment, or vein quartz also separate pillows. A granular selvage of igneous rock separates some pillows that are close together. Pillowed lava also grades into pillow breccia by successive frag- mentation of most of the pillows and, locally, inter- mediate stages of fragmentation may be observed (Drewes and others, 1961, fig. 85). Igneous or pillow breccias are commonly associated with pillowed lavas (for example, Fuller, 1931, p. 292; Hoffman, 1933, p. 194; Noe-Nygaard, 1940, pls. 3 and 4; Henderson, 1953, fig. 2, p. 27, 29, 81 ; Satterly, 1941, p. 28 ; 1948, p. T ; 1952, p. 18; 1954, p. 12; Carlisle and Zeck, 1960, p. 2053). Unbrecciated pillows occur locally in a matrix of con- torted largely sedimentary rocks (fig. 19). Very small pillows are completely surrounded by siliceous argillite in a small area of the sea cliff on the east side of But- tress Point (fig. 10). In the Chernofski Harbor area large quantities of green jasperoid sediments are included among the pillows. Rarely argillite is folded into the centers of Unalaskan pillows. Locally, as along the coast west of Chernofski Harbor, secondary quartz and chalcedony are prominent as crusts between pillows. The interpillow matrix must be considered in terms of the type of material that existed in the region at the time of pillow and pod formation. A thick section of stratified mud, now lithified to argillite, was invaded by magma. Parts of the argillite are volcanic derived, but the pyroclastic or epiclastic episode preceded pil- low formation; and the source for the mud (on the basis of its texture, fine lamination, and continuous even stratification) was remote from the area of pil- lowed lava. In other geologic environments palag- onitic ash has been generated locally by an explosive or decrepitative process at the time of pillow formation (Fuller, 1981; Waters, 1960). Some of the granular interpillow matrix on Unalaska may have a decrepita- tive origin, but deformed chunks of laminated argillite between pillows could not have been generated in this way. There is no direct evidence for explosion, or frothing, at the time of formation of these pillows. Contemporaneous tuff deposits, if they exist at all, are minor and incidental. LAVA PODS Lava pods are equant, tubular, or tabular bodies of concentrically layered igneous rock, which range in minimum dimensions from tens to many hundreds of feet and average several hundred feet in diameter. They form a continuous series ranging in shape from tabular sills (fig. 7) to isolated laccolithic intrusions (fig. 3), but, unlike some sills and laccoliths, lava pods are generally intimately associated with, or surrounded by, pillowed lavas (figs. 4, 17). The size of most lava pods is many times the average size of most pillows, but the smallest pods are about the same size as the largest pillows. Large pillows on Unalaska do not contain the repeated concentric layers that character- ize lava pods. Many features are common to all lava pods and are described collectively in the following section. Local features, found in a few areas, are described separately. GENERAL FEATURES Lava pods on Unalaska are basalt, andesite, or dacite with a lithoidal and porphyritic texture and a dull purplish or greenish color. They appear as connected or disconnected bodies in thick sheets of pillowed lava and peperite. A sheet containing lava pods and pil- lows may grade laterally into a very large lava pod or a uniform columnar-jointed sill (for example, figs. 4, 17). Many lava pods are partly or completely col- umnar jointed; and jointing, where present, is com- monly more prominent than compositional layers, which are about perpendicular to the joints in many places. Lava pods are commonly several hundred feet in diameter. The largest lava pods are about 1,000 feet wide and 600 feet high (fig. 4 and Drewes and others, B6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY EXPLANATION OM Massive andesite Columnar jointed where shown L AHL LI Argillite, tuffaceous argillite oes Sea level -- 4 f - R - $ 29 100 FEET FicurE 3.-Section of laccolith intruding rocks exposed in sea cliff south-southeast of Spray Cape, Unalaska. 1961, p. 598). Lateral dimensions generally exceed the vertical (an exception is shown in fig. 18). Many different shapes are seen in cross section (figs. 4, 7, 8, 14, 15, 16, 17, 18; Drewes and others, 1961, fig. 86). The contact of a lava pod with the surrounding pillowed lava or massive lava may be sharp and curvi- planar or gradational and irregular; the contact of a lava pod with surrounding argillite is always intrusive. Locally, the outermost layer of a lava pod may inter- finger with pillows similar to it in composition and texture (fig. 19). Differentially (weathered concentric layers are a striking and characteristic feature of all observed lava pods and of some sills. Layered tabular lava pods or tubular lava pods in long section form a continuous series with massive sills. Intermediate stages in in- ternal layering are represented by sills whose layers die out laterally or downward. Layers in sills and tabular pods parallel upper and lower contacts even where they bend around a blunt end (fig. 7). Alter- nate reddish and greenish layers weather differentially so that the bedrock exposures on many wave-cut benches resemble a freshly plowed field (fig. 8). The layers range in thickness from several inches to several feet. Reddish-gray resistant layers commonly are thicker than greenish-gray nonresistant layers, though locally they are about the same size. Interstitial quartz in the resistant layers and interstitial carbonate in the weak layers of a lava pod at Buttress Point (table 2) may explain the differential erosion in that area. Drawn from a photograph. Chemical analyses of the resistant and nonresistant layers of albitized dacite in the Buttress Point lava pod are compared in table 2 with an analysis of fresh plllow glass collected from a small area of unaltered lava in the same igneous sheet just off the east edge of the area shown in figure 7; a closeup view of the hyered lava at this locality is shown in figure 12. Attention is directed to columns 6, 7, and 8 of table 2 in which the recalculated water-free analyses are compared. The albitized resistant layer of rock is very similar to the fresh pillow glass except for a slight difference in Al,O;, content and a reversal in the amounts of Ca) and Na,0O. Albitization during batholithic intrusion, possibly aided by connate waters, is probably responsi- ble for this difference, according to Drewes and others (1961), and is suggested by analyses of other fresh and altered rocks given in their table 1. The chemical com- position of the nonresistant layer differs markedly from that of the resistant layer and from that of the fresh glass. SiO, is appreciably lower in the nonresistant layer; Al;0; is slightly higher, and iron, magnesia, and potash are much higher; CaO and CO, show a slight parallel rise over these constituents in the resistant layer, reflecting the presence of a small amount of calcite in the nonresistant layer. The origin of these differences in composition and the process of formation of the layers in the lava pods will be discussed in a later section. No reports of lava pods exactly like those described here were found in a partial review of the literature, though similar features are reported from other areas. PILLOWED LAVAS, I: LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA The exposures on Unalaska are unusually large, and possibly lava pods like these will be found in equally good exposures of pillowed lavas in other parts of the world. The nearest equivalents in the Aleutians occur in basaltic lava at Casco Point, Attu Island, Alaska TaBL® 2.-OChemical analyses and petrographic descriptions of altered dacitic lava pod layers and associated unaltered pillow lava, Buttress Point, Unalaska Island New analyses in columns 3 and 5 by P. L. D. Elmore, S. D. Botts, M. D. Mack, and J. Goode. Elmore and H. Thomas have made duplicate determinations of FeQ and K»O in the specimens represented in columns 2 and 3. The results are: 0.94 FeO and 2.2 K;O for column 2, and 2.4 FeO and 0.83 K2O for column 3. 'These results have been averaged in column 4. New analyses are rapid analyses by the U.S. Geological Survey (Shapiro and Brannock, 1956); weight percentages are given to 2 or 3 significant figures, and the totals are omitted] 1 2 3 4 5 6 v 8 71.2 70.2 70.7 | 54.9 68. 2 70. 8 56.7 13.7 13.9 13.8 | 17 15.8 13.8 17.6 2.5 2.3 2. 4 3.8 1.9 2.4 8.9 19 2.8 1.6 2.9 2 1.6 3 .82 . 59 +7 3.2 1.2 +4. 3.3 1.1 1 1.1 2.6 4.5 1.1 2.7 6.2 7.3 6.8 4.2 4.2 6.8 4.8 2.2 .82 1.5 5.8 1.2 1.5 6 . 68 «70 +7 . 87 .8 4 .9 . 28 .25 .8 . 33 2 .8 .8 A17 A .2 19 .2 .2 .2 T7 1 .9 B/B c .05 .08 1 1 0 1 1 1. Light dacite (Rittmann, 1952) vitrophyre from amygdular pillow lava along coast east of Buttress Point, Unalaska Island. Original analysis (Drewes and others, 1961, table 1, anal. 20) includes 0.07 percent BaO, 0.03 percent Cl, 0.04 percent F, and 0.04 percent S. Black glassy specimen was crushed to granule and coarse sand size and handpicked free of white amygdules before analysis. Texture: porphyritic, hypocrystalline, trachytic. Phenocrysts: slightly progressively zoned; corroded or perfectly euhedral plagioclase (An 37) with inclusions of apatite, 4 percent; euhedral colorless clinopyroxene, 1 percent; slightly pleochroic hypersthene, trace; magnetite, trace. Groundmass: brown glass containing scattered green blobs (chlorite?), about 75 percent; skeletal crystals of andesine in rectangular tablets 0.1 by 0.02 mm with acicular projections 0.03 mm long extending parallel to the crystals from the short ends, especially the corners of the lathes, about 15 percent; clinopyroxene(?) needles as large as 0.3 by 0.01 mm but generally about 0.03 by 0.001 mm, about 5 percent; the smaller clino- pyroxene(?) needles are attached in a bristling array to the margins of the larger skeletal crystals and phenocrysts. Chalcedony and (or) zeolite amygdules and veinlets c)ompose 4 percent of the rock (not included with other percentage estimates). 2. Albitized dacite from resistant lava pod layer at base of active sea cliff one-half mile west of Buttress Point, Unalaska Island. For exact location see figure 12. Original analysis (Drewes and others, 1961, table 1, anal. 24) includes 0.02 percent S. Texture: porphyritic, felty. Phenocrysts: euhedral plagioclase, 4 percent; colorless to light-green clinopyroxene, 1.5 percent; magnetite, 0.5 per- cent. Groundmass: zoned quartz, 14 percent; plagioclase laths with attenuated acicular ends like in specimen 1, about 40 percent; apatite, 0.1 percent; crypto- crystalline mush probably largely glass before alteration, about 40 percent. All skeletal groundmass crystals and all but a few ragged andesine patches (0.1 percent) in the plagioclase phenocrysts are albite; sericite in plagioclase pheno- erysts, 0.1 percent; clinopyroxene generally very fresh. An intense kaolin and limonite alteration affects all plagioclase and the cryptocrystalline or glassy groundmass and gives the dull purplish tint to the rock. Olive-green chlorite or serpentine (0.2 percent) fills cavities. 3. New duplicate analysis of specimen 2 performed on a different but adjoining hand specimen. 4. Average of specimens 2 and 3. 5. New analysis of albitized contaminated(?) dacite from nonresistant lava pod layer at base of active sea cliff one-half mile west of Buttress Point, Unalaska Island; collected within 1 ft of specimens 2 and 3. _ For exact location see figure 14. Texture: porphyritic, felty. Phenocrysts: euhedral plagioclase, 3 percent; colorless clinopyroxene, 0.5 percent; magnetite, 1 percent. Groundmass: inter- grown aggregate of small plagioclase with irregular overgrowths on sides and on ends of crystals, about 60 percent; amoeboid areas of clear orthoclase, 4 per- cent; calcite, 1.5 percent; apatite, 0.1 percent; remainder (about 28.5 percent) is interstitial amoeboid areas of green opaque chlorite(?), which gives the rock its dull light-green color, and very cloudy alkali feldspar(?). The chlorite(?) may represent included mud or may be devitrified glass. Except for a few ragged andesine patches (0.2 percent) in the plagioclase phenocrysts, all the plagioclase is altered to albite or kaolin. _ Late clear, olive-green chlorite or serpentine (0.2 percent) fills voids. 6. Column 1 (pillow glass) recalculated to 100 percent omitting HO. 7. Column 4 (resistant lava pod layer) recalculated to 100 percent omitting HO. 8. Column 5 (nonresistant lava pod layer) recalculated to 100 percent omitting H;O. B7 (Olcott Gates, H. A. Powers, J. P. Schafer, and R. E. Wilcox, written communication). A map of this wave- cut bench that is more than 1,300 feet long shows an intricately faulted sequence of pillowed basalt, sand- stones, siltstones, and tuffs. Here pillowed basalts contain faintly layered columnar-jointed pods of uniform basalt 150 feet long; sheets of massive lava 25 feet thick are interbedded in the sequence. Another concentrically jointed basaltic dome, on the north shore of central Kanaga Island, also resembles the lava pods on Unalaska. Recent examples of the Unalaskan sills and lava pods may be present in the sea-floor muds of Pratt Depression northeast of Little Sitkin Island (Snyder, 1957, p. 167, pl. 22). Similar structural features are reported from New Zealand, Oregon, Quebec, and Radnorshire. Bartrum (1930, p. 447, 455) describes ovoid masses of lava in Auckland, New Zealand, as much as 80 feet long, with radiating columns. He believes these masses represent giant pillows derived from submarine flows. Lava tube fillings formed subaerially are similar to the Un- alaska lava pods in many areas but generally are much smaller. (See for example, Wentworth and Mac- donald, 1953, p. 46, fig. 23.) Waters (1960, fig. 2, p. 354) reports two of these masses, about 35 feet high, in an olivine basalt in Oregon. They have radiating columns and a crude concentric structure near their margins. Wilson (1938, p. 77) describes massive andesite from Quebec "in irregular poorly defined masses of varying size within pillowed andesite." Jones and Pugh (1948, p. 43-94) have described and mapped clusters of laccolithic bodies in shale at Radnorshire; these bodies are unlayered, range from 10 to possibly 700 feet in diameter, and, although believed to have been intruded into unconsolidated muds, are not asso- ciated with pillowed lavas. Endogenous volcanic domes in many areas resemble generally the Unalaskan lava pods in shape and in internal concentric banding (Williams, 1982, p. 145; Coats, 1936, p. 71-74; Cotton, 1952, p. 163), but they are not found with pillowed lavas. Concentric joints and concentric layers of alter- nate nonvesicular and vesicular lava are common in many pillows, and some of them contain concentrically oriented inclusions of wallrock (Lewis, 1914, pl. 21). DESCRIPTIONS OF LAVA PODS IN SPECIFIC AREAS The relations between lava pods, sills, peperite, pil- lowed lava, and argillite are well displayed in the sea - B8 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY WW” Welln (We 11w“,Mnnli'ianuwm Sea level/ [ f.‘ t [F, Tal xmumuflffiu mets | ¢ | mnunum MM t Illilm |“lu'm't'l'h'fl‘f'l‘m‘M.- WU mye tS] C Andesite Layered or columnar jointed as shown Blank areas indicate no data Pillowed andesite, peperite Coarse andesitic tuff y c o y Argillite, tuffaceous argillite FrGurE of photographs 500 1000 FEET a eL 22 au ooc bl Overlapping areas of figures 5 and 6 shown by insets 4.-Sketch showing geologic relations in sea cliffs on south and southwest sides of Tower Point, Unalaska Island drawn from a series fig. 86), is the largest one known with completely exposed concentric layering Lava pod on right, also shown in Drewes and others (1961 ife in A ke n ot cca FiGur® 5.-Stereophotograph of 1,200-foot sea cliff, Tower Point, Unalaska Island. The largest boulders on the beach are the size of a large house An igneous sheet of layered lava pods surrounded by pillowed lava and peperite underlies the lower half of the cliff. Argillite shows prominent horizontal bedding near the center of the cliff. A thick sill (?), columnar jointed near its base and horizontally layered near its top at the prominent break in slope, underlies the top part of the cliff. Horizontally bedded coarse tuff underlies the uppermost crags Photographs by H. F. Barnett, Jr. PILLOWED LAVAS, I: LAVA PODS AND Layered andesite Resistant layers in black 0 10 FEET enn ct FrGurs 6.-Upper contact of layered lava pod with argillite, exposed in small headland near head of cove west of Tower Point, Unalaska Island; drawn from a photograph. Siliccous and calcareous sedi- mentary inclusions are abundant in the layered lava in the wave-cut rock bench surrounding the headland. cliffs and tidal benches of seven areas, which are de- scribed in detail in the following sections. TOWER POINT AREA The vertical exposure in a rock bench, sea cliff, and ridge crest at Tower Point is about 1,200 feet, and the exposed section comprises 3 argillite units, a tuff unit, a sill or flow unit, and 2 sheets containing pillowed lava mixed with lava pods (figs. 4, 5; Drewes and others, 1961, fig. 86). The largest complete cross section of a lava pod is exposed here and, the relations bet ween sedi- mentary, igneous, and mixed units are unusually well shown. The base of the section is a sheet of pillowed lava con- taining lava pods, which is conformably overlain by a thin argillite unit. A thick zone of greenish-white peperite lies along the contact between the lava pod and the argillite, as shown in figure 6. Siliceous and cal- PILLOWED LAVA, UNALASKA ISLAND, ALASKA B9 careous xenoliths derived from the sedimentary rock are included in the lava pod as much as 30 feet below the contact. The lower argillite unit is concordantly overlain by a mixed igneous and sedimentary unit occupying half the height of the sea cliff (fig. 5). On the west side of the point the mixed igneous and sedimentary unit con- sists of a basal sill with columnar joints and faint lay- ers, a medial argillite wedge, and a sheet of pillows, peperite, and lava pods. The pillow and pod sheet thickens and constitutes the whole unit on the east side of the point, and the medial argillite layer is apparently represented only by the interpillow peperite. The larg- est complete cross section of a concentrically layered lava pod dominates the lower half of the east end of the cliff. The upper half of the Tower Point section, above the mixed igneous and sedimentary unit, consists succes- sively of thin argillite, a thick sill(?) jointed and faintly layered near its base and well layered near its top, and a coarse blue-green tuff. The lowermost layer of the argillite (shown in black in fig. 4) has not been visited in the field and its origin is not known. This may be a particularly massive baked argillite, as shown, or it may be a layer of black glass or dense lava similar to that exposed in the middle of the Riding Cove sea cliff several miles to the west. This layer has been partially drawn into boudins on the south side of Tower Point and appears to be cut on the east side of the point by the large concentrically layered lava pod mentioned previously. BUTTRESS POINT AREA Three mixed igneous and sedimentary units and a tuff unit are exposed in the 1,200-foot sea cliffs at Buttress Point (fig. 7). The relations between sills, pillows, and lava pods are shown unusually well. Some of the rocks are analyzed chemically in table 2. The basal unit is a sheet of pillowed lava and lava pods. A layered lava pod is exceptionally well exposed in both rock bench and sea cliff on the east side (figs. 8, 9). The layers of this pod generally are parallel, but they merge with each other locally. The top of the pod abuts against a small lens of tuffaceous argillite, siliceous argillite, and tuff (visible in the upper left corner of fig. 9). Tiny pillows in siliceous argillite near this contact (fig. 10) consist of lava lithologically similar to that in the lava pod and possibly continuous with it. The west end of the Buttress Point exposures con- tains a prominent lens-shaped lava pod (fig. 11) which is completely surrounded by pillowed lava. Layered lava interfingers with pillowed lava at the upper con- tact of the pod. A closeup of the layered lava is shown in figure 12. Chemical analyses of albitized resistant SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY B10 'wrease;p go qred equoo 3431 Uf [IIs poju;o{-reuun|0o poio4tt 4pure; ;o uopeurua) jinagqe agor 4q umouys gt g soinSg Jo stout Surdder1oaq 'sydu1sojoud Jo sotios t WoJ UMBIP { 'jUrOq SsoIj}ng JO sopts jsomMJNOs put jstoyjnos Uo sJIJO tos Uf 91801098 YoJoXS-'Z HHNOLT 'ay[[1d1y A T ae Ana tame o op m 13340001 0 Jnq 23 TTI _ , lena 285 0 To $5.8 Sete 300 0 & per 80° 03 0%o0 20900 gs 000 ppp ou aqporpur svaun yung - 'umoys s» papuriof 10 paishD7 o 0 no «9,0 20 © € 1 ainB1q Ck cE NOLLYNYVTIA4X3 Ess" PILLOWED LAVAS, I: 1 LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA B11 FIGURE 8.-Photopanorama of layered lava pod in wave-cut rock bench on east side of Buttress Point, Unalaska Island. low tide and from the same place as figure 9 but from the opposite direction. constructed by John Stacy. and nonresistant layers shown in this photograph are compared (table 2) with an analysis of fresh pillow glass collected from a small area of unaltered lava in the same sheet immediately east of the edge of the area shown in figure 7. A thick argillite unit is wedged apart by a sill in the middle part of the Buttress Point sea cliff (fig. 7). The sill is columnar jointed and faintly layered. It pinches out abruptly toward the east, and the layers remain parallel with the contact at the blunt termination. A third unit of mixed rock in the upper part of the cliff contains layered lava grading upward, through a gneissoid zone, to pillowed lava (fig. 13). The elongate masses of peperite in the transition zone resemble non- resistant layers of the lava below and are parallel with them. Several of the pillows are higher than they are wide; this shape suggests that they were surrounded and supported by a fluid or plastic medium during for- mation. The pillowy zone grades upward into massive structureless rock at the skyline. \ A coarse blue-green tuff caps this section and is prob- ably correlative with the tuff capping the Tower Point section. A similar and probably correlative tuff caps all the highest hills in this part of the island. It is not safe to correlate argillite units or igneous sheets even between adjacent headlands, because argillite in one see- tion may be represented by interpillow peperite in an adjoining section, and igneous sheets may change char- acter markedly along strike. Vertical multiple dikes cut the rocks of this section and resemble the dikes that were feeders of the sill on Cape Aiak. TOWER POINT-LION BIGHT AREA T'wo of the best exposed lava pods are in sea cliffs between Tower Point and Lion Bight. The first, about a mile east of Tower Point, is exposed so well on three successive small headlands that its three-dimensional 663374 0O-63--3 Photographed at Man in right middle distance for scale. Photopanorama shape can be clearly seen to resemble that of a derby (fig. 14). This pod is as thick as the sheet of pillowed lava in which it occurs, and it appears to crosscut part of the bedding of the overlying argillites. It is divis- ible immto two distinct units: (1) an older upper carapace of crudely layered or roughly columnar to massive lava that appears to grade laterally into the pillowed lava; (2) a younger derby-shaped lava pod, apparently self- contained, which crosscuts the layering of the carapace along its east margin. The derby-shaped pod is layered and unjointed in its semispherical upper part and faintly layered but remarkably well jointed in its lower part, even out to the edges of the derby's brim. Another lava pod exposed in three dimensions, but semiellip- soidal rather than derby shaped, may be seen in any of three successive headlands about midway between Tower Point and Lion Bight (fig. 15). It also lies in a lava sheet containing pillows and lava pods, and it resembles the derby with its carapace of crudely layered, roughly columnar older lava and its core of well-layered lava that is remarkably uniformly jointed along its base. SURVEYOR BAY AREA Another lava pod which appears to be slightly younger than parts of the surrounding igneous sheet is exposed in the sea cliff at Surveyor Bay. This pod is hourglass shaped, and the lava is prominently layered and nonglassy. The narrow central part of the pod transects a sheet of dacitic(?) glass. Small apophyses from the lava pod cut the glass near the base of the sea cliff. The upper margin of the lava pod is gradational with an overlying nonglassy pillowed lava. CAPE PROMINENCE AREA The section exposed in the sea cliffs on the southwest side of Cape Prominence (fig. 16) is composed of a thick lower sheet of pillowed lava containing lava pods, B12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 9.-Layered albitized dacite in active sea cliff on east side of Buttress Point, Unalaska Island. Upper contact of lava pod against small lens of tuffaceous sediment shown in upper left of photograph; for detail see figure 10. Photographed from the same place as figure 8 but from the opposite direction. PILLOWED LAVAS, I: EXPLANATION Pillowed dacite 0 1 FOOT Siliceous argillite FiGURE 10.-Tiny pillows in sedimentary matrix within 10 feet of upper contact of layered lava pod exposed in sea cliff on east side of But- tress Point, Unalaska Island; drawn from a photograph. Ficur®E 11. ground and steep cliff above layered lava in center of picture are pillowed lava. right. LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA Layered albitized dacite lava pod in sea cliff west of Buttress Point, Unalaska Island. B13 a thin but persistent central sheet of bedded argillite, and a thick upper sheet of columnar lava, pillowed lava, and coarsely bedded tuffaceous argillite. Part of the bedding of the central argillite sheet is definitely cut by the upper margins of two large lava pods of the lower igneous sheet. The upper tuffaceous argillite frays out into pillowed lava along an intricate digitated contact. The pillowed lava appears to engulf and replace the argillite at its base, side, and top throughout a zone, 100 feet wide and 100 feet deep, shown on the northwest (left) side of figure 16. The columnar sill, which cuts the argillite shown in the center of figure 16, appar- ently formed a pillowed carapace in the partly engulfed mud above. Southeast of the area shown in figure 16 on Cape Prominence, the igneous rocks in the upper sheet pre- viously mentioned are conformable to sedimentary lay- ers above and below, but the sheet is divided by a central necklace of at least 12 deltoid lava pod "beads" (fig. 17). The lava pods stretch out for about half a mile, and their bases maintain a roughly accordant level. The Rocks in wave-cut rock bench in fore- Dark agillite strata and a massive sill show in upper Figure 12 is a closeup of the layered lava at the base of the sea cliff just left of the small cave shown in the center of the photograph. B14 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 12.-Layered albitized dacite lava pod in active sea cliff west of Buttress Point, Unalaska Island. Closeup of central part of Figure 11. Specimens for chemical analyses 2, 3, and 5, table 2, were collected from the resistant and nonresistant layers just over the geologist's head. Resistant layers contain quartz, and nonresistant layers contain a carbonate. pillowed lava at this level has a distinct but discon- tinuous parting. This parting probably represents the base of the second phase of a two-phase emplacement for this igneous sheet, the lava pods being included in the second phase. Vertical multiple dikes are the youngest rocks exposed. EAGLE BAY AREA Another area with layered lava pods arranged at an accordant level is visible in the sea cliff at the east en- trance to Eagle Bay (fig. 18). This exposure is also an example of a layered lava pod whose vertical dimension is larger than its lateral dimension in the plane of exposure. LANCE POINT AREA Exceptional sea cliff exposures 114 miles west of the tip of Lance Point permit detailed observations of typi- cal relations between pillows, peperite, lava pods, and argillite (fig. 19). Irregular lenses of baked deformed green argillite occur in the center of interstitial masses of peperite. Connecting necks between classical pil- lows, irregularly shaped masses of structureless lava, and layered lava pods are common, more common than is apparent in figure 19. Many of the pillowy masses which are shown as separate bodies in this two-dimen- sional drawing can be seen to be connected in the three- dimensional exposures on the cliff face. ORIGIN OF PILLOWED LAVA AND LAVA PODS ON UNALASKA Pillowed lava and lava pods on Unalaska Island have been formed by the intrusion of fluid magma into semi- consolidated and unconsolidated ocean-bottom muds. Pillows were formed as unstable apophyses or immisci- ble masses during digital advance of magma fronts and engulfment of mud and water in magma. The peperite matrix of most pillowed lavas is a mixed igneous-sedi- mentary flow breccia formed while both lava and sedi- ments were in various states of fluidity or plasticity. Lava pods were large contained masses, tongues, or ducts of magma whose concentric internal layers were PILLOWED 0 50 FEET beeen nne tein Ficurs 13.-Massive and pillowed lava overlying layered lava in cliff exposure high on Buttress Point, Unalaska Island; drawn from a photograph by H. F. Barnett, Jr. formed by flow in a congealing and possibly contami- nated magma. INTRUSIVE ORIGIN The lateral gradation and vertical alternation of pod and pillow lava with massive sills substantiate the theory of the intrusive origin of the pod and pillow lava. Further evidence is given by local detailed re- lations, summarized below. ; Delicate apophyses of some pillows, such as those at Raven Bay, penetrate overlying argillite. Other pil- lows, such as those at Buttress Point and Chernofski Harbor, lie in a deformed but purely sedimentary matrix. Layers of pillows in exceptional exposures (figs. 4, 16) cut across or completely cut out argillite layers. Peperite is a special type of igneous flow breccia with abundant sedimentary fragments. Both its igneous and its sedimentary components appear to have been liquid or plastic at the same time. This material is not pyro- clastic in the conventional sense, for no evidence of explosions or lava fountains was found. Peperite is probably intrusive in origin, for it is found throughout sheets of pillows stratigraphically above sheets of con- temporaneous massive or layered lava (figs. 4, 6, 13, 15). Here sediment had to exist above the lava at the time of emplacement, though doubtless it was quietly wedged or floated upward by the intruding magma. All sheets of pillows examined, some hundreds of feet thick, have their pillows set in a peperite matrix from top to LAVAS, I: LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA B15 bottom. The entire sedimentary component of the peperite could not have come from basal contamination nor could it have filtered in from above; deformed stratified chunks prove it was not precipitated contem- poraneously. Four types of evidence of intrusive contact of layered lava pods or sills with overlying argillite have been observed : (1) truncation of sediment beds (figs. 4, 16) ; (2) development of contact breccia and peperite (figs. 6, 13); (3) development of small pillows in contact sediments (fig. 10) ; and (4) warping of overlying sedi- ment layers (fig. 7). No examples of sedimentary con- tacts between a layered lava pod and overlying argil- lite have been observed. Most of the lava pods are so intimately related to the surrounding pillowed lava (figs. 4, 7, 11, 18, 16, 17, 18, 19) that there can be no doubt that they are practically the same age as the rest of the igneous material. (See also columns 6 and 7, table 2.) Several layered lava pods are definitely younger, if only by a short time, than the surrounding igneous rock (fig. 14), but none are older. The Unalaskan globular intrusions considered as a whole are flows into tenuous mud close to the sediment- water interface (Wells, 1923, p. 68). Lewis (1914, p. 652) discusses the semantic problem of what to call an intrusive flow. In many places Unalaskan pillowed lava is demonstrably intrusive, though it obviously possesses ze $1982 EXPLANATION wi 0 100 FEET inl grrr [i Argillite, tuffaceous argillite FreUur® 14.-Derby-shaped layered lava pod exposed in three successive small headlands along coast east of Tower Point, Unalaska Island ; drawn from a series of photographs. Dissection is sufficiently com- plete to indicate that a cross section taken perpendicular to the coast would be identical. Central derby is younger than coarsely columnar carapace which grades laterally into pillowed lava. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY B16 'mojeq IIIs pogurof -1euwn[09 4q jn St put tar; ojut oj1[[IS1® snosouyn3 poppoqg-yory; doddp off[IISI® Sufdf104o go Sutppaqg ino spod tat poio4t| 1omoT 'sqde1Sojoyd Jo t wouJ { pUZISI adr; Jo opts jsomujnos UO JIP tos u; posodxo spod tar; Surure]u0) tar; pomofIId JO SHNDLT 1334001 0 11 snosve;n} 'oy[[131y PLI o- 3 oquadad paMoIIId »»p ou aqparput spain yung cumoys auoym porur0l «o paiah»7 opsopuy Tl \“\.|vJJ NOLLYNYV Iq X3 "BA¥[ pomor[td out sopeas yoryA Ury)] 1oSuno4 st pjosdIIJ® TB1ju9,;) '[torjuUOpI 0G pINOM jst%00 ou} Oj uoyu} uop)98 t jt4J opeorpU; 0; ogordwroo 4ppuorogns st uonooss( 'ydeasojouyd t uroa; UMEIp ' ®XStTeU (491g UofT puU® jujOJ doMOJ, uooMJog AemptUI sput[pHY [[¥WS Uo pasodxo pod tart poot yo porojsoy-'CT a7{[{31e snosoe3jn3 'ayf[{181y ===: pae. 13314001 0 I | Ce- I oquodad 'ajtsopue pamMoIIIJ ana| gag ppp ou aqparput spain yung cumoys ajoym poruriol wo pauah»7 aqrsopuy oxip aqisopuy © NOILYNYV 1dX 3A B17 LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA PILLOWED LAVAS, I 'spIO}IOP 9} J0 [oA] qUutp10098 oy} UjIMA juop;ou100 Supaed ao wos joUnstp t sey spIOJJOp Sutpunouins BARB poMOIIIY "14311 oy} wou; 9T Jo ® st amnsy sty) 'des [ews t Jo; 'sydeasojoyd Jo sorios t wo}; UMtIpP { pUtjsI 'sououtwoid od¥;) JO OpIS YJNOS UO JJJO tos UI BAR pomoj[Id uf spod tar; projtop poso{t[ JO jo9[§-'LT _w>w_mww 1334001 0 + f : § ; aA ] T3 R =- iz % s 20 i rit Ail vor iio. % ° 0950 20 9° dod ' o se 6 222,000,009 0 teo aquadad 3 aco 54,00 0" 400 00 2.98980" 2 2050 a R o $s 0d a "a e0, 29 000° 209 42.0 nle "908, bes .9 0,8 sca g 0°", / 0 °, 08 200099 3 2 90 0 2, %* au a 2:04005,0° 2009 " a 200 b° 0° ,0 2,02 ° ao Wess » 200 bo. ot n a a 0 0 9 °C $9 0942 +025" cHusnot 9 0 ne-oOunMuaa 4° % 8 , °, ° 29 MDMu.oooono ss sud mt to as00 0 a 0 22950 ° 5C 2 02 9 0° # 502 , 800 0 0 9 o e C $ "00" 5° eunuch. 0° a eqs o °o umoys wwwéi‘ Engage. f cheeses CAAA] 22.3000 40 f C = Pecs sat s besos t a i \ 20020400 + a : 35 2, rtsopuy } $ oB (lool aCe st. 0°, * ® r : $e 60.90 20800, 2 00 ; o # 05% BOOL Sed ease s* § o, a aso h 0% © $ ol so "ney $40° 5 0 0040 09,9, 2000 68 ° o 299°9 0 a +o [e* 20000 ° 40,000 00 0 0 i $ 280 s soytp ajtsopu ¢ $ $ady» $us® a+e $00) .. 8 on st Pd : s $ A Ig * p s nm Y Has aa | - 69 e 88 ho Ca # 9 ©, 990 a 2200 9 20 az 2 © 80,9 j 2st 5 08 bte e" ® 59 Po 4958 e 200500 s 0% 9 e 0402 0° cognaafluann Me = 2200" 53°00" ,* 00 5 6 k dorms, NOILYNYV Td X4 mee B18 Sea level ~~ EXPLANATION Andesite in layered lava pods or irregular pillows 0 100 FEET Pillow selvages, peperite / f Argillite, tuffaceous argillite FicurE 18.-Association of layered lava pods with peperite and irregu- larly shaped pillows in sea clif at east entrance of Eagle Bay, Unalaska Island; drawn from a photograph. Note accordant base level of the layered lava pods. flowlike attributes. Basal muds were not the only muds incorporated in the lava, nor were the flows blanketed by new mud from above. Inclusions and large blocks in the tops of sheets of pillows cannot be explained, as some have claimed, by basal contamination or by con- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY temporaneous precipitation of sediment, but they must have been derived from overlying sediments at the time the magma was emplaced. Exceptional exposures on Unalaska offer evidence for intrusion not found in many areas, and the old concept of intrusive pillows (Pla- tania, 1891, p. 42) would seem to be a necessary work- ing hypothesis in many areas where pillows occur in a sedimentary matrix. The Unalaskan pillows probably formed beneath deep water, as shown by the primary features of the enclosing sedimentary rocks, and as supported by obser- vations of geologists in other areas. The thick argillite section is nearly all fine grained and well laminated. Northeast of the pillow-rich area some argillite layers can be traced from headland to headland for miles. Coarse sediments, agglomerates, tuff breccias, local un- conformities cut and fill structures, and fossils-all present in shallow marine volcanic deposits elsewhere on the island and elsewhere in the Aleutians-are vir- tually absent in the argillite-pillowed lava section. This evidence suggests that regionally 'stable and uniform conditions of sedimentation existed. Magmas were in- truded into the muds of a deep basin whose sediments came from a remote source. The scarcity or absence of vesicles and the lack of pumice, scoria, bombs or essential lapilli in the pillowed lavas is unusual, because andesites and dacites are normally explosive. Likewise a magma fluidity ap- proaching that of pahoehoe, indicated by textural and Sea level EXPLANATION ute S a 5A SX Pillowed, layered, or columnar jointed andesite SX Peperite Argillite 0 10 20 FEET FrGURE 19.-Pillowed lava in sea cliff exposure 1% miles west of tip of Lance Point, Unalaska Island; drawn from several photographs. Lava necks typically connect pillows with each other and with a layered lava pod at deformed argillite occurs in center of peperite masses. the lower right. Baked PILLOWED LAVAS, I: LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA structural features of the lava, is also unusual, because the normal habit of andesite and dacite is short viscous block-lava flows intercalated with massive agglomerates and tuff breccias formed explosively. Thus, the tex- tural and structural evidence suggests that juvenile volatiles were retained by the magma at pressures above the critical point of water. This may explain the re- markable fluidity of the magma. In fact, the large amount of water (6 to 9 percent) trapped in unaltered pillow glass suggests that both connate and juvenile water are present (table 2, column 1; also Drewes and others, 1961, table 1; subaerial vitrophyre of similar composition contains only 0.2 percent H4O). Accord- ing to Sosman (1947, p. 287) a pressure gradient toward an intrusion is possible, and magma may actually ab- sorb water from surrounding rocks. Rittmann (1986, p. 52) suggests a depth of at least 2,000 m for nonex- plosive submarine eruptions. A sticky blanket of mud may lessen the required water load on this part of Unalaska. Others have also favored a deepwater marine environ- ment for pillowed lavas (Daly, 1903, p. 77; Harker, 1909, p. 64; Dewey and Flett, 1911, p. 244; Park, 1946, p. 308), and Harker suggests an intrusive rather than an extrusive origin for the pillows. EMPLACEMENT IN MUDS AND DEVELOPMENT OF MUD-MAGMA EMULSION Abundant fluid mud was available during the pillow- forming epoch on Unalaska. That the sediments were very fluid is shown by penecontemporaneous folding in the thick argillite section along the south coast of Unalaska Island. The original thickness of uncon- solidated sediment during intrusion cannot be directly estimated, but seismic and core studies show that an unconsolidated layer of sediments exists in most ocean areas. In the central and eastern Pacific Ocean, for ex- ample, this layer averages about 0.5 km thick (Raitt, 1956, p. 1635; Press in Benioff, Gutenberg, Press, and Richter, 1958, p. 725; Hamilton, 1959, p. 1407). In places such unconsolidated sediments may contain 50 to 80 percent water by volume (Kuenen, 1950, p. 383). In a basin receiving volcanic sediments, mud accumu- lates rapidly and probably retains water to considerable depth. When fluid sediments of this type are pene- trated by an intrusive column of magma, the magma must bulge out and intrude the sediments, probably along bedding planes, before it ever reaches the sedi- ment-water interface (Wells, 1923, p. 68). Magmas that retain their flowlike forms after penetrating a sedimentary layer must have intruded mud that was extremely watery. Abundant pillows at contacts between intrusive B19 masses and a wet sedimentary matrix and the striking resemblance in shape between pillows and drops of liquid suggest that some force akin to surface tension is instrumental in the formation of the Unalaskan pillows. The pillow-peperite mixture probably is a giant emulsion, with the lava in the pillows equivalent to the liquid of highest surface tension in the emulsion. The idea of an emulsion was first suggested by Lewis (1914, p. 639) who speculates that "it may well be found * * * that some of the pillows that are inter- mingled with the finer marine muds and oozes have been injected into the semifluid and immiscible sedi- ment and thus have formed a sort of giant emulsion." This idea was amplified by Fuller (1940, p. 2022) who says: The ellipsoidal structure of basaltic lavas is considered by the writer to have been formed as the gigantic disperse phase of an emulsion in which the disperse medium was essentially aqueous. As in all emulsions, the dispersal of the fluid with the higher surface tension may have been attained either by the agitation of the two phases or by its entry as detached units. Aside from the magmatic force, the agitation is attributed principally to the explosive action of generated steam, but its effect would have varied according to the pressure. In sub- marine extrusions and where deepseated intrusions encountered ground water, the superheated steam would have retarded the chilling of the basalt and would have contributed to the mobility of the gigantic emulsion, thus permitting the wide develop- ment of the compacted structure in massive formations. Molecular surface tension, however, can scarcely con- tain 40-foot "drops" of heavy lava, and the customary chilled pillow skin is required to perform the task. The great strength and elasticity of lava skins are well dem- onstrated in Hawaiian pahoehoe: "While a pahoehoe toe is active the skin remains tough and flexible. It is so resistant to rupture that one can jump on the top of a small toe and cause the internal liquid to squirt out the end without breaking the skin on the top" (Mac- donald, 1953, p. 174). Some pillows probably form by detachment of lobes and layers from the more massive parts of sills and pods, and these probably break into smaller globules by a process analogous to the formation of drops when immiscible liquids are stirred together. The surface digitations common on fluid flows( see below) may be important in furnishing abundant contact surfaces for the formation of chilled skins. Probably some incipient dikes will form along the tops of sills and, because they lack support and are in contact with mud, will collapse and separate into pillows. "Sprouting" on active aa flows has been observed in Hawaii (Macdonald, 1953, p. 178), and it probably is an effective mechanical mixer. This sprouting hypothesis finds support in several places where layered pod lava grades into pillows (fig. 19). B20 ORIGIN OF LAYERS IN LAVA PODS AND SILLS The layers in lava pods and sills formed while the magmas were still moving, as suggested by their many parallel undulations, local deformation, and transition to breccia or pillows. They had to form in a great variety of container sizes and shapes, including sills perhaps miles long and 600 feet thick. Consequently, any static process, any process which is exclusively cellular and confined, or any process which is known to operate only on a very small laboratory scale cannot be considered. Contraction, convection, crystal settling, and chemical diffusion (that is, Leisegang's rings) are among the hypotheses that might be invoked to explain the pod layers which have to be rejected at the outset. Nearly all the layered patterns that are found on Unalaska are approximated in miniature by flow laminae in thin pahoehoe flows on the island of Hawaii. Repeated concentric flow layers or "laterale Scher- fliachen" of alternate physical character are known from subaerial cylindrical lava tubes in Hawaii and on Vesuvius (Philipp, 1936, p. 342). Concentric flow layers in a few surface domes (Williams, 1932, p. 145; Coats, 1936, p. 71-74) are analogous but less perfect, probably because of low-pressure conditions that permit general autobrecciation of the type described by Curtis (1954, p. 465). Analogy, therefore, suggests that a similar but high-pressure flow process caused these Unalaskan structures, even though composition and scale differences can be large. Very similar flow pat- terns, with an even greater departure in composition and scale factors, can be seen in photographs from physics and engineering laboratories where watery liquids and even gases are dyed or marked with particles in laminar flow systems (Prandtl and Tietjens, 1934, plates 1-27). Contrasting layers, regular and repeated, can be seen in all systems. The layers undulate, merge, and divide, but they do not cross. Physical similitude, in spite of enormous differences in materials and sizes, can be understood by referring to the equation of the dimensionless Reynolds number (R) : where p=density ; +=velocity ; d=diameter of the con- duit or depth of the tabular flow system ; and «= viscos- ity. If this number is lower than about 500, laminar flow must take place for any reasonable conduit shape, even a flow system with a free surface. Rouse and Howe (1953, p. 129) say the following about critical Reynolds numbers : Because different lengths are used in the Reynolds number to describe different boundary forms (the diameter of a pipe, the spacing of parallel boundaries, or the depth of free-surface SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY flow), and because convergent boundaries tend to stabilize the flow and divergent boundaries to promote instability, the crit- ical Reynolds number may be expected to have different magni- tudes for different boundary conditions. A value of about 2,000 is generally accepted for pipes, 1,000 for parallel boundaries, and 500 for flow with a free surface. The appropriate values for non-uniform boundary shapes, the variety of which is obviously without limit, may be determined only through experimental measurement. Because the two most important parameters of the Reynolds number, viscosity and velocity, are unknown for initial conditions on Unalaska, the Reynolds number can only be used as a criterion to deduce the direction of change in state of the magma with falling tempera- ture (from turbulent toward laminar conditions) and the necessary final laminar condition. As a magma cools, slows, and eventually stops moving, a becomes very large and v approaches zero. In addition, d, originally probably large enough to induce turbulence in a hot, fluid magma, is reduced piecemeal; flowing magmas form into toes, lobes, or apophyses of succes- sively smaller dimensions, and peripheral cooling re- duces the dimensions of any still-mobile fraction. Thus, all the variables in the Reynolds number change with time in a direction that reduces the size of the number, so that eventually only laminar flow is possible in a moving magma. The magmas at Unalaska must have passed through a stage in which laminar flow was general, and the regular internal layered patterns de- scribed seem to be reasonably attributable to such flow. In laboratory systems the fluid flow layers disperse as soon as motion stops. In magmas motion may con- tinue until viscosity is high enough to preserve the layers. The terminal relation between viscosity and motion is critical, for if motion stops too soon the layers disperse, and if motion continues too long brecciation may destroy the fluid structure. Among the many fac- tors which control viscosity, entrapment of volatiles under high pressure may have been especially impor- tant on Unalaska. This would provide a long period of fluidity during which the laminar sorting process (see below) could operate. Sustained movement is further insured by the great size of the sills and pods, and the tenuous nature of the confining mud. The effect of chilling is difficult to evaluate because we do not know how thoroughly the thick masses were chilled by stirred-in mud. The mechanical process by which a flowing liquid or plastic material sorts and arranges dyes, particles, or any heterogeneous components into visible regular layers or lines is basically rotary within the system of laminar flow. This conclusion is based on field observa- tions in areas remote from Unalaska. The large, viscid, evolving, and freezing systems of geology permit us to see rotation inside flow layers. Where layers are PILLOWED LAVAS, I: LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA large enough to see and the particles within layers are also visible, each discrete layer apparently has boundary conditions which impose on it an internal velocity pro- file not unlike the velocity profile known to exist inside a water pipe. The interior of a layer moves faster than the boundary. Such differential movement induces a controlled internal turbulence or rotation (evinced by the swirling trachytic flow structure of petrography) which moves impurities, crystals, or vesicles toward the static margins of each flow layer where, because of the relatively stopped condition, many of them become trapped and immobilized. There is, moreover, some evidence that the layers become larger as the melt be- comes more viscous, and some layers are bonded to- gether so that a new layer, with a much larger radius of controlled turbulence, is formed. Minute layered systems are folded and refolded recumbently (Balk, 1937, fig. 17, p. 51). In this way, layers seem to grow. The molecular or infinitesimal flow layers, which physi- cists treat mathematically, can evolve, in a cooling melt, into the visible layers that geologists see and map. Curiously some flow layers retain a pasty mobility long after the bulk of the rock is brittle enough to fracture. On Novarupta dome, Alaska, and on Kilauea Volcano, Hawaii, we have seen piecemeal extrusion of individual flow laminae (from a fraction of an inch to several inches thick) into voids opened by fracture of the lava. Extrapolating from this we presume a dif- ferential translational mobility, together with an im- perfect rotary movement, to be -generally present in layers of extremely viscid systems (Balk, 1937,fig. 17, p. 51). Andrade (1951) shows the rotary nature of laminar flow and the laminar nature of vortical flow but he does not relate these to the generation and evolu- tion of individual layers in a cooling melt. On Unalaska initial uncontrolled turbulence occurred as the huge masses of liquid burst through their walls into tenuous mud. This turbulence mixed in the muds and created the emulsion for marginal pillows. The chaotic or turbulent conditions were rapidly damped as the contaminated magma was chilled; and fluid laminar flow followed turbulent flow. The contami- nants, together with original and derived heterogeneous components in the cooling magma, were then sorted and arranged by the laminar process. Where layers are preserved and deformed and where the layered rock grades into autobreccias with a crude gneissoid pattern, some sort of laminar flow continued into the plastic state and even into the solid state. Where columnar joints are dominant and flow layers weak, lava was probably ponded and motion stopped before the fluid was viscous enough to perfect and preserve the flow structure. B21 The difference in chemical composition between the resistant and nonresistant layers cited (table 2) for the Buttress Point lava pod can be explained either by sort- ing during laminar flow or by later differential altera- tion. If the obvious effects of the late albitization can be neglected for the moment, the composition of the nonresistant layers could be approximated by adding illite-chlorite clay (plus minor calcite) to the original magma. - Analyses of unaltered and tuffaceous argillites which make up the sedimentary rocks in this part of the island are not available, but it is probable that the orig- inal composition approximated an illite-chlorite clay (plus minor calcite). Possibly argillitic muds stirred into the magma during initial turbulence were streaked out and sorted into regular layers during subsequent laminar flow. Or possibly postsolidification hydro- thermal solutions, which moved along regularly dis- posed but compositionally similar flow surfaces in the lava pod, differentially changed alternate layers with the result observed. RECONSTRUCTION OF A TYPICAL IGNEOUS EPISODE A typical igneous episode started with upward pene- tration of andesitic and dacitic magmas into a thick layer of deep submarine mud, which is now thin-bedded argillite. Penetration continued to a point where the heavy magma began to bulge out into the lighter uncon- solidated bottom muds somewhere beneath the floor of the sea. The magmas spread out horizontally in an intricately lobate manner within the muds and engulfed much mud along the magma-sediment interface. On contact with the mud, pillows formed, especially at the tops and sides of the lobes and tubes. Extension of the active intrusive front took place by extension of the supplying lobes and tubes, in many places with imme- diate formation of surrounding pillows and peperite. Some of the large lobes and tubes were pinched off and formed closed lava pods (for example, figs. 14, 15) similar to the giant "pillows" of Bartrum (1980) in New Zealand. Many apparently closed lava pods are cross sections of ducts that supplied magma. Layered sills, in some places, may be long sections of elongate lobes or tubular ducts. Lava pods with accordant base levels (figs. 17, 18) probably are cross sections of tubes which connect laterally and in depth with a central sup- plying duct. Conformable flow layers with concentric cross sections formed in the constantly stiffening lavas as they moved through the supplying tongues or were squeezed by the overlying weight of mud and water into large pods. Later these layers may have been accent- uated by differential hydrothermal alteration, and still later they were accentuated by weathering. Similar genetic relations between sills, feeder ducts, and lacco- B22 liths are inferred by Griggs (1939, p. 1102) and Hunt and others (1953, p. 141) but the igneous bodies they describe were emplaced in solid rock and are neither in- ternally layered nor surrounded by pillows. Interme- diate depth conditions between the sills of Griggs and Hunt and the lava pods of Unalaska may be recorded by the small dolerite laccoliths of Radnorshire (Jones and Pugh, 1948, p. 43-94). Pillows have not been de- scribed from this area, but the laccoliths are believed to have been intruded into unconsolidated muds; it has been noted by Jones and Pugh (1948, p. 71) "the largest and most continuous bodies occur at the lowest horizon, and at each successive horizon upwards the dolerite masses become more and more divided * * *." REFERENCES CITED Andrade, E. N. da C., 1951, Viscosity and plasticity : New York, New York. Chemical Publishing Co., Inc., 82 p. Balk, Robert, 1937, Structural behavior of igneous rocks (with special reference to interpretations by Hans Cloos and collaborators) : Geol. Soc. America Mem. 5, 177 p. Bartrum, J. A., 1930, Pillow-lavas and columnar fan-structures at Muriwai, Auckland, New Zealand: Jour. Geology, v. 38, no. 5, p. 447-455. Benioff, Hugo, Gutenberg, Beno, Press, Frank, and Richter, C. F., 1958, Progress report, seismological laboratory of the California Institute of Technology, 1957: Am. Geophys. Union Trans., v. 39, no. 4, p. 721-725. Burling, L. D., 1916, Ellipsoidal lavas in the Glacier National Park, Montana : Jour. Geology, v. 24, p. 235-237. Carlisle, Donald, and Zeck, W. A., 1960, Pillow breccias in the Vancouver volcanic rocks and their origin [abs.]: Geol. Soc. America Bull., v. 71, no. 12, pt. 2, p. 2053. Coats, R. R., 1936, Intrusive domes of the Washoe district, Nevada : California Univ. Pubs., Dept. Geol. Sci. Bull., v. 24, no. 4, p. 71-84. Cotton, C. A., 1952, Volcanoes as landscape forms, 2d ed.: Christchurch, New Zealand, Whitcombe and Tombs, 415 p. Curtis, G. H., 1954, Mode of origin of pyroclastic debris in the Mehrten formation of the Sierra Nevada: California Univ. Pubs., Dept. Geol. Sci. Bull., v. 29, no. 9, p. 453-502. Daly, R. A., 1903, Variolitic pillow lava from Newfoundland : Am. Geologist, v. 32, no. 2, p. 65-78. Dewey, Henry, and Flett, J. S., 1911, On some British pillow- lavas and the rocks associated with them: Geol. Mag., new ser., Decade 5, v. 8, p. 202-209, 241-248. Drewes, Harald, Fraser, G. D., Snyder, G. L., Barnett, H. F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geol. Survey Bull. 1028-8, p. 583-676. Fuller, R. E., 1931, The aqueous chilling of basaltic lava on the Columbia River plateau: Am. Jour. Sci. 5th ser., v. 21, p. 281-300. 1940, Ellipsoidal structure as the gigantic disperse phase of an emulsion [abs.] : Geol. Soc. America Bull., v. 51, no. 12, pt. 2, p. 2022. Griggs, D. T., 1939, Structure and mechanism of intrusion, in Hurlbut, C. S., Jr., Igneous rocks of the Highwood Moun- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY tains, Montana, pt. I, The laccoliths: Geol. Soc. America Bull., v. 50, no. 7, p. 1043-1112. Hamilton, E. L., 1959, Thickness and consolidation of deep-sea sediments: Geol. Soc. America Bull., v. 70, no. 11, p. 1399- 1424. Harker, Alfred, 1909, Natural history of the igneous rocks: London, Methuen and Co., 384 p. Henderson, J. F., 1953, On the formation of pillow lavas and breccias: Royal Soc. Canada Trans., 3d ser., v. 47, see. 4, p. 28-32. Hoffman, M. G., 1933, Structural features in the Columbia River lavas of central Washington: Jour. Geology, v. 41, no. 2, p. 184-195. Hunt, C. B., Averitt, Paul, and Miller, R. L., 1953, Geology and geography of the Henry Mountains region, Utah : U.S. Geol. Survey Prof. Paper 228, 234 p. Johannsen, Albert, 1939, A descriptive petrography of the igneous rocks, 2d Ed.: Chicago, IlL, Univ. Chicago Press, v. 1, 318 p. Jones, O. T., and Pugh, W. J., 1948, A multi-layered dolerite complex of laccolithic form, near Llandrindod Wells, Radnorshire; and The form and distribution of dolerite masses in the Builth-Llandrindod inlier, Radnorshire: Geol. Soc. London Quart. Jour., v. 104, p. 43-70 and 71-94, re- spectively. Kuenen, P. H., 1950, Marine geology: New York, John Wiley and Sons, 568 p. Lewis, J. V., 1914, Origin of pillow lavas: Geol. Soc. America Bull., v. 25, no. 4, p. 591-654. Macdonald, G. A., 1953, Pahoehoe, aa, and block lava: Am. ~ Jour. Sci., v. 251, no. 3, p. 169-191. Noe-Nygaard, Arne, 1940, Sub-glacial volcanic activity in an- cient and recent times: Folia Geog. Danica, v. 1, no. 2, p. 5-67. Park, C. F., Jr., 1946, The spilite and manganese problems of the Olympic Peninsula, Washington: Am. Jour. Sci., v. 244, no. 5, p. 305-323. Philipp, Hans, 1936, Bewegung und Textur in magmatischen Schmelzfliissen [a study of flow structure and laminated texture in extrusive rocks]: Geol. Rundschau, v. 27, no. 4, p. 321-365. Platania, Galtano, 1891, Geological notes of Acireale, in John- ston-Lavis, H. J., Editor, The South Italian Volcanoes: Naples, F. Furchheim, chap. 2, p. 37-44. Prandtl, Ludwig, and Tietjens, O. G., 1934, Applied Hydro- and Aeromechanics ; translated by J. P. Den Hartog: McGraw- Hill Book Co., Inc., (1957 Dover ed.), 311 p. Raitt, R. W., 1956, Crustal thickness of the Central Equatorial Pacific, pt. 1 of Seismic-refraction studies of the Pacific Ocean Basin: Geol. Soc. America Bull., v. 67, no. 12, pt. 1, p. 1623-1639. Rittmann, Alfred, 1936, Vulkane und ihre Tatigkeit [Detailed study of volcanoes and volcanic activity]: Stuttgart, Ferdinand Enke, 186 p. 1952, Nomenclature of volcanic rocks proposed for use in the catalogue of volcanoes, and key-tables for the de- termination of volcanic rocks: Bull. Voleanol., v. 2, no. 12, p. 75-102. Rouse, Hunter, and Howe, J. W., 1953, Basic mechanics of fluids : New York, John Wiley and Sons, 245 p. PILLOWED LAVAS, I:; LAVA PODS AND PILLOWED LAVA, UNALASKA ISLAND, ALASKA Satterly, Jack, 1941, Geology of the Dryden-Wabigoon area [Ontario]: Ontario Dept. Mines 50th Ann. Rept., v. 50, pt. 2, 67 p. 1948, Geology of Michaud Township [Ontario]: Ontario Dept. Mines 57th Ann. Rept., v. 57, pt. 4, 27 p. 1952, Geology of Munro Township [Ontario]: Ontario Dept. Mines 60th Ann. Rept., v. 60, pt. 8, 60 p. 1954, Geology of the north half of Hollaway Township [Ontario]: Ontario Dept. Mines 62d Ann. Rept., v. 62, pt. 7, 88 p. Shapiro, Leonard, and Brannock, W. W., 1956, Rapid analysis of silicate rocks: U.S. Geol. Survey Bull. 1036-C, p. 19-56. Smedes, H. W., 1956, Peperites as contact phenomena of sills in the Elkhorn Mountains, Montana [abs.] : Geol. Soc. America Bull., v. 67, no. 12, pt. 2, p. 1783. Snyder, G. L., 1957, Ocean floor structures, northeastern Rat Islands, Alaska : U.S. Geol. Survey Bull. 1028-G, p. 161-167. Snyder, G. L., and Fraser, G. D., 1958, Intrusive layered lava pods and pillow lavas, Unalaska Island, Aleutian Islands [abs.] : Geol. Soc. America Bull., v. 69, no. 12, pt. 2, p. 1646. B23 Sosman, R. B., 1947, Some geological phenomena observed in an iron and steel plant: New York Acad. Sci. Trans., ser. 2, v. 9, no. 8, p. 287-290. Stark, J. T., 1939, Discussion: Pillow lavas: Jour. Geology, v. 47, no. 2, p. 205-209. Uttley, G. H., 1918, The volcanic rocks of Oamaru, with special) reference to their position in the stratigraphical series: New Zealand Inst. Trans. and Proc., v. 50, p. 106-117. Waters, A. C., 1960, Determining direction of flow in basalts (Bradley volume): Am. Jour. Sci., v. 258-A, p. 350-366. Wells, A. K., 1923, The nomenclature of the spilitic suite, pt. 2 of The problem of the spilites: Geol. Mag., v. 60, no. 704, p. 62-74. Wentworth, C. K., and Macdonald, G. A., 1953, Structures and forms of basaltic rocks in Hawaii: U.S. Geol. Survey Bull. 994, 98 p. Williams, Howel, 1932, The history and character of volcanic domes: California Univ. Pubs., Dept. Geol. Sci. Bull., v. 21, no. 5, p. 51-146. Wilson, M. E., 1938, The Keewatin lavas of the Noranda dis- trict, Quebec: Toronto Univ. Studies, Geol. ser. 41, p. 75-82. Pillowed Lavas, II: A Review of Selected Recent Literature By GEORGE L. SNYDER and GEORGE 1). FRASER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL: SURVEY - rPROFESSLONAL _ PAPER ~454-C - ..----....-'_u---a_------_---'..__--..-..-......-..----____-_-...-_..£_..---_-_..-'-..---..-_--_---..‘--------_a-', odu on----._-_-_-____.._-------------,._-..____--_------_--_{,,--_--.‘fl------_--__,--__---_-_-..__..-..__- —--_,-__—__-----..--__-___--_-._---..--_-__---‘.__....-___..-----_..-..-_----_----_-~- i d «5326315 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY PILLOWED LAVAS, II: A REVIEW OF SELECTED RECENT LITERATURE By Grores L. Sxyorr and Grorcer D. Fraser ABSTRACT A review of literature after 1914 on pillowed lavas discloses general agreement, but important exceptions, on some aspects of pillow formation and contradictory ideas about other areas of fact or interpretation. Most students believe pillow formation is due to the juxtaposition of hot fluid magma and a cold fluid, generally water or mud, but pillows do occur rarely in locations where the presence of excess water has not been demonstrated. Many thick layers of pillows containing interstitial sediments are probably near-surface intrusive bodies rather than extru- sive bodies. The distinction previously made between pillow and pahoehoe structure is valid. There is no general agreement on the time of pillow formation with respect to the time of em- placement of the magma body. Pillows are most common in subsilicic igneous rocks, but they are found throughout a broad spectrum of compositions. INTRODUCTION The authors have a varied background upon which to base a survey of lava structures. Snyder studied the structures of subaerial and submarine lavas and near- surface intrusions in the Aleutians Islands and Alaska Peninsula from 1949 through 1954. Fraser studied similar and also some of the same structures in the Aleutian Islands from 1952 through 1954. Fraser studied also lava structures on Hawaii from 1956 through 1959 and currently is engaged in geologic mapping in the area adjacent to the north edge of Yellowstone National Park. In 1953 and 1954, the authors jointly studied many remarkable pillows and larger lava pods that are well exposed on Unalaska Island, Alaska. These have been described in previous publications (Drewes and others, 1961; Snyder and Fraser, 1963). The present short review of literature after 1914 on pillowed lavas is an outgrowth of the in- terest developed during study of the lava structures on Unalaska. The following discussion is a product of the authors' experience with the Unalaskan and other fea- tures and represents an attempt to resolve or delineate several aspects of pillow formation about which there has been disagreement among many geologists. IS WATER NECESSARY? Ellipsoidal lava structures have puzzled geologists since at least 1834. According to Tyrrell (1929, p. 37) the term "pillow" was first used in 1890 by G. A. J. Cole and J. W. Gregory to describe ellipsoidal structures in the variolitic rocks in the area of Mount Genévre on the border of France and Italy. Many diverse theories have been advanced to account for the formation of ellipsoids or pillows, and many early hypotheses are well summarized by Daly (1903, p. 65-78), Dewey and Flett (1911, p. 202-209, 241-248), Sundius (191%, p. 317-333), Lewis (1914b, p. 591-654), and Johannsen (1939, p. 228, 229). There would be little advantage in recounting the older literature here, and the inter- ested reader is referred to the aforementioned authors for the proper historical perspective. Since Lewis' classic paper in 1914, most observers have considered pillows to be general, though not infallible, criteria of submarine or subaqueous extrusion or extrusion into local water bodies, over damp ground, or under ice (Capps, 1915, p. 45-51 ; Burling, 1916, p. 237 ; Sampson, 1923, p. 572; Foye, 1924, p. 337; Buddington, 1926, p. 824; Moore, 1928, p. 59; Bartrum, 1930, p. 447, 455; Fuller, 1931, p. 292; Burrows and Rickaby, 1934, p. 15; H. T. Stearns, 1938, p. 252-2538; McKinstry, 1989, p. 202-204; Fuller, 1940, p. 2022; Noe-Nygaard, 1940, p. 5-67; Wilson, 1942, p. 64; Park, 1946, p. 305, 308; Cotton, 1952, p. 290; Henderson, 1953, p. 28, 31; Stearns, 1953, p. 207; Murthy, 1954, p. 298; Gage, 1957, p. 38; Gass, 1958, p. 242; Kudryashova, 1958; Malde and Powers, 1958, p. 1608; Byers, 1959, p. 326, pl. 48; Waters, 1960, p. 356, 361; Wilson, 1960, p. 97; Yagi, 1960, p. 919). Wager and Bailey (1953, p. 68) and Bailey and McCallien (1956, p. 472, 475) report basic pillows with fine-grained margins against a matrix of granophyre or porphyry, which they believe to have re- sulted from nearly simultaneous injection and mixing of basic magma and cooler acid magma. - Reynolds (in Wager and Bailey, 1953) believes that at least part of these pillows were formed by injection of basic lava into water and later by injection of granitic material. Other authors suggest that some pillows formed wholly sub- aerially (Lewis, 1914a, p. 32; Cooke, James, and Mawds- ley, 1931, p. 43, 48; Hoffman, 1933, p. 192, 194 [for an C1 C2 opposed account see Fuller, 1931, p. 292] ; Stark, 1938, p. 225-238; Simmons, 1946, p. 192-193 [for an opposed account see Reid and Dewey, 1908, p. 269]). Several authors have noted the tendency of melts of artificial or natural substances to form cellular structures (Bé- nard, 1900; Dauzére, 1908; Osborn, 1946; 1947; 1949) and Green (see accounts in Lewis, 1914b, p. 644, and in Osborn, 1949, p. 77) actually observed spheroidal masses in subaerial lava from the 1859 flow of Mauna Loa. Osborn (1949, p. 73, 76) has attributed these structures to convection flow and concludes that "* * * the structures in lava variously called ellipsoidal, pil- low, or globular may have formed by convection flow modified by horizontal movement of the lava stream and followed by rather rapid quenching." The general absence of pillow structure in most subaerial flows, however, militates against the general effectiveness of all subaerial mechanisms. We believe that the juxtapo- sition of hot fluid magma and a cold fluid, generally water or muds, is generally necessary for pillow formation. EVIDENCE FOR THE INTRUSIVE ORIGIN OF SOME PILLOWS Because much of the argument about pillow origin has been concerned with proof or disproof of subaque- ous origin, most geologists have accepted an extrusive origin as axiomatic, and intrusion has seldom been con- sidered. Wilson (1918, p. 121), for example, defines pillow structure as "a flow phenomenon characteris- tically developed in extrusive lava only"; so it is not surprising when he later (1942, p. 64) concludes that "it is scarcely conceivable that [pillow] forms could develop in magma confined in a dike." McKinstry (1939, p. 204) has stated that " 'typical' pillows are pretty certainly diagnostic of extrusive origin * * *" and many others (Thomson, 1947, p. 4; Pichamuthu, 1957, p. 19) have felt that pillow structure was a con- venient criterion with which to distinguish extrusive igneous rocks. However, "typical" pillows, pillow breccias, or globular, ellipsoidal, or spheroidal struc- tures similar to pillows have been reported in dikes (Clapp, 1917, p. 260, 285; Worth in Wells, 1923, p. 67; Ellitsgaard-Rasmussen, 1951, p. 83-101; Chapman, 1955, p. 1541), in dikes, stocks, and lopoliths (Lawson, in Moore, 1930, p. 138), in sills (Ransome, 1894, p. 195, 201, 202, 209; Uttley, 1918, p. 114; Gage, 1957, p. 37), in a volcanic plug (Woodworth, 1903, p. 17-24), and in irregular intrusions (Ransome, 1898, p. 104; Lawson, 1914, p. 7; Clapp, 1917, p. 285; Benson, 1943, p. 120; Jones, in Vuagnat, 1952, p. 297 ; and Chapman, 1955, p. 1541). Ransome (1894, p. 195) reports a pillowed "fourchite" sill with continuous zones of locally intense contact metamorphism in sandstone adjacent to its SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY upper and lower surfaces. Yagi (1960, p. 913, 915) cites metamorphosed shale above sheets of pillow-con- taining alkali rocks. The presence of marine sediments in masses, blocks, and igneous-sedimentary breccias within the layer of pillows is often cited as proof of submarine origin. In many places the bedding in the blocks of sediment may be truncated against the pillows (for example, Satterly, 1941a, p. 130; 1941b, p. 11). Park (1946, p. 309) speaks of "many fragments rang- ing in size from small chips to blocks 30 feet or more across * * * engulfed in the lavas." Several workers have noted sediments within individual pillows (Fox and Teall, in Lewis, 1914b, p. 603, see also pl. 21; Sat- terly and Armstrong, 1947, p. 8; Thomson, 1947, p. 4). Buddington (1926, p. 827) reports pillow lavas with interstitial limestone that grade upward into breccias with a limestone matrix. These observations prove a watery origin, and they should also suggest an origin by intrusion into watery sediments because many other igneous-sedimentary breccias in the absence of pillows do result from intrusion. Phrases from the literature such as "isolated pillows," pillows "with chilled margins intact and sometimes with intervening cavities filled with shale," and brecciated lava which "is in fact a macadam-like agglomerate" (Bailey and McCallien, 1957, p. 47) suggest that some rock interpreted as pyroclastic (agglomerate) could actually be flow breccia in lava or peperite. Intrusion, and mixing of mud and magma seem possible. Simi- larly, Bartrum and Turner (1928) describe some curi- ous New Zealand rocks, and their descriptions would fit rocks we have seen on Unalaska. They document two cases of mixed sedimentary and igneous rock (p. 107, 110) and one of intrusive pillows (p. 110), but do not stress these ideas in interpretation of large volumes of "crushed" or "shattered" rock which occur enig- matically between layers of unshattered pillows. The crushed rocks appear to be sediments "entangled in associated lava" (p. 129), and all have a high percent- age of altered, comminuted material that could be either igneous or sedimentary. Two previous field parties thought that most of this rock was sedimentary. Bart- rum and Turner insist that it is nearly all igneous. Perhaps some is peperite brecciated by its own move- ment, and more than one pillowed sheet may be intrusive. According to Macdonald (1939, p. 336) the term "pépérite" was first used by Scrope in 1827 for certain basaitic tuffs and breccias of the Limagne region, France, which had formed from the intrusion of basaltic magma into poorly consolidated sediments. The term has found wider usage in Europe than America, but rhyolitic pépérites have been described from Marysville Buttes, Calif. (Williams, 1929, p. 168, PILLOWED LAVAS, II: A REVIEW OF SELECTED LITERATURE PI. 16b), basaltic pépérites, from San Pedro Hill, Calif. (Macdonald, 1937, p. 330; 1939, p. 329-338), and basaltic and andesitic pépérites, from the Elkhorn Mountains, Mont. (Smedes, 1956, p. 1783.) In all three localities the resulting breccias have been ascribed to the intrusion of magmas into incoherent poorly consolidated or moist sediments. Elsewhere sedimentary material between pillows is so common that it has been noted in nearly all descrip- tions and even forms part of the definition of pillow structure quoted (from Tyrrell) in the recent A.GI. Glossary (Howell, 1957, p. 221). One of the three fol- lowing explanations is generally given for the presence of this material: (1) Contamination from below the extrusive lava sheets; (2) infiltration from later de- posits or contemporaneous precipitation; or, (3) mix- ing during intrusive flow into water-rich mud. Evi- dence supporting the last explanation has been cited for the rocks of Unalaska Island (Snyder and Fraser, 1963). Capps (1915) records the squeezing of soft sediments into basal pillows with a diminution in the amount of interstitial sediment upward in the sheet of pillowed lava; such an observation correctly indicates extrusion onto soft mud. Others record primary strati- fication of sediment within the tops of pillow layers (for example, Prest, 1951, p. 13), and such observations . suggest an infiltration hypothesis. In many pillow layers, however, the muds, which are commonly fossili- ferous, permeate the entire pillow sequence or are con- fined to the top part where they are mixed in as deformed chunks. The basal layers of some pillow-con- taining sheets are massive or the sheet is very thick so that mud could not have squeezed through from below. This relation has been interpreted by several (for example, Lewis, 1914b, p. 630ff) as evidence for shallow (with respect to the sea floor) intrusion into mud and is exactly the interpretation we give to the Unalaskan pillows. We believe that similar sedimentary or igneous-sedimentary matrices in pillowed lavas in other areas should lead one to suspect an intrusive origin. PILLOWS VERSUS PAHOEHOE In Lewis' classic review of the pillow literature be- fore 1914, he compares pillows with the pahoehoe struc- tures of fluid basalts and concludes that they were formed by analogous processes. H. T. Stearns (1938, p. 252, 253), Wilson (1942, p. 63), and Macdonald (1953, p. 173, 174) sharply disagree with this descrip- tion, and Macdonald has formulated criteria for dis- tinguishing a heap of pahoehoe toes from pillowed lava. In pahoehoe budding, as described by many authors, a small stream or arm of molten lava runs rapidly out for a short distance from the main lava C3 flow, stiffens, expands, cracks, and permits another short stream to issue forth (the first bulbs and arms may be covered by subsequent lava, but commonly pa- hoehoe toes are a terminal phenomenon of a single eruption). The connecting necks between pillows on Unalaska (Snyder and Fraser, 1963), and perhaps pillows elsewhere, do not extend from cracks where lava extrudes from one pillow to form another, but rather the neck and pillow surfaces all form a con- tinuous smooth surface, and in some places the whole mass (fig. 13) grades into massive lava which suggests that the entire mass must have been liquid at about the same time. We agreé that pillows are morphologically distinct from interconnected pahoehoe toes even though connecting necks between pillows are probably more common on Unalaska Island than in many other areas. The attenuated necks between pillows form a pattern on clean tidal flats or other good exposures which super- ficially resembles the anastomosing, amoeboid imbrica- tion of some types of subaerial pahoehoe. The prin- cipal differences between pillowed lavas and heaps of pahoehoe are abundant matrix and a much greater vol- ume of nonconnected globular structures in true pillows. Furthermore, most vertical exposures of pillowed lava exhibit at least 1 or 2 pillows with greater vertical than horizontal dimensions (for example, Snyder and Fraser, 1963, figs. 13, 19). This is difficult to explain by the gradual piling up of the lava from bottom to top, as would be necessary with pahoehoe. Vertically elon- gated pillows require the support of a mud or peperite matrix or adjacent plastic pillow masses during their solidification. The superficial similarity bet ween pillows and pahoe- hoe has been unnecessarily confusing. Practically every modern textbook with a section on pillowed lavas describes an observation about the recent lava pillows actually seen by Anderson (1910, p. 633, 639) in the process of formation on Samoa. Actually, Anderson's original observations and photograph make it plain that he was observing pahoehoe forming by a budding proc- ess which happened to take place at the shoreline. Globular pahoehoe toes were formed similarly both above and below the waterline, and the only difference in the two structures was a roughly granular surface on the submarine toes as compared to the normal corded pahoehoe surface. Fraser examined large areas con- taining subaerial pahoehoe on the island of Hawaii and found that few pillowlike bodies of any degree of per- fection, in section or in plan, were present, and none of the deposits contained an abundant sedimentary matrix like that of the Unalaskan pillows or many other pil- lows. This evidence supports the views of Sampson (1923, p. 572) and Buddington (1926, p. 824) who be- C4 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY lieve that a great volume of pillows form only in con- tact with water. The cross sections of Hawaiian pahoe- hoe toes and tubes are ellipsoidal, but nonconnected ellipsoids are mostly confined to the stagnant edges of a few flow units or are locally formed near secondary vents and probably are never abundant. Of the six differences between pahoehoe toes and pillows noted by Macdonald (1953, p. 174), the more abundant matrix between pillows and the greater number of vesicles in pahoehoe are most important in comparing Unalaskan pillows and Hawaiian pahoehoe. TIME OF PILLOW FORMATION Three sets of time relations between the formation of pillows and the emplacement of the magma have been invoked to explain the time of pillow formation : (1) the pillows form abundantly at the moment of con- tact of the magma with an aqueous medium or during subsequent mixing and movement of the magma; (2) the pillows are formed after the magma is emplaced and activity subsides; or (3) the pillows form consec- utively as the magma advances in a series of toes and buds, the lowermost pillows then being slightly older than the uppermost pillows (see previous discussion of pahoehoe). Most students favor the first explanation but there is no general agreement. Reid and Dewey (1908, p. 269) and others speak of a flowing mass of spheres rolling on the sea bed. Stark (1938, p. 234) and Satterly (1941a, p. 122) note the extreme distortion of pillows in some flows, suggesting that they were formed before the close of movement. M. G. Hoffman (1933, p. 192), who thinks that pillows are formed by the turbulence caused by underlying surface irregularities, mentions that "at the time of formation of the pillows most of the mass was in motion." Henderson (1953, p. 31) thinks that "the pillows form as globules of lava with tough glassy skins and are transported as entities to their final place of deposition"; according to this explanation the pillows must be transported individ- ually rather than in an emulsionlike mass because he states (p. 26) that "each pillow was deposited subse- quently to the pillows on which it rests." Osborn (1949, p. 76) , working with cellular artificial glasses, notes that "the final pattern of cells is essentially the same as that which first appears, and commonly this pattern is affected by the direction and speed of movement of the liquid across the mold." Foye is adamant, however, in his belief that the explanation represented by (2) is most applicable for the pillows in the basalts of Triassic age in Connecticut. He states (1924, p. 337), "The field evidence is conclusively in favor of the view that the pillow structure developed in lava flows which had come to rest before the structure was formed," and (p. 341), "Again, the pillows were developed after the sheet ceased to flow and not as a result of its advance." Cooke, James, and Mawdsley (1931, p. 43, 48) feel that the pillows which commonly occur only at the tops of northern Canadian flows were formed after the extru- sion of the underlying massive lava. Lewis (1914a, p. 32; 1914b, p. 647) is the chief advocate of (3), but others have subscribed to the process of individual bulbous budding (Clapp, 1917, p. 283; Macgregor, 1928, p. 19; Burwash, 1933, p. 50). McKinstry (1939, p. 203) feels "* * * that each pillow is a distinct entity and, in a sense, an individual flow which cooled within its own crust; that the ellipsoidal shapes could not have come into being while the material was in place as a part of a thick mass of lava * * *." Thomson (1985, p. 6; 1948, p. 6) and Wilson (1942, p. 64; 1960, p. 97, 101) agree that fitted pillows show that the lower ones formed ear- lier, although F. Hoffman (in Lewis, 1914b, p. 597) concluded long ago that fitted pillows prove contempo- raneous formation. Actually, both of these attitudes are too restrictive. Fitted pillows show either that the lower pillows are earlier or that the entire mass was simultaneously in a plastic state. Wilson (1960, p. 97) stated that pillows were formed as "globules about in the same way that oil globulates when mingled with cold water * * *" and that they were transported individ- ually to their final resting place "partly from the buoy- ancy of the vesicular lava and partly from the uplift effect ot escaping steam." This mechanism of transport may be locally important, but it cannot be operative in areas where many pillows are interconnected complexly (Snyder and Fraser, 1963, figs. 13, 19) or where evi- dence for abundant gas emission is negative, as on Unalaska. Fuller's emulsion theory (1940, p. 2022), which was previously cited in detail (Snyder and Fraser, 1963), requires abundant formation of pillows during initial contact or flow mixing of magma and an aqueous medium, as in relation (1), followed by trans- port of the pillows as a body.. We feel that this expla- nation of the time of formation of the pillows is the most important one for Unalaska. Continuous lobate budding, as in relation (3), may be a locally important process on Unalaska. Deformed and brecciated pil- lows, locally present, cannot have formed after cessa- tion of motion, as in relation (2). COMPOSITION OF PILLOWED LAVA Most geologists realize that pillows are most common in subsilicic lavas (Howell, 1957, p. 221; Johannsen, 1939, p. 228; Park, 1946, p. 308). Some geologists would restrict the formation of pillows to basalts or related basic lavas (Dewey and Flett, 1911, p. 202, 245; Lewis, 1914b, p. 595, 646; Tyrrell, 1929, p. 38; Daly, PILLOWED LAVAS, II: A REVIEW OF SELECTED LITERATURE 1933, p. 419). As late as 1953 it has been stated that "Andesitic pillow lavas have not been reported, * * *. Pillow lavas, so far as is known, develop only from pahoehoe flows of basalt" (H. T. Stearns, 1953, p. 207) ; and "Pillow structure is * * * known only in basic lavas" (Reynolds, in Wager and Bailey, 1953, p. 70). These statements are certainly mistaken. Andesitic and more silicic pillowed lavas are well known from the Keewatin rocks of the Canadian shield. Between 1928 and 1954 the Ontario Department of Mines published at least 30 papers describing andesitic pillowed lavas and at least 14 papers dealing with pillows of trachytic, dacitic, or rhyolitic composition (for chemical analyses see Satterly, 1941a, p. 125, 131; 1941b, p. 10; Hogg, 1954, p. 16). Pillowed andesites have also been reported in Quebec (Cooke, 1919, p. 76; Cooke, James, and Mawdsley, 1931, p. 40; Wilson, 1988, p. T7; 1942, p. 59-62; 1960, p. 97, 101), in Alaska (Buddington, 1926, p. 825), in Ireland (Geikie, in Lewis, 1914b, p. 608), in New Zealand (Bartrum, 1930, p. 447), and in Guam (N. D. Stearns, 1938, p. 7), and pillows are known in Norwegian rhomb porphyry lava (Dons, 1956, p. 14). Mafic alkalic pillows on the Nemuro Peninsula (Yagi, 1960, p. 918, table 3) are latites according to the chem- ical classification of Rittmann (1952). Ultrabasic pillows are possible too. Glassy limburgite pillows have been analyzed in Southern Rhodesia (Macgregor, 1928, p. 49). . Analyses of vitrophyric olivine-rich pic- rite basalt pillows on Cyprus compare well with Nock- old's average peridotite (Gass, 1958, p. 248, 249). The pillows of andesitic and dacitic composition on Una- laska, as illustrated by the new analyses cited previously (Snyder and Fraser, 1963), reinforce the view that, although pillows may be most common in subsilicic igneous rocks, they may be found throughout a broad spectrum of compositions. REFERENCES CITED Anderson, Tempest, 1910, The volcano of Matavanu in Savii: Geol. Soc. Quart. Jour., v. 66, no. 264, p. 621-639. Bailey, E. B., and McCallien, W. J., 1956, Composite minor in- trusions, and the Slieve Gullion complex, Ireland: Liver- pool and Manchester Geol. Jour., v. 1, pt. 6, p. 466-500. 1957, The Ballantrae serpentine, Ayshire: Edinburgh Geol. Soc. Trans., v. 17, pt. 1, p. 33-53. Bartrum, J. A., 1930, Pillow-lavas and columnar fan-structures at Muriwai, Auckland, New Zealand: Jour, Geology, v. 38, no. 5, p. 447-455. B Bartrum, J. A., and Turner, F. J., 1928, Pillow-lavas, perido- tites, and associated rocks of northernmost New Zealand : New Zealand Inst. Trans. and Proc., v. 59, pt. 1, p. 98-138. Bénard, Henri, 1900, Les Tourbillons cellulaires dans une nappe liquid: Rev. gen. sci. pures et appl., v. 11, p. 1261-1271, 1309-1338. Benson, W. N., 1943, The basic igneous rocks of eastern Otago and their tectonic environment, part 4 in The mid-Tertiary C5 basalts, tholeiites, and dolerites of Northeastern Otago : Royal Soc. New Zealand Trans. and Proc., v. 73, pt. 2, p. 116-138. Buddington, A. F., 1926, Submarine pillow lavas of southeastern Alaska : Jour. Geology, v. 34, no. 8, p. 824-828. Burling, L. D., 1916, Ellipsoidal lavas in the Glacier National Park, Montana: Jour. Geology, v. 24, p. 235-237. Burrows, A. G., and Rickaby, H. 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Assoc. Bull. 15, 27 p. Prest, V. K., 1951, Geology of Guibord Township: Ontario Dept. Mines 60th Ann. Rept., v. 60, pt. 9, 56 p. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Ransome, F. L., 1893, The eruptive rocks of Point Bonita [Marin County, Calif.] : Calif. Univ. Pubs., Dept. Geol. Sci. Bull., v. 1, no. 3, p. 71-114. 1894, The geology of Angel Island: Calif. Univ. Pubs., Dept. Geol. Sci. Bull., v. 1, no. 7, p. 193-234. Reid, Clement, and Dewey, Henry, 1908, The origin of the pillow lava near Port Isaac in Cornwall: Geol. Soc. Lon- don Quart. Jour., v. 64, p. 264-272. Rittmann, Alfred, 1952, Nomenclature of volcanic rocks pro- posed for use in the catalogue of volcanoes, and key-tables for the determination of volcanic rocks: Bull. Voleanol., v. 2, no. 12, p. 75-102. Sampson, Edward, 1923, The ferruginous chert formations of Notre Dame Bay, Newfoundland : Jour. Geology, v. 31, no. 7, p. 571-598. 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H., 1918, The volcanic rocks of Oamaru, with special reference to their position in the stratigraphical series: New Zealand Inst. Trans. and Proc., v. 50, p. 106-117. Vuagnat, Marc, 1952, Variolites et spilites; comparison entre quelques pillow-lavas alpines et britanniques [abs. with discussion]: Internat. Geol. Cong., 18th, Great Britain, Rept., pt. 13, p. 297. Wager, L. R., and Bailey, E. B., 1953, Basic magma chilled against acid magma: Nature, v. 172, no. 4867, p. 68-69. (Discussion by D. L. Reynolds, p. 69, 70.) PILLOWED LAVAS, II: A REVIEW OF SELECTED LITERATURE Waters, A. C., 1960, Determining direction of flow in basalts (Bradley volume) : Am. Jour. Sci., v. 258-A, p. 350-366. Wells, A. K., 1923, The nomenclature of the spilitic suite. Pt. 2. The problem of the spilites: Geol. Mag., v. 60, no. 704, p. 62-74. Williams, Howel, 1929, Geology of the Marysville Buttes, Cali- fornia: Calif. Univ. Pubs., Dept. Geol. Sci. Bull., v. 18, no. 5, p. 103-220. Wilson, M. 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Geology Rev., v. 2, no. 10, p. 912- 920. 2... . .. f p- IS T (AZ ‘ Glaciation of Little Cotton- wood and Bells Canyons, Wasatch Mountains, Utah UUVIUE uirT y J ep c- G# GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-D TTP He Udo nego an Ody O ac caa -~ VUV BAW UHLuwo CVE UILLLLL UV EXVIUT Glaciation of Little Cotton- wood and Bells Canyons, Wasatch Mountains, Utah By GERALD M. RICHMOND SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-D A study of the sequence of advances and recessions of the Quaternary glaciers and their relations to the rises and falls of Lake Bonneville UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director The U.S. Geological Survey Library has cataloged this publication as follows: Richmond, Gerald Martin, 1914- Glaciation of Little Cottonwood and Bells Canyons, Wasatch Mountains, Utah. Washington, U.S. Govt. Print. Off., 1964. iv, 41 p. illus., maps (2 fold. col. in pocket) diagrs., profiles, tables. 29 cm. (U.S. Geological Survey. Professional paper 454-D) Shorter contributions to general geology. Bibliography : p. 40-41. 1. Glacial epoch-Utah-Wasatch Mountains. 2. Geology-Utah- Wasatch Mountains. 3. Geology, Stratigraphic-Quaternary. I. Title. (Series) For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS T :- - .-. io cale earn n ne an aer ao ana d oa ne ede or s col od Erevious 00 col bedrock ___ ul 2 cle snel rll ne . _. lel ds dll EILL ILCA ba el aia a= a Bo An ie a nein a rhe boe in aca (as mn i be mle in in ae in nene a a e halle 36 j TABLES Page TABLE 1. Altitudes of end moraines and rock glaciers of successive late Pleistocene glaciations and stades in Little Cottonwood and Bells ___. sn D21 2. Correlation of nomenclature of the glacial deposits of Little Cottonwood and Bells Canyons-________-_-_-.--.-. 34 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH By M. Ricumoxnp ABSTRACT Little Cottonwood and Bells Canyons lie on the west slope of the Wasatch Mountains about 15 miles south of Salt Lake City, Utah. The glaciation of these canyons has long been of interest because the moraines at their mouths are in contact with the deposits of Lake Bonneville. The purpose of this paper is to describe the glacial and associated deposits of the canyons, to interpret their history, and to discuss their correla- tion with the deposits of Lake Bonneville which were studied concurrently by R. B. Morrison. Little Cottonwood and Bells Canyon are short steep glacial gorges that rise in altitude from about 5,200 feet at their mouths to about 10,600 feet at their headward divides. The concordant profiles of interfluves projecting into Little Cotton- wood Canyon suggest that at an early stage of erosion the canyon was a broad shallow upland valley. Remnants of a lower broadly U-shaped valley rim the inner steep-walled canyon. Both the upper and the lower broad valley surfaces have been uplifted along normal faults at the west base of the range. A deposit of possible till, the oldest in the area, lies on a remnant of the lower surface north of the mouth of Little Cottonwood Canyon. A younger till of postcanyon and pre- Lake Bonneville age locally caps the divide separating Little Cottonwood and Bells Canyons. Both tills are inferred to be of middle Pleistocene age. Deposits of two younger late Pleistocene glaciations occur on the floors of the canyons. The older of these deposits comprises two sets of large mature moraines correlated with the Bull Lake Glaciation of Wyoming. The moraines represent 2 distinct advances of the ice that reached average altitudes of 4,980 and 5,000 feet, respectively, at the mouths of the canyons and were separated by a withdrawal of the ice to the upper parts of the canyons and possibly to the cirques. The till of the moraines contains abundant deeply disintegrated boulders, and is more clayey and compact than that of the younger glaciation. A mature soil formed on these deposits during the succeeding interglaciation when the ice disappeared entirely. Deposits of the younger late Pleistocene glaciation, cor- related with the Pinedale Glaciation of Wyoming, comprise three sets of moraines. These are located in the middle and upper parts of the canyon at average altitudes of 6,570, 7,220, and 9,190 feet, respectively. They mark one maximum and two minor readvances of the ice, separated by relatively short recessions. During the succeeding interglacial interval, the altithermal interval of Antevs (1948), the glaciers disappeared entirely and a submature soil formed on the deposits. Later, in Recent time, two sets of small moraines or rock glaciers formed in the cirques. These are correlated with the Temple Lake and historic stades of Neoglaciation (Little Ice Age of Matthes, 1939) in the Wind River Mountains of Wyoming. The older set of moraines bears an azonal soil and vegetation; the younger set bears neither soil nor vegetation. Correlation of the glacial deposits with the deposits of Lake Bonneville was determined jointly with R. B. Morrison. The lower till of the Bull Lake Glaciation intertongues with, and is overlain by, the deposits of the first rise of Lake Bonneville (Alpine Formation of Hunt and others, 1953), which attained an altitude of about 5,100 feet. The upper till intertongues with, and is overlain by, deposits of the second rise of the lake (Bonneville Formation of Hunt and others, 1953), which formed the Bonneville shoreline (alt, 5,135 ft). The maximum of both rises seems to have shortly followed the glacial maxima. De- posits formed during the fall of the lake, during its stillstand at the Provo shoreline (alt, 4,800 ft) (Provo Formation of Hunt and others, 1953), and during its subsequent desiccation are correlated with those of the recession and disappearance of the Bull Lake glaciers. The'lower, middle, and upper tills of the Pinedale Glaciation are inferred to correlate with the deposits of three fluctuations of a post-Provo rise of the lake discovered by R. B. Morrison (1961). These attained upper limits of 4,770, 4,470, and 4,410 feet, respectively. Deglaciation accompanied the final fall and desiccation of Lake Bonneville, Deposits of the Temple Lake and historic stades of Neoglacia- tion in the cirques are inferred to correlate respectively with the deposits at the Gilbert Beach alt, 4,240-4,245 ft) ( Eardley and others, 1957) and the upper few feet of bottom sediments of Great Salt Lake. INTRODUCTION The canyon of Little Cottonwood Creek and adjacent Bells Canyon, in the Wasatch Mountains about 15 miles south of Salt Lake City, have long been famous among geologists because it was here that Gilbert (1890) first demonstrated a relation between the glacial deposits at the mouths of the canyons and Lake Bonneville. The area drained by these two canyons covers about 30 square miles and lies between lat 40°30" and 40°37" 40" N. and long 111°30' and 111°47'30"' W. (fig. 1). The purpose of this paper is to describe the Quater- nary deposits of these canyons and to discuss their geo- logic history and correlation with the deposits of Lake Bonneville. The work was done concurrently with a study of the deposits of Lake Bonneville in the adjacent Draper area to the west by R. B. Morrison. Morrison and the writer together examined and mapped that part D1 D2 42° 41° 40° 39° 38° SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY‘ 114° F- 0 1> 1° HAH NEVADA WYOMING 4. (2 UTAH oA . *. ou lan nle fee s ince ose nines ine oo meen, nt op | 50 MILES FIGURE 1.-Index map showing location of Little Cottonwood and Bells Canyons, Utah. GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH of the area at the mouths of Little Cottonwood and Bells Canyons where the lake and glacial deposits inter- tongue, and are in agreement as to their interrelations. They visited the area together first in 1950 and again briefly in 1952, and the author spent about 4 weeks during the summer of 1959 studying the glaciation in the area. PREVIOUS WORK Evidence of glaciation along Little Cottonwood Can- yon was first recorded by Emmons (in Hague and Emmons, 1877, p. 353-354), who observed that moraines at the mouth of the canyon "extended as low as the ancient lake which once filled Utah basin." Subse- quently, King (1878) inferred from the dual character of the deposits of Lake Bonneville that there had been two periods of glaciation separated by an episode of aridity. Gilbert (1890) described the moraines at the mouth of the canyon, but failed to find any evidence of a lakeshore cut on them. He therefore inferred that the moraines were formed while the lake level stood at the Provo shoreline after erosion of its outlet had caused it to fall from the Bonneville shoreline. Gilbert also inferred that there must have been an earlier glaciation coincident with a high stand of the lake which pre- ceded, but attained a lower level than, the stand at the Bonneville shoreline. In 1909, Atwood made the first, and to date the only, survey of the glaciation of the Wasatch Mountains as a whole. He observed differences in the distribution, weathering, and erosion of the moraines at the mouths of little Cottonwood and Bells Canyons that clearly proved that two advances of the ice had extended below the Bonneville shoreline at the mouths of the canyons. He called these the "earlier" and "later" epochs of glaciation and included moraines higher in the canyons as recessional deposits of the later epoch. Atwood also discovered that till of the "earlier epoch" at the mouth of Bells Canyon is overlain by lake deposits, thus substantiating Gilbert's inference that glaciation paralleled both high fluctuations of the lake. Subsequent workers have added considerable detail to this general history. Blackwelder (1931) found deltaic deposits of the lake in the breach of Little Cottonwood Creek through the moraines of the later epoch. He therefore concluded that the prograding activity of streams flowing off the glacier prevented notching of the moraines by the high shore of the lake, which could thus have been coincidental with the glacial maximum. Antevs (1945, 1952) agreed with these general conclusions and with those of Atwood (1909). Calkins and Butler (1943), in a discussion of the mining district in the upper part of Little Cottonwood D3 Creek, mentioned "a terminal moraine of a late stage" at the mouth of Gad Valley. Marsell (1946) indicated that deposits of three glaciations were present on Little Cottonwood Creek, the first two of which he believed to be of pre-Bonneville age and the last of Provo age. Ives (1950) described evidence for five advances of the ice: (a) a very old glaciation, established principally on the basis of erratics; (b) a glaciation virtually equivalent to the earlier epoch of Atwood ; (c) a glacia- tion virtually equivalent to the later epoch of Atwood, but represented by two sets of moraines; (d) an upper canyon glaciation represented by moraines at the con- fluence of Little Cottonwood Creek with White Pine Fork and with Gad Valley; (e) a valley-head glacia- tion represented by moraines 1 to 11/4 miles from the cirque head walls, which he belived were formed during the "Little Ice Age" of Matthes (1939, 1942), or less than 4,000 years ago. Later workers (Marsell and Jones, 1955; Jones and Marsell, 1955) have provided new facts from their studies of the mouth of Little Cottonwood Canyon; for example, that the thickness of the gravelly out- wash deposits just west of the moraines is as much as 1,000 feet. Recently, Eardley, Gvosdetsky, and Marsell (1957) reviewed the evidence for multiple glaciation in the Little Cottonwood area, enlarging upon the conclu- sions reached by Marsell in 1946. BEDROCK GEOLOGY The bedrock geology of the headwaters of Little Cottonwood Creek was fully described by Calkins and Butler (1943), and a summary of a study of the entire area was published by Crittenden, Sharp, and Calkins (1952). The reader is referred to these reports for descriptions of the stratigraphic units in the area, to which occasional reference is made in this paper. CLIMATE The climate of Little Cottonwood and Bells Canyons ranges from semiarid at the mountain front to sub- arctic in parts of some of the higher cirques. Annual precipitation is in excess of 50 inches at Alta and ranges from 15 to 20 inches at the mountain front. Maximum precipitation occurs from December to April, mostly as snow. - Annual snowfall at Alta is about 350 inches. The mean annual temperature is about 35°F at Alta and about 55°F at the mountain front. Monthly average altitudes of the freezing isotherm (0°C) at Salt Lake City (alt, 4,220 ft) range from below the ground surface to about 15,000 feet (fig. 2). Readings below 8,000 feet are affected by local tem- perature inversion conditions, and therefore fluctuate D4 ALTITUDE (feet) 16,000 15,000 { a. h.. / \_\ EXPLANATION o 14,000 ~ ~f X 1959 " 4 " in'! 13,000 4 \i \ o-=~-0 1957 /’/;/ 12,000 - $ "\ \ Freezing isotherm if" 4. \ y | \ I f 11,000 _Mgi_nym_alt_ih£e_\3 \ _______________ / fais: Average altitude \ '-_\. of cirque floors of recently active rock glaciers A y 10,000 { \ yas | 30 4. c S. 2. Fa a.. 9000 - \\ K 2 >. i/ 8000 1 4 #. (TeX X #? f 7000 - G % u" Alf y:» A Ia aa + 6000 1 s=] /y k \D» $ 5000 { o J+, 4220 Ser f.. > 4 ; : a Sa t pap, gif a lt c o 5 &. 5 Sis. $e t ars es ia is s Ficurp 2.-Monthly average altitudes of freezing isotherm at 5:00 a.m., Salt Lake City, Utah, for years of record-1957, 1958, 1959. widely. Of interest in its relation to glaciation in Little Cottonwood and Bells Canyons, however, is the fact that the freezing isotherm is below an altitude of 10,000 feet from about October 15 to April 15, a period of 6 months. This altitude is in close correlation with the average altitude of 10,200 feet for cirque floors occupied by rock glaciers that are known to have been active within the last 1,000 years (fig. 2). The writer agrees with Ives (1950, p. 113) that some of these rock glaciers seem to be active at present, and that the area is marginally glacial. Ives suggested (p. 106) that an "over-all lowering of temperatures by about 10°F would re-establish glacial conditions in the summit area." - This would mean lowering the freezing isotherm by about 2,000 feet, which would bring it to an altitude of about 12,000 feet in July. Lowering the freezing isotherm by 3,000 feet in July would intersect the peaks and permit the formation of ice caps on the divides. As the divides were covered by ice in only a few places at the time the late Pleistocene glaciers extended to the mouths of the canyons, the writer is inclined to believe that lowering of the freezing iso- therm by only about 1,000 feet would result in the for- mation of small glaciers in the cirques and a marked rejuvenation of activity of the rock glaciers. This is equivalent to lowering the mean July free-air temper- ature only 4° or 5°F. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY VEGETATION The vegetation of Little Cottonwood and Bells Can- yons has many characteristics common to that on the western slope of the middle Rocky Mountains; it also includes many aspects of the vegetation on the High Plateaus of Utah to the south. Timberline along ridge crests is between 10,800 and 11,000 feet altitude, or just below the summits of the highest peaks. In north-facing cirques the upper limit of trees extends as low as 9,500 feet as a result of local orographic conditions, including the distribution of bare rock cliffs, rock glaciers, and talus deposits. No- where does wind seem to be a significant agent in its control. On the north side of Little Cottonwood Can- yon, timberline parallels the contact of the quartz-mon- zonite stock and overlying rocks for a considerable dis- tance. In Albion Basin, Collins Gulch, and Peruvian Gulch mining operations have extensively deforested the slopes, but the former position of timberline is readily established. An Alpine zone is probably lacking, for areas above timberline are largely rocky slopes, and such vegetation as exists is mostly grass. Flora typical of the Alpine zone is scarce. The Hudsonian zone lies at altitudes between 11,000 and 9,500 feet, but it has a vertical extent of only 100 to 200 feet. The Canadian zone lies be- tween an upper limit of 11,000 to 9,000 feet and a lower limit of 6,000 to 7,000 feet. The Transition zone has an upper limit of about 9,000 feet and a lower limit of about 5,000 feet. The Upper Sonoran zone lies be- | low about 5,200 feet. The distribution of forest types, as compiled from field observations and inspection of aerial photographs, is shown in figure 3. A spruce-fir climax lies below an upper limit that ranges from 11,000 to 9,700 feet and above a lower limit that ranges from 6,000 feet on south- facing slopes to 7,000 feet on north-facing slopes. It consists predominantly of Engelmann's spruce (Picea engelmanni), but includes some Alpine fir (Abies lasio- carpa), white fir (Abies concolor), whitebark pine (Pinus albicaulis), limber pine (Pinus flexilis), and, locally, Douglas-fir (Pseudotsuga tazifolia). Willow (Saliz spp.), mountain alder (Alnus tenuifolio), and red birch (Betula fontinalis) are abundant along water courses and in swampy areas. Stands of quaking aspen (Populus tremuloides) are common throughout the lower part of the zone below altitudes that range from about 8,500 feet in Hogum Fork to 9,700 feet in Albion Basin. A zone of ponderosa pine (Pinus ponderosa), which occurs both to the north and to the south along the Wasatch Mountains, is lacking in Little Cottonwood GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYON, WASATCH MO'IjNTAINS, UTAH D5 0 Ye 1 MILE CONTOUR INfERVAL 1000 FEET DATUM IS MEAN SEA LEVEL EXPLANATION Alder-willow Valley-bottom associa- tion at higher altitudes Spruce-fir Tundra Mostly barren cliffs and rock glaciers. Some grassy tundra along divides Upper limit of aspen along valley bottoms 'Maple Oak-juniper Sagebrush-grass Valley-bottom associa- tion at lower altitudes 4 $ s f Drainage Divide FicurE 3.-Vegetation zones in the drainage of Little Cottonwood and Bells Canyons. and Bells Canyon. No obvious reason for this lack was noted. An oak climax lies between altitudes of 5,000 and 9,000 feet along the front of the mountains and also extends up Little Cottonwood Canyon along its north slope to about 9,000 feet. Gambel oak (Quercus gambeli?) and Utah oak (Quercus utahensis) predominate, forming dense stands that cover large areas or scattered clumps that are separated by areas of grass and sagebrush (Artemesia tridentata). Rocky Mountain juniper (Juniperus scopulorum), Utah juniper (Juniperus utahensis), and one-seed juniper (Juniperus mono- sperma) occur sparsely throughout, but they are espe- cially common in the lower part of the range. Other intermixed brush include western chokecherry (Prunus virginiana), mountain mahogany (Circocarpus ledi- folia), western sarvisberry (Amelanchier utahensis), quininebush (Cowania stansburiana), and boxelder (Acer negundo). 3 The floor of Little Cottonwood Canyon upstream from an altitude of 7,500 feet is characterized by a mixed valley-bottom forest consisting mostly of quaking aspen (Populus tremuloides), local patches of Engelmann's 723-113 0O-64--2 spruce (Picea engeimanni), and scattered mountain ash (Sorbus sitchensis), elderberry (Sambuscus glauca), and various species common to the oak climax on the adjacent lower slopes of the north wall of the valley. The creek tends to be bordered by alder (Alnus tenui- folia), willow (Saliz spp.), red birch (Betula fonti- nalis), and scattered blue spruce (Picea pungens engel- manni). From about 7,500 feet downstream to the mouth of the canyon, the valley-botton forest consists primarily of maple (Acer glabrum and A. grandidentatum), which attains a height of 20 to 30 feet. Intermixed are oak (Quercus gambelli and Q. utahensis), western thornapple (Crataegus douglassii), western sarvisberry (Amelanchier utahensis), boxelder (Acer negundo), western chokecherry (Prunus virginiana), and scattered narrowleaf cottonwood (Populus angustifolia). A sagebrush and grass climax occurs at areas within the lower part of the oak climax and at altitudes below 5,000 to 5,200 feet. Its upper limit coincides in many places with the Bonneville shoreline (5,135 ft). Secondary species within this climax are those common to the Upper Sonoran zone. : D6 GENERAL PHYSIOGRAPHY OF THE CANYONS Little Cottonwood Canyon is a steep spectacularly U-shaped gorge (fig. 4). The lower sector is mostly in the quartz monzonite of the Little Cottonwood stock, and the upper sector is mostly in Precambrian and Pale- ozoic sedimentary rocks. The glaciated lips of tribu- tary hanging valleys are about 600 feet above the creek along the upper sector and about 1,000 feet above the creek along the lower sector. The canyon floor rises in an easterly direction from an altitude of 5,200 feet at its mouth to 9,600 feet in Albion Basin, 11 miles up- stream, a gradient of 400 feet per mile. As the divide at the head of the canyon is about 1,200 feet above the cirque floor, the overall relief along the canyon is about 5,600 feet. Bells Canyon rises 4,700 feet in 5 miles, a gradient of 940 feet per mile, and has an overall relief of 6,050 feet. The maximum relief in the area is 6,233 feet-from the mouth of Little Cottonwood Creek to Twin Peaks (alt, 11,483 ft) at the head of Gad Valley. ASYMMETRY As pointed out by Calkins and Butler (1943), the Wasatch Mountains are topographically asymmetric, the highest part of the range being west of the actual drain- age divide. At the head of Little Cottonwood Canyon (fig. 5), peaks along the divide have an average altitude of about 10,625 feet, whereas those to the west on either side of the canyon have an average altitude of 11,150 feet (fig. 5A). This asymmetry, though partly due to the resistance of the Little Cottonwood stock that under- lies many of the western peaks, is primarily the result of uplift of the range along normal faults along the mountain front. The asymmetry is reflected in the relief of the canyon walls, which ranges from 3,500 to 5,000 feet in the lower sector of the canyon and from 1,400 to 2,600 feet in the upper sector. FiGurs 4.-Lower sector of Little Cottonwood Canyon showing profile of lower broad valley surface entrenched by inner U-shaped gorge. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY A second obvious asymmetry is displayed by the dif- ference in character of the tributaries on the north and south sides of Little Cottonwood Canyon as noted by Ives (1950). Tributaries from the north are short steep unglaciated gullies that head in avalanche chutes: the one heading on Dromedary Peak (fig. 5B) rises 3,950 feet in a total length of only 11/4 miles at a gradient of 2,660 feet per mile; the one heading on Superior Peak rises 3,000 feet in a total length of only 1 mile. In contrast, tributaries from the south are long glacial gorges whose gradients become successively less steep from west to east. Hogum Fork rises 5,000 feet in 3 miles, a gradient of 1,660 feet per mile. Gad Valley Gulch rises 3,580 feet in 314 miles, a gradient of 1,020 feet per mile. Possible reasons for this asymmetry are the differences in moisture accumulation and in isolation between north-facing and south-facing slopes. These factors af- fect the headward growth of tributaries not only during glaciation but also during interglacial stream erosion. The magnitude of the asymmetry suggests that late Pleistocene glaciation has augmented differences in trib- utary growth that probably became apparent shortly after uplift of the range by normal faulting began. No structural or lithologic differences in the bedrock that might affect the rate of tributary growth on the two sides of the canyon have been observed. EROSION SURFACES Little Cottonwood Canyon comprises an inner narrow U-shaped gorge, about three-quarters of a mile wide, that is cut within a deep broadly U-shaped valley about 11, miles wide (fig. 5B). The concordant profiles of ridge crests separating the major tributaries further suggest that a still higher broad valley once occupied the present drainage of the canyon (fig. 6). The dis- tribution of remnants of the two broad valley surfaces and a reconstruction of their long profiles are shown in figures 5A, B. The profile of the lower broad valley lies 300 to 400 feet above Little Cottonwood Creek at the head of the canyon and about 1,000 feet above it at the mouth of the canyon (fig. 5A). The latter figure may indicate the amount of relative uplift of the surface by normal faulting at the mountain front. The present gradient of the profile is about 430 feet per mile. A projection of the gradient to the canyon mouth intersects a rem- nant of an erosion surface between 6,100 and 6,200 feet altitude along the north side of Little Cottonwood Can- yon; this surface is capped by 100 feet or more of ar- kosic sandy bouldery gravel (pl. 1). Most of the boul- ders are 12 to 18 inches in diameter, but some are as much as 3 feet. They are predominantly quartzite; but GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH D7 Pre-Bull Lake alluvial pa-w'j ) ase f fan gravel or till + Zor Suec res Location of Section shown on figure 4 2 k u ‘Q\.C\a Lake till *~ T ELLs Ca ye. % EXPLANATION e Possible remnant of lower broad valley surface Z Accordant ridge crest repre- senting possible remnant of upper broad valley surface Al 11,000" 10,000 ‘ Upper broad valley surface. . o. XF NOO I & 9000' C 3» 8000' 7000' B 12,000’—] Lone Peak xe | § Fes f a a 0 w eva ae Shur ake haas Pr fif sot. 11,000 /// sya" r‘xng/f‘, -W—\\_/.~4__z\\/ ~ X. NQ Q- so 10,000 // A 2 surface ieee sen oes _ Upper, broad __. Nalley . canbe norco oil ao r 9000 sof sss: broad 8000' North nm>_// 8 Lowe! T 7000' South rim\ ”479". ’,///’ mm”, r vk ao vi Ls 6000' Gradient 5000' 0 To MILES | 1 1 i 5.-Profiles showing asymmetry of Wasatch Mountains and of Little Cottonwood Canyon and map and profiles of upper and lower broad valley surfaces in Little Cottonwood Canyon. A, Long profile of Little Cottonwood Canyon showing (1) gradient of canyon, (2) projected gradient of lower broad valley surface, (3) projected gradient of upper broad valley surface, (4) profile of south rim of canyon (fine dashed line) and profile of north rim of canyon (fine dotted line) showing east-west asymmetry of Wasatch Mountains. «B, Section A-A', cross profile of upper and lower broad valley surfaces along divide east of Red Pine Fork and Tanner Gulch. Section B-B', cross profile of Little Cottonwood Canyon along Tanner Gulch and Red Pine Fork. Sections show north-south asymmetry of canyon. C, Map of possible remnants of upper and lower broad valley surfaces in Little Cottonwood Canyon. Profiles A4-4' and B-B' are shown in figure 5B ; profile C-C' in figure 7. D8 quartz, quartz-muscovite gneiss, amphibolite, quartz- biotite gneiss, diabase, quartz monzonite, porphyritic quartz monzonite, and granodiorite were also observed by the writer. Some of the cobbles and boulders are well rounded, some are irregular in shape, and some are soled across their internal structure in a concave man- ner. Striations were noted on a few quartzite cobbles. R. B. Morrison (written communication, 1960) inter- prets this deposit as an ancient alluvial fan gravel. The writer, however, agrees with Crittenden and others (1952, pl. 1) that it is a high-level till. The deposit is included in the altitude range of erratic boulders inter- preted to be of glacial origin and referred to as M1 by Eardley and others (1957). Unfortunately, no con- clusive evidence as to the origin of the deposit has been found. The upper broad valley appears to have been 2 to 3 miles wide, about 700 feet deep at its head, and 2,000 feet deep at its mouth. No deposits related to it were found. Reconstruction of the long profile of the valley suggests that its present gradient is about 200 feet per mile. The profile lies about 300 feet above the lower broad valley surface in the upper sector of Little Cotton- wood Canyon and about 2,500 feet above that surface at the canyon mouth. The latter figure may suggest the amount of relative uplift of the surface at the mountain front by normal faulting at the time the lower surface was being cut. AGE OF THE EROSION SURFACES Eardley (1944) has described two ancient erosion surfaces in the northern part of the Wasatch Mountains SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY southeast of Ogden (fig. 1). The older, known as the Herd Mountain surface and now preserved at altitudes ranging from 8,500 to 9,100 feet, slopes gently into the upper parts of the valleys and is cut on rocks as young as Oligocene in age. The younger surface, known as the Weber Valley surface, is a dissected pediment that, in its type area, is cut primarily on soft sedimentary rocks of Cretaceous and Tertiary age. Eardley believes that the surface was cut in late Pliocene or early Pleis- tocene time. Crittenden, Sharp, and Calkins (1952) suggested that the subdued topography along the crest of the Wasatch Mountains east of Salt Lake City may represent the Herd Mountain surface, and that remnants of an en- trenched pediment along Emigration Canyon, east of Salt Lake City, probably represent the Weber Valley surface. The writer found no erosion surface on the divides enclosing Little Cottonwood and Bells Canyons that he would correlate with the Herd Mountain surface. The upper broad valley surface of this report may be of late Pliocene or early Pleistocene age and, though proof is lacking, it was probably the surface on which the first glaciation of the area occurred. Its relation to the Herd Mountain surface is unknown, but it was clearly related to the present drainage and was not a continu- ous upland plain or pediment. The lower broad valley surface is believed by the writer to be of middle Pleistocene age and is correlated * This belief is based on the fact that the oldest of three pre-Wisconsin tills in the La Sal Mountains, 200 miles to the southeast, was deposited by glaciers flowing on the older of two high-level broad valley surfaces (Richmond, 1957, 1962). Ficurs 6.-Upper sector of Little Cottonwood Canyon showing remnants of lower broad valley surface above 'inner U-shaped gorge and higher accordant intertributary ridges which are believed to represent an upper broad valley surface. GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH with the remnants of an entrenched pediment along Emigration Canyon which Crittenden, Sharp, and Cal- kins (1952) correlated with the Weber Valley surface. QUATERNARY DEPOSITS The Quaternary deposits of Little Cottonwood and Bells Canyons include tills of at least three major Pleistocene glaciations * and two minor Recent regener- ations of the ice. In addition, there is a variety of alluvial and colluvial deposits whose stratigraphic and geomorphic relations to the tills, to each other, to dis- conformities, and to soil profiles make possible their correlation with the glacial sequence. The three Pleistocene glaciations are correlated with those of the Wind River Mountains, Wyo. (Blackwel- der, 1915; Holmes and Moss, 1955) as pre-Bull Lake ® Bull Lake, and Pinedale. Glacial deposits of the Re- cent Neoglaciation (Moss, 19512) represent two stades. The deposits of the earlier or Temple Lake Stade are correlated with the Temple Lake Moraine (Hack, 1943; Moss, 1951a, b; Holmes and Moss, 1955) ; the deposits of the later stade, called simply the historic stade, are correlated with the cirque moraines of Moss (1951a). This terminology is applied to the deposits in the area of this report to avoid introduction of new names. Deposits of at least one pre-Bull Lake glaciation antedate Lake Bonneville. Deposits of the Bull Lake Glaciation, which includes two stades, lie at the mouths of the canyons and stratigraphically intertongue with the deposits of Lake Bonneville in such a way that they can be correlated directly with the two high-level fluc- tuations of the lake. - Deposits of the Pinedale Glacia- tion, which includes three stades, lie too far up the canyons to have direct contact with the lake deposits, and the out wash gravels are too alike and discontinuous to be traced from the moraines to the canyon mouths. On the basis of comparative weathering, however, these deposits can be correlated with a sequence of alluvial terraces that are graded to deposits of three intermedi- ate-level fluctuations of the lake. Deposits of the Temple Lake and historic stades of the Neoglaciation are correlated indirectly with two Recent low-level fluctuations of Great Salt Lake. TILL OF A PRE-BULL LAKE AGE If the bouldery deposit on the remnant of the lower broad valley surface north of the mouth of Little 2 The terms "glaciation" and '"stade" are used in this report in the sense recommended by the American Commission on Stratigraphic No- menclature (1961) in lieu of the terms "stage" and "substage," respectively. * The term "pre-Bull Lake" is applied here in preference to the term "Buffalo" (Blackwelder, 1915) because deposits of the "Buffalo stage" are known to represent more than one glaciation (Richmond, 1957, 1962). D9 Cottonwood Canyon, described on page D6, is till, it lies well above the upper limit of Bull Lake ice and is the oldest glacial deposit in the area. ' Younger distinct till of pre-Bull Lake age occurs in the saddle along the divide between Little Cottonwood and Bells Canyons at an altitude of 6,800 to 6,900 feet (pl. 1). The till comprises two rather different de- posits. One is thin and consists of boulders and cob- bles in a coarse arkosic sandy matrix. Most of the boulders are derived from quartzite of Precambrian age that underlies the ridge; but some are of quartz monzonite from the Little Cottonwood stock to the east, and others are of tillite of Precambrian age, quartz- ite, and granodiorite of Paleozoic age from the upper part of Little Cottonwood Canyon. Several of the stones are soled or faceted, and striations are preserved on a few of the quartzite cobbles. The deposit bears no soil, and is being eroded by slope processes at pres- ent. Boulders at its surface are hard, but very few nonresistant components remain. The material ex- tends from the saddle downslope into Bells Canyon to an altitude of 6,600 feet-the upper limit of striated surfaces and less weathered erratics of the Bull Lake Glaciation. The other deposit of younger till of pre-Bull Lake age lies just upslope from the first on the Bells Canyon side of the saddle. It forms an abrupt ridge which appears to be a remnant of a lateral moraine from Bells Canyon. The ridge extends from an altitude of 7,000 feet to about 7,120 feet. It is 30 to 40 feet high and is composed predominantly of large boulders as much as 10 feet in diameter, some of which are soled and faceted. The entire deposit is composed of quartz monzonite from the Little Cottonwood stock, which is the only rock type upstream in Bells Canyon. Its lower limit is about 200 feet above striated ledges and erratics that mark the upper limit of Bull Lake ice. These two deposits probably represent the same pre- Bull Lake glaciation and, on the basis of their topo- graphic setting, seem to be of postcanyon age. The fact that morainal topography is preserved on one of them suggests that they correlate with the youngest of three tills of pre-Bull Lake age in the Rocky Mountain region (Richmond, 1957). DISCONFORMITY BETWEEN PRE-BULL LAKE AND BULL LAKE DEPOSITS Most of the erosion of Little Cottonwood and Bells Canyons appears to have taken place in Pleistocene time before the formation of a very strongly developed thick reddish clayey soil, called the pre-Lake Bonneville soil (Morrison 1961). Just north and south of the canyons (pl. 1), this soil is formed on pre-Lake Bonneville fan D10 gravel and is overlain by the outer moraines of Bull Lake Glaciation. It occurs at altitudes as low as 5,160 feet on the east side of the fault zone along the moun- tain front (pl. 1). This altitude is only 75 feet above the bedrock floor of Little Cottonwood Creek on the east side of the fault zone (fig. 7), and suggests that erosion of the canyon since soil formation has been rela- tively slight. Moreover, the erosion has been of only temporary character, for at least 160 feet of gravel and till lies above the bedrock floor of the canyon east of the fault zone (fig. 7), and at least 1,000 feet of gravel lies west of it (Marsell and Jones, 1955). These con- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY ditions indicate that, despite intermittent deepening of the canyon, deposition has more than kept pace with erosion resulting from uplift of the mountains since formation of the pre-Lake Bonneville soil. DEPOSITS OF THE BULL LAKE GLACIATION Deposits formed during the Bull Lake Glaciation in the drainage of Little Cottonwood and Bells Canyons include till, outwash gravel, and colluvium (fig. 8). These deposits locally overlap the pre-Lake Bonneville soil, and the upper limit of the till lies downslope from till of pre-Bull Lake age. S N C' C 5440' - Till late stade, Bull Lake Glaciation -£ 5400' - - x x A35 RQ ax? '* ais 5300' -I fel cX Alluvial fan gravel, we fri XK Pinedale age a j s \ oF Till, late stade, Bull /6,; kel 9 "a Lake Glaciation [G. \ p92 r. Nae N 2 kg ' :$o°| _ \Qutwash gravel, Pinedale]: O: ed st! 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Aue3 8 3 Taks. api igus -- ~ ~~ 1. ~miepould S11 ae & oroig rog Coot _ srasspow <\4 Loie assign} thts ysempn S Ay Sag m o at Arm. ___ [ «B ESMO waQ/éix/N/E, apersiaqul 912] TALL o_ __s__ = ~f Lam T Howr #s o> spas ait" emuovr h | uonere|S19ju! jerse|Soap - ajepaul I [L_ -- Ca @ A sysodap ion 2, 202 0 9a p 3D 4901 pue IIL XT apers ayeq ardwa} af imguuog H jos jeuozy (Jeuoze) flos auojsiy-a427 ardwa | x: apersioqui ouoisty -aye7 ajdwa| | e v, ° 2 o aye71-1804 2823 9 eBes 2028935 3°C 2 Sa unmiy yooy --L - apes (1961 'uosuop : > 'E667 'sewou} pus seuiea junk wou; pordepy) SNOANYO $7738 UNV AHdVHOILVMIS 311IAINNO8 3MV1 AHdVHOILVMLS TVIOVIO D36 GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH lated to the recessional phase of Bull Lake Glaciation. In contrast, the soils on deposits at the three post-Provo shorelines and on the lower three alluvial terrace gravels along Little Cottonwood Creek west of the mountain front are relatively immature zonal soils like those on the lower, middle, and upper tills of Pinedale Glaciation. If this correlation is correct, it may be speculated that, as the Pinedale glaciers had attained their maxi- mum advance (average alt, 6,570 ft) at the time the level of the lake was at about 4,770 feet, the Bull Lake glaciers probably extended to a similar position in the canyons at the time the lake stood at 4,825 feet (the Provo shoreline) and the alluvial gravel on the highest of the four terraces was being deposited. REVISED CORRELATION After this report had been prepared, additional evi- dence was found which shows that Lake Bonneville rose to the Bonneville shoreline at least once in Pinedale time, and that its fall to the Provo shoreline, owing to erosion of the outlet at Red Rock Pass, and its subse- quent stillstand at the Provo shoreline occurred in Pine- dale time. The evidence in the Little Cottonwood area consists of deposits of bedded clean lake sand and sandy well- rounded lake gravel that have the post-Pinedale soil developed on them and that overlie the post-Bull Lake soil on older deposits at the Bonneville shoreline. At one locality, in a recent cellar excavation in NW! NEL sec. 11, T. 3 S., R. 1 E., this lake sand, containing local pebble lenses, rests on the post-Bull Lake soil developed on lake gravel of the second rise of Lake Bonneville (Bonneville Formation of Hunt and others, 1953) at an altitude of 5,135 feet. Another locality at an altitude of 5,140 feet on the north bluff of Little Cottonwood Creek about 1,100 feet south of the Murray City Power Plant in SEV,SE!4 sec. 2, T. 3 S., R. 1 E., provides additional evidence. Here, a deposit of lake gravel 7.5 feet thick, which is ascribed to the Bonneville Formation on page D16 of this report, was found to rest on a partly eroded profile of the post-Bull Lake soil that is developed on the upper till and associated outwash gravel of the Bull Lake Glaciation. Following development of the post-Bull Lake soil, the lake must thus have risen again to the Bonneville shoreline in Pinedale time. Erosion of the lake outlet at Red Rock Pass and the fall of the lake to the Provo shoreline must have been subsequent to this rise and therefore also in Pinedale time. A revised correlation of the glacial and lake deposits is given in the following table: D37 GLACIAL STRATIGRAPHY LAKE BONNEVILLE STRATIGRAPHY Post-Pinedale soil Post-Lake Bonneville soil Upper till Post-Provo deposits (lake maxima at 4,410, 4,470, 4,770 ft) Pinedale Glaciation Middle till | Provo Formation (stillstand at 4,800 ft) and unnamed lake deposits (at least one lake Lower till maximum at 5,140 ft) Post-Bull Lake soil Middle Lake Bonneville soil Upper till Bongesvge Formation (lake maximum at Bull Lake Glaciation a Lower till Alpine Formation (lake maximum at 5,100 ft) CORRELATION OF NEOGLACIAL DEPOSITS Correlation of deposits of the Temple Lake and historic stades of Neoglaciation with those of Great Salt Lake is extremely tenuous. Eardley, Gvosdetsky, and Marsell (1957) have described beaches and wave-cut benches at an altitude of 4,240 to 4,245 feet in the basins of Great Salt Lake and the adjacent Great Salt Lake _ Desert, to which they apply the term "Gilbert Beach." They noted (p. 1156) that this beach does not coincide with the expansion rim (alt., 4,221 ft) which separates the two basins and at which a temporary stand of the lake might be expected. They concluded (p. 1196) that the beach "may mark an expansion-stability level of the lake in its general retreat from the Stansbury (shoreline) to the present"; or that "it may also mark a minor pluvial maximum." The fact that the Gilbert Beach is 20 to 25 feet above the expansion rim suggests to the writer that it marks a minor pluvial maximum that could correlate with the Temple Lake Stade of Neoglaciation. The historic stade is probably correla- tive with the modern sediments of Great Salt Lake, which probably include not more than about the top 5 feet of these sediments if the radiocarbon dates of cores of the upper 40 feet of bottom sediments of the lake are meaningful (Eardley and others, 1957, p. 1169- 1170). GLACIAL HISTORY OF LITTLE COTTONWOOD AND BELLS CANYONS PRECLACIAL SETTING Available data for Little Cottonwood and Bells Can- yons provide few clues as to the appearance of the Wasatch Mountains at the close of Tertiary time. Ac- cording to Eardley (1944), very late Pliocene or early Pleistocene tilting along a system of normal faults bordering the west side of the range uplifted an already mountainous area along whose summits were preserved remnants of a widespread erosion surface-the Herd Mountain surface of late Oligocene or Miocene age. No remnants of this surface were observed in the Little Cottonwood area. D38 EARLY AND MIDDLE PLEISTOCENE TIME The history here postulated for early and middle Pleistocene time can be described only as speculative. Profiles of the high ridges that separate the tributaries of Little Cottonwood Canyon suggest that a broad valley 10 miles long, 2 to 3 miles wide, 700 feet deep at its head, and 2,000 feet deep at the mountain front was carved into the mountain upland at some time after at least 2,000 feet of uplift by normal faulting had occurred. This valley lay in the present drainage of Little Cot- tonwood Canyon, but probably also included the present north-trending drainage of Bells Canyon. The writer infers that this broad valley was probably the surface down which ice of a first major glaciation in the area advanced in early Pleistocene time. Erosion resulting from uplift along normal faults at the margin of the range continued after recession of the ice, and deep broad valleys were cut into the older surface along creeks ancestral to both Little Cottonwood and Bells Canyons. The valley along the site of Little Cottonwood Canyon was 14 to 14 mile wide. Its head- ward sector was cut about 200 feet below the older sur- face, and its floor is at least 2,500 feet below that surface at the mountain front. The writer believes that ice of a second major glacia- tion in the area advanced over this surface in early mid- dle Pleistocene time, and deposits inferred to be till rest on a remnant of the surface of the mountain front. Following recession of this ice, erosion resulting from continued uplift of the range along normal faults cut the present inner gorge of the canyon, which is about three-quarters of a mile wide. The floor of the canyon is 400 feet below the next higher surface along its head- ward sector and about 1,000 feet below it at the moun- tain front. It is virtually at the present level of the stream, which thus appears to have been established in middle Pleistocene time after more than 6,000 feet of uplift and dissection of the mountain front since the beginning of Pleistocene time. A third major glaciation, represented by the till of pre-Bull Lake age on the divide between Little Cotton- wood and Bells Canyons, probably occurred in late mid- dle Pleistocene time. Little is known of the character of the interglacial intervals separating these three major glaciations, ex- cept that a thick red clayey soil formed during the last interval. LATE PLEISTOCENE AND RECENT TIME BULL LAKE GLACIATION Bull Lake Glaciation comprised two advances of the ice, an early stade and a late stade, separated by an in- terstade of erosion and glacial recession. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Early stade.-During the early stade, glaciers formed in all the cirques in the drainage of Little Cottonwood and Bells Canyons and advanced down each tributary into the main canyons to form a single mass (pl. 2). They covered an area of about 26.2 square miles, and had an estimated volume of 3.61 cubic miles. In Little 'Cottonwood Canyon the ice extended about a mile out into the basin beyond the mountain front to an altitude of 5,040 feet. From Bells Canyon it extended about three-quarters of a mile west to an altitude of 4,920 feet. Aprons of bouldery outwash gravel extended beyond the fronts of the moraines. Subsequently, Lake Bonneville, which had been gradually rising in response to the pluvial climate under which the glaciers ad- vanced, rose over the crests of the moraines to an alti- tude of 5,100 + feet (pl. 2) and deposited lake sediments of the Alpine Formation on them. The fact that these sediments contain no bouldery outwash suggests that the ice may have withdrawn slightly from the terminal moraines, behind which outwash was trapped. Intra-Bull Lake interstade.-During the intra-Bull Lake interstade the ice receded and the lake fell to alti- tudes at least as low as 4,390 feet (Morrison, 1961). The extent of the fall suggests that the ice probably receded at least to the upper parts of the canyons, if not to the cirque heads, but that it probably did not disappear entirely. Valleys as much as 150 feet deep were cut into the deposits of the first rise of the lake and underlying till, but no evidence that a soil formed during the interval was found in the area studied. A soil at this stratigraphic position at an altitude of about 4,700 feet along Parleys Canyon in the southeastern part of Salt Lake City was shown to Morrison and the writer by R. E. Marsell in 1950. Its swamp-type profile and occurrence in lake sediments suggested that it formed near the border of the lake, but provided no evidence as to the regional climate. Late stade.-During the late stade the glaciers ad- vanced again from each tributary into the main canyons and attained a position at the canyon mouths only a short distance back of their termini during the early stade (pl. 2). The glacier from Little Cottonwood Canyon reached an altitude of 5,080 feet; that from Bells Canyon, an altitude of 5,100 feet. They covered an area of 25.5 square miles, were 1,000 feet deep along parts of the canyons, and had an estimated volume of about 3.57 cubic miles. The second rise of Lake Bonne- ville lapped against the fronts of the moraines at an altitude of 5,135 feet, the Bonneville shoreline (pl. 2), where a bench was cut and lake gravel of the Bonne- ville Formation was deposited on it. The glaciers had probably ceased to advance at the time the lake attained its maximum, but could not have receded noticeably for, GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH as pointed out by Marsell (1946), the lake did not enter the lower part of Little Cottonwood Canyon below 5,135 feet altitude. The fact that the second rise of the lake was 135 feet higher than the first, whereas the late advance of Bull Lake Glaciation both in this area and in most others in the Rocky Mountains known to the writer is less ex- tensive than that of the early advance, suggests that some local factor influenced the lake. R. C. Bright (oral communication, 1959) has suggested that diver- gence of the waters of the Bear River (fig. 1) into Lake Bonneville at this time may have been responsible for this excessive rise and the overflow of the lake at Red Rock Pass, Idaho. Erosion of the outlet of the lake to the level of the Provo shoreline (alt, 4,825 ft) was accompanied by recession of the ice and the deposition of bouldery gravel along Little Cottonwood and Dry Creeks from the narrows through the moraines to the Provo shore- line. Analogy with conditions during Pinedale Glacia- tion suggests that during the stand of the lake at the Provo shoreline the terminus of the ice may have lain at an altitude of about 6,500 feet in Little Cottonwood Canyon and at about 5,700 feet in Bells Canyon. BULL LAKE-PINEDALE INTERGLACIATION The glaciers disappeared entirely from the cirques during the Bull Lake-Pinedale interglaciation, and Lake Bonneville may have become completely desiccated (Morrison, 1961). Slopes stabilized and a mature Brown Podzolic soil formed from the tops of the moun- tains down to the upper slopes of the basin. Toward the close of the interval as the climate became wetter, Little Cottonwood and Dry Creeks lowered their courses about 20 to 30 feet at the mountain front. PINEDALE GLACIATION The record of Pinedale Glaciation comprises a maxi- mum advance followed by two recessional halts or minor readvances of the ice. These are here called the early, middle, and late stades of Pinedale Glaciation. They are separated by two interstades of recession and erosion that were probably short lived. Early stade.-During the early stade, glaciers de- veloped anew in all cirques tributary to Little Cotton- wood and Bells Canyons, except those at the head of Grizzly Gulch and that on the south side of Flagstaff Mountain northwest of Alta, which had been occupied during Bull Lake Glaciation. The glaciers of each tributary, as far west as Hogum Fork, merged with the glaciers along Little Cottonwood Canyon to form a single mass of ice that terminated at an altitude of 6,600 feet adjacent to, but not coalescing with, the glacier in Hogum Fork (pl. 2). The ice front was ab- D39 rupt. It rose 1,400 feet in the first half mile, but upslope from this point along Little Cottonwood Canyon it had an average gradient of 450 feet per mile, which is about the same as that of the canyon floor. The gradient of the ice along tributary valleys was at least 1,000 feet per mile. The glacier in Bells Canyon extended down to an altitude of 5,680 feet, or nearly to the mouth of the canyon. Its gradient, if parallel to that of the canyon floor, was about 1,000 feet per mile, or about the same as that on the tributaries to Little Cottonwood Canyon. The depth of the ice ranged from 600 to 700 feet in the canyon of Little Cottonwood Creek and from 400 to 600 feet in the hanging tributary valleys. The ice covered an area of about 17.0 square miles in Little Cottonwood and Bells Canyons, and had an estimated volume of about 1.75 cubic miles. During this stade, Lake Bonne- ville rose again to an altitude of 4,770+ feet (Morrison, 1961). Early interstade.-During the early interstade of Pinedale Glaciation the ice probably receded between 1 and 214 miles along Little Cottonwood Canyon and its tributaries and separated in such a way that individ- ual glaciers existed along each tributary west of Gad Valley Gulch. The precise extent of the recession is not known. Lake Bonneville was lowered by evaporation to an altitude at least as low as 4,450 feet (Morrison, 1961). Middle stade.-During the middle stade, glaciers from the heads of Little Cottonwood Canyon, Collins Gulch, Peruvian Gulch, and Gad Valley merged to form a single terminal moraine on the canyon floor at an altitude of 7,760 feet (pl. 2). Separate glaciers in White Pine Fork and Red Pine Fork also reached the floor of Little Cottonwood Canyon, where they formed moraines at 7,240 and 6,970 feet altitude, respec- tively. Glaciers in Maybird Gulch, Hogum Fork, and Coalpit Gulch failed to reach the hanging rim of these valleys above Little Cottonwood Canyon. The glacier in Bells Canyon extended to 5,720 feet. The average altitude of all end moraines formed during this stade is 7,525 feet. The glaciers had about the same gradients as those formed during the early stade of Pinedale Glaciation. They covered an area of about 14.3 square miles and had an estimated volume of about 1.36 cubic miles. During this stade, Lake Bonneville rose to an altitude of 4,470 feet (Morrison, 1961). Middle interstade.-During the middle interstade the glaciers receded at least from a quarter of a mile in the western part of the area (Hogum Fork and Bells Can- yon) to 4 miles in the eastern part of the area (Albion Basin) and disappeared entirely from some cirques in the eastern part of the area. The precise extent of D40 recession is not known. Lake Bonneville was lowered by evaporation to an altitude at least as low as 4,360 + feet (Morrison, 1961). C Late stade.-During the late stade of Pinedale Glacia- tion the ice was so separated that individual glaciers ~ existed in all tributaries to Little Cottonwood Canyon, and in some, such as White Pine Fork and Albion Basin, the ice had subdivided into two or three separate masses (pl. 2). The lower limits of the glaciers lay at altitudes ranging from 9,840 feet in Collins Gulch and Maybird Gulch to 6,560 feet in Bells Canyon. Their average altitude, including that in Bells Canyon, is 9,195 feet. The ice was relatively shallow ; maximum thickness in the several canyons was probably between 100 and 250 feet. The total area covered by the ice was only about 6.45 square miles, and the estimated volume of ice was probably only about 0.50 cubic mile. During this time Lake Bonneville was at an altitude of about 4410+ feet (Morrison, 1961). PINEDALE-NEOGLACIAL INTERGLACIATION The Pinedale-Neoglacial interglaciation occurred during the "altithermal age" of Antevs (1948) from about 4000 to 2000 B.C. The ice disappeared entirely from the cirques, and Lake Bonneville was probably completely desiccated. Slopes in the mountains stabi- lized as solifluction and frost action gradually ceased. An immature zonal Brown Podzolic soil formed on all deposits of Pinedale age, as well as on older exposed deposits, from the tops of the mountains down onto the basin slopes. Toward the close of the interval, Little Cottonwood and Dry Creeks lowered their channels 10 to 15 feet as the climate cooled and rainfall increased somewhat. NEOGLACIATION The Neoglaciation is the "Little Ice Age" of Matthes - (1939, 1942), which includes the time since about 2000 B.C. Glaciers or rock glaciers have twice formed, and melted away in the cirques. Temple Lake Stade.-During the Temple Lake Stade -from about 2000 B.C. to shortly before the birth of Christ-10 small glaciers and 20 rock glaciers formed in the more sheltered north- or northeast-facing parts of cirques that had been fully occupied during Pinedale Glaciation (pl. 2). Many cirques were not reoccupied -such as the one at the head of Collins Gulch and the east and west cirques of Albion Basin which have high floors and low headwalls. The lower limits of the gla- ciers and rock glaciers ranged in altitude from 9,160 to 10,200 feet and were, in general, lower in the western part of the area and higher in the eastern part. Their average altitude was 9,800 feet. The ice covered an area of about 1.55 square miles and had an estimated volume of about 0.05 cubic mile. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Temple Lake-historic interstade.-During the Tem- ple Lake-historic interstade, from shortly before the birth of Christ to about A.D. 1400, the ice probably disappeared entirely from the area for a short time. Moraines and other deposits of the Temple Lake Stade stabilized and an incipient azonal soil began to form on them. Historic stade-During the last or historic stade, which is estimated to have extended from about A.D. 1400 to the present and to have attained a maximum in the latter part of the 19th century, 15 rock glaciers formed in those cirques which had been occupied during the Temple Lake Stade and whose high headwalls offered the most shelter (pl. 2). Some of the rock glaciers formed back of moraines of Temple Lake age; others were the product of regeneration of the head- ward parts of rock glaciers of Temple Lake age. Their termini range in altitude from 9,300 to 10,600 feet and average 9,955 feet. They cover an area of about 0.5 square mile and had an estimated volume of only about 0.01 cubic mile. OTHER EVENTS OF RECENT TIME The record of solifluction and frost activity in Re- cent time is much more complete than during earlier glaciations. - Frost action, as reflected in the formation of talus, protalus ramparts, and upland frost rubble, was widespread throughout the area during the Temple Lake Stade, but appears to be largely restricted to the cirque heads at present. - Solifluction, as reflected in the formation of talus flows, was also widespread during the Temple Lake Stade, but appears to have occurred in relatively few localities in historic time. Conditions favoring the formation of block fields were never wide- spread and are not active at present. Great Salt Lake is known to have fluctuated in Recent time. One such fluctuation, marked by Gilbert Beach (Eardley, and others, 1957), is believed to have taken place during the Temple Lake Stade. The level of the lake at the time the area was first settled (alt, 4,207 ft) may have been contemporaneous with the maximum of the historic stade. REFERENCES CITED American Commission on Stratigraphic Nomenclature, 1961, Code of stratigraphic nomenclature: Am. Assoc. Petroleum Geologists Bull., v. 45, no. 5, p. 645-665. Antevs, E. V., 1945, Correlation of Wisconsin glacial maxima : Am. Jour. Sci., v. 243-A, Daly Volume, p. 1-39. 1948, Climatic changes and pre-white man, in A symposi- um on the Great Basin, with emphasis on glacial and post- glacial times: Utah Univ. Bull., v. 38, no. 20, p. 168-191. 1952, Cenozoic cuimates of the Great Basin: Geol. Rundschau, v. 40, no. 1, p. 94-108. Atwood, W. W., 1909, Glaciation of the Tinta and Wasatch Mountains: U.S. Geol. Survey Prof. Paper 61, 96 p. GLACIATION OF LITTLE COTTONWOOD AND BELLS CANYONS, WASATCH MOUNTAINS, UTAH Bissell, H. J., 1952, Stratigraphy of Lake Bonneville and as- sociated Quaternary deposits in Utah Valley, Utah [abs.] : Geol. Soc. America Bull., v. 63, p. 1358-1359. Blackwelder, Eliot, 1915, Post-Cretaceous history of the moun- tains of central western Wyoming: Jour. Geology, v. 23, p. 97-117, 193-217, 307-340. 1931, Pleistocene glaciation in the Sierra Nevada and Basin Ranges: Geol. Soc. America Bull., v. 42, no. 4, p. 865-922. Bryan, Kirk, 1934, Geomorphic processes at high altitudes : Geog. Rev., v. 24, no. 4, p. 655-656. Calkins, F. C., and Butler, B. S., 1943, Geology and ore deposits of the Cottonwood-American Fork area, Utah: U.S. Geol. Survey Prof. Paper 201, 152 p. Crittenden, M. D., Sharp, B. J., and Calkins, F. C., 1952, Geology of the Wasatch Mountains east of Salt Lake City; Parleys Canyon to Transverse Range: Utah Geol. Soc. Guidebook to the Geology of Utah, no. 8 (Geology of the Central Wasatch Mtns., Utah), p. 1-37. Eardley, A. J., 1944, Geology of the north-central Wasatch Mountains, Utah: Geol. Soc. America Bull., v. 55, no. 7, p. 819-894. Eardley, A. J., Gvosdetsky, Vasyl, and Marsell, R. E., 1957, Hydrology of Lake Bonneville and sediments and soils of its basin (Utah) : Geol. Soc. America Bull., v. 68, no. 9, p. 1142-1201. Gilbert, G. K., 1890, Lake Bonneville: U.S. Geol. Survey Mon. 1, 438 p. Hack, J. T., 1943, Antiquity of the Finley Site: Am. Antiquity, v. 8, no. 3, p. 235-245. Hague, Arnold, and Emmons, S. F., 1877, U.S. Geological ex- ploration of the 40th parallel; V. 2, Descriptive Geology : U.S. Army Eng. Dept. Prof. Paper 18, 890 p. Holmes, G. W., and Moss, J. H., 1955, Pleistocene geology of the southwestern Wind River Mountains, Wyoming: Geol. Soc. America Bull., v. 66, no. 6, p. 629-653. Hunt, C. B., Varnes, H. D., and Thomas, H. E., 1953, Lake Bon- neville: Geology of northern Utah Valley, Utah: U.S. Geol. Survey Prof. Paper 257-A, 99 p. O D41 Ives, R. L., 1950, Glaciations in Little Cottonwood Canyon, Utah : Sci. Monthly, v. 71, no. 2, p. 105-117. Jones, D. J., and Marsell, R. E., 1955, Pleistocene sediments of lower Jordan Valley, Utah: Utah Geol. Soc. Guidebook to the Geology of Utah, no. 10 (Tertiary and Quaternary his- tory of the eastern Bonneville basin), p. 85-112. King, Clarence, 1878, Report of the geological exploration of the fortieth parallel; V. 1, Systematic Geology : U.S. Army Eng. Dept. Prof. Paper 18, 803 p. Marsell, R. E., 1946, The relations of the Little Cottonwood and Bell Canyon glacers to Lake Bonneville [abs.] : Utah Acad. Sci. Proc. 1945-1946, v. 23, p. 18 [1947]. Marsell, R. E., and Jones, D. J., 1955, Pleistocene history. of lower Jordan Valley, Utah: Utah Geol. Soc. Guidebook to the Geology of Utah, no. 10 (Tertiary and Quaternary geol- ogy of eastern Bonneville basin), p. 113-120. Matthes, F. E., 1939, Report of Committee on Glaciers, 20th . Ann. Mtg.: Am. Geophys. Union Trans., pt. 4, p. 518-523. 1942, Glaciers, in Meinzer, O. E., ed., Physics of the Earth, Pt. 9, Hydrology: New York, McGraw-Hill, p. 142- 219. Morrison, R. B., 1961, New evidence on the history of Lake Bonneville from an area south of Salt Lake City, Utah, in Short papers in the geologic and hydrologic sciences: U.S. Geol. Survey Prof. Paper 424-D, p. D125-D127. Moss, J. H., 1951a, Early man in the Eden Valley [Wyo.] : Pennsylvania Univ. Mus. Mon., p. 9-92. 1951b, Late glacial advances in the southern Wind River Mountains, Wyoming: Am. Jour. Sci., v. 249, no. 12, p. 865- 883. Richmond, G. M., 1957, Three pre-Wisconsin glacial stages in the Rocky Mountain region : Geol. Soc. America Bull., v. 68, no. 2, p. 239-262. 1962, Quaternary stratigraphy of the La Sal Mountains, Utah: U.S. Geol. Survey Prof. Paper 324, 135 p. Richmond, G. M., Morrison, R. B., and Bissell, H. J., 1952, Cor- relation of the late Quaternary deposits of the La Sal Mountains, Utah, and of Lakes Bonneville and Lahontan by means of interstadial soils [abs.] : Geol. Soc. America Bull., v. 63, no. 12, pt. 2, p. 1369. E PROFESSIONAL PAPER 454-D UNITED STATES DEPARTMENT OF THE INTERIOR , V f § PEATE 1 GEOLOGICAL SURVEY Pinedale Glaciation Bull Lake Glaciation Pre-Bull Lake glaciations EX P L A NA T 1 O N ROCKY MOUNTAIN EQLIAN GEOLOGIC-CLIMATIC UNITS GLACIAL DEPOSITS ALLUVIAL DEPOSITS COLLUVIAL DEPOSITS DEPOSITS % A ~ f =~ Nf y ya & ay !. S y o g a 8 3 § £3 Corps 5g T fisting Fas SX "of - S A to 'vnf v fong: '. & nbr. 31 § §) 4 3 < i y 5 3 y 3 al Mist Active talus ess $ S 3 % $ I Fan gravel Gravelly alluvium ; Colluvium Inactive talus ) Block rubble Frost rubble Eolian sand f §’ 5 3 / Till Rock glacier Bouldery to sandy Flood-plain gravel, Gravelly to sandy Talus flow Protalus Coarse rubble developed _ Angular rubble developed >, | A Stony to blocky nhr, upper unit, deposits sand, and silt slope deposits nhtf, fresh blocky talus flow . nhp, active protalus. from stony mantle from bedrock sandy till ntr, lower unit 2 nttf, inactive soil-covered talus flow ntp, inactive protalus 3 erst DisconFoRmiTy R. 3 E. 1/1]: 37 30 ZZ 77> 2/ - he - - - Protalus Landslide dposits *Early *Middle *Late stade stade stade Rock glacier Outwash Fan gravel Gravelly alluvium Talus pru, upper unit, Bouldery to sandy Till prm, middle unit deposits Gravelly alluvium Stony to blocky loose pam, middle unit. sandy till. pal, lower unit ptu, upper till. ptm, middle till, ptl, lower till ) > DisconFoRMmiTy P [1 3 < Bedrock z < Gravelly alluvium p feast. s C ft. e! Correlative with the Provo L 3 Formation 7 LACUSTRINE DEPOSITS Contact 5 =- s 3 C s A f < 3 f se ) 5) tike. s ] * f 2 m $ Fault active in Quaternary time xXx Gravelly alluvium 8 Bogmevflle Formation Dashed where approximately located; dotted where O alle Correlative with the Bonneville erma é) 8, gravel. bs, sand concealed. U, upthrown side; D, downthrown side N L x > o bt Formation - feta-ea: “E ore) plks) badass g w -| aes" Thks ~s Fe a 8 4 a P ad > | C § LL Colluvium 5 Sand of Bonneville had: | | i Till Sandy to silty locally derived m and Alpine For- Alpine Formation Upper limit of glaciation f R b a | ( l ; Doy CG NNY ST LL .z ox Stony, sandy to silty compact tills Bouldery to sandy deposits deposits on upland divide east $ mations ag, gravel. a S 7 i & / 7 7 ; NU rE > l: ) **btu, upper till. **bou, upper unit. of Albion Basin S as, sand. i 33 e btl, lower till bol, lower unit y ac, clay Crest of moraine BM ; DISCONFORMITY Younger till Fan Gravel Ston colluvium Bouldery glacial deposits on interfluve between Little Cottonwood Creek and Bells Canyon i DisconFroRmiTy Older till or fan gravel On high bench on morth side of Little Cottonwood Canyon Pre-Lake Bonneville deposits D U *Informal usage **Correlative with the Bonneville Formation 42'30" 111°47'30" 40°35" nc Ae z 3230" N 40°30" 111°38 INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-1964-G6é2334 40°30" Tel 4230" : 40" fle R 5C. GEOLOGIC MAP OF QUATERNARY DEPOSITS OF LITTLE COTTONWOOD AND BELLS CANYONS, UTAH "m j SCALE 1:24000 4 o 1 MILE ; E ==: pa- F I r m I = LOCATION OF AREA 111°47'30" RTE. -R. 2 E: Base from U.S. Geological Survey Geology by Gerald M. Richmond, 1959 topographic quadrangles TRUE NORTH APPROXIMATE MEAN DECLINATION, 1964 (s - 1 '0 0 1 KILOMETER & t & * CONTOUR INTERVAL 40 FEET DOTTED LINES REPRESENT 10 FOOT CONTOURS DATUM IS MEAN SEA LEVEL UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-D GEOLOGICAL SURVEY PEATE 2 Recent Pleistocene Upper Pleistocene Bull Lake Glaciation y a $x$ Pex ye EX Xx ENCS X YX | ere! ¢. > 2 S SAE s EXPLANATION 3 Second high stand of Lake Bonneville Bonneville shoreline al- #; titude 5135 ft ~ RS] First high stand of Lake Bonneville Altitude 5100 ft Neoglaciation Middle stade -__ Boundary of area covered by ice Dashed where approxi- mately located Pinedale Glaciation QUATERNARY Eafly stade ~3 Late stade Glaciated col Arrow indicates direction of ice movement Early stade J INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-1964-G62334 DISTRIBUTION OF GLACIERS AT THE MAXIMUM OF SUCCESSIVE LATE PLEISTOCENE GLACIATIONS AND STADES IN LITTLE COTTONWOOD AND BELLS CANYONS, UTAH SCALE 1:48000 1 1 5 o j -= 1 5 0 5 2 3 KILOMETERS TH H -E- pe- CONTOUR INTERVAL 200 FEET DATUM IS MEAN SEA LEVEL 2 3 MILES gers pcfi ~ y. ¢: £ New Data on the Isostatic Deformation of Lake Bonneville GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-E New Data on the Isostatic Deformation of Lake Bonneville By MAX D. CRITTENDEN, Jr. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEQLOGICAL SURVEY PROFESSIONAL PAPER 454-E UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 CONTENTS Page | Possible causes of deformation-Continued enn car lunes E1 Isostatic deformation-Continued Page introduction ->. ele ect en i Coincidence of uplift and load._._._._________.___._ E16 Acknowledements --.. l.. c 3 Degree of isostatic compensation______________ 17 Purposc iand 3 Rate of response.. llc c 19 Extentiof le lice ial. 3 Geologic chronology....__-.-::._._..__:._..l_ 19 Nomenclature of Lake Bonneville events_____________. T Relation between geologic chronology and Identity of the highest shoreline ._____________________ 8 isostatic deformation.______._._________ 21 Observed 8 Value of T, for Lake Bonneville. _________ 21 (Water 1O0atl >. ~.. _ . } ne.: nnn ced ee nian an ea nee aes 8 Present rate of 24 Possible causes of 8 Comparison with Scandinavia___________. 24 Superficial versus deep-seated effects ____________ w 8.1 Geologic 26 Elastic compression of the crust 18 Vertical spacing of Alpine and Bonneville shorelines. 26 Epsirogenic 13 Vertical spacing of Provo shoreline.______________. 27 Regional 13 Recent warping of 27 Regional doming. 14 Absolute movement on the Wasatch fault_________. 27 Local warping .:.... lut. 15 Relation of isostatic uplift to Basin and Range struc- Isostatic 15 g:: sb 29 Mode of lll. 2 15] Conclusions -.} 00022 e 29 Crustal: 16) References ClfoU 30 Page 1. Map of Lake Bonneville:.__.._'!~.._. [_. .:. ls o ll tiie ctc ren tol g cp eC E2 2. Generalized history and nomenclature of Lake Bonneville used in this report: l l 7. 8. Map showing deformation of the Bonneville _L. 9 4, 5. Maps showing depth of water averaged over circles of 25- and 40-mile radius, 10, 11 6. Profiles showing observed deformation and average depth of 12 7. Comparison of observed deflection with depth of water averaged over various radii___________________________ 18 8. Graphs showing interpretations of Lake Bonneville history lt l EOI LOCC 20 9, 10. Calculated deflection based on- o; Morrison's Curves. __ ll nell. cee eae n oo pide o aniem eee anon ae n enone i n ae a e 22 10: Chronology-.of-Searles LM Lolli tfi fc tat 23 11. Graph showing difference between first-order levels across part of the Bonneville basin in 1911 and 1953. i ex 25 12. Diagrammatic profile showing Wasatch fault displacement at the eastern margin of Lake Bonneville___________. 28 TABLE Page Tarun 1. Bonneville «horelinc elevations. ........_. ..} .LA t cl oot NOt UOC E4 a Ay evict figs SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY NEW DATA ON THE ISOTATIC DEFORMATION OF LAKE BONNEVILLE By Max D. Crrrrenorxn, Jr. ABSTRACT Domical upwarping of the area formerly occupied by Pleisto- cene Lake Bonneville is verified by 75 new measurements of elevation on the Bonneville shoreline. - Gilbert's conclusion that this uplift was an isostatic response to the removal of load is confirmed by maps which show that the deformation is closély correlated with the former distribution and average depth of water. | The area of maximum uplift is west of Great Salt Lake, where the Bonneville shoreline reaches an elevation of 5,300 feet, compared with 5,090 feet at the south end near Lund and 5,085 feet at the former outlet in Red Rock Pass in southern Idaho. The 210-foot difference is about 75 percent of that theoretically possible if the lake had reached complete isostatic compensation. Isostatic movements accompanying and following changes in the depth of water would explain the observed differences in elevation between the first and second stands at the Provo shore- line, the recent tilting of the basin floor, and several other fea- tures of lake history. According to the most recent of several chronologies for Lake Bonneville, the anomaly created by removal of the lake water 1 A switlh P was reduced to o of its initial value in somewhere between 4,000 and 10,000 years. On this basis, the calculated viscosity of the subcrust in this area is 10" poises, compared with 10" poises in Scandinavia. Recent displacements on the Wasatch fault are normal-that is, down on the west; this is opposite in direction to the effects of isostatic unloading, which tend to elevate the valley block relative to the mountains. It is inferred that the two types of deformation are independent, one operating within the crust and the other mainly within the subcrust: INTRODUCTION In the first monograph of the U.S. Geological Survey, G. K. Gilbert (1890) recorded in remarkable detail the widespread traces left by Lake Bonneville, the largest of the Pleistocene lakes of the Great Basin. He showed that the lake at its maximum was some 325 miles long, 125 miles wide, and had a surface area of about 20,000 square miles-nearly a quarter as large as the State of Utah (fig. 1). It extended from the site of Lund, near the southwest corner of the State, to Red Rock Pass in southern Idaho, and from the front of the Wasatch Range, where it flooded the sites of Logan, Ogden, Salt Lake City, and Provo, to the Toana Range, 10 miles west of the Utah-Nevada State line. Its maximum depth was a little more than 1,100 feet in the main northern body near the west edge of the present Great Salt Lake. To the south, the lake extended through passes between the ranges into what is now the Sevier Desert, where its average depth was about 500 feet. Although\Gilbert's study (1890, p. 363) consisted pri- marily of examining the bars, spits, and beach deposits that formed within the ancient lake, he soon perceived that the water surfaces delineated by these ancient fea- tures were no longer level. More than 50 islands and mountain headlands stood above the surface of the an- cient lake, and on each of these a record of the ancient water surfaces was carved.) Many shore features were close to the present Great Salt Lake, so that by using its surface as a plane of reference Gilbert was able to show (1890, pl. 46) that the ancient shorelines had been warped upward as much as 180 feet and that the uplift had been greatest near the west edge of the present lake where the water of the ancient lake was deepest. | Gil- bert inferred from this that the earth's crust had been domed upward in response to removal of load as the water evaporated.*) But because he did not measure the elevations of any points around the west and southwest sides of the basin and because the absence of geodetic control forced him to rely on barometric measurements for elevations in the southern part of the basin, the im- pression has grown in recent years that many of his ele- vations were unreliable and that the evidence for iso- static readjustment was inconclusive (Eardley and others, 1957, p. 1164). At the same time, the extent of actual shoreline deformation has been further obscured because most modern studies of Lake Bonneville have *It has recently been pointed but to me by Frank Calkins that though the word '"isostasy" appears in the index to Monograph 1, it is followed by only a single page reference ; but the word is not used on that page, nor apparently on any other. Indeed, "isostasy" had first been clearly defined only 10 years before Gilbert's work was finished (1890), and the principle still was not widely accepted in this country. Gilbert's atten- tion to shoreline elevations in the field and his awareness of their significance therefore seem all the more remarkable. E1 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY E2 114° 42° I S Hogu)\p 0 Pis 0 Mountains 1 [a] fre D € $1 a g; e 0 © I a 3 +i P oj 0 £3: 41° = 5&5 YJ 2 Q 0 Vendover d © G .A Bonneville Salt Flats A Wildcat Mountain Cedar Mountains %: & % McDowell Moustains Leamington amingt ‘Q’e, < Sevier C p Delta Desert 3 39° 3\| [4 53: 112° 111° w < \ EXPLANATION rat x /, Milford Outline of lake at Bonneville \ shoreline & Surrounding area patterned x I : 3s. Lund ' \\ Escalante Desert 38\ Existing Lakes Mas X&Y RRAC A 10 0 10 2.0 30 MILES FicuRE 1.-Map of Lake Bonneville. NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE been restricted to small areas along the Wasatch Range front, where the shorelines are comparatively uniform in elevation. One result is that the figure 5,135 feet has been somewhat loosely used as representing the approxi- mate elevation of the entire Bonneville shoreline. Today, however, when the topography of this region has been delineated by an abundance of aerial photo- graphs and a rapidly increasing number of large-scale topographic maps, it is possible to establish the eleva- tion of shoreline features in many parts of the basin. The(results fully confirm Gilbert's inferences regard- ing isostatic response to unloading; they indicate, in fact, that it was somewhat greater than he supposed. They also indicate that broad epeirogenic movements, though probably not negligible, were small compared with deformation of other types.. They clearly record local deformation due to post- Bonneville faulting; and, together with the depositional record, they throw much light not only upon the history of Lake Bonneville but upon some broader problems concerning the character of the earth's crust. ACKNOWLEDGMENTS It is a pleasure to acknowledge the assistance of Robert C. Bright, W. J. Carr, Leonard Izett, Robert Maurer, H. T. Morris, Roger Morrison, G. I. Smith, M. H. Staatz, Peter B. Stifel, and D. J. Varries, who have supplied shoreline elevations and other information used in this paper. I am deeply indebted also to A. H. Lachenbruch and D. R. Mabey for constructive and patient discussion of the problems of earth deformation, and to Mabey, Morrison, Varnes, and F. C. Calkins for critical review of the manuscript. PURPOSE AND METHODS The present reexamination of Bonneville shoreline elevations was undertaken primarily to determine whether the shoreline, despite the fact that it had been warped by isostatic movements, might not be of use in establishing the absolute direction of the most recent movement on the Wasatch fault. ___ As the data accumulated, the desirability of reevalu- ating Gilbert's evidence for isostatic deformation be- came evident, and this in turn led to the consideration of broader geologic and geophysical problems. The method used was to obtain aerial photographs from par- ties engaged in geologic or topographic mapping and E3 to locate salient lakeshore features on them by photo- geology. For present purposes, only those on the high- est shoreline (Bonneville) have been used. These fea- tures were then transferred to a topographic base by Kail plotter, by projection, or by inspection, depending on the accuracy of the base available. The best results were obtained by using 1 : 20,000 photographs and base maps at 1: 24,000. Where such work has been checked in the field, as it has been along the front of the Wasatch Range and in parts of the Confusion Range, the results proved to be nearly as accurate as any that could have been obtained by trigonometric measurement of eleva- tions. In some places where the shorelines are very faintly marked they can be located not only with great- er ease but with more accuracy from photographs than on the ground. Even in such places, however, deter- mination of the ancient water level involves some judg- ment, which Gilbert (1890, p. 125, 365), with character- istic frankness, expressed as a probable error of +214 to 3 feet under the most ideal conditions; he increased this to +35 feet where further uncertainty was caused by his having to depend on barometric leveling. The best determinations made during the present work are regarded as subject to errors of +5 feet arising from uncertainty of geologic interpretation. Those made from high-altitude photographs and 1 : 24,000 maps are subject to errors of +10 feet. Only 10 of the 90 points depend entirely on 1 : 250,000 scale maps; for these, the shorelines were tied to spot elevations rather than to contours wherever possible, but in spite of this they are probably subject to errors of +20 to 30 feet. All the elevations available, together with informa- tion about their exact location and how each was ob- tained, are listed in table 1. Of the 90 localities, 9 are taken directly from Gilbert without modification, 4 use Gilbert's spirit-level measurements corrected by being tied to new bench-mark elevations, 10 depend en- tirely on 1 : 250,000 maps, and 18 are obtained from vari- ous published and unpublished sources. The remaining 49 are determined from aerial photographs and from quadrangle maps that are mostly on a scale of 1 : 24,000. EXTENT OF LAKE The outline of Lake Bonneville at its highest level, together with all the shoreline elevations now available, was first plotted on base maps at a scale of 1: 250,000. These outlines, further reduced by projection, are shown in figure 1. f E4 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Taus 1.-Bonneville shoreline elevations No. Name Township and Range, Salt Lake Source Elevation Notes base line meridian (except as noted) in feet 1 | Red Rock Pass, Idaho._| T. 12 S., R. 38 E. (Boise | Gilbert (spirit level) and USC&GS 5, 085 meridian). BM at Swan Lake. 2 | Franklin, Idaho..---- T. 16 S., R. 40 E. (Boise | Gilbert (spirit level) and USC&GS 5, 131 meridian). BM at Franklin Station. 3 | T.12 Ny, R. I E.::..... Gilbert (spirit level) and USGS 5, 142 BM at old Logan Station. 4 | Blacksmith Fork.. NEL sec. 11, T. 10 N., 1:20,000 photographs and 7%- 5, 160 | Leonard Izett and Tom K. 16. minute Paradise quadrangle. Mullens (written com- munication, 1960). 5 | Baxter Ridge.... S}’2Rsec.El}9, T. 10 N., asado _ ahs 5, 180 Do. . 1 E. 6.) Willard. .. T.8 N.. R_2 Gi§bert (hand level) from lake sur- 5, 184 ace. T4 Huntsville. ...--... T. 6 N., R2 Lofgren (1955, p. 5, 150 §: Ogden-.._.......... T. O N;; R. 1 W......_.. Gilbert (hand level) from Ogden | 5,179 Station (4303). 9 | Weber Canyon-----_. Naélsec.E 25, T. 5 N., Ogden 7%4-minute quadrangle ___.. + 5, 200 I B. 10 | Hobbs Canyon------- Sec. 12, T. 4 N., R. 1 W..] Kaysville 74-minute quadrangle_--| 5, 160 11 Boemtiful )(Ward Sec. 21, T. 2 N., R. 1 E..] Bountiful 74-minute quadrangle.] 5, 180 anyon). 12 | Salt Lake salient___--| See. 13, T. 1 N., R. 1 W..] Aerial photographs and Salt Lake 5, 220 City North 7%-minute quad- rangle. 19 | Fort 1: 20,000 photographs; Fort Doug- | 5, 180 las 7}4-minute quadrangle; and Gilbert (spirit level). 14 | Bells Canyon.-...---- Sec. 14, T. 3 S., R. 1 W-] Draper 7%-minute - quadrangle 5, 140 | Downthrown block of on ground. Wasatch fault. 15 | Draper..-..«=.s..-.. Sec.od4, T: 98. R.1 5, 180 | Upthrown block of Wasatch fault. 16 | Corner Sec. 4, T. 4 S., R. 1 E-___| Lehi 7%4-minute quadrangle on 5, 160 | Downthrown block of ground. Wasatch fault. 17 | Point of Mountain--_| See. 24, T. 4 S., R. 1 W-] Jordan Narrows quadrangle; Gil- 5, 160 bert (spirit level) 18 | American Fork__----- NW% sec. 32, T. 4 S., R. | Lehi 7%-minute quadrangle on 5, 190 | Upthrown block of 2 E. ground. Wasatch fault. 19 Ir._cdo.c sag 5, 140 | Downthrown block of Wasatch fault. 20 | Spanish Fork____-__- Sec. 23, T. 8 S., R. 3 E___| Spanish Fork 7%4-minute quad- | 5, 120 rangle. PY Sec.a, T.O8.; R3 5, 125 | Bar west of canyon mouth. 22 | Loafer Canyon-_____. Sec. 23, T. 9 S., R. 2 E-__| Spanish Fork Peak 7%4-minute 5, 090 quadrangle. 23 | West Mountain-___-- Sec. 15, T. 9 S., R. 1 West 1¥Iountain T}-minute quad- 5,125 | Bar. rangle. 24. | cele ren s Gilbert (spirit level) °____________ 5, 107 25 | Tintic Mountain-.__. Secs. 13-14, T. 11 S., R. | Tintic Mountain 7}4-minute quad-| 5,120 | H. T. Morris (written 2 W. § rangle on ground. communication, 1960). 26 | Allens Ranch-_-_--_- Sec. 5, T. 9 S., R. 2 W.__| Fivemile Pass 7}!4 minute quad- | 5, 150 Do. rangle on ground. 27 |- Butterfield Canyon...{ -T. 3 8.. R.2 W._______.._. Eardley and others (1957, fig. 7). -| 5,165 25 | CGarfield............. Sec. O1, S.; R.2 W..! ll 5, 195 29 | Black Rock...._.:._. See. 19, T. 1 S., R. 3 W.__| Gilbert (spirit level) checked on 5, 208 ground with Garfield quadrangle. , 30 | Antelope Island_____. Sec. 9, T. 2 N., R. 3 W...] Antelope Island 74-minute quad- 5, 250 | Bar. rangle. S1 | See. 24, T. 4 S., R. 4 W._.| 1:20,000 aerial photographs and 5, 250 Stockton 15-minute quadrangle. 32 | Fivemile Pass-______. SEM sec. 7, T.78., R.3 W. 1:62,000 photographs and Five- | 5, 185 mile Pass 7!4-minute quadrangle. 33 | South Mountain-___-. Sec. 12, T. 4 S., R. 6 W.___| 1:20,000 photographs and Grants- 5, 255 ville 7}4-minute quadrangle. 34 | Granteville. _______._. See. 5, T. 3 S., R. 6 W...] 1:37,680 photographs and Timpie 5,274 | USGS _ bench mark on : 15-minute quadrangle. shoreline. 35 | Kimball Canyon.-___-. Sees. 1-2, T. 2 8., R. 7 W.J.__.__ pee nece Lan ad < ans 5, 280 36 | North end Stansbury | NW HM see. 28, T. 1 S., R. | 1:31,000 photographs and Timpie 5, 300 Mountains. T W. 15-minute quadrangle. (Gilbert (spirit level, mean of two deter- 5,271 minations). 57 | Delle Ranch.....i... 1:37,000 photographs and Timpie 5, 290 Sees. 12-13, T. 3 S., R. 8 w. 15-minute quadrangle. NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE TABLE 1.1-Bonneville shoreline elevations-Continued E5 No. Name Township and Range, Salt Lake Source Elevation Notes base line meridian (except as noted) in feet 38 | Antelope Canyon.... See. 25, T. 4 S., R. 8 W..] 1:37,000 photographs and Deseret | 5, 270 Peak 15-minute quadrangle. S9. Dty Canyon.:....... Bee. T, T..6 B.; R8 W-... dors: 5, 260 40 | Davis Knolls-_______. See. 21, T. 7 S., R. 7 1:23,300 photographs and Davis 5, 230 Knolls 7%4-minute quadrangle 41 | Davis Mountain-____. See. 19, T. 8 S., R. 7 W-] 1:23,300 photographs and Indian 5, 230 | Bar. Peaks 7}4-minute quadrangle. 42 | Little Davis Moun- | NEM see 32, T. 7 S., R., | 1:23,300 photographs and Camels 5, 250 | Bar. tain. 8 W. Back Ridge NE quad quadrangle. 43 | Tabby Mountain.... T.48., R JO W...~..... Tabby Mountain 74-minute quad- | 5,270 | Robert Maurer, Univ. of rangle on ground. Utah (written com- munication, 1959). 44 | North of Browns See. 7, T. 4 8., R. 10 W-! 1:33,300 photographs and Wig 5, 300 | Well-formed bar. Spring. Mountain NE 714-minute quad- rangle. 45 | Cedar Spring.______. See.306, T. 4 8., R. 11 W.}.:..._ Omer cns ele 5, 285 46 | Wig Mountain-_____ fee. 1, T. 6 S... R. 11 W._| Wig NlIountain 7}4-minute quad- 5, 255 rangle. 47 | Wildeat Mountain.---! T. 4 8., R18 W._._..:___ 1:33,300 photographs and Wig 5, 300 § Mountain NE 7%4-minute quad- rangle. 48 | Granite Mountain....! T. 8 8... R. 18 W.___.._.__ 1:23,700 photographs and Granite 5, 220 Peak 7}4-minute quadrangle. 49 | Cannon Sec. 5, T. 10 S., R. 12 W.] Dugway Range 7}4-minute quad- | 5,210 | M. H. Staatz and W. J. rangle on ground. Carr (written communi- cation, 1958). 50 | Cup Butte..........: N. edge see. 3, T. 11 S., Hand level from BM on Coyote | 5,221 | Roger Morrison (written R. 9 W. Springs 7%4-minute quadrangle. communication, 1961). §1 | Thomas Pass______.__| NW! sec. 12, T. 13 S., Topaz Mountain 7%4-minute quad- | 5,205 | Bar. M. H. Staatz and R. 11 W. rangle on ground. W. J. Carr (written communication, 1958). 52 | Drum T. 14 8., R. 10 W...... 1:31,000 photographs and Delta 5, 200 sheet at 1:250,000. 53 | Desert T. 12 8; Delta sheet at 1:250,000 on ground.] 5, 210 | Bar. 54+ leans cabal Gilbert (spirit level), and USC&GS | 5, 115 M at Leamington. 55 | Leamington Canyon T.A146., Three barometric traverses from 5, 110 | Inner edge of rock-cut of the Sevier River. USGS BM F45. bench in quartzite on south side of canyon (D. F. Varnes, written communication, 1961). 56 | Sevier Bridge NE} see. 5, T. 17 S., R. | Controlled barometric traverse--__| 5,090 | Cut bench on ridge of vol- Reservoir. 1 W. canic rock, east shore of reservoir (D. F. Varnes, written com- munication, 1961). 57 | Oak City quadrangle.. NEL see. 17, T. 16 S., Controlled barometric traverse 5,126 | Break in slope, inner edge R. 4 W. between bench marks. of bench cut on south- f west corner of ridge of conglomerate (D. F. Varnes, written com- : munication, 1961). $8 !.-..> Near center see. 2, T. USGS BM elev. 5149_._.._______._ 5, 150 | Bench mark is on outer & 18 8., R. 5 W. edge of rock-cut bench on nose of conglomerate (D. F. Varnes, written communication, 1961). 59 | Pillimore.l._-........l:l ri olo lol Gilbert (barometric) ._.__.__.._.__. 5, 145 60 | Southeast of Milford__| Sec. 4, T. 29 S., R. 10 W.] 1:37,000 photographs and Cave 5, 110 Canyon 7!-minute quadrangle 5, 107 Dennis (1944, p. 123). 6: NEM sec. 30, T. 32 S., 1:37,000 Photographs and Avon 5, 090 R. 14 W. NW 7%-minute quadrangle. 62 | Milford Plat.... Sec. 25, T. 28 S., R. 11 W.] 1:20,000 photographs and Milford 5, 105 Flat 7}4-minute quadrangle. 65 | Black Rock.....:.... T. 24 S., R. 11 1:63,360 photographs and Preuss 5, 150 Valley 4 NE 7%4-minute quad- rangle. f 64 | Cricket Mountains____| T. 21 S., R. 10 W._._____._ 1:63,360 photographs and Rich- 5, 220 | Elevation believed too . field sheet at 1:250,000. high-point ignored in contouring fig. 3. 65 | Lakeview Reservoir___| T. 25 S., R. 12 W._______ 1:63,360 photographs and Preuss 5, 135 690-220 O-63--2 Valley 4 NW 7%4-minute quad- rangle. E6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 1.-Bonneville shoreline elevations-Continued No. Name Township and Range, Salt Lake Source Elevation Notes base line meridian (except as noted) in feet 66 | South of Newhouse.---| N% see. 34, T. 27 S., 1:63,360 photographs and Lund 5, 100 R. 14 W. 2 NW 7%4-minute quadrangle. 67 | Wah Wah Mountains.| T. 25 S., R. 14 W___-___| 1:63,360 photographs and Preuss | 5,115 Valley 3 NW 7%4-minute quad- rangle. 68 | Taylors Canyon.... Sec. 1, T. 20 S., R. 14 W| 1:63,360 photographs and Ante- | 5, 140 lope Mountain 7}4-minute quad- ; rangle. 69 | Kings T. 20 8. R. 18 W...... 1:20,000 photographs and Con- | 5,125 fusion Range 4 SE 7}4-minute quadrangle. 70 | Cowboy Pass East____| T. 17 N., R. 16 W.___-_-- 1:20,000 photographs and Con- | 5, 150 fusion Range 1 SW 7}4-minute quadrangle. 71 | Confusion T. 15 8.,. R. 16 W...... 1:20,000 photographs and Con- | 5, 175 fusion Range 1 NW 7%4-minute quadrangle. 72 | Foute T.A46 N.;R. I8 W...... 1:20,000 photographs and Con- 5, 155 fusion Range 2 NE 7}-minute quadrangle. 73 | Cowboy Pass West___| T. 17-18 S., R. 17 W____| 1:20,000 photographs and Con- | 5, 120 fusion Range 2 SE 7%-minute quadrangle. 74 | Conger Range____---- T. 20 S.. R. I8 W...... 1:20,000 photographs and Con- 5, 120 fusion Range 2 SW 7%-minute quadrangle. 70 1 Gold Hill............ Sec. 7, T. 7 S., R. 17 W-] Nolan (1935, pl. 2, and p. 54)___-.- 5, 205 76 | Wendover Beacon, T.32 N.. R. 70 E. 1:63,360 photographs and Elko | 5, 200 Nev. Mount Diablo sheet at 1: 250,000. Meridian. T7 | Wendover, T. 33 N., RK. 70 E. Altimeter traverse from point on 5, 200 Mount Diablo Elko sheet at 1: 250,000. Meridian. 75 | Leppy Pass....._.._. T.A N, R. 19 W...... Schaeffer (1960, p. 112) .--_------ 5, 204 79 | Silver Zone Pass T. 34 N., R. 68 E. 1:63,360 photographs and Elko | 5,190 East, Nevada. Mount Diablo sheet at 1: 250,000. Meridian. 80 | Pilot Range East-. T.;6 N.. R. 19 W...... 1:63,360 photographs and Wells 5, 200 sheet at 1: 250,000. 81 | Pilot Range North N., R. 19 W...... Gilbert (spirit level) _.__._...._.._. 5, 182 (Tecoma). 82 | Loray,.Nev....-_.... Sec. 3, T. 38 N., R. 68 1:63,360 photographs and 5, 167 E. Mount Diablo USC&GS level line along South- Meridian. ern Pacific Railroad. 83 | Muddy Creek._____-- Sec. 2, T. 10 N., R. 15 W| 1:63,360 photographs and Brig- | 5, 200 ham City sheet at 1: 250,000. $ £ 84 | Hogup Mountains Sec. 6, T. 9 N., R. 11 W| Barometer traverse from USC&GS 5, 250 | Peter B. Stifel, Univ. of North. BM. Utah (written com- munication, 1961). 85 | Hogup Mountains Sec. 3, T. 8 N., R. 11 W| 1:63,360 photographs and Brig- 5, 300 | Elevation believed too Southeast. ham City sheet at 1:250,000. high-point ignored in contouring on fig. 3. 86 | Peplin Mountain... T. 11 N., K.12 W...... . Gilbert (spirit level) __._.-._._._-.-.- 5, 282 87 | Morris Ranch___-___- Sec. 32, T. 13 N., R. 12 W.] 1:62,500 photographs and Kelton 5, 210 Pass 15-minute quadrangle. 88 | Summer Ranch Sec. 36, T. 13 N., R. 8 W.] 1:62,000 photographs and Brig- 5, 180 Mountains. ham City sheet at 1:250,000. 89 | Mount Tarpey------- T. 9 N., R. O W._....-.-.- Cilbert (spirit level)..__......... 5, 252 90 | Little Mountain._-- Secs. 13 and 24, T. 10 1:33,200 photographs and Bear | 5, 220 N., R. 4 W. River City 7%4-minute quad- rangle. The outline of the lake is drawn largely on the basis of the contouring on the 1 250,000 maps, combined with the shoreline data obtained from all sources for each area. With one exception, the outline as thus deter- mined agrees well with that shown by Gilbert's map on a scale of 1 : 800,000 (1890, in pocket). Gilbert's Es- calante Bay, however, at the extreme south end of the lake, is now known to be in error. This was recognized independently, by P. E. Dennis (1944) and by C. L. Hubbs (written communication, 1961) and is confirmed by the present study. It is of some interest to note that Gilbert himself did not have an opportunity to examine the supposed shorelines south of Lund (fig. 3), and he was clearly somewhat doubtful regarding both the shorelines and the elevations in that area. Of the former, he notes (1890, p. 369) : NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE A comparative study of these systems of bars showed that the oscillations had been essentially the same at all localities, and it is thus known that throughout the area of their occurrence the shoreline belongs to the same high-water stage. The demonstra- tion applies to the entire main body of the lake and its principal dependencies, and to the Sevier body and Preuss Bay, but it does not apply to Escalante Bay. [Italic mine.] He noted, moreover, that the shoreline record was re- ported by his assistants Howell and Webster to be "* * * faint and difficult of determination" (Gilbert, 1890, p. 370). Part of the reason for the difficulty that the early workers had in tracing these shorelines is to be found on the aerial photographs. Well-marked strandlines can be traced on the photographs from the vicinity of Milford southward along both sides of the valley to a point about 1 mile southwest of Lund, but there they become lost in an expanse of patchy ground that must formerly have been a marsh. Farther southwest, a series of low discontinuous scarps can be traced at least 5 miles into the Escalante Desert; careful study of the photographs reveals, however, that these features split and branch and cut across topography in such a way as to show that they are fault scarps rather than shore- lines. Recognition of this fact clears up the doubts that Gilbert clearly felt regarding this area and which pre- sumably led him to conclude with these words the dis- cussion quoted in part above (Gilbert, 1890, p. 370) : In view of these conclusions the Escalante data will be dis- regarded in the subsequent discussion of the deformation of the Bonneville shore. NOMENCLATURE OF LAKE BONNEVILLE EVENTS Because the chronology of Lake Bonneville is still in a state of flux, the names applied to the various still- stands and to the deposits formed during each of them are subject to disagreement. It is therefore necessary to define the terms that will be applied to the salient events in the history of the lake throughout this report. Lake Bonneville is defined as the body of water that occupied the Bonneville basin after the formation of the thick, mature pre-Bonneville soil of Hunt (in Hunt E7 and others, 1953, p. 15, 43) ; any bodies of water that may have occupied the basin earlier are referred to as pre-Bonneville lakes. The lake deposits younger than that soil in the north- ern Utah Valley are believed by Hunt (in Hunt and others, 1953, p. 17) to contain a record of two high stands that he called the Alpine and the Bonneville, and of two lower stands that he called the Provo and the Stansbury. These correspond respectively to what Gil- bert (1890, p. 90-152) referred to as the Intermediate, Bonneville, Provo, and Stansbury "Stages." A similar sequence of events has been inferred by Eardley and others (1957, fig. 20), who were the first to attempt to construct an absolute time scale, in years, for part of the sequence. Recent work in the area of the Sevier River delta by Varnes and Van Horn (1961) has led them to conclude that deposits equivalent to Hunt's Al- pine Formation record as many as three lake maxima, and still other modifications and refinements of Hunt's chronology are likely to be made as work is extended into other areas. As the controversial aspects of chronology and stra- tigraphy are outside the scope of this paper, the follow- ing nomenclature is selected somewhat arbitrarily for the present purpose and is not urged for more general use. The basic unit of lake history (fig. 2) is termed a "cycle" ; it consists of a major rise and fall, whether or not the lake returned to the starting level. The earliest major rise is designated the Alpine cycle; it is regarded by some as having occurred entirely within a single cycle and by others as forming parts of more than one cycle. The culminating event in the history of the lake was the Bonneville cycle during which the lake over- flowed at Red Rock Pass and initiated the downcutting of the outlet to the level of the Provo shoreline. The latter part of the Bonneville cycle is therefore denoted the Provo I stillstand. A subsequent rise to this same level is designated the Provo II stillstand. A later cycle culminated at the Stansbury shoreline, and others probably at still lower levels, but no attempt has been made to name each of them here. 34 C 25) : P TC I: 3 | % (c C Alpine maxima Bonnevill i j 5 g p onneville maximum Bonneville tn: E shoreline 3 c o o Provo I stillstand Provo II stillstand Provo 5 3 4 shoreline 1 fo - ‘\ - S5 |} #: + ; LJ e a R ; /\ Fa 3 Alpine cycle(s) Bonneville cycle 3 /\ 9 % -=«+~-- OLDER TIME SCALE IS RELATIVE AND NOT NECESSARILY CONSISTENT YOUNGER ---» FicURB 2.-Generalized history and nomenclature of Lake Bonneville used in this report. E8 IDENTITY OF THE HIGHEST SHORELINE Gilbert gave the name "Bonneville shoreline" to the highest strand of the ancient lake. The question of whether this shoreline is everywhere of the same age was discussed by Gilbert (1890, p. 369) and was an- swered in the affirmative because he believed he could recognize a similar series of shoreline embankments at all the places he examined. -It seems probable that Gil- bert was correct, but the matter cannot be settled with certainty until detailed stratigraphic studies have been completed in all parts of the basin. In any case, even though some uncertainty must remain for shoreline ele- vations determined entirely by photogeologic methods, all the newly determined elevations are here assigned to the Bonneville shoreline. OBSERVED DEFORMATION The present configuration of the highest shoreline of Lake Bonneville is shown by means of contours in fig- ure 3. As already noted, the shore features delineating the ancient water surface, originally level, now exhibit a broad domical uplift that reaches a maximum height of a little more than 200 feet. - This amount is some 20 feet greater than Gilbert estimated, but the pattern of uplift he showed in the northern part of the lake is remarkably close to the one that has now been worked out with the help of much fuller data. The points of minimum deformation are at the extremities of the lake, near Lund at the south and Red Rock Pass at the north, The area of maximum uplift lies somewhere near the ~center of what Gilbert referred to as the main body- the large expanse of deep water that occupied the pres- ent area of Great Salt Lake and extended across the Great Salt Lake Desert. Both the precision and the completeness of the data regarding shoreline elevations are still deficient in many places because of the absence of accurate topographic maps and vertical geodetic control. These deficiencies are particularly serious in the area around Lakeside, Newfoundland, and Hogup Mountains, where the only bench marks available are along the railroads; the ele- vations of U.S. Coast and Geodetic Survey triangula- tion stations within the ranges have not been estab- lished. WATER LOAD In order to analyze the history of observed deforma- tion of the shorelines in the Bonneville basin in quantitive terms, it is necessary to know the load that was there placed upon the earth's crust and subsequently removed. In this respect Lake Bonneville is one of the most satisfactory of Nature's experiments with isostasy. The large number of islands and headlands that pro- jected above the surface and their wide distribution over SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY all parts of the lake make it possible to reconstruct the outline and the depth of the ancient lake with much greater accuracy than is possible for the Fennoscandian ice sheet, for example, whose center lay so close to the Baltic Sea that its maximum thickness can never be determined accurately. The present estimates of load were prepared by deter- mining the difference in elevation between the existing surface of land or water, as shown on the 1: 250,000 AMS sheets, and the original water surface when the lake stood at the Bonneville shoreline, as determined from figure 3. To allow for small irregularities in the lake bottom and shoreline, average depths over squares 6 miles on a side were estimated from the map by in- spection, and these values were plotted at each township corner throughout the basin. The results indicate that the water of Lake Bonneville, when it was full, weighed 10 * tons. The effect of this load, however, depended not only on its magnitude but on the fact that it was distributed unevenly over a total area of about 35,000 square miles. To allow for the irregularities of area and depth, two diagrams are included that show the average depth of water over circles of different radius; in figure 4 the radius is 25 miles, and in figure 5 the radius is 40 miles. To prepare these diagrams, the depths at each township corner were transferred to a 1:1,000,000-scale base; a circle of the chosen radius was then centered successively over every fourth town- ship corner, the average depth within the circle at each point was calculated, and the resulting values were con- toured. In order to provide closer control near the edge of the lake where the values are changing rapidly, aver- ages were calculated for every township corner along two east-west lines. The 100-foot contour interval selected for these maps results in a spacing approximate- ly equal to that of the 20-foot contours of the observed deformation, an aid to visual comparison. A series of profiles (fig. 6) based on figures 3, 4, and 5 affords still another means of comparison. POSSIBLE CAUSES OF DEFORMATION SUPERFICIAL VERSUS DEEP-SEATED EFFECTS Inasmuch as the surface of Lake Bonneville at its highest level stood some 500 to 1,000 feet above the floors of the present intermontane valleys, the Bonneville shoreline is generally high on the piedmont or mountain slopes and is therefore cut into or close to bedrock. As a result, the differences in elevation shown in figure 3 cannot be ascribed to slumping in areas of deep sedi- ment fill, to local compaction, or to any other super- NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE 113" 114° 37 5290 43 / gg 5270-5300 35 527052798 "39 \ 5250 5260 5280 34. 5274 5255 % 31 & S (Aes I 67 3 5150 I yas \ Nes 5100 $\/G 'A < s110 Xx I %A Ag 38° 114° sos 13 ~ 10 0 10 20 30 MILES \o _se\ \EXPLANATION 24 5107 ® Tim >. Point where elevation of shoreline 112° has been determined Lower number gives elevation of 2 shoreline, in feet Outline of lake at Bonneville shoreline Surrounding area patterned 5300 ---- Contour showing present elevation of deformed shoreline Dashed where inferred. Interval 20 feet Wasatch fault FicURE 3.-Map showing deformation of the Bonneville shoreline. EQ E1O SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 113° 114° sae} 361 figs/{fig}? 92‘0 ~A * pas 413 352 136 1 B $50 176 54 B o 144 \ 23 85.6 $60 1'16> 198! ( e 56, 10 2 (84 478 32 A $ o, i 356 168 222 ?_337 308) x 39° Ky (39° \’T§ ® 112° 111" 1 10 \\\\\ > 1 \ I i 259 Center of circle and average depth E of water, in feet O xy" _ w | Kg Outline of lake at Bonneville Z shoreline 38° 4 o Surrounding area patterned I 8 0 N 114 six 1 13\i\ 600 Line connecting points of equal 10 ~ g. ". 10.. 20. 30 Mites average depth (OLL - . fro ad FIGURE 4.-Map showing depth of water averaged over circles of 25-mile radius. NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE 113" EXPLANATION "109 Center of circle and average depth of water, in feet yom Outline of lake at Bonneville *s x<§\ shoreline 38° t 38° Surrounding area patterned 112° \f\\ 300 Line connecting points of equal 10 : 40 20. 30 MILES & average depth HLLEL LL FiGURE 5.-Map showing depth of water averaged over circles of 40-mile radius. E11 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY E12 0 o o D 0001 1334 NI 'H3IVM 140 H1d30 '1oreM ;o ujdop put uo) BULIOJop SUIMOUS HHAOLT OE X NOILYH3D9VX3 TVOILN3A T T T T T T T ren s31IW 09 OS Of Os Of ~ Of 0 OIT , a-a NIN SNOT¥ 3711404d ~a -Z T Coa_g_ - Nrg esses * ' ~~~ wmcwm has /, z ne- -\ yoouueg ink aul , yidap eSesore 104 saningp (poyianu1) ajyoid enjoy - RelleA BIH \ * aguey |_ 'ssed pejew | SBurds sewoy | aBuey - 49084 nwmmEI SOM ong siw Aioquowo4g apisexe7 1epap eSuey asnoH iii e aaa aie o oo ae ee aati aia alin o i olin o iii a SPG nne ee ane nooo Ind E- uopewiojap 3 C a 1334 NI 'M3ILVM 10 HLd30 10 H1d30 1334 NI 'M3LVM 1334 NI 'H3 LVM 10 0 g s 2.40 008 OOO1 00 0001 , 3-0 SNN SNOTY 3711140H4d T aguery SiW yoresem Ringsuers T ajyoid jenjoy r ll/IIII , \0||\\0.I- L {\\\\\f\co_umr¢h3wu paniasqo L - J J , 8-8 3Nn SsNo4v 3711404d Acs ra uidap eSeane 104 saniny" [~~~=> filly/“Ry”! a5-- ~ OY 5s he | aBuey SIW SIW SiW yo;esem yaiinbo Kingsuers 1epap (payianu1) ajyoid enjoy E- \\o‘\\ ne. ge h sow—mm“; ||||| === \/:o_«mE‘_oBu paniasqo 4 4 w-V INN ONOTY 371404d =<< f opr -~ ARA \av.\ S= | yidap Beane 104 sanin 5 i- Suey . \_ eme -t - - (poyianuy1) ajyoud jenjoy siW puejpunomay aBuey 10|!d 2 ill’Iléll \\\0.\\\ = ="s--. arn" Putra s nen a a i ae i Lin in mins irene n ea an hee pan erin nn ie n C> \/:o_umELEou paniasqo & L a V V OOT 002 OO€ OOT eels OO€ OOT 002 elelst 1334 NI '(ULINdIN) 1334 NI 'ULdININ) 1334 NI NOILVW#4043G0 OOT 002 00€ 1334 NI (U41Nd4N) NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE ficial effects. Although this conclusion is evident from the magnitude and great lateral extent of the deforma- tion alone, it is reinforced by the fact that shorelines extend in many places from one range to another across areas of deep fill without appreciable deviation. More- over, the observed deformation requires first subsidence, then uplift,) a sequence of events that could never be produced by local surficial means. Because the defor- mation has affected the crust of the earth over an area of more than 35,000 square miles, the processes by which this deformation took place must have operated at great depth-probably below the crust. The possible causes to be examined include (a) elastic compression of the crust, (b) epeirogenic movements unrelated to Lake Bonneville such as tilting, warping, and arching, and (c) isostatic response brought about by plastic flow be- neath the crust or by some other mechanism. ELASTIC COMPRESSION OF THE CRUST The first and most rapid mode by which the earth responds to a load like that of Lake Bonneville is by elastic compression of the crust. That this response requires only a few years is shown by the fact that Lake Mead has depressed the crust in some places as much as 7 inches in 15 years, an amount close to that predicted by theory (Raphael, 1954, p. 1). To calculate the elas- tic compression caused by Lake Bonneville it will be assumed that a load (s;) of 1,000 feet of water is placed on a column of crust 50 km thick, for which Young's modulus (Z) is approximately 7x10" dynes per ecm and Poisson's ratio (v) is 0.25. - For simplicity it will be assumed that the load is of infinite horizontal extent, and that deformation of the column in the horizontal plane is zero. Under these conditions, e,, the unit shortening in the vertical direction becomes €z=%[(1+u)(1—2v)]’ 1-y and the total shortening, AZ=eZ. Substituting the values given above, AZ=178 em or approximately 6 feet. A more sophisticated treatment of elastic deforma- tion involving the earth as a whole was presented Te- cently by Slichter and Caputo (1960), who show that for an ice load 900 km in diameter, the elastic deflection would be 3 percent of the ice thickness. But because this percentage decreases as the load decreases in diam- eter, a load the size of Lake Bonneville (200 km in diameter) would result, by extrapolation of the values Slichter and Caputo have given, in elastic deflection in the center of the load of only about 0.5 percent, or for 690-220 O-63--3 E13 900 feet of water, 4.5 feet. This is the same order of magnitude as that obtained earlier. Since both values are within the limits of error in many of the shoreline elevations, it is obvious that elas- tic compression is not the principal mechanism in- volved; its effects will therefore be ignored, for the present, in dealing with the isostatic deformation. EPEIROGENIC DEFORMATION It has been argued (for example, HeyImun, 1960) that the observed deformation of Lake Bonneville shorelines could have resulted entirely from secular movements that had nothing to do with the presence of the lake; the coincidence of the load with the pattern of deformation being either fortuitous or due to long- continued deep-seated secular movements that gave rise to both the basin and the deformation. Such move- ments might, in theory at least, involve almost any com- bination of (a) tilting on a regional scale, (b) doming or subsidence of the entire basin, or (c) local uplift or warping within the basin. Let us examine the evidence for and against each of these. REGIONAL TILTING Tilting on a large scale is eliminated as the principal causative factor by the symmetrical character of the domical uplift that affected the shorelines of Lake Bon- neville. It is nevertheless desirable to consider the pos- sibility that tilting on a smaller scale has occurred but is partly concealed by some larger phenomenon. This can be done by comparing the elevations of the shore- lines at the extremities of the lake. The places least subject to effects related to the lake itself are at the ends of long shallow arms that ex- tended well away from large areas of deep water. The site of Lund, near the south end of the lake, lay at the end of such an arm-a narrow one that extended to a point 30 miles south of Milford, with an average depth of less than 50 feet. The elevation of the Bonneville shoreline decreases gradually from 5,105 and 5,110 feet near Milford (fig. 3) to 5,090 feet at the extreme south end of this arm. It is 5,100 feet at the extreme south end of the adjoining Sevier Lake arm and 5,120 feet at the south end of the Snake Valley arm, farther north- west, Since neither of these localities was so far from deep water as the arm near Lund, 5,090 feet may be regarded as the normal elevation for this end of the lake. This figure is confirmed by Varnes' determina- tion of 5,090 feet on a similar narrow arm that extended up the Sevier River to the site of the Sevier Bridge Reservoir. At the north end of the lake, in southern Idaho, there is, unfortunately, no topographic control in Cur- E14 lew Valley (fig. 1) or in the valley near Malad. In Cache Valley, however, along the north end of the Wasatch Range, the Bonneville shoreline gradually descends northward, being 5,142 feet at Logan, 5,131 feet at Franklin, and 5,085 feet at Red Rock Pass. The last figure is 23 feet less than Gilbert's, which was 5,108 feet (1890, p. 412, table 23), and about 60 feet less than the estimate of Williams (1952). It was obtained by using Gilbert's spirit-level measurement of 303 feet for the difference in elevation between the Bonneville shoreline and the Swan Lake station and adding this amount to the elevation of the USC&GS bench mark Y-261 on the railroad at Swan Lake; it was further checked in the field by locating the shoreline along the north edge of Poverty Flats (T. 13 S., R. 39 E.), a few miles to the southeast, where it consistently falls below the 5,100 contour on the map of the Preston quadrangle. As the elevation of the shoreline at Red Rock Pass, ac- cording to the newest figures, is only 5 feet less than it is near Lund, there cannot have been any appreciable tilting of the basin as a whole in a north-south direction. Tilting or warping in an east-west direction is more difficult to measure because the lake is mainly bounded on the sides by relatively steep linear mountain slopes along which deep water reached almost to the shore. On the west side, where there are no deep reentrants, the effects of loading extend well beyond the limits of the old shoreline. The problem is further complicated on this side by the fact that there was a high-level lake in the adjoining basin of Goshute Valley. This lake con- tributed to the load, but because it was not connected with Lake Bonneville its shorelines do not aid in meas- uring the deformation. Conditions on the east side are somewhat better, be- cause the lake entered two of the deep river canyons near Ogden and flooded the back valleys behind the Wasatch Range. Unfortunately, however, the useful- ness of this fact is reduced because of uncertainty re- garding the extent of the post-Bonneville faulting along the mountain front. Although the amount and direc- tion of fault displacement can be measured at the range front, the extent to which these movements affected the elevations of the shorelines in the back valleys cannot be determined independently. The only means, there- fore, of estimating east-west tilt is to compare the aver- age water levels on the east and west sides along shores of equal steepness and depth. -It is evident from figure 3 that the distribution of islands and of open water along the two sides of the lake was so unequal that precise comparisons cannot be made without detailed computa- tion of loads, and this cannot be made until we have reliable shoreline elevations at many more points along the west side of the basin than we do now. In general, SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY however, the elevations along the west side average about 5,200 feet; whereas those along the east side, in places where there has been little or no faulting, average about 5,175 feet. This suggests a possible uplift on the west side of from 20 to 30 feet. REGIONAL DOMING Heylmun (1960, fig. 1) noted that the pattern of up- lift shown on Gilbert's map (1890, pl. 46) resembles that postulated by Harris (1959, p. 2639) for a Mesozoic uplift in western Utah and eastern Nevada, and he therefore concludes : As outlined by Harris, the Sevier Arch has a configuration very similar to the contouring shown on figure 1, so it is sug- gestive, if not positively proved, that the warping is, in fact, the result of the continued influence of the Sevier Arch. This conclusion is untenable for the following reasons : 1. The supposed resemblance between the two patterns of deformation depends on Gilbert's incomplete data in the central part of the lake and on his er- roneous data regarding Escalante Bay. 2. It ignores the fact that the central part of the Bon- neville basin contains the lowest point in the east- ern Great Basin, a condition that could not have resulted from doming. 3. It requires a belated rebirth within this limited area of an uplift that was formed early in the Laramide orogenic activity and that extended over all of easternmost Nevada and the western part of Utah. This uplift, moreover, has been thoroughly broken up by the block faulting that characterizes the Basin and Range province. Viewed broadly, the evidence recorded by the old shorelines of Lake Bonneville is inconsistent with any hypothesis involving prolonged secular changes. As will be shown later in discussing chronology, the part of the Bonneville sedimentary record already deci- phered reveals as many as three high stands prior to that at the Bonneville shoreline. But both Gilbert's pioneer work and the recent more detailed studies show that whereas the whole system of shorelines has been domed upward some 200 feet in the center, there is not enough divergence in many places between the early strand- lines and later ones to be detectable without detailed study. This would not be so if the basin or any large part of it had undergone continuous tilting. If it had, the younger shorelines would have become progressively higher on one side of the lake and lower on the other. At present there is no evidence that they do. Secular upwarping or subsidence that fortuitously coincided with the lake basin would have had a similar effect, but the difference of elevation would have been concentrated in the center of movement; any given NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE strandline would in the first instance be lower than all its predecessors, whereas in the latter instance it would be higher. This result, too, is out of accord with the known facts. The history of Lake Bonneville is so complex that the effects of relatively slow secular movements could well be obscured by the differences in elevation between the thresholds that controlled the major cycles. Never- theless, it is clear that the amount of secular movement that took place between the Alpine and Bonneville cy- cles is very small compared with the movement that has taken place since. Present evidence indicates that there is only one way in which the observed shoreline deformation could have been produced by purely for- tuitous means. The lake basin would have had to re- main virtually stationary during all of the Alpine cycle and the early part of the Bonneville cycle, so that the Alpine and Bonneville shorelines would be, at most, only a few tens of feet apart. Upwarping must then have begun and proceeded at the rate required for iso- static adjustment, but it must now have almost if not wholly stopped. The uplift must, moreover, have been domical in outline and must have affected an area just large enough to include all of Lake Bonneville. The amount of coincidence required by this explanation makes it hard to accept. LOCAL WARPING In spite of the lack of evidence for large-scale secular movements, certain minor irregularities in the shore- lines suggest that local warping has occurred at some places within the basin. It is evident from figure 3 that the normal slope characterizing the domical upwarp in the northern part of the lake, whatever its cause, is 2 to 2% feet per mile. On the southwest side of the Cedar Mountains, however, the surface rises northward at a rate of 41/4 feet per mile between stations 44 and 46 but flattens abruptly to the south between stations 46 and 49. (See also section D-D', fig. 6.) As no re- cent faulting is known to have occurred along the Cedar Mountains, these irregularities seem to be best explained by local warping. Similar irregularities are evident in the profile across the Stansbury and Oquirrh Mountains (profile B-B', fig. 6), though it is possible that these are due to faulting. j Recent data from D. J. Varnes (written communica- tion, 1961) show similar anomalies along the southeast edge of the basin near Leamington ; three stations spaced at intervals of about 2 miles along the Bonneville shore- line beginning 314 miles northeast of station 57 (fig. 3), show a continuous decrease in elevation from 5,126 feet at that point through 5,125, 5,100 and 5,090 feet, yet the shoreline rises again to 5,110 feet at the next station E15 (Leamington, 55). Other local irregularities will per- haps be revealed as more accurate elevation data ac- cumulate. ISOSTATIC DEFORMATION MODE OF RESPONSE Because of the inadequacy of the preceding alterna- tive explanations, I am forced to conclude, as Gilbert did, that the principal cause of the observed doming of the earth's crust in the Lake Bonneville area was an isostatic response to removal of the load of water. It is desirable to state explicitly just how that response is be- lieved to have taken place. f When subjected to a load whose magnitude has been estimated, the earth's surface is presumed to have been bent downward by an amount proportional to the load and at a rate determined by the physical properties of the crust and the material beneath it. If time were sufficient for this process to reach its conclusion, the amount of deflection would be exactly that required to restore isostatic balance. It is further assumed that while the earth was thus depressed, the water of the lake formed beaches and rock-cut terraces that recorded the exact position of the shoreline both on the margins of the lake and on islands and headlands near the center. Finally, when the water evaporated and the load was re- moved, the earth again sought to return to a condition of equilibrium. - As a result, the once-level shorelines were bowed upward ; and if time permitted, they would rise by an amount theoretically equal to the initial downward deflection. Obviously this picture is vastly oversimplified. In practice it is unlikely that any surface load, particularly one of small extent, would be fully compensated, or that recovery would be complete when the load was removed. It is evident also that inasmuch as the only measure of the amount of initial downwarping is the present up- ward doming, any extent to which the earth has failed to return to its original position will further reduce the apparent degree of compensation. What is more important, the process depicted above as relatively static and consisting of a single cycle actually consisted of a continuous response to a constantly varying load. In the following pages, some but not all of the simplify- ing assumptions are discussed and evaluated. Theoretical examination of the mechanical and hy- drodynamic processes within the earth that give rise to this surface response has been carried out by Daly (1934), Haskell (1935), Gutenberg (1941), Niskanen (1948), Vening Meinesz (1937), and many others. Al- though the individual treatment of the problem varies, it is generally agreed that the basic mechanism is an essentially hydrostatic response of a floating crust sup- ported by a highly viscous but fluid substratum. \ The E16 crust is presumed to act as an elastic plate sufficiently strong to resist the shear stresses caused by the load. This shear strength is assumed to affect the configuration of the response by acting to distribute a point load over a finite area; but otherwise, the crust will be assumed to be essentially inert and to follow more or less closely the plastic movement of the subcrust. Analysis of the isostatic phenomenon is therefore concerned almost ex- clusively with the viscous response of the substratum. Some writers have dealt with the resulting move- ments within the substratum in terms of spherical harmonics, as if they involved virtually the entire globe (Niskanen, 1948); others have dealt with harmonic loading in a two-dimensional model in which the curva- ture of the earth is neglected (Heiskanen and Vening Meinesz, 1958, p. 361). Both groups, however, have reached the following conclusions regarding the essen- tial nature of the process : 1. A central depression is developed beneath the load by outward flow of material in the subcrust. 2. A peripheral bulge due to the presence of this out- ward-moving material should, at- least in theory, form around the initial depression. 3. The time required to attain a given degree of iso- static adjustment, or recovery, will vary directly as the viscosity of the substratum and inversely as the diameter of the load but is essentially independent of its magnitude. Another mechanism, that of phase changes, has been widely discussed recently as a possible explanation of both the Mohorovicic discontinuity itself (hereafter re- ferred to as the Moho) (Kennedy, 1959) and of smaller discontinuities at much deep levels (see for example, Birch, 1951). In either case, however, though phase changes may modify the rate of movement, they are incapable of accounting for both such movements and isostatic adjustment. MacDonald and Ness (1960, p. 2180) also discussed the long-term changes in surface elevation as related to phase changes at the Moho, but in every example they ascribed the isostatic adjustment to some unrelated, more deep-seated, and much more rapid mechanism. Similarly, Vening Meinesz (Heis- kanen and Vening Meinesz, 1958, p. 369) took deep- seated phase changes into account in deriving an effec- tive value for the viscosity of the subcrust from the data for Fennoscandia, but he believed the principal mechanism to be viscous flow. The phase-change mechanism was examined most recently by Broecker (1962), who concluded that for probable values of the geothermal gradient and of the heats of transformation, phase changes at the Moho are insufficient to account for more than 1/4 to 1 of the rebound observed at Lake Bonneville. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY CRUSTAL MODEL To evaluate the significance of isostasy as a mech- anism of crustal response, it is necessary to establish a model of the sort of crust to which a load is being applied. A very simple model will suffice, in which the following parameters are assumed : Crust Mantle 50 km souk Mean density 2.80 3.25 Bulk modulus_________ 10° dynes per cm' ens The thickness of the crust in this area includes part of the intermediate layer with a compressional-wave velocity of 7.59 km per see as determined by Berg and others (1960, p. 529) by seismic methods. The mean density of the crust is determined by combining their velocity model with Woollard's relation between veloc- ity and crustal density (1959, fig. 7). Although the value of 50 km assumed for the thickness of the crust in this area is larger than that obtained by a more re- cent seismic study (L. C. Pakiser, written communica- tion, 1962), it is not unreasonable when dealing with problems of isostatic compensation. D. R. Mabey (written communication, 1960) analyzed isostatic anomalies for 12 pendulum stations in the Basin and Range province and found that Pratt-Hayford anomalies are smallest for a depth of compensation of 56.9 km. Hayford's (1910, p. 58) observation of de- flections of the vertical over another area of similar extent indicate a probable depth of compensation of 66 km. COINCIDENCE OF UPLIFT AND LOAD The most obvious method of determining whether isostasy is a significant cause of the observed uplift of Lake Bonneville is to compare the uplift with the load. A remarkable coincidence between the pattern of uplift (fig. 3) and that of the load represented by the ancient lake (figs. 4, 5) can be seen almost at a glance. The greatest uplift occurred over the deepest water, between the present west shore of Great Salt Lake and the Bon- neville Salt Flats. A secondary lobe of uplift extended southward over the area of deep water that occupied what is now the Sevier Desert. Smaller lobes corres- pond in position with the arms that occupied Cache Val- ley and Malad Valley. Examination of the 5,200-foot contour shows that except for the possibility of a small secular eastward tilt, noted earlier, the configuration is nearly symmetrical with respect to the outline of the lake. The highest shorelines observed stand at an elevation of 5,300 feet in the area of the Cedar Mountains, on Wildcat Mountain, and in the Hogup Mountains. The distribution of these points with respect to deep water NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE suggests that equal or perhaps slightly greater eleva- tions may be found in the Newfoundland or Lakeside Mountains. In any case, the maximum height now known (5,300 feet) indicates uplift of some 210 feet above the elevations of the shorelines at the south end of the lake and above its outlet at the north end. Ex- cluding Gilbert's dubious points in the Escalante Desert, this figure is about a fourth larger than the range of 177 feet observed by Gilbert between the lowest point and that at the north end of the Stansbury Mountains (Gilbert, 1890, p. 366-367). In spite of these differ- ences, the results derived from the newest information show such close correlation between doming and load as to fully confirm Gilbert's conclusions that the deforma- tion was caused by isostatic response to unloading. DEGREE OF ISOSTATIC COMPENSATION Knowing both the load that has been applied to a segment of the earth's crust and the amount of deflection that has resulted, it should theoretically be a simple matter to calculate the extent to which isostatic balance has been reached. Let us assume that a load is placed on a floating crust supported by a viscous substratum with a density of 3.25. In this theoretical model, both the strength of the crust and the viscosity of the subcrust will be neglected, and isostatic compensation is there- fore assumed to be complete. The result of loading under these conditions will be to depress the crust until the weight of the subcrustal material displaced is equal to the load. On this basis, the deflection (w) produced by a given load would be inversely proportional to the ratio between the density of the load (p) and that of the substratum (p'). Because the load is water with a den- sity of 1, w= 1L, , where A is the depth of the water. The 1,100 feet ofpwater in the central part of the basin would thus be theoretically capable of depressing the crust 340 feet. But this figure was the maximum spot depth whereas islands and other irregularities in the floor of the basin make the average depth considerably less. As shown by figure 4, the maximum depth of water in the central part of the basin over a circle of 25-miles radius was about 980 feet, a little south of the tip of Promontory Point. This amount of water would have been capable of depressing the crust about 306 feet, so that the observed uplift of Bonneville shore- line, 20 feet, indicates that isostatic compensation is 68 percent complete. On this same basis, 70 percent compensation is indicated for the northern Stansbury Mountains, and 59 percent is indicated for the northern Dugway Range. Similar estimates for other parts of the basin would seem to indicate that the maximum ob- served uplift is on the order of 70 percent of the theo- retical maximum. E17 This figure, however, is probably too low, for each attempt to evaluate one of the original simplifying assumptions brings the actual isostatic response more nearly into agreement with that required by theory. For example, because the shear strength of the crust is not zero, the point loads applied at the surface may be effectively distributed over an area materially larger than the 25-mile radius used to derive the original figure of 68 percent compensation. A simple empirical means of allowing for this factor is to increase the size of the circles over which the depth of water is averaged until the slope of the resulting curve (fig. 7) matches that of the deflection observed at the edge of the load. By interpolating between the curves for 25 and 40 miles, it seems likely that a value of 35 miles would produce a reasonable match. At that value the greatest average depth of water is about 925 feet, which would make the calculated deflection about 285 feet if the assumed crustal density is 3.25. On this basis, the degree of isostatic adjustment represented by an up- lift of 210 feet would be increased from 68 percent to about 73 percent. Another factor open to question is the density as- sumed for the material displaced from beneath the load. The value 3.25 used here is in good agreement with the value obtained by applying the compressional-wave velocity of 7.97 km per see determined by Berg and others (1960, p. 530) for material below a depth of 72 km in the vicinity of Great Salt Lake to the curves given by Woollard (1959, p. 1530, fig. 7) for the rela- tion of velocity to density. But this value holds good only if compensation is effected entirely by movement of material immediately below the crust. Daly (1934, p. 188), recognizing this problem, calculated what might be called the effective density of the material displaced beneath the Fennoscandian ice cap, as follows: If, as seems probable, the ice cap was full-bodied for a time longer than the Post-Glacial epoch, the Fennoscandian crust was basined almost or quite to the limit demanded for equilib- rium with the rest of the earth. If the assumption is correct, we can secure an estimate of the density of the material that was displaced horizontally when the crust was basined. The thickness of the ice cap at its center was probably at least 3,000 meters. In order that the central non-elastic deepening of the basin should be 550 meters, the mean density of the material horizontally displaced, beneath the crust, was about 4.9. If the thickness of the ice at the center was 3,500 meters, the mean density of the material so displaced was about 5.7 Unfortunately, Daly does not explain how these val- 3,000 a 3,500 __ 550 5.4 and———550 6.3, it seems probable the smaller values included some al- lowance for the fact that the loads are of finite rather than of infinite horizontal extent. ues were obtained ; but as E18 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY T T T T I T T T T T T r-0 octet. c oto EXPLANATION -| 300 & Ca h LJ --=p=3.2 # 7 d . xe ldJJ € s $ h=depth of water G < Z 3 p=density of substratum - 200 ~ a € 4 a a Observed deflection az 3 500 |- Antelope Island ~*~ ae o t a 5G O 6 L C C t E ® ={ 100 8 LS Farmington Huntsville}Q\\ (projected) {s & 4o = f\e 0 1 1 1 1 1 o 1 $ 1 1 1 0 60 50 40 30 20 10 0 10 20 30 40 50 60 DISTANCE FROM EDGE OF BASIN, IN MILES FIGURE 7.-Comparison of observed deflection with depth of water averaged over various radii. Later, however, Daly (1940, p. 320) abandoned the idea of deep flow in favor of movement concentrated at the base of the lithosphere. Gutenberg (1941, p. 757), however, apparently still favored the theory, for he says: * * * the conclusion seems inevitable that the movements extend to many hundreds of kilometers downward with scarcely de- creasing amplitudes. However this may be, if even the smaller of Daly's ef- fective values for Fennoscandia were used for Bonne- ville, the maximum theoretical uplift would be reduced 1,000 to e 204 feet, which would indicate that isostatic adjustment was more than 100 percent. Actually Daly's figures may have quite another sig- nificance. They are based, as indicated by his words «"* * * almost or quite to the limit demanded by equilib- rium * * *," on the assumption that isostatic adjust- ment under the given load was complete, a condition that is inherently improbable. And as any failure to attain complete compensation would serve to increase the effective value of the density, the surprisingly high values Daly found may indicate a lack of isostatic ad- justment rather than a high density. If, for example, the 550 meters of nonelastic deflection of the crust re- corded by Daly represented only 75 percent isostatic compensation, the amount of movement that should have taken place would be —5—5—O—=747 meters. - The 0.15 resulting density would then be reduced from 4.9 to 3.6, a value that seems much more reasonable. At any rate, because the thickness of the ice cap, which Daly gave as 3,000 meters, has been estimated by others (Charlesworth, 1957, p. 42) as ranging from 1,000 to 4,000 meters, the evidence from Fennoscandia does not seem capable of yielding reliable information about either the degree of compensation or the density of the material displaced. As applied to Lake Bonneville, this conclusion indi- cates that the density of 3.25 provisionally used must assuredly be a minimum, for if any large part of the outflow of material from beneath the crust was sig- nificantly deeper than 75 km, the assumed density would have to be increased, and the apparent degree of com- pensation would consequently be even greater than the 75 percent already calculated. A still more effective means of evaluating the overall degree of compensation is to compare the total load of water, obtained from figures 4 or 5, with the weight of material displaced, as derived from figure 3. To do so, the contours on each figure were first completed around the margins of the lake by projection using a spacing comparable with that within the lake where some con- trol is available. The area within each contour was determined by planimeter, and the volume between each contour was calculated by the formula V=¥4 (4m+ Ant+VAm41) (m-n), where m and m are given con- tours, and 4, and A, are the areas within those contours, respectively. The total volume displaced, deter- mined by this method, was found to be 1.0 X 10% cu. ft. Using a density of 3.25, this represents 1.03 X 10" tons. Because of the lack of control beyond the margin of the NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE lake, this value is not significant beyond the first figure. The corresponding value for the weight of water, ob- tained from figure 5 by an identical method, is 1.15% 10° tons. The agreement between these figures sug- gests that compensation during the high stand of the Bonneville cycle may well have been essentially com- plete, but the error involved in extending the contours on figure 3 and errors due to lack of geodetic control in parts of the lake may affect the volume displaced by as much as 10 or 20 percént. The coincidence should, therefore, be regarded only as verifying that the de- gree of compensation is high; probably in excess of the 75 percent already calculated. RATE OF RESPONSE Evidence has been presented that the high shorelines of Lake Bonneville have been domed upward by an amount equivalent to at least 75 percent of that re- quired for complete isostatic adjustment. It is desir- able now to consider the evidence available from geol- ogy regarding the rates at which this response has taken place. GEOLOGIC CHRONOLOGY Estimates vary widely for both the duration and the timing of the salient events in the history of Lake Bonneville. Only a few radiocarbon dates have been obtained from woody material, and still fewer have been well tied to the geologic record. Many dates have been obtained from tufa and shell material, but the evidence they provide is in conflict with that obtained by ordinary geologic methods and hence is of uncertain value. The graphs in figure 8 illustrate the present range of opinion on the lake history and chronology. The first three graphs are based on studies of the sedi- ments of Lake Bonneville and associated glacial de- posits and soils Eardley and others (1957, fig. 20; adapted here as fig. 84) regarded the Alpine "Stage" as possibly equivalent to the Kansan glaciation of the midcontinent area and suggested a later history that does not include any long interglacial intervals. Morrison (1961a, 1961b, and written communication, 1961) studied the stratigraphy of the lake deposits in the Jordan Valley south of Salt Lake City where these deposits intertongue with glacial sediments at the mouths of Little Cottonwood and Bells Canyons. Fig- ure 8B illustrates his interpretation of the lake history. He subdivided and correlated the deposits mainly on the basis of soils formed during interglacial intervals. The oldest soil, a very strongly developed one referred to by Hunt and others (1953, p. 43) as the pre-Lake Bonneville soil, is directly overlain by sediments of the Alpine cycle and also by glacial deposits that Morrison correlated with the earlier of two stades of the Bull E19 Lake Glaciation in the Rocky Mountain region. A second soil, somewhat less strongly developed, which he called the mid-Lake Bonneville soil, was formed on deposits as young as those of the Bonneville cycle and also on the deposits of the later stade of Bull Lake Glaciation. Morrison therefore correlated these early lake cycles with the Bull Lake and Tahoe Glaciations of early Wisconsin (Iowan) age. The youngest soil (moderately developed) formed on the youngest Lake Bonneville sediments and on glacial deposits that Mor- rison correlated with the Pinedale Glaciation. This glaciation is now commonly believed, from radiocarbon dating, to have begun about 26,000 years ago and to have ended between 6,500 and 7,500 years ago. The absolute age of the Alpine and Bonneville cycles, how- ever, can only be estimated by extrapolation beyond the range of radiocarbon dating.? Varnes and Van Horn (1961) made a stratigraphic study of the deposits of Lake Bonneville along the Sevier River between Leamington and Delta, Utah. The sequence of events recorded there seems to be more complicated, and presumably more complete, than that recorded elsewhere. The time interval that Gilbert originally ascribed to the deposition of the yellow clay (Alpine) is now believed to include three periods of high water separated by two recessions, one of which may be equal in duration to that which separated the Alpine from the Bonneville. The only evidence for the absolute age of these deposits is carbon-14 dates for inorganic carbonate and shells from the white marl that yielded ages of 15,000 to 19,000 years B.P. As with other carbon-14 dates on marl and shells, these are much younger than the dates obtained on woody ma- terial associated with glacial deposits of apparently comparable age. Broecker and Orr (1958) obtained carbon-14 dates as young as 16,000 years B.P. from tufa carbonate at the Bonneville shoreline. Their chronology (fig. 8C) therefore agrees with that of Varnes and Van Horn rather than that of Eardley (fig. 84) or Morrison (fig. 8B). A chronology assigning a greater age to some Lake Bonneville features is that of figure 8D, which I have developed by analogy with a record prepared by Smith (1958, and written communication, 1960) from the sub- surface deposits of Searles Lake, Calif. These deposits * Recent work in the Little Cottonwood area by Richmond and Morri- son (written communication, 1962) has revealed the existence of a well-developed soil believed to be the mid-Lake Bonneville soil between the moraines formed during the late stade of Bull Lake Glaciation and gravel deposits formed during the rise of the Bonneville shoreline. On this basis, plus evidence from other parts of the basin, Morrison now believes that the Bonneville overflow took place during the early stade of the Pinedale Glaciation, probably about 20,000 years ago. Only the Alpine cycles are now believed to correlate with the Bull Lake and Tahoe Glaciations, and to be older than 40,000 years. E20 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY IIlinoian Stages of Wisconsin Glaciation Kansan (?) Glaciation -- . i tess" A > yaka" Glaciation Yarmouth Sangamon (?) Iowa2-\azwe rady ary ankato 5000 eus Interglaciation _ Interglaciation s ~ Provo | stage ame" e k af RL Lant. \ Stansbury stage Alpine __\. _; # j ) x/ Bonneville f serem fsa S a 160 140 120 100 80 60 40 20 10 0 z A. Lake Bonneville, after Eardley and others (1957) g 3 P P £ A 5 P - Z Bull Lake Glaciation Interglaciation - Pinedale Glaciation & e _/Bonneville overflow soo0 is a”, A /A < ,» \ I,” shoreline (41328) ti: # 8 je cylcle Yy \\ (4800) /\7,\? “41210 1200 6 120 100 d 60 40 20 10 0 br B. Lake Bonneville, Morrison (1961 and written communication, 1961) g - E «Bonneville / f $ 5000 n Thousands of years l,’ Xm, t* before present F4 Str r i 1 i i 1 w 4200 ; 120 100 80 60 40 20 10 0 a C. Lake Bonneville, Broecker and Orr (1958) E < S % L _I __________________ -__- overflow s0006 "* //— "%% Fé \\_ELQ\_/(_>_I_§tillstand Provo II stillstand x," Alpine cycle _ /' Bonneville cycle \ 7% st ad | | \‘\ z” 1 1\\ / | "s ats 4200 120 100 80 40 20 10 0 D, Lake Bonneville, as suggested by Searles Lake 1000g er 12g Inter- Tioga - tJ I t L-- CO- E _______ Tathfe—_G_?fla_t_|c_>9______~_~\ _ . -------. Last overflow" glaciation - Glaciation 500 <>(E ———————————— Jae Mud 9 Mud Walt Hz 1 i 1 1 eX 1 XML 1 XOX _ m 0 t 160 140 120 100 80 60 40 20 10 0 E. Searles Lake,after Smith (1958 and written communication, 1960) X Organic carbon dates from Flint and Gale, 1958 FIGURE 8.-Graphs showing interpretations of Lake Bonneville history. consist of alternate layers of mud formed during glacial maxima and salt formed during the intervening periods of relative desiccation. A series of dates ranging from 8,000 years to as much as 45,000 years has been ob- tained on the organic-carbon fractions from this se- quence (Flint and Gale, 1958, p. 707) ; the age of the deposits older than 45,000 years is estimated by extrap- olating the sedimentation rate measured in the more fully dated upper part. Correlation between this se- quence and that of Lake Bonneville hinges on the as- sumption that the deposits laid down in Searles Lake during the time interval between the Tahoe and Tioga Glaciations are of the same age as the soil formed on deposits of Lake Bonneville during the time interval between the Bull Lake and Pinedale Glaciations (fig. 8B). It also presumes that the Alpine and Bonneville cycles (figs. 2, 8D) together are equivalent to the whole of the Bull Lake Glaciation in the Wasatch Range and that this in turn is equivalent to all of the Tahoe Gla- ciation in the Sierras. This correlation is supported by the stratigraphic and soil records of Lake Lahontan, in western Nevada (Morrison, 19612), which, like Searles Lake, received its principal water supply from the Sierra Nevada. In both the Lahontan and Bonneville records the best-developed soil is that which precedes the deposits correlated with the Bull Lake and Tahoe Glaciations. A less well-developed soil was formed at each place during the time interval between these gla- ciations and the younger Pinedale and Tioga Glacia- tions. In view of the great thickness of salt formed during this latter time interval, characterized in the Lake Bonneville area by only moderately developed soils, it seems improbable that the earlier, more strongly developed soils are to be correlated with either of the weakly recorded minima of the Searles Lake record (fig. SE, 70,000 or 105,000 years BP.). As a result, the chronology derived from Searles Lake, which agrees well with that of Morrison (fig. 8B) after about 40,000 NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE years BP., makes the Alpine and Bonneville cycles about twice as long as Morrison estimated. Not enough evidence is now available to determine which of these chronologies is the most nearly correct. RELATION BETWEEN GEOLOGIC CHRONOLOGY AND ISOSTATIC DEFORMATION Graphs that relate depth of water to time (fig. 8) form a convenient basis from which to calculate the rate of isostatic response if the relation between depth and load is known. Fortunately, the northern part of the lake, where the deflection was greatest, has an unusually flat floor and steep sides (profiles, fig. 6), and the curve relating depth to volume is approximately linear (Eard- ley and others, 1957, p. 1145, table 1, and fig. 2). For such a body, the curves of figure 8, which show varia- tions in depth of water or elevation of lake surface, may be used directly as an expression of load. Before at- tempting to deal with the effects of such continuously varying loads, however, it is desirable to examine the way in which the earth responds to a load that is ap- plied (or removed) instantaneously. This is conven- iently expressed by an equation that relates the frac- tion (¢) of the ultimate response to the time (¢), in years, since the application (or removal) of the load. t d=1—e_Tf The term "7," (called the relaxation time by Heiskanen and Vening Meinesz, 1958, p. 369) is the time, in years, during which the deviation from isostasy diminishes to 31 of its initial value.: In terms of the deflection, (d), this is equivalent to 1—2, or 0.63212 of its ulti- mate value. Accordingly, the deflection resulting from a given load will amount to 63 percent of its final value at the end of 7, years, will attain 63 percent of the re- mainder during the next 7, years, and so on. This re- lation is expressed graphically for 7, of 5,000, 10,000, and 40,000 years in figure 9C. The more rapidly the earth responds to a given load, the smaller the value of i. To apply these relations to a continuously changing load, such as that of Lake Bonneville, it is necessary to integrate the effects of each increment of load over the period of time extending from its application to the present. - This has been done for Morrison's chronology in steps of 2,000 years, and the result for 7, values of 5,000 and 10,000 years forms figure 9B. A similar cal- ® The fraction 5=fi was used by Vening Meinesz and will be used here ; any other fraction could be used, with the appropriate modi- fication of Tr. E21 culation based on the chronology derived from Searles Lake is shown in figure 10. Both graphs involve an assumption as to the initial isostatic condition of the basin. For present purposes, isostatic equilibrium is assumed to have been complete at the beginning of the Alpine cycle; the deflection curves of figures 92 and 10B therefore begin at zero. This assumption, though apparently arbitrary, is not unreasonable. Although the basin was undoubtedly loaded and unloaded repeat- edly during earlier parts of the Pleistocene, it seems theoretically probable that the intervals of time that separated the major divisions of the Pleistocene were longer than those that separated individual glaciations. This is further supported by the fact that the only de- posits that have been observed beneath the deposits of Lake Bonneville along the Wasatch Range are alluvial fans; lake deposits, if they existed, are buried so deeply as to be concealed. Comparison of these curves with the deformation observed during each cycle is a powerful tool for ana- lyzing the extent of isostatic adjustment and the sig- nificance of different geologic chronologies. It is evi- dent that increasing the value of 7, causes a decrease in the total deflection resulting from a given lake cycle and a time delay in both warping and recovery. The maximum deflection resulting from the Alpine cycle, for example, is reduced from the theoretical maximum of 290 feet (T,=0) to 220 and 160 feet for values of T, of 5,000 and 10,000 years, respectively. The effect is also delayed some 2,000 to 3,000 years. Actually, the elevation at a given high stand must be determined not in terms of the maximum deflection but by the deflec- tion at the time when that particular stand occurred. On that basis, the calculated deflection during Mor- rison's Alpine maximum is reduced from 220 feet for T,.=0, to a little less than 200 feet for 7,=5,000 years. Other geologically significant relations to be obtained from these graphs will be discussed later. VALUE OF T, FOR LAKE BONNEVILLE In spite of the uncertainties regarding the absolute chronology of Lake Bonneville, it is possible to use the graphs of calculated response to set certain limits on the value of 7,. Examining first the curve derived from Searles Lake (fig. 10B), it is evident that even on this extended time scale a 7, of 40,000 years would produce a downwarp- ing at the end of the Alpine cycle (placed at 82,000 years B.P. on this time scale) of 140 feet. But inas- much as the deflection observed is measured by upwarp- ing, this must be reduced by the 75 feet of uplift that would still remain to take place at ¢=0 (present). Hence, the maximum uplift of the Alpine deposits for E22 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY [es A. Load H- 5200 Bonneville overflow LJ < uw 3 u. L6 z Provo I stillstand Provo I1 stillstand z ui o 2 E g Alpine cycle Bonneville cycle 4200 . 1 1 1 u. "avg 60 50 40 30 20 10 0 Time,t,in thousands of years before present 70 E i 0 3 As o h > ul— juasaid a10j9q jo spuesnoy] fP oS 09 OL 08 06 OOT OIT OCT m B T T T T T T z 5 3 g 3 5 a1049 ajfinguuog aurd|y mz puejsjjiis |J ood = 0 puejsjjijs | oao4d Z A , & mojpiano ajfinauuog docs: m - 3 f A peoj :y E24 rison's curves; and though this is not the shortest of the time scales, it seems to represent the most reason- able minimum value for Lake Bonneville. The above values of 4,000 and 10,000 years for 7, are based on the shortest and longest time seales and there- fore represent the limiting values that are reasonable for Lake Bonneville.* PRESENT RATE OF UPLIFT It is evident that estimates of the rate of uplift based on existing geologic chronology are none too satisfac- tory ; at best they yield only a range of possible values. Another method of determining the rate is the direct geodetic measurement that has been used so successfully in Scandinavia. -But because the total amount of uplift in this area is only an eighth of that in Scandinavia, the rate and amount of movement is so low that it can be. detected only by precise leveling repeated at widely separated times. Unfortunately, such releveling has not been carried out on any of the lines that cross the center of the basin, where the uplift was greatest. A line of first-order levels was established, however, by the U.S. Coast and Geodetic Survey in 1911 along the route of the old Central Pacific Railroad across the northern rim of the basin, and this line was releveled between 1953 and 1958. Comparison of these two sets of levels, which extended well beyond the edge of the basin, reveals (fig. 11) that there is a systematic dif- ference between the two, recorded on this graph as a more or less continuous slope. Although the slope ap- pears large, the actual difference in elevation between one end of the line and the other is only 470 mm (1.544 feet) in a horizontal distance of 848 km (528.8 miles)-a ratio of 1:2,000,000. According to the Coast and Geodetic Survey (written communication, 1960), discrepancies of this order of magnitude may be the result of an unusually large accumulation of the small errors inherent in all physical measurements and probably do not represent actual changes in elevation. Yet apart from this systematic difference there is a marked upward deflection of the curve between Valley Pass, Nev., and Corrinne, Utah, of exactly the character that would be expected if this area were responding slowly to residual isostatic forces. The maximum up- ward deflection amounts to 100 mm in a horizontal dis- tance of 34 km, a ratio of 1:360,000-some six times greater than the average for the line as a whole. This * After this manuscript was prepared, Morrison concluded (written communication, 1962) that his correlation of the Bonneville overflow event with the late stade of Bull Lake Glaciation was in error; he now believes the lake rose to the Bonneville shoreline during the early stade of the Pinedale Glaciation, or about 20,000 years ago. This revision reduces by half the shortest time scale here considered (fig. 9) and sug- gests that the value of T for Lake Bonneville is at or near the lower limit of the range given-that is, approximately 4,000 years. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY coincidence, though highly suggestive, is still not con- clusive, and verification of actual continuing isostatic adjustment must await releveling of some of the lines that extend across the center of the basin. In order to give some idea of the differences in eleva- tion that are likely to result from continuing isostatic adjustment, calculated values of the amount of residual uplift and the rate of uplift corresponding to three values of 7, have been taken from the tables on which figures 9 and 10 were based and are shown below. Calculated amount and rate of residual uplift Amount of _ Rate of residual uplift Tr uplift mm (yr) (t) per yr 5000: 2 2222 LET aa ea aa annem 10 0. 6 $0,000 2 EZINE LLL nL ne 25 . 9 £0,000 " ? 2 oe o nn annie a nal na 75 . 4 COMPARISON WITH SCANDINAVIA Although the uncertainties as to the absolute timing of the Lake Bonneville events make it impossible to establish the value of 7, more closely than somewhere between 4,000 and 10,000 years, it is of considerable interest to compare this result with those obtained in Scandinavia. Gutenberg (1941, p. 760) estimated that a f i 1 a the anomaly in Scandinavia was reduced to > of its initial value in about 14,000 years. Vening Meinesz (Heiskanen and Vening Meinesz, 1958, p. 369), after correcting the rate of observed uplift for elastic re- sponse and phase changes, derived a value of 5,280 years. These values, though widely discordant, are of the same order of magnitude as those obtained for Lake Bonneville despite the fact that the Scandinavian ice sheet was 10 times the diameter of Lake Bonneville and therefore, according to the papers cited above by both Gutenberg and Vening Meinesz, should have re- sponded 10 times more rapidly. The relation between dimension of load and rate of response was expressed by Vening Meinesz as a simple equation : 7,£ =%, in which % is a constant; 7, the re- laxation time, here in thousands of years; and L the width, in thousands of kilometers, of a load of infinite length. According to this equation, Gutenberg's figure of 14,000 years for the relaxation time in Scandinavia yields a value of 16.8 for the constant, whereas Vening Meinesz's figure of 5,280 years yields the value 6.3. It must be noted, however, that in Vening Meinesz's orig- inal calculation the ice load in Scandinavia was approx- imated by a strip of width Z and of infinite length. For a load with the finite dimensions ZL J/, in thousands of kilometers, Vening Meinesz gave the formula NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE 22 M __ -s /L-M _ For Lake Bonneville, which can be reasonably approxi- mated by a load 200 km square, this reduces to 7, x 0.1445=k. With this modification, the constant 16.8 corresponding with Gutenberg's figure of 14,000 years for 7, in Scandinavia would give a relaxation time of about 100,000 years for Lake Bonneville. This is more than twice the largest estimate for the time since the lake last stood at the spill point and almost 10 times the smallest estimate. The constant 6.3, corresponding with Vening Meinesz's figure of 5,280 years, on the other hand, yields a relaxation time of about 45,000 years for a load the size of Lake Bonneville. Although Vening Meinesz warned that the formulas given above for the relation between the dimensions of the load and the rate of response are only approximate, it still seems surprising to find that the values of 7, derived by extrapolation from Scandinavia (45,000 and 100,000 years) differ by an order of magnitude from those based on observation at Lake Bonneville (4,000 to 10,000 years). E25 The difference may represent an actual difference in viscosity. On the other hand, it could be accounted for by other means: the basic theory of viscous flow may not be correctly applied, or the present geologic inter- pretations, particularly in regard to chronology of Lake Bonneville, may be in need of revision. The effective viscosity for the subcrust beneath Lake Bonneville can be calculated from the limiting values of T, already derived from the existing geologic chronol- gies. The necessary equation was given by Vening Meinesz (Heiskanen and Vening Meinesz, 1958, p. 364) as k= 21,719; in which % is an expression of time equal to %, in seconds, p=3.27, g=980 d per sq cm, 1=the dynamic viscosity of the substratum, and f is a func- tion of the horizontal dimensions LM, in centimeters, T CM _ L2+M2 this becomes $107 or 2.2 X10~' _ Transposing and being equal to For a load 200 km square, solving for », we find it to range from 0.9% poises 'at o ¢ >, o $. 15 § z 3 0 -< ~ fol el 3 £ s B 1 up 5% $ E al S a fast g 3 3 a a ¢ a 8 ad pa = o g m [=! o A = 8 l = © E4 & ® E £ ce B 55> & -100 hed 4.0..0. 0 o & t 2 7 T & a ° SA 4 1 *A */ ~s Relative uplift, possibly due “$1 */ % to isostatic rebound = e o & bd 3 ( o = e® 3-200 *--, \\ Z- > 5 > 2 86 ig 5 2 * 4 7 ee \ - g 2 gi =f o < 3 2a o g a1 -300|E 5.3 & Le. LJ _o @ < > \ & €) 3 x b o -400 & L L iz J $ \\ \\ A Effect of Hansel Valley earthquake, 1934 -500 6 0 100 200 300 400 500 600 700 800 900 DISTANCE, IN KILOMETERS FiGURE 11.-Graph showing difference between first-order levels across part of the Bonneville basin in 1911 and 1958. E26 to 2X10*#* poises. This value, in round numbers, 10" poises, is one order of magnitude less than the value of 10% poises calculated by Vening Meinesz for Seandinavia. __ Although it seems intuitively reasonable that the Basin and Range province should be more mobile than the Fennoscandian shield, the indicated difference in apparent viscosity is surprisingly large. Daly (1940, p. 394) and others suggested that the low viscosity under the Great Basin implies an abnormally thin crust, per- haps underlain by a gigantic batholith, still partly liquid. The character of the crustal warping under Lake Bonneville, together with its independence of the faulting that is an inherent part of the Basin and Range framework, are such as to permit Daly's conclusion re- garding the subcrust, but they do not contribute directly to information regarding the thickness of the crust. There has been much discussion recently of the sig- nificance of phase changes as an explanation for the discontinuity at the Moho. This mechanism offers at- tractive features, particularly in regard to the relation of rate of response to horizontal dimension of load. If, for example, the phase changes, and hence the amount of uplift, depend essentially on upward flow of heat, the rate should exhibit the same independence of horizontal dimension that is suggested by the fact that the value of 7, obtained above (p. B24) for Lake Bonneville is nearly identical with that obtained by Vening Meinesz for the much larger area in Scandina- via. It is obvious, of course, that the phase-change theory as now applied to the problems of geosynclinal history (MacDonald and Ness, 1960, p. 2189) is not adapted to the present problem, but further study of this and related mechanisms may, nevertheless prove fruitful (Broecker, 1962). Another avenue of approach is through modifications of the viscous-flow hypothesis, perhaps in terms of the depth at which the flow takes place. It is to be hoped that ultimately it will be possible to obtain enough pre- cise information about the nature of the response under Lake Bonneville to suggest ways in which the theory should be modified. The third alternative is to look for major errors in the chronology of Lake Bonneville. There is, in fact, a pressing need for more and better information about almost all aspects of Lake Bonneville history. Addi- tional detailed stratigraphic studies are needed to es- tablish a stratigraphic sequence applicable to all parts of the basin. These should be widely distributed over the lake basin rather than concentrated along one edge in order to establish the relative heights of the various lake deposits in the center and along the west and north edges, where data are virtually lacking at present. Cor- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY relation by means of soil stratigraphy, combined with radiocarbon or potassium-argon dating, should be ap- plied as fully as possible to establish a more complete series of absolute dates. In spite of the inadequacy of present data, it seems unlikely that revisions of Lake Bonneville chronology can account for the order-of- magnitude difference between the figures obtained in this area and in Seandinavia. GEOLOGIC CONSEQUENCES Lake Bonneville at least twice remained full long enough for the basin to reach a high degree of isostatic compensation, and this fact points to some conclusions of considerable geologic interest. VERTICAL SPACING OF ALPINE AND BONNEVILLE SHORELINES Isostatic theory suggests, on the basis of the curves (figs. 9, 10), that within certain limits a marked dif- ference in the duration of Alpine and Bonneville cycles would result in a difference in the elevation of their shorelines in the center of the basin even though they might have had the same threshold. If, therefore, the Alpine cycle lasted appreciably longer than the Bonne- ville as Gilbert supposed, the Alpine shorelines would probably have reached a correspondingly greater de- gree of compensation and, having originally been farther depressed, would now appear higher in relation to those of the Bonneville cycle in the center of the basin than they do at the edge. Although there are only a few places where the elevations of the Bonneville and Alpine shorelines can be compared in adjacent ex- posures, this idea has received some support. Roger Morrison (written communication, 1961) supplied the following information based on his detailed work near Little Cottonwood Canyon and on brief reconnaissance at Cup Butte, just northeast of McDowell Mountains: At Cup Butte, near the mid-point of the western side of the Old River Bed (Coyote Springs 7%-minute quadrangle) the highest shoreline is at an altitude of 5,221+2 feet. Here, unfortunately, I cannot separate the Alpine from the Bonne- ville deposits with assurance. A coarse angular (blocky) iron- and manganese-stained gravel makes up most of the spit com- plex at Cup Butte. This is overlain by finer gravel, made up of fairly well-rounded pebbles scantily coated with desert var- nish; this gravel appears to range from a foot to rarely. more than 10 feet in thickness. The lower, blocky unit, to judge from its bulk and stratigraphic position, probably belongs to the Alpine Formation of Hunt (in Hunt and others, 1953, p. 17), and the upper pebbly unit could well be his Bonneville Forma- tion. The upper gravel coarsens toward the rocky crag (5,241 feet) into which the high shoreline is carved, and there I was not sure of being able to distinguish between the two gravels. It is evidently uncertain whether the deposits of the Alpine and Bonneville cycles at Cup Butte are in their NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE normal relation or are reversed. Morrison's data sug- gest, however, that the deposits of the Alpine cycle have been warped upward at least 30 feet more in this part of the basin than those of the Bonneville cycle; if the deposits should prove to be reversed, this amount would be increased to 50 feet. Only a detailed study of the stratigraphic relations over much wider areas will make it possible to determine whether this effect is actually the one predicted by isostatic theory. The few available data bearing on this question are tabulated below : Relative elevation of Bonneville and Alpine shorelines Central part East edge of basin of basin (Below mouth of (Cup Butte, near Little Cotton- Oldp River Bed) wood Canyon) Difference Bonneville cyele.________ 8, 221 5, 140 80 Alpine cycle_____________ 5, 200 5, 100 110 Inadequate as they are, the above data have sug- gested a further working hypothesis regarding a possible threshold during the Alpine cycle. If the deposits of the Alpine cycle were arched upward iso- statically, the fact that they coincide closely with the Bonneville shoreline near the center of the basin but are some 40 feet below it along the east edge leads one to expect that they will be still lower near the extremi- ties of the basin. The Alpine deposits in northern Cache Valley may thus prove to be as low as 5,000 or 5,025 feet; and the threshold, if one existed, would have been correspondingly low. VERTICAL SPACING OF PROVO SHORELINE A second possible effect of the isostatic readjust- ment of the lake during loading and unloading is that as the water receded rapidly from its high stand at the Bonneville shoreline to that at the Provo shore- line the central part of the basin, and to some extent its steep sides also, would have been overcompensated (fig. 9B, 53,000 years B.P.). If that were so, the shore- lines cut during the ensuing stillstand (Provo I) should now be higher than the threshold. When, after a long period of dessication, the lake again rose to the Provo shoreline, most if not all of the compen- satory uplift should have taken place; and the lake, in its newly filled condition, should have been under- compensated (fig. 92, 18,000 years BP.). The new strand deposits should therefore be correspondingly lower than the old ones and should coincide more closely with the elevation of the threshold. Lake de- posits along the east side seem to record just such a history (fig. 82). According to Eardley and others (1957), the deposits associated with the Provo I still- stand have an average elevation of about 4,800 feet ; E27 whereas according to Morrison (written communica- tion, 1961), the younger deposits, formed during the Provo II stillstand, have an elevation of about 4,770 feet. A further and closely related consequence of a high degree of isostatic compensation depends on the fact that isostatic movements were greater and more rapid in the center of the basin than on its sides. One would therefore expect the beaches formed during a general stillstand to have a wider vertical distribution-to be more "smeared out"-near the center of the lake than at its margins. Such an effect has, in fact, been observed by Eardley and others (1957, p. 1163, fig. 10), who re- corded a vertical spread of as much as 50 feet in a group of beaches near the middle of the lake that corresponds to a single well-marked shoreline on the rim. RECENT WARPING OF BASIN The surface of the Bonneville Salt Flat has been shown by Eardley and others (1957, p. 1156, and fig. 1) to slope gently westward from the Cedar Mountains, where its elevation is about 4,230 feet, to Wendover on the Utah-Nevada State line, where its elevation is 4,211 to 4,214 feet. They conclude, * * * the basin of the Great Salt Lake Desert has a closure of 7 to 10 feet below the 4,221-foot contour, and presents an ideal example of the bar theory of salt formation. In view of other evidence of uplift near the center of the basin, Don R. Mabey suggested (oral communica- tion, 1960) that much of the closure noted above and much of the westward slope of the salt flats may be a direct result of the last increments of isostatic read- justment. What is probably a similar effect was noted by Varnes (written communication, 1961) on the east side of the Sevier Desert, where delta deposits of the Sevier River have been backtilted to such an extent that the coarse gravels of the Provo II stillstand no longer have suffi- cient gradient to account for their having been trans- ported westward. Varnes attributed this effect to iso- static warping of the Sevier arm of the lake (fig. 3). ABSOLUTE MOVEMENT ON THE WASATCH FAULT Both the recent displacements on the Wasatch fault and the total movement over long periods have con- sisted of normal faulting in which the mountain block has apparently always moved upward relative to the adjoining valley block. It is nevertheless of geologic interest in examining a given increment of this dis- placement, such as that resulting in the fresh post- Bonneville scarps, to determine if possible the domi- nant direction of movement relative to some fixed datum. The hope that the shorelines of Lake Bonne- E28 ville might provide such a datum was, in fact, the original motive for making this study. If no isostatic adjustment had occurred in this region, it would be an easy matter to establish the elevation of some shoreline, such as the Bonneville, over a large area and to use this value as a datum from which to measure the displacement on any fault that cut this shoreline. The actual problem, however, is by no means so simple; there is no single elevation that can be regarded as the normal level for the Bonneville shoreline; moreover, the total difference in elevation due to isostatic changes is, on the average, 5 or 10 times the amount of recent displacement on any of the faults along the Wasatch front. It is therefore necessary to compare the ob- served elevations not with a well-established datum but with a hypothetical datum based on inferences regard- ing the character and extent of isostatic adjustment. Figure 12 shows a typical example of the relation be- tween faulting and isostatic deformation along the east margin of the basin. The solid line indicates the pres- ent position of the deformed Bonneville shoreline, and the dots indicate the location of the points at which it was determined. The base of the diagram is close to the original position of the shoreline, as indicated by its elevation at the south end of the lake and at the north- ern outlet. In order to analyze the throw of the faults, the projected position of the shoreline is also shown for two assumptions: (a) that only the mountain block was active, and (b) that only the valley block was active. In the first instance, the projected position of the shoreline would reach the base line at a point marked A, some 10 miles east of the mountain front, and the eleva- tion of the Bonneville shoreline at the front before the SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY faulting would have been about 5,135 feet. Absolute uplift of the range is opposed by two lines of reasoning. (a) The curves for isostatic deformation should, in theory, approach either the maximum or minimum val- ues asymptotically, a requirement met by the pattern of deflection in the two places where the curve can be ob- served as it approaches zero. If all the fault displace- ment were up on the east, the resulting curve would be carried at its maximum slope to within a mile or two of the point where it intersects the base line. (b) Because the wavelength of the deformation (profile fig 5) does not exceed the width of the load (200 km), the water in a relatively flat-floored basin such as that of Lake Bonneville would be similar in effect to that on a plate, and the deflection would therefore be approximately symmetrical across its margins. The elevation of the Bonneville shoreline along an unfaulted edge of the lake should therefore be about midway between the maximum and the minimum, or just under 5,200 feet. The western margin, along which there has not been any recent faulting, supports this hypothesis reasonably well; although, as indicated earlier, the shoreline is in general a little higher on this margin than on the east- ern margin. This reasoning suggests that the normal elevation along the steeper parts of the shoreline, for example between Salt Lake City and Ogden, should be more nearly that now observed on the mountain block- namely 5,160 to 5,180 feet-and also supports the con- clusion that the greater part of the movement was down on the west. This conclusion conflicts with that of Bissell (1959), who states, "* * * thefootwall has been the most active element * * *" and "Sediments of the Lake Bonneville W Stansbury Ogquirrh Wasatch Range E Mountains c Toogle | _ Mountains & & Valley 9 € a o 5300 % 'o r = full # o +7 4 * > ag. FQ 0 c 2 O % sA @ w 3 < [+] 40-3 T Rl cee $.. o 4G g'5 en NL 3 + o o 2 --- 4 *s. x o 3 3 I ~ ~~ C *- 4 -we Bx 7 0 £5 ! 9 to s ~ hi 5 9 1 o ® xii Pre-, # SEE a * % Ths=-=-~~c. fe S 0/S C 5200" NX **-~-2 OMS $ 5 a € Xx S cna. = 6 \’\ © 'at @ C sae I-k\ w ~. (C an 10 20 MILES ~ I4 Iki lh a i i i i 1 need -. feud VERTICAL EXAGGERATION x 400 I, ( A 5100' m- =- le r --- Observed shorelines See text the west Original position if absolute motion on Wasatch fault is all down on Original position if absolute motion on Wasatch fault is all up on the east FIGURE 12.-Diagrammatic profile showing Wasatch fault displacement at the eastern margin of Lake Bonneville. NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE group, in some localities, have been carried up on the footwall as much as 200 feet above the elevation at which they were deposited." This statement is open to some question, because unless allowance is made for the effects of isostatic deformation, it is impossible to deter- mine the level at which a given set of shoreline sedi- ments was deposited. The conclusion may nevertheless be essentially correct for the Provo area, because the amount of isostatic uplift should be considerably less in the deep reentrant now occupied by Utah Lake than on the open shorelines north of Salt Lake City, and the ele- vation before the faulting should there have been corre- spondingly lower. There is no reason, moreover, why the footwall may not have been the active block along one segment of the fault while the hanging wall was active along another. In any case, regardless of the movement during recent faulting, the long-term dis- placement must have involved both blocks, for the top of the range now stands at nearly 12,000 feet above sea level, and the base of the fill in parts of the basin has sunk below sea level (Cook and Berg, 1961, p. 82). RELATION OF ISOSTATIC UPLIFT TO BASIN AND RANGE STRUCTURES One of the most challenging aspects of the isostatic deformation of the Bonneville basin is its apparent total independence from the areally coincident phenom- ena of Basin-and-Range faulting. Owing to the steep- ness of the mountain slopes, the waters of Lake Bonne- ville were supported almost entirely by the floors of the intermontane basins, on which they exerted, over large areas, as much pressure as a blanket of sediments 400 feet thick. Such loads adjoined major normal faults not only along the full length of the Wasatch Range but in other areas nearby-for example, along the west sides of the Oquirrh, Stansbury, and House Ranges and along the east sides of the Deep Creek and Fish Springs Ranges. These faults are major features of the earth's crust, the Wasatch fault having a length of as much as 150 miles and a displacement of as much as 15,000 feet. Some of the faults have given rise to earthquakes in re- cent times. Post-Bonneville faulting has occurred on many of the range fronts in this region, and the Wasatch fault has undergone a 20- to 80-foot displace- ment for much of its length since the disappearance of Lake Bonneville. Although this displacement took place at a time when the center of the basin was still unloading-that is, when the forces of isostasy would have tended to make the valley block move upward- the throw was invariably down on the valley side. The movement has thus been in the direction opposite to that which would be expected if it were in any way related to the isostatic response to unloading. E29 It seems probable that this independence is due to fundamental differences in both the mechanism and the site of operation of the two phenomena. The active element in the isostatic process is believed to be the sub- crust, whereas the faults that characterize the Basin and Range province must be essentially features of the crust. This conclusion has rather paradoxical conse- quences: the normal faults, which are the shallower of the two sets of features, are the older, the more per- sistent, and the more widespread ; but the forces leading to the more deep-seated isostatic response have been transmitted through the crust, apparently without effect on the normal faults. The movement on the faults is always downward on the valley side, whereas it would be upward if it constituted a direct response to isostatic unloading. These facts pose a problem that cannot be solved without a thoroughgoing analysis of the forces involved in isostatic adjustment on the one hand and normal faulting on the other. (For further discus- sion, see Crittenden, 1963.) One further comment is in order. The relatively del- icate state of isostatic balance of this area of the earth's crust, as revealed by its ready response to the rise and fall of Lake Bonneville, brings into sharp focus the unanswered questions regarding the origin of the Basin Ranges. It has often been said rather casually that erosion of material from the tops of ranges and depo- sition in the adjoining basins provides an adequate mechanism for the formation, or at least for the con- tinued development of these structures. From the point of view of isostasy, this is unlikely; the valley blocks, now covered by as much as 10,000 feet of uncon- solidated sediments, are not heavy, as their depressed position would imply, but are already too light; the adjoining mountain blocks, composed of solid rocks, are already too heavy; yet the valleys continue to sub- side, and the ranges continue to rise, maintaining all the while a delicate regional isostatic balance. The origin of the local driving forces within the crust that give rise to this process have yet to be clearly explained. CONCLUSIONS 1. A review of deformation of the high shoreline of Lake Bonneville, made with the help of photogeology and utilizing modern geodesy where available, fully confirms G. K. Gilbert's belief that the earth has re- sponded isostatically to the fluctuations of Lake Bonne- ville. The maximum elevation of the highest shore- line in the central part of the basin is 5,300 feet. This is at least 210 feet higher than its elevation at the south end of the lake and at its former northern outlet in Red Rock Pass. £30 2. These facts indicate that isostatic recovery has reached at least 75 percent of the theoretical maximum, as calculated on the assumption that it took place in a segment of relatively weak crust floating on a sub- stratum of negligible viscosity and a density of 8.25. 3. The effects of isostatic adjustment and recovery may account for several geologic features of the Bonne- ville area. Among these are differences in elevation of the two Provo stillstands, westward tilting and closure of the Bonneville Salt Flats near Wendover, eastward tilting of the Sevier River delta, and possible differential uplift of deposits of the Bonneville and Alpine cycles. 4. Post- Bonneville displacements on the Wasatch fault are opposite in direction to those that would be expected to result from isostatic movements caused by the dwindling of Lake Bonneville. This indicates that the two processes operate independently and by differ- ent mechanisms-Basin-and-Range faulting within the crust, isostatic compensation within the subcrust. De- tails of the mechanisms of these processes are still im- perfectly understood and offer an outstanding regional problem for future work. 5. Existing chronologies for Lake Bonneville differ widely, especially for the time prior to the Bonneville overflow. The estimates best supported by organic- carbon dating (Morrison, 19612, 1961b) and one derived from Searles Lake (Smith, 1958) indicate that the relaxation time, 7, (the time required for an anomaly to be reduced to i; of its initial value), for Lake Bonne- ville is between 4,000 and 10,000 years. 6. Based on this range for 7,, it is calculated that the apparent dynamic viscosity of the subcrust in the Bonneville area is 10% poises, compared with 10° poises calculated for Scandinavia by Niskanen, Gutenberg, Vening Meinesz, and others. 7. Because both the load and the isostatic response can be measured precisely, Lake Bonneville is one of the most ideal of Nature's experiments in isostasy. To take advantage of this precision, however, more accu- rate and widespread information is needed on (a) shoreline elevations in the western and northwestern part of the basin, (b) stratigraphy of lake deposits, particularly in the central and western parts of the basin, (c) the ages of these deposits, and (d) the rate of present uplift, if any. When satisfactory data on these points have been obtained, it should be possible to determine the apparent viscosity of the subcrust more accurately than has yet been done, and by com- bining these results with seismic data, to evaluate the rigidity of the crust in this segment of the Basin and Range province. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY REFERENCES CITED Berg, J. W., Cook, K. L., Narans, H. D., and Dolan, Wm. M., 1960, Seismic investigation of crustal structure in the east- ern part of the Basin and Range province: Seismol. Soc. America Bull., v. 50, no. 4, p. 511-535. Birch, Francis, 1951, Remarks on the structure of the mantle, and its bearing upon the possibility of convection currents. Am. Geophys. Union Trans., v. 32, p. 583-534. Bissell, H. J., 1959, Wasatch fault in central Utah [abs.] : Geol. Soc. America Bull., v. 70, p. 1710. } Broecker, W. S., 1962, The contribution of pressure-induced phase changes to glacial rebound : Jour. Geophys. Research, v. 67, no. 12, p. 4837-4842. Broecker, W. S., and Orr, P. C., 1958, Radio carbon chronology of Lake Lahontan and Lake Bonneville: Geol. Soc. America Bull., v. 69, p. 1009-1032. Charlesworth, J. K., 1957, The Quaternary Era: London, Ed- ward Arnold, 1700 p., 2 vols. Cook, K. L., and Berg, J. W., 1961, Regional gravity survey along the central and southern Wasatch front, Utah : U.S. Geol. Survey Prof. Paper 316-E, p. 75-89. Crittenden, M. D., Jr., Effective viscosity of the earth derived from isostatic loading of Pleistocene Lake Bonneville: Jour. Geophys. Research, v. 68, no. 19 (in press). Daly, R. A., 1934, The changing world of the ice age: New Haven, Yale Univ. Press, 270 p. 1940, Strength and structure of the earth: New York, Prentice-Hall, 434 p. Dennis, P. E., 1944, Shorelines of the Escalante Bay of Lake Bonneville [abs.]: Utah Acad. Sci. Proc., 1941-43, v. 19-20, p. 121-124. Eardley, A. J.. Gvosdetsky, Vasyl, and Marsell, R. E., 1957, Hydrology of Lake Bonneville and sediments and soils of its basin: Geol. Soc. America Bull., v. 68, p. 1141-1201. Flint, R. F., and Gale, W. A., 1958, Stratigraphy and radiocarbon dates at Searles Lake, California: Am. Jour. Sci., v. 256, p. 689-714. Gilbert, G. K., 1890, Lake Bonneville: U.S. Geol. Survey Mon. 1, 438 p. Gutenberg, Beno, 1941, Changes in sea level, postglacial uplift, and mobility of the earth's interior: Geol. Soc. America Bull., v. 52, p. 721-772. Harris, H. D., 1959, Late Mesozoic positive area in western Utah: Am. Assoc. Petroleum Geologists Bull., v. 43, p. 2636- 2652. Haskell, N. A., 1935, The motion of a viscous fluid under a sur- face load : Physics, v. 6, p. 265-269. Hayford, John F., 1910, Supplementary investigation in 1909 of the figure of the earth and isostasy: U.S. Coast and Geod. Survey Pub., 58 p. Heiskanen, W. A., and Vening Meinesz, F. A., 1958, The earth and its gravity field: New York, McGraw-Hill, 470 p. Heylmun, E. B., 1960, The Pleistocene of western Utah, in Guide- book to the geology of east central Nevada : Intermountain Assoc. Petroleum Geologists 11th Ann. Field Conf., p. 142- 147. Hunt, C. B., Varnes, H. D., and Thomas, H. E., 1953, Lake Bonneville-Geology of northern Utah Valley, Utah: U.S. Geol. Survey Prof. Paper 257-A, p. 1-99. NEW DATA ON THE ISOSTATIC DEFORMATION OF LAKE BONNEVILLE Kennedy, G. C., 1959, The origin of continents, mountain ranges, and ocean basins: Am. Scientist, v. 47, p. 491-504. Lofgren, B. E., 1955, Résumé of the Tertiary and Quaternary stratigraphy of Ogden Valley, Utah, in Eardley, A. J., ed., Tertiary and Quaternary geology of the eastern Bonneville basin : Utah Geol. Soc. Guidebook no. 10, p. 70-84. MacDonald, G. J. F., and Ness, N. F., 1960, Stability of phase transitions within the earth: Jour. Geophys. Research, v. 65, no. 7, p. 2173-2190. Morrison, R. B., 1961la, Correlation of the deposits of Lakes Lahontan and Bonneville and the glacial sequences of the Sierra Nevada and Wasatch Mountains, California, Ne- vada, and Utah, in Short papers in the geologic and hydro- logic sciences: U.S. Geol. Survey Prof. Paper 424-D, p. 122-124. 1961b, New evidence on the history of Lake Bonneville from an area south of Salt Lake City, Utah, in Short papers in the geologic and hydrologic sciences: U.S. Geol. Survey Prof. Paper 424-D, p. 125-127. Niskanen, E., 1948, On the viscosity of the earth's interior and crust: Ann. Acad. Sci. Fennicae, ser. A. 3, no. 15, 22 p. Nolan, T. B., 1935, The Gold Hill mining district, Utah: U.S. Geol. Survey Prof. Paper 177, 172 p. Raphael, J. M., 1954, Crustal disturbances in the Lake Mead area : U.S. Bur. Reclamation Eng. Mon. 21, 14 p. E31 Schaeffer, F. E., 1960, Stratigraphy of the Silver Island Moun- tains, in Schaeffer, F. E., ed., Geology of the Silver Island Mountains, Box Elder and Tooele Counties, Utah, and Elko County, Nevada : Utah Geol. Soc. Guidebook no. 15, p. 15-112. Slichter, L. B., and Caputo, Michele, 1960, Deformation of an earth model by surface pressures : Jour. Geophys. Research, v. 65, no. 12, p. 4151-4156. Smith, G. I., 1958, Late Quaternary stratigraphy and climatic significance of Searles Lake, California [abs.]: Geol. Soc. America Bull., v. 69, p. 1706. Varnes, David J., and Van Horn, Richard, 1961, A reinterpre- tation of two of G. K. Gilbert's Lake Bonneville sections, Utah, in Short papers in the geologic and hydrologic sci- ences: U.S. Geol. Survey Prof. Paper 424-C, p. 98-99. Vening Meinesz, F. A., 1937, The determination of the earth's plasticity from the post-glacial uplift of Scandinavia ; iso- static adjustment: Koninkl. Nederlandse Akad. Wetensch. Proc., v. 40, no. 8, p. 654-662. Williams, J. Stewart, 1952, Red Rock Pass, outlet of Lake Bonneville, [abs.] : Geol. Soc. America Bull., v. 63, p. 1375. Woollard, G. P., 1959, Crustal structure from gravity and seis- mic measurements: Jour. Geophys. Research, v. 64, no. 10, p. 1521-1544. 22 "7 3 (S Rel Ad -~ / "Chk" ** w£ .as / C CUA » . Z @& 1//~ (1/4454:/: Smaller Foraminifera From the Late Tertiary Of Southern Okinawa GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-F Smaller Foraminifera From the Late Tertiary Of Southern Okinawa By L. W. LEROY SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-F Treatment of Pliocene and Miocene smaller Foraminifera of southern Okinawa and their general stratigraphic relationships as assemblages UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 CONTENTS Page F1 | Correlation summary of Yonabaru and Katchin Hanto Introduction. 1 1 | General comments on Okinawan and South Pacific middle Stratigraphy c 3 and late Tertiary microfaunas-____________________- 3 | Bathymetric interpretation of the southern Okinawan Yonabaru Member of Shimajiri Formation-___. 3 S@CtIOML L c Loxzostomum pacificum fauna______________ 3 | Systematic descriptions______________________________ Nonion nicobarense-Cibicides macneili fauna _ 6 Family Rhizamminidae-______-______--_-_-------- Poorly developed calcareous T Family Arenaceous fAungccccccclccccccccccccll~ 7 Family Ammodiscid&e________________________-_-- Miocene or Pliocene________. o 7 Family Lituolid&ae.____________________________-- Shinzato Member of Shimajiri Formation___... T Family Textulariidae___________________________-- 8 Family Verneuilinidae-_____________-____-____----- Chinen Sand 8 Family Valvulinidae...---____________________-- Naha Limestone___________________________- 9 Family Silicinidae____________________________--- 10 Family Miliolidae______________________________- Yontan Limestone 10 Family Ophthalmidiidae-______________________-_-- Machinato Limestone______________________- 10 Family Stratigraphic summary of Yonabaru 1__._____________- 10 Family Polymorphinidae-_______________________- 10 Family Nonionidae.__._______________________-- 10 Family Nonion nicobarense-Cibicides macneili fauna Family Peneroplidae__________________________--- (O-1,250 ft) 1 10 Family Heterohelicidae._______________________--- Poorly developed calcareous fauna (1,250- Family Buliminidae____________________________- 2,450 ft) LLL 10 Family Ellipsoidinidae....____________________-- Arenaceous fauna (2,450-4,036 ft) _ __ ________- 10 Family Stratigraphic summary of Katchin Hanto 1._____--___. 12 Family 13 Family Naha Limestone (0-55 13 Family Chinen Sand (55-360 ft) 13 Family Cassidulinidae-_______-____--------------- Yonabaru Member of Shimajiri Formation Fam§1y Ch1195t°fn?lhdae """"""""""""" (360-1,900 ft) L LL 13 Famfly Globlgerlnlfiae --------------------------- Biostratigraphy._____________ccclccccccccccccccl 13 Family GIObOIOF a.ludae """""""""""""" - Family Anomalinidae.-_.---_-_______________----- Naha Limestone (0-55 ft)-_________________-- 13 Family Chinen Sand (55-860 ft)-_________________.--- 13 | Description of sample localities.___________________--- Yonabaru Member of Shimajiri Formation Selected (860-1,900 ft) L LLL 13 | Index of species. LLL. ILLUSTRATIONS [Plates 1-16 follow index] Prates 1-16. Smaller Foraminifera. FrcuRrE 1. Surface sample (field numbers) index map of southern 2. Generalized stratigraphic section of southern Okinawa showing major foraminiferal 3. Foraminiferal assemblages, 'X 10, of stratigraphic units of southern Okinawa. C, D, mainly planktonic species; Orbulina universa common. and ostracodes common. of feldspar associated with mafic minerals. Ot a A, B, shell fragments, bryozoa, E, F, clear grains G, H, restricted variety of Foraminifera; pyrite aggregates . Correlation of Yonabaru 1 and Katchin Hanto 1, southern . Stratigraphic ranges of some important arenaceous foraminiferal species in lower part of Yonabaru 1, southern Okinawa; ranges based on residue assemblages of ditch samples; only tops are considered accurate _______. 6. Suggested bathymetric variations of the southern Okinawan section based on benthonic Foraminifera ______. TABLE TABLE 1. Stratigraphic summary of Tertiary deposits of southern IH Page F14 14 15 15 15 15 15 17 17 18 18 19 19 21 21 27 27 28 28 29 29 36 36 39 40 40 41 42 483 43 46 46 48 53 Page F2 12 16 Page F3 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY SMALLER FORAMINIFERA FROM THE LATE TERTIARY OF SOUTHERN OKINAWA By L. W. LeRoy ABSTRACT Of the 333 species of smaller Foraminifera from the Miocene and Pliocene deposits (5,0004+ ft thick) of southern Okinawa that are described in this paper, 18 species and 5 varieties are new. 'The faunas of the Yonabaru Member (Miocene) of the Shimajiri Formation reflect a deep-neritic to bathyal environ- ment with the exception of the upper 1,500+ feet which is shallow neritic. The faunas of the overlying Shinzato Member (Miocene or Pliocene) of the Shimajiri represent an open-sea shallow-neritic environment and consist primarily of globigerine forms. The Foraminifera of the Chinen Sand (Pliocene) are very shallow neritic types and as an assemblage differ markedly from those of the Yonabaru and Shinzato. The Naha (Plio- cene) Foraminifera, restricted in both genera and species com- pared to the older units, represent a warm shallow-water en- vironment. Most of the recorded species commonly occur in Recent and late Tertiary sediments of the Central and South Pacific and Indo-Pacific regions. INTRODUCTION Okinawa, the largest island of the Ryukyu chain, is between long 127°38" and 129°20' E., and lat 26°04" and 26°52" N. It is 67 miles long, ranges in width from 2 to 15 miles, is oriented approximately N. 30° E., and is bounded on the east by the Philippine Sea and on the west by the East China Sea (fig. 1). The island is composed of two major geomorphic pro- vinces. The northern province, representing about three-fourths of the area, has a basement of Paleozoic sedimentary rocks that have 'been deformed, metamor- phosed, and intruded by various igneous types. These rocks produce a rugged matured relief. The southern province, comprising the remaining part of the island, is covered by shales, sandstones, and limestones of Miocene, Pliocene, and Pleistocene age that reflect low hills, broad valleys, and flat-topped, dissected, and faulted limestone plateaus ranging from 380 to 500 feet above sea level. Marine terraces, beaches, and fringing reefs occur intermittently along the coastlines. The Foraminifera of the late Tertiary deposits of southern Okinawa treated in this paper are based on surface samples collected by members of the U.S. Geo- logical Survey mapping party during 1946-48, and on continuous ditch samples from Yonabaru 1 (total depth, 4,036 ft) and the Katchin Hanto 1 (total depth, 1,900 ft). Both wells were drilled by the U.S. Navy for water. The samples, obtained at 10-foot intervals, were described, plotted, disaggregated through 20- and 150- mesh sieves, and the washed residues were examined for their microfaunal and mineralogical components. From these residues Foraminifera were selected, iden- tified, and checklisted. The illustrated specimens are deposited in the collection of the U.S. National Museum, Washington, D.C. Because of poor exposures, questionable structural control, and field-time limitations, no continuous sur- face section was measured or systematically sampled. Therefore, accurate stratigraphic placement of the microfaunas within each of the major stratal units was not possible. There are 333 species recorded in this paper, of which 18 species and 5 varieties are considered new. Previous work on the smaller Foraminifera of south- ern Okinawa is meager. Newton and Holland (1902) listed 36 species from a sandstone near the town of Itoman in southwestern Okinawa. The stratigraphic position of this fauna was not clarified. Hanzawa (1925) recorded 254 species from 9 randomly collected surface samples included within his Shimajiri Group, which unconformably underlies the "raised coral reef formation" (probably in part or total, the Naha, Yon- tan, and Machinato Limestones of the present paper). Hanzawa's faunas appear to be from the Shinzato and uppermost part of the Yonabaru Members as defined herein. ACKNOWLEDGMENTS Thanks are extended to F. C. Whitmore, Jr., F. S. MacNeil, P. E. Cloud, Jr., G. Corwin, and H. S. Ladd of the U.S. Geological Survey for their courtesies and interests during the preparation of this manuscript. I am deeply indebted to Ruth Todd of the U.S. Geologi- cal Survey for her comments and suggestions pertain- ing to the systematics of the report. The fullest credit F1 F2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY = Kerabaru e FSMm-440 TKRS -Z ® FSM-450 EAST CHINA SEA ® FSM-470 KATCHIN HANTO 1 ® WF-2720 BUCKNER BAY Futema Airfield e WF-2730 EXPLANATION Foraminiferal locality ol ® WF-2740 Chinen e RS-54A Shinzato Yonabaru (shallow facies) o ®r5-1290 I YONABARU 1 % "* Yonabaru Yonabaru (deep facies) Naha Airfield e RS-198 A fs-3306, ® RS-150 A Rs-322G e® e ® RS-197A @ RS-3240 RS-3146 e ... ® RS-149A & ® RS-196A o fm 120 C"" Fry -220 RS-152 A ML 168 ® FSM-31 © Rs'islo ®r3 -372 Q = Itoman RS-360 € a Philippine Sea ® RS-366 © e Rs-376 © oRS-3500 ® R5-377 0 i 1 2 3 = 4 5 MILES o 15 MILES L_L_L__J Index map of Okinawa FicUurE 1.-Surface sample (field numbers) index map of southern Okinawa. FORAMINIFERA FROM TERTIARY OF OKINAWA is given to J. R. Stacy, scientific illustrator of the U.S. Geological Survey, for the detailed illustrations of 275 species. J. D. Spart, also of the Survey, assisted in the illustration program and completed the drawings of T5 species. STRATIGRAPHY The Tertiary stratal units of southern Okinawa are summarized in table 1. TaBts 1.-Stratigraphic summary of Tertiary deposits of southern Okinawa [Modified after MacNeil, 1960] Post-Pleistocene : Raised beach deposits. Pleistocene : Thickness Ryukyu Group: (feet) Machinato Limestone_______________________ 0-100 Yontan Limestone 0-200 Pliocene : Naha Limestomne____________________________ 0-200 Chinen Sand _ 0-50 Rotorbinella chinenensis fauna Calcarina fauna Unconformity Pliocene or Miocene : Shimajiri Formation : Shinzato Member___________________________ 0-200 (@loborotalia punctulate fauna) Unconformity-(Major foraminiferal change) Miocene : Yonabaru Member (base not defined) ______ 4, 550+ Lozostomum pacificum fauna Nonion nicobarense-Cibicides macneili fauna Poorly developed Calcareous fauna ' Arenaceous fauna (Cyclammina, Schenckiella, Goesella, Ammodiscus, Glomospira, and Miliammina) * * In subsurface below 1,060 ft. in Yonabaru 1. The Shimajiri Formation includes the Yonabaru and Shinzato Members; the Shinzato represents the younger of the two members. The Yonabaru, which unconformably underlies the Shinzato, consists mainly of dark-gray shale, sandy shale, siltstone, and fine-grained shaly sandstone and is assigned to the Miocene. The basal limit of this mem- ber has not been defined. The lowest deposits of the Yonabaru were penetrated in Yonabaru 1. The Shinzato Member consists principally of soft light-gray foraminiferal shale and tuff. It lies uncon- formably below the Chinen Sand where tuff is present. Foraminifera are inconclusive in determining whether this member is late Miocene or Pliocene. On mollus- can evidence, MacNeil (1960) assigned it to Miocene or Pliocene. A major micropaleontologic break occurs at the Shinzato-Yonabaru boundary. The Ryukyu Group (Chinen Sand, N aha, Yontan, and Machinato Limestones) includes deposits of both F3 Pliocene and Pleistocene age (table 1). According to MacNeil (1960) considerable lateral variation is ex- hibited in the Chinen and Naha part of the section. The Yontan and Machinato Limestones are also non- homogeneous. At some localities the Chinen Sand is absent because of unconformity relation ; in other areas it appears to grade laterally into carbonates similar to those in Naha. Normally the Chinen overlies the Shinzato ; locally it is in contact with the Yonabaru as in the Katchin Hanto 1 at a depth of 360 feet. Because of inadequate surface and subsurface struc- tural control, lack of dip data in the Yonabaru well, poor outcrops, and nondefinition of the base of the Yonabaru Member and possibly older formations, the thickness of the Tertiary sequence of southern Okinawa is undetermined. At least 5,200 feet of section is be- lieved to be involved in the study presented in this paper, provided contemporaneous deformation is non- existent and stratal dips in the Yonabaru well do not exceed 10°. The relation of the major formational and faunal units is believed to be correct; however, further analyses of the section with better stratigraphic and structural control could modify some of the comments and interpretations here given. MIOCENE Miocene strata, represented by the Yonabaru Mem- ber of the Shimajiri Formation, are exposed widely in southern Okinawa and consist of alternate shallow- to deep-neritic fine-grained clastic deposits Only the upper 4,550+ feet of the member is treated in this paper. YONABARU MEMBER OF THE SHIMAJIRIL FORMATION The Yonabaru consists mainly of dark-gray shale containing interbeds of siltstones and fine- to medium- grained sandstones. It is overlain unconformably by tuffs and tuffaceous shales of the Shinzato Member or sandstones of the Chinen. The lower limit of the mem- ber and its relation to older deposits is not known. These deposits are complexly faulted according to Mac- Neil (1960). The Yonabaru as studied is divided (fig. 2) into four stratigraphically diagnostic foraminiferal assemblages, which from the youngest to the oldest are: (a) Lozo- stomum pacificum fauna (surface), (b) Nonion nico- barense-Cibicides macneili fauna (surface and subsur- face), (c) poorly developed calcareous fauna (subsur- face), and (d) arenaceous fauna (subsurface). LOXOSTOMUM PACIFICUM FAUNA This fauna appears to be the youngest of the Yona- baru assemblages; however, further work may place it within the section penetrated in the upper 1,250 feet of F4 sap MACHINATO (20-100 ft) Peistocens ____YONTAN (100 ft)] Rotorbinella chinenensis NAHA (100 it / Calearina - spp Pliocene - CHINEN (5-30 ft) - SHINZATO (60-100 ft) punshdats § YONABARU Lozostomum pacificum 'C L_ ___ L222 L_ ___ S/ # @ & @ 3 ||: Feet = nore £ -0 g. g Nonion micobarense 2 Cibicides macneili 0 12. |- 500 -1000 Feet 1250 :| Sandstone A Surface section not |-1500 :| exposed below this point Foraminifera scarce Related to assemblages above -2000 Sandstone -B 1.7 Major faunal break 2320 2450 4 Adercotryma glomerata |-2500 2730 | Cyclammina sp A 4 Sandstone C 27757| Schenckiella okinawaensis Sandstone D Sandstone E 3170 - Cyclammina ezcensis 3300 - Goesella schencki 3420 - Glomospira |-3500 glomerata 1 Sigmoilina schlumbergeri Orbulina _ universa Well developed present Total depth 4020 ft FicurE 2.-Generalized stratigraphic section of southern Okinawa showing major foraminiferal subdivisions. the Yonabaru well. That the Foraminifera are shal- low-neritic warm-water types is further substantiated by their association with water-worn molluscan frag- ments, polished rock particles, ostracodes, bryozoan debris, and glauconite. According to MacNeil (1960) the Yonabaru mollusks indicate moderately shallow to moderately deep water-probably not exceeding 300 fathoms for the deeper facies. Unweathered horn- blende and feldspar are common in the washed residues. Foraminifera listed as follows represent an average assemblage of this fauna. Species marked by an asterisk (*) appear to be most diagnostic. C= common, +50 specimens; R=rare, 10-50 specimens; S=scarce, less than 10 specimens. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Amphistegina madagascariensis d'Orbigny________________ wanneriana Fischer Anomalina bradyt Said __ glabrata * Asterorotalia trispinosa (Thalmann) ___________________- *Baggina totomiensis Makiyama_______________________- Bolivinita quadrilatera (Schwager) (large var.) ___________ . Bulimina inflata Seguengzac __ Cassidulina inflata LeRoy okinawaensis LeRoy, n. sp Cibicides macneili LeRoy, n. sp-_______________________- pseudoungeriamnus (Cushman) -______________________ Clavulina yabei akiensis Asano_________________________- Eggerella bradyi (Cushman) -__________________________- Elphidium fax bararbense Nicol (small var.) ___-_________- Eponides praecintus (Karrer) procerus (H. B. Brady) subornatus (Cushman) *Gaudryina siphonifera (H. B. Brady) -_________________-- Globoquadrina altispira (Cushman and Jarvis) _______-__ _. Globigerina bulloides d'Orbigny ____________________-___--- dubia Egg@PLLLLLLLLLLLL L222 Globigerinoides triloba immatura LeRoy________________ _- Globorotalia menardii multicamerata Cushman and Jarvis___ tumida (H. B. Brady) (large var.)________________--- Gyroidina altiformis R. E. and K. E. Stewart____________- *Hanzawaia nipponica Asano__________________________- Hoeglundina elegans (d' Orbigny) _______________________- Lagenonodosaria scalaris (Batsch) _____________________--- *Loxostomum pacificum LeRoy, n. sp-__________________- *Marginulinopsis nozimaensis (Asano) ________________ _- - *Neoconobina opercularis pacifica LeRoy, N. Nodosaria insecta Schwager acuminata Hantken var. uniforminata LeRoy________. vertebralis (Batsch) var. albatrossi____________ ___ ___ - Nonion pompilioides (Fichtel and Moll) var. okinawaense LeRoy, N. Operculina gaimairdi (d'Orbigny) ______________________- Orbulina universa *Planorbulinella larvata (Parker and Jones) _.________----.- Pullenia bulloides (d'Orbigny) _ ________________________- Quinqueloculina akneriana d'Orbigny __ contorta d'Orbigny c L carinata Rectobolivina bifrons (H. B. Brady) *Reussella spinulos@ (Reuss)___________________--------- Robulus calcar (Linng) ______________cclclcccclccccccccc~~- *Rotalidium okinawaensis LeRoy, n. sp-__________-_------ Rotalia stacht AS&RO________________cccccccccccccc~~~-- Schenckiella communis (d' Orbigny) -___________________--- Sigmoilina schlumbergeri A. Silvestri________________----- Siphogenerina raphanus (Parker and Jones) __ Sphaeroidina bulloides d'Orbigny_.________________------- Sphaeroidinella seminulina (Schwager) ____________-_-_-_----- *Spiroloculina communis Cushman-_________________----- Stilostomella lepidula (Schwager) __________________------ *Textularia sagittula Defrance var. fistulosa H. B. Brady. *Triloculina tricarinata d'Orbigny__________________-__---- *Trifarina bradyi Uvigerina crassicostata Schwager _____________________-_-- striatell@ Reuss L *gemmaeformis. SChwWAger-_______________________--- peregrina Cushman var. dirupta Todd_________-__-- -- *Vaginulina yoshthamaensis Inoue and Nakaseko._-__.__-- FORAMINIFERA FROM TERTIARY OF OKINAWA F5 FIGURE 3.-Foraminiferal assemblages, X 10, of stratigraphic units of southern Okinawa. A, B, Chinem Sand; shell fragments, bryozoa, and ostracodes common. C, D, Globorotalia punctulata fauna of Shinzato Member; mainly planktonic species; Orbulinae universe common. E, F, Lowostomum pacificum fauna of Yonabaru Member; clear grains of feldspar commonly associated with mafic minerals. nicobarense-Cibicides macneili fauna of Yonabaru Member; restricted variety of Foraminifera; pyrite aggregates common. G, H, Nonion F6 Amphistegina madagascariensis d'Orbigny, A. wan- neriana Fischer, Asterorotalia trispinosa (Thalmann), Eponides praecintus (Karrer), Operculina gaimairdi (d'Orbigny), Planorbulinella larvate (Parker and Jones), and SipAogenerinae raphanus (Parker and Jones) infer that the Lozostomum pacificum fauna, for the most part, developed under tropical to subtropical shallow-neritic conditions. NONION NICOBARENSE-CIBICIDES MACNEILL FAUNA West of Buckner Bay, sedimentary rock containing this fauna crops out extensively; it is also well repre- sented in the Yonabaru and Katchin Hanto wells be- tween 0 and 1,250 and 360 and 1,675 feet respectively. The deposits consist principally of dark- to bluish- gray shale and sandy shale with a few thin fine- to medium-grained graywacke-type sandstones. Washed residues contain considerable amounts of pyritized plant remains. The fauna is distinct from that of the overlying Lozgostomum pacificum assemblage, although a few species are common to both. Species diagnostic to this fauna are indicated by asterisks (*). *Bolivina plano-conveza Cushman and Todd______________ S robusta H. B. Brady__________________ ne cece C *Bolivinita quadrilatera (Schwager) (small var.)__________._ R *Bolivinopsis hiratat C *Bulimina gutta C inflata C *Chibicides macneili LeRoy, n. sp-______LLLLLLLLLLLLLLLL_ C haidingerii (d'Orbigny) var. pacificus (Cushman) ___. C pseudoungerianus (Cushman) C wuellerstorfi (Schwager) R Eggerella (Cushman) - C Eponides hyalinus (Hofker) __ _______LLLLLLLLLLLLLLLLLOL R *Globoquadrina altispira (Cushman and Jarvis) _ __________ C Globigerina bulloides d'Orbigny ._ __________LLLLLLLLLLLL__ C dubia C *Globigerinoides mitra Todd ____________________________ S triloba immatura LeRoy-_L C Globorotalia menardii multicamerata Cushman and Jarvis___ R tumida (H. B. Brady) (small var.) __________________ S Gyroidina cibacensis Bermudez R trincherasensis R *Hoeglundina elegans (d'Orbigny).______________________ C Nodosaria subtertenuata Schwager __________________.____ C *Nonion nicobarense Cushman-____L__LLLLLLLLLLLLLLLL__ C Orbulina universa d'Orbigny (small var.)_________________ C *Osangularia bengalensis (Schwager) _____________________ R Pleurostomella alternans Schwager-______________________ R Pseudoeponides umbonatus (Reuss) ______________________ R Pullenia bulloides (d'Orbigny) _ __________LLLLLLLLLLLLLL_ R Pyrgo murrhina (Schwager) - R Quinqueloculina akneriana d'Orbigny _ ___________________ R *Schenchkiella communis (d'Orbigny) hosoyaensis (Asano) -__ C *Sigmotilina schlumbergert A. Silvestri____________________ C Siphotextularia flintii Cushman var. pacifica LeRoy, n. var-. R Sphaeroidina bulloides d'Orbigny________________________ R SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Sphaeroidinella seminulina (Schwager) __ C Spiroloculina ctrcularis Cushman-________________________ S Stilostomella lepidula (Schwager) ________________________ C *Uvigerina peregrina Cushman var. dirupta Todd________ C proboscidea Schwager var. vadescens Cushman.-_______. R In addition to the above species, the following were observed in the upper part (0-1,250 ft) of the Yona- baru well. Amphistegina madagascariensis d'Orbigny____________ ___. S Bulimina subaffinis S subcalva Cushman and Stewart_____________________ S Calearina rustica Todd and Post________________________ S Cassidulina orientale Cushman-____________LLLLLLLLLL___ R pacifica C Chilostomella colina Schwager.__________________________ S Cibicides shinzatoensis LeRoy, n. sp-____________________ S Clavulina yabei akiensis Asano__________________________ S Elphidium fax barbarense Nicol (small var.) ____________ _- S Eponides praecintus (Karrer) ___________________c___QQ__ S procerus (H. B. Brady) S subornatus S Globigerinella aequilateralis (H. B. Brady)-____________-- _- S Globobulimina pacifica Cushman. S *Gyroidina neosoldanit _- S Laticarinina pauperata (Parker and Jones) __ S Operculina gaimairdi S Quinqueloculina carinata d'Orbigny-_____________________ S Rectobolivina bifrons (H. B. Brady) var. striatule (Cush- R Rectuvigerina striata (Schwager) _________________________ S Schenckiella communis (d'Orbigny) ____________._________ R Trifarina bradyi S Uvigerina crassicostata Schwager-______________________-- S hispida Schwager. LL R Microfaunal evidence suggests that the sediments of this part of the Yonabaru accumulated under alter- nately subtropical shallow- to deep-neritic conditions but in deeper water than that typified by the Lowosto- mum pacificum fauna. Species absent or rare in this assemblage, but which occur abundantly in the @loborotalia punctulata fauna of the Shinzato Member, include : Anomalina bradyi Said Bolivina albatrossi Cushman Bulimina aculeata d'Orbigny marginata d'Orbigny yonabaruensis LeRoy, n. sp. Candeina nitida d'Orbigny Cibicides fijiensis (Cushman) okinawaensis LeRoy, n. sp. Discanomalina japonica Asano Globigerinoides triloba fistulosa (Schubert) Globorotalia punctulata (d'Orbigny) Hyalinea baithica (Schroeter) Pulleniatina obliquiloculata (Parker and Jones) Rectobolivina dimorpha (Parker and Jones) Schenckiella victoriensis (Cushman) Sphaeroidinella dehiscens (Parker and Jones) Uvigerina aculeata d'Orbigny Vagocibicides nipponicus Asano Vulvulina pacifica Cushman FORAMINIFERA FROM TERTIARY OF OKINAWA POORLY DEVELOPED CALCAREOUS FAUNA This fauna was penetrated in the Yonabaru well be- tween 1,250 and 2,450 feet. The strata in this interval are extremely arenaceous and contain poorly developed foraminiferal assemblages having affinities with the overlying Nomion nicobarense-Cibicides macneili fauna. The details of this assemblage could not be determined because of ditch sample contamination. ARENACEOUS FAUNA This fauna was penetrated in the Yonabaru 1 be- tween 2,450 and 4,036 feet. Medium-gray shales and several thin graywacke-type sandstones occupy the in- terval. The top of the fauna marks a conspicuous foraminiferal change within the Yonabaru section (fig. 2) by the prominent introduction of Adercotryma, Cy- clammina, Schenchiella, Goesella, Glomospira, Ammo- discus, and Miliammina. Species frequent in this assemblage are listed as fol- lows. Those indicated by an asterisk (*) appear to be stratigraphically restricted. *Adercotryma glomerata (H. B. Brady)-__________________ C *Ammodiscus dominicensis var. deformis Bermudez.________ R Bolivinopsis hiratat R Bulimina inflata Seguenzac cc S subaffinis S *Cyclammina ezoensis Asano C sp. A. R Eggerella bradyi (Cushman) _. R Globigerina bulloides d'Orbigny__________L_______________ C dubia C Globigerinoides mitra Todd__.__________________________ S triloba immatura LeRoy______LLLLLLLLLLLLLLLLLLLLL__ C *Glomospira glomerata C *Goesella schencki R Hoeglundina elegans (d'Orbigny) ________________________ S *Miliammina echigoensis Asano and Inomata_____________ S Orbulina universa d'Orbigny cL R Pseudoeponides umbonatus (Reuss) __ ____________________ S Schenckiella communis (d'Orbigny) hosoyaensis (Asano).__ ___ R okinawaensis LeRoy, n. sp R victoriensis Cushman. R Sigmoilina schlumbergeri A. Silvestri____________________ C Sphaeroidinella seminulina (Schwager) ___________________ R Uvigerina hispida Schwager ____LLLLLLLLLLLLLLLLLLL____ S peregrina Cushman var. dirupta Todd_______________ R proboscidea Schwager var. vadescens Cushman. R The microfauna and lithology of this interval suggest the sediments accumulated under deep-neritic to shal- low-bathyal conditions. The rock containing this fauna does not crop out in southern Okinawa. The age of these deposits based on the general foraminiferal assemblages is assigned tentatively to the late Miocene, although a middle Miocene allocation would not be unreasonable. The lowest ditch samples in Yonabaru 1 appear to contain large forms of Orbulinae universe d'Orbigny; therefore, these strata are inferred to lie F7 above the Orbulina surface (LeRoy, 1948) which is placed at the base of the middle Miocene in cen- tral Sumatra. In the Caribbean region, Orbulina extends through the late Oligocene. In the Mediter- ranean area its lowest extent marks the Oligocene-Mio- cene boundary. These discrepancies may be due to inaccurate usage of the European terminology in terms of chronological contemporaneity rather than to the time value of the lowest occurrence of this planktonic genus in a continuously deposited deep-sea stratal sequence. MIOCENE OR PLIOCENE SHINZATO MEMBER OF THE SHIMAJIRI FORMATION The Shinzato, assignable to either late Miocene or Pliocene, consists primarily of light- to medium-gray shaly tuff and silty shale lying unconformably above the Yonabaru Member and separated from the over- lying Pliocene Chinen Sand or Naha Limestone by an unconformity. The deposits are characterized by the distinct well- developed foraminiferal fauna listed as follows. Species marked by an asterisk (*) are seemingly diag- nostic of the member. A=abundant, more than 100 specimens. Anomalina bradyt Said _L LLLLLLLLLLLLLLLLLLLLLLLLLLLLL R *Bolivina albatrosst R robusta H. B. C *spinescens S Bolivinita quadrilatera (Schwager) (large var.) ____________ S *Bulimina aculeata d'Orbigny c _ R inflata c R marginata d'Orbigny cL S *Candeina nitida d'Orbigny c C *Cassidulina okinawaensis LeRoy, n. sp__________________ C orientale Cushman L LL R *pacifica C subglobosa H. B. C *Cibicides fijtensis (Cushman) _____LLLLLLLLLLLLLLLLLLLL__ R lobatulus S *okinawaensis LeRoy, n. sp R pseudoungerianus (Cushman) L_ C (Schwager) R *Discanomalina japonica S Eggerella bradyi (Cushman) - R Elphidium fax barbarense Nicol_ ________________________ -S Eponides hyalinus (Hofker) __ R Globigerina bulloides d'Orbigny c L _ _ A dubia A Globigerinella aequilateralis (H. B. Brady).______________. R *Globigerinoides ruber (d'Orbigny) (large var.) ____________ A triloba immatura A RAstulosa R *Globorotalia tumida (H. B. Brady) (large var.)___________ A menardit multicamerata Cushman and _. C praemenardii Cushman and Stainforth_______________ R *punctulata (d'Orbigny) . A Gyroidina cibaoensis S trincherasensis Bermudeg_________________LLLLLLL___ C F8 Hoeglundina elegans (d'Orbigny) R Hyalinea balthica S Karreriella bradyi (Cushman) Lagenonodosaria sealaris (Batsch) _____________LL_L_LLL__ C Lozostomum amygdalaeformis (H. B. Brady) var. tokense S Nonion pompilioides (Fichtel and Moll) S pompilioides (Fichtel and Moll) var. okinawaense LeRoy, n. S *Orbulina universa d'Orbigny (large var.)--______________ A Osangularia bengalensis (Schwager) (large var.)___________ S *Patellinella jugosa (H. B. Brady) -______________________ S Pleurostomella alternans Schwager-_____LLLLLLLLLLLLLL___ R brevis S Pullenia bulloides (d'Orbigny) _ R *Pulleniatina obliquiloculata (Parker and Jones) ___________ C Pyrgo murrhina S *Ramulina globulifera H. B. S *Rectuvigerina striata (Schwager) _______LLLLLLLLLLLLLLLLL S Rectobolivina bifrons (H. B. Brady) var. striatula (Cushman). _ R dimorpha (Parker and S Rectoglandulina laevigata (d'Orbigny) S Rotalidium okinawaensis LeRoy, n. sp-_-_______L_LL_____ S Schencktella victoritensis (Cushman) ___ ___LLLLLLLLLLLLLLLL, S Sigmoilina schlumbergeri A. Silvestri-______LLLLLLLLLLLL__ R *Siphonina australis R Siphotextularia flintii (Cushman) var. pacifica LeRoy, n. var-. _ S *Sphaeroidinella dehiscens (Parker and Jones) __ A Stilostomella lepidula (Schwager) C Trifarina bradyi Cushman R *Uvigerina aculeata d'Orbigny L R nitidula R proboscidea Schwager var. vadescens Cushman.-_-____. R *Vagocibicides nipponicus Asano. S *Vulvulina pacifica R Foraminifera of the Shinzato Member appear to have developed under a moderately deep neritic open-sea subtropical to tropical environment. Many species of the middle and late Tertiary and Recent deposits of the Indo-Pacific Islands, as well as those of the late Tertiary of Japan and the Philippines, are well repre- sented in the fauna. The Shinzato assemblage is designated in this paper as the G@loborotalia punctulate fauna. The benthonic species are exceptionally well developed as are the planktonic forms @lobigerinoides ruber (d'Orbigny), G. triloba fistulosa (Schubert), G. mitra Todd, G@lobo- quadrina altispirae (Cushman and Jarvis), Orbulina universa d'Orbigny, Candeina nitida d'Orbigny, G@lo- borotalia tumida (H. B. Brady), G. menardii multi- camerata Cushman and Jarvis, Pullemiatina obliqui- loculata (Parker and Jones), and Sphaeroidinelle dehiscens (Parker and Jones). The stratigraphic range of these planktonics should be carefully con- sidered in future biostratigraphic work in the Western, Southern, and Central Pacific, in establishing long- range time correlations within late Tertiary deposits of these regions. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY PLIOCENE CHINEN SAND The Chinen has a restricted areal distribution in the southeastern part of the island. It rests unconform- ably on either the Yonabaru or the Shinzato deposits, is overlain unconformably by the Naha Limestone, and consists mainly of bluish-gray to tan fine-grained sandstones and siltstones. In Katchin Hanto 1, the formation was penetrated between 55 and 360 feet and is in unconformable contact with the deepwater Nomion nicobarense-Cibicides macneili fauna of the Yonabaru Member. The Foraminifera are varied in both species and genera, many of which, particularly those in the upper part of the formation, are small compared to those in the underlying Shinzato. Several Shinzato forms occur in the lowermost part of the Chinen due to re- working. Based on well cuttings from Katchin Hanto well and surface samples, and discarding the possibility of re- worked species from pre-Chinen strata, the following listed forms occur frequently in the deposit. Those marked by an asterisk (*) seemingly are restricted. Amphistegina madagascariensis R wanmeriana Fischer S Angulogerina japonica Asano S Anomalina glabrata S Baggina totomiensis MakiyamaLL_L___LL_LLLLLLLLLLLLLO_ S Bolivina albatross? S Bolivinita quadrilatera (Schwager) (small var.)__________-- S Bulimina inflata Seguenza LLL S marginata d'Orbigny _ s subaffinis S Buliminoides williamsonianus (H. B. Brady) __________-__-- R Calcarina rustica Todd and Post________________________ R spengleri (Gmelin) cL R Cancris auriculus (Fichtel and Moll) S Candeina nitida d'Orbigny c _ s] Cassidulina orientale Cushman-_.____LLLLLLLLLLLLLLLLL__ R Chilostomella oolina Schwager-_________________________- s Cibicides lobatulus (d' Orbigny) _________________________- R pseudoungerianus (Cushman) ______________________- S tenuimargo (H. B. Brady) _________________________- S Ehrenbergina bosoensis var. decorata Takayanagi_______-.. R Elphidium fax barbarense Nicol_______________________--- R jenseni (Cushman) R Eponides praecintus (Karrer) R subornatus (Cushman) R Globigerina bulloides d'Orbigny _ _______________________- R dubia R Globigerinella aequilateralis (H. B. Brady) ____________---- S Globigerinoides ruber (d' Orbigny) _______________________- R triloba immatura R Globobulimina pacifica Cushman... en eee ece S Globorotalia menardii multicamerata Cushman and Jarvis___ R punctulata (d'Orbigny) . LL R tumida (H. B. Brady) R Gypsina globula (Reuss) S FORAMINIFERA FROM TERTIARY OF OKINAWA Hanzawaia nipponica Asano S Hoeglundina elegans (d'Orbigny) R Hyalinea balthica (Schroeter) S Lagenonodosaria sealaris (Batsch) _____________LLLLLLLL__ S Lozostomum amygdalaeforme (H. B. Brady) var. tokense S Neoconobina opercularis (d'Orbigny) _____________LLL_____ S *nakamurat (Asano) - S pacifica LeRoy, n. R Nodosaria insecta Schwager _c S longiscata S Nonion akitaensis (Asano) ___ S japonicum (Asano) _L S Operculina gaimairdi R Orbulina universa S Patellinella jugosa (H. B. Brady) -______________L_LLLL___ S Planorbulinella larvata (Parker and Jones) ___ ____________ S Pulleniatina obliquiolculata (Parker and Jones) ____________ S Quinqueloculina akneriana d'Orbigny _ ___________________ R elongata R carinata C Rectobolivina bifrons (H. B. Brady) var. striatule (Cushman). S virgula (H. B. Brady) - S *Rotorbinella chinenensis LeRoy, n. sp-__________________ C Rotalidium okinawaensis LeRoy, n. sp-_________LLLLL____ S Reussella spinulosa (Reuss) R Siphogenerina raphanus (Parker and Jones) _ _ ___________. R Siphonina australis S Siphotextularia flinti? (Cushman) var. pacifica LeRoy, n. var. S Sphaeroidina bulloides d'Orbigny________________________ S Sptroloculina communis R Stilostomella lepidula (Schwager) _ _______________________ S Streblus beccarit tepida (Cushman) _- -___________________ R Textularia candeina -S sagittula Defrance var. fistulosa (H. B. Brady) _______. S Trifarina bradyi Cushman. S Triloculina tricarinata S Uvigerina striatella Reuss S proboscidea Schwager var. vadescens Cushman________ S Ostracodes, bryozoans, and molluscan fragments are common. The presence of Amphistegina madagascar- tensis d'Orbigny, A. wanneriana Fischer, Calcarina rustica Todd and Post, C. spengleri (Gmelin), Epon- ides subornatus (Cushman), Gypsina globula (Reuss), Hanzawaia mipponica Asano, Operculina gaimairdi d'Orbigny, Planorbulinellae larvate (Parker and Jones), Siphogenerina raphanus (Parker and Jones), and Streblus beccarii tepida (Cushman) indicate these sediments accumulated under shallow-water subtropical environments. Chinen assemblages differ from those of the under- lying Shinzato by the absence or poor development of Anomalina bradyi Said, Bulimina aculeata d'Orbigny, Cassidulina pacifica Cushman, Cibicides fijiensis (Cushman), Eggerella bradyi (Cushman), Globigeri- noides triloba fistulosa (Schubert), Globorotalia pune- tulate (d'Orbigny), Karrerielle bradyi (Cushman), Pullenia bulloides d'Orbigny, Pulleniatina obliquilo- culina (Parker and Jones), Nigmoilina schlumbergeri A. Silvestri, SpAhaeroidinella dehiscens (Parker and FQ Jones), Uvigerina aculeata d'Orbigny, and Vulvulina pacifica Cushman. NAHA LIMESTONE The Naha consists of gravel, coarse-grained car- bonate sand, bluish-gray shale, argillaceous sand, and sandy to pure hard dense to porous brecciated coral- algal limestone. Recrystallization of the limestone has occurred throughout but to a much greater degree at and near the surface of present exposures. The formation ranges in thickness from 0 to about 200 feet, the latter probably close to its original maximum thickness. The Naha rests on the Shinzato Member where the Chinen Sand is absent as a result of either unconform- ity or facies change. Because of ground-water leaching, the Foraminifera are poorly preserved. Those most common in the formation are: Amphistegina madagascariensis d'Orbigny________________ S Anomalina glabrata S Baggina totomiensis S Bolivina striatula S Buliminoides williamsonianus (H. B. Brady) _____________ S Bulimina marginata d'Orbigny S Cancris communis Cushman and Todd___________________ S Calcarina rustica Todd and Post________________________ S spengleri (Gmelin) L S Cassidulina pacifica Cushman S Cibicides lobatulus (d'Orbigny) R pseudoungerianus (Cushman) L_LLLLLLLLLLLLLLLLLLL__ S Clavulina yabet oktiensis S Cymbaloporetta bradyi (Cushman) S Ehrenbergina bosoensis var. decorata Takayanagi__________ S Elphidium fax barbarense Nicol _ __________________LL____ R Eponides margaritiferus (H. B. Brady) ___________________ S praecintus (Karrer) R subornatus (Cushman) R Globigerina bulloides d'Orbigny _ ________L__LLLLLLLLLL_L S dubia S Globigerinoides ruber (d'Orbigny) ____________LLLLLLLLL___ S triloba immatura LeRoy S Globorotalia menardii multicamerata Cushman and Jarvis___ S tumida (H. B. Brady) S Hanzawaia nipponica Asano______LLLLLLLLLLLLLLLLLLL_L s Lozostomum amygdalaeforme (H. B. Brady) var. S Orbulina universa S Planobulinella larvata (Parker and Jones) _.______________. R Quingqueloculina akneriana d'Orbigny _ ___________________ S carimata d'Orbigny c S Reussella spinulosa S Rotalia stacht Asano R Siphogenerina raphanus (Parker and Jones) ______________ R Streblus beccarit tepida (Cushman) -_____________________ S Uvigerina striatella Reuss ____LLLLLLLLLLLLLLLLLLLLLOLOL S proboscidea S Coral, algal, bryozoan, and molluscan fragments are common; ostracodes occur in limited numbers. The Naha Limestone appears to contain fewer genera and F10 species of Foraminifera than the underlying Chinen Sand, but all those occurring in the formation have been observed in the Chinen. PLEISTOCENE The Pleistocene deposits are included within the Ryukyu Group that consists of the Yontan and Machi- nato Limestones. YONTAN LIMESTONE This limestone, according to MacNeil (1960), is sim- ilar to the Naha but in general is coarser textured. It is highly porous to dense and has a maximum thickness of about 200 feet-average thickness about 40 feet. Intertongues of gravel are numerous. In places (where its lower contact was observed) it rests on Paleozoic rocks, on shales and tuffs of the Shimajiri, or on the Naha. The Foraminifera of this deposit were not studied. MACHINATO LIMESTONE This unit consists of foraminiferal sands, conglom- erate, and detritus composed of coral and mollusks. The Foraminifera of this deposit are not treated in this paper. STRATIGRAPHIC SUMMARY OF YONABARU 1 Yonabaru 1, drilled by the U.S. Navy in 1946 in southern Okinawa (fig. 1), penetrated Yonabaru de- posits between 0 and 4,036 feet (fig. 4). LITHOSTRATIGRAPHY (On the basis of controlled ditch cuttings and their washed residues, four major lithologic units were rec- ognized in the well. Lithologic description of Yonabaru 1 Depth (feet) Shale, siltstone, and sandstone, interbedded, sandy. Shale and siltstone are dark gray to medium gray. Sandstone is gray, fine to medium grained, of graywacke to subgraywacke type. Two sandstones (A and B) occur between 1,250 and 1,400 ft and 2,180 and 2320 ft, re- spectively. Both beds contain considerable argillaceous matrix, mafic minerals, and dark rock fragments. A thin dark-red shale was found at 2,050 Shale, dark- to medium-gray. The strata in this interval begin the dominantly argillaceous part of the well section-__________________________ 2, 320-2, 775 Shale and sandstone; consists of dark- to medium- gray shale and fine to medium-grained gray- wacke sandstone which occur in approximately equal amounts. The most important sandstones in the interval are designated as C (2,775-2,850 ft), D (2,975-3,030 ft), and E (3,120-3,170 ft)-2,775-3,170 Shale, dark- to medium-gray and a few minor fine grained thin-bedded sandstones. A dark-red shale, similar to that at 2,050 ft, is present in the lower part (3,780 ft) ____________________ 3, 170-4, 036 0-2, 320 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY BIOSTRATIGRAPHY Only the lower three of the four previously dis- cussed (p. F3) foraminiferal faunas of the Yonabaru Member occur in this well and from youngest to oldest are as follows: NONION NICOBARENSE-CIBICIDES MACNEILL FAUNA (0-1,250 FT) The Foraminifera contained in these deposits are well represented by both genera and species and are the same as those that occur in outcrop. The base of the deposit that contains this predominantly calcareous fauna lies approximately at the top (1,250 ft) of sand- stone A. The assemblages indicate alternately shal- low- and deep-neritic tropical to subtropical conditions of sedimentation. The exact stratigraphic positions of the various assemblages within the interval cannot be placed because of contamination by recirculated cuttings. Shallow-water deposits are suggested by such species as AmpAistegina madagascariensis d'Or- bigny, Calcarina rustice Todd and Post, E'ponides praecintus (Karrer), E. procerus (H. B. Brady), Plan- orbulinella larvata (Parker and Jones), and Penerop- lis pertusus (Forskal). The deeper water deposits are indicated by such forms as Bolivinopsis Mratai Uchio, Bulimina gutte Chapman and Parr, B. inflata Seguenza, Eggerella bradyi (Cushman), Nonion nico- barense - Cushman, - Pseudoeponides _ umbonatus (Reuss), and Uvigerina pereginae Cushman var. di- rupta Todd. Other well-represented species in these deposits are Bolivinita quadrilatera (Schwager), Bulimina sub- calva Cushman and Stewart, Cibicides pseudoungeri- anus (Cushman), @Gyroidinae meosoldanii Brotzen, G@loborotalia tumida (H. B. Brady), Hoeglundina elegans (d'Orbigny), Schenchiello communis (dOr- bigny) Aosoyaensis (Asano), Nodosaria insecta Schwager, N. longiscata d'Orbigny, N. tosta Schwager, Orbulina universa d'Orbigny, Rotalia: stachi Asano, Sigmoilina schlumbergeri A. Silvestri, Sphaeroidinella seminulina - (Schwager), - Stilostomella - lepidula (Schwager), and Uvigerina proboscidea Schwager var. vadescens Cushman. POORLY DEVELOPED CALCAREOUS FAUNA (1,250-2,450 FT) Foraminifera contained in these deposits are similar to those between 0 and 1,250 feet but are restricted in the number of individuals per species because of the arenaceous nature of the section. Many of the re- corded species could have resulted from sample con- tamination from stratigraphically higher levels. ARENACEOUS FAUNA (2450-4,036 FT) A conspicuous microfaunal change occurs in the see- tion at 2,450 feet. Several new arenaceous genera and FORAMINIFERA FROM TERTIARY OF OKINAWA YONABARU 1 t YONABARU MEMBER (no dip control) Gray sandy shale and sandstone I J CALCAREOUS FAUNA WELL DEVELOPED POORLY DEVELOPED CALCAREOUS FAUNA Gray shale Shale and sandstone Shale with minor sandstone ARENACEOUS FAUNA WELL DEVELOPED Fee 0 Red clay 2180 Sandstone B 2320 t ho 450 Top Adercotryma glomerata \ Deepwater fauna below this point - 2730 Cyclammina sp A { Sandstone C 34-2850 Schenckiella okinawaensis 2975 3030 3 Sandstone D i70 Sandstone E 1 No /s Cyclammina exoensis 3300-Goesella schencki - 3420 Glomospira glomerata - 3520 | Eggerella bradyi frequent |- 3620 3500 - [ 4 Red clay ORBULINA UNIVERSA PRESENT 4000 - TO TOTAL DEPTH _FigurE 4.-Correlation of Yonabaru 1 and Katchin Hanto 1, southern Okinawa. of Katchin Hanto 1, 1,900 feet. Sigmoilina schlumbergeri frequent KATCHIN HANTO 1 _Feet Feet 55 NAHA LIMESTONE z Rotorbinella chinenensis| $9 T< 280 - 5" g Calcarina spp. o 645 - 760 a lud m a 3 9 L +7 = 5 3 a 4C 28 Z 1450 P2 1675 1800 0 12 MILES Korn INDEX MAP Total depth of Yonabaru 1 is 4,036 feet and Lithologic and faunal units are based on ditch samples. F11 F12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY species are introduced and many of the calcareous forms that were present in the overlying assemblages are absent to very rare. The upper limits (tops) of the most important arena- ceous species below 2,450 feet are given. For further details on the stratigraphic ranges of these species see figure 5. Depth (feet) Adercotryma glomerata (H. B. Brady) -________________ 2, 450 Cyclammina sp. A LeRoy______________________________ 2, 730 Schencktella okinawaensis LeRoy, n. Sp_________________ 2, TTG Cyclammina ezoensis Asano___________________________ 3, 170 Goesella scheneki Asano_______________________________ 3, 300 Glomospira glomerata Hoglund________________________ 3, 420 Ammodiscus dominicensis var. deformis Bermudez_______ 3, 500 Miliammina echigoensis Asano and Inomata_____________ 3, 850 The Foraminifera between 2,450 and 4,036 feet indi- cate a deep-neritic to shallow-bathyal type of environ- ment-much deeper water conditions that seemingly prevailed during deposition of the beds penetrated be- tween 0 and 2,450 feet. This environment is supported also by the argillaceous nature of the section. The section below 2,450 feet is of special interest from several viewpoints: (a) Most of the lithology is shale (excluding sandstones C, D, and E) ; (b) the arenaceous Foraminifera are more frequent than in the section above; (c) the strata have not yet been recognized in outcrop in southern Okinawa; (d) both the Foramini- fera and lithology suggest a deep-neritic to shallow- bathyal cool-water environment of deposition ; and (¢) Orbulina universe Orbigny appears to continue throughout ; however, this range may be in error because of recirculated well cuttings. The vertical distribution of the 11 arenaceous species is shown in figure 5. The highest occurrence of each species is considered reasonably accurate. Their lower limit is questionable because of recirculation of the well cuttings. STRATIGRAPHIC SUMMARY OF KATCHIN HANTO 1 Katchin Hanto 1, drilled on the Katchin Hanto Peninsula of Okinawa by the U.S. Navy in 1946 (figs. 1, 4), penetrated the following deposits: , Depth Pliocene : (feet) Naha LimestON@_____________cccccccc______ Lec - 0-55 Chinen 55-360 Rotorbinella chinenensis fauna Calcarina fauna Unconformity Miocene : Yonabaru Member of Shimajiri Formation-______ 360-1, 900 (Nonion nicobarense-Cibicides macneili fauna) f & "o © > .% ® um P4 S‘s r” . £0 }: 1% 3 L. 's *s : & G § § $ E He 5 g § f m s s & o 2 0 oi $4 $f s g $ 46 s 2 $ f $f $8 5 og So o ° § 6 ggg Rog t t Feet > 8 3 § f An 4 % & Gg $ § pf $ is 23001.'B:] < 8 a 8 6 s a < § a § §] I T 1 | [ | 1 1 | o= Base of Sandstone "B" (See figure 4) E- | =-3 2450 ft 25003 5s - 2730 ft f: 2775 ft ‘ pale a s © s | 5 30001 m 0 . 1 9 tod S io 5 1 “l- T & g z ig M |s170 it 5 [| 1 e _ S I o | ®® | 3300 ft o I > I- 7 . H 3420 ft 35004 35°I°3§2M f i | 1 3690 ft 1 3850 ft 40004 FicurE 5.-Stratigraphic ranges of some important arenaceous foraminiferal species in the lower part of Yonabaru 1, southern Okinawa; ranges based on residue assemblages of ditch samples; only tops are considered accurate. stratigraphically higher in total section. Asterisk indicates forms FORAMINIFERA FROM TERTIARY OF OKINAWA LITHOSTRATIGRAPHY NAHA LIMESTONE (0-55 FT) Composed of tan to white soft fine-crystalline fossilif- erous porous limestone; the Naha is the youngest strati- graphic unit penetrated. It rests conformably on the Chinen Sand. CHINEN SAND (55-360 FT) The Chinen consists of interbedded soft silty shale, shaly siltstone, and fine-grained friable sandstone. Be- tween 280 and 360 feet it is conglomeratic and contains a few beds of hard light-gray calcareous tuffaceous shale. YONABARU MEMBER OF SHIMAJIRL FORMATION (360-1,900 FT) The Yonabaru lies unconformably below the Chinen Sand and consists principally of interbedded dark- to medium-gray shale, sandy shale, and soft fine-grained graywacke sandstone; shale predominates over sand- stone. Sandstone A, found in Yonabaru 1 between 1,250 and 1,400 feet, was penetrated between 1,675 and 1,800 feet in this well. The Shinzato fauna was not recognized in cuttings in this well and is absent also in a surface exposure about 11%, miles west-northwest of the well site. BIOSTRATIGRAPHY The boundaries of the faunal assemblages in this well correspond to those of the lithic units previously described. NAHA LIMESTONE (0O-55FT) Foraminifera of the Naha Limestone are only moder- ately well preserved because of leaching by ground waters and recrystallization. The more common species are: Amphistegina madagascariensis d'Orbigny, Ano- malina glabrata Cushman, Buliminoides williamsoni- anus (H. B. Brady), Cibicides lobatulus (d'Orbigny), Clavulina yabei akiensis Asano, Eponides margar- itiferus (H. B. Brady), Eponides praecintus (Karrer), Eponides subornatus (Cushman), G@lobigerina dubia Egger, G@lobigerinoides triloba immatura LeRoy, Glo- bigerinoides ruber (d'Orbigny), Globorotalia menardii multicamerata Cushman and Jarvis, G@loborotalia tumi- da (H. B. Brady), Hanzawaia nipponica Asano, Orbu- lina universa dOrbigny, Planorbulinella larvata (Park- er and Jones), Rotalia stachi Asano, SNiphogenerina raphanus (Parker and Jones), and Uvigerina striatella (Reuss). Ostracodes, bryozoans, coral and algal fragments are common and indicate a shallow, warm-water, tropi- cal environment of deposition. CHINEN SAND (55-360 FT) The Chinen consists of two foraminiferal assemblages (55-280 and 280-360 ft respectively). These faunas F13 are at considerable variance with each other as well as with those of the overlying Naha and underlying Shinzato and Yonabaru. Rotorbinella chinenensis fauna (55-280 ft.). -The Foraminifera of this assemblage suggest a shallow- neritic moderately cool water environment. The more persistent forms include: Anomalina glabrate (Cush- man), Bolivina robusta (H. B. Brady), Bulimina mar- ginata d'Orbigny, Caneris auwriculus (Fichtel and Moll), C. communis Cushman and Todd), Cassidulina orientale Cushman, Cibicides lobatulus (d'Orbigny), Elphidium far barbarense Nicol (small), E. jenseni (Cushman), Missurinae spp., G@lobigerina bulloides d'Orbigny, @. dubia Egger, G@lobigerinoides ruber (d'Orbigny), G. triloba immatura LeRoy, Globorotalia menardii (d'Orbigny), Hanzawaia nipponica Asano, Hyalinea bailthica (Schroeter), Lagena spp., Lagenono- dosaria scealaris (Batsch), Lozostomum amygdalae- forme (H. B. Brady) var. iokense Asano, Neoconobina pacifica LeRoy, N. opercularis (d'Orbigny), N. naka- murai (Asano), Nodosaria insecta Schwager, N. Longis- cata d'Orbigny, Nonmion japonicum (Asano), Patelli- nella jugosa (H. B. Brady), P. inconspicue (H. B. Brady), Pullemiatina obliquiloculata (Parker and Jones), Quinqueloculina alkneriana d'Orbigny, Q. elon- gata Natland, Reusella spinulosa (Reuss), Rotorbinella chinenensis LeRoy, Siphogenerina raphanus (Parker and Jones), Stilostomella lepidula (Schwager), Streb- lus beccarii tepida (Cushman), Trifarina bradyi Cush- man, T'riloculina tricarinata d'Orbigny, and Uvigerina proboscideqa Schwager var. vadescens Cushman. Bryozoa (flat type), ostracodes, sponge spicules, and molluscan fragments are rather common. Calearina fauna (280-360 ft.). -This fauna is a shallow-neritic tropical type and includes, in addition to many species of the overlying Rotorbinella chinenensis fauna, the following forms: Amphistegina madagas- cariensis d'Orbigny, Calearina rustica Todd and Post, C. spengleri (Gmelin), Eponides margaritiferus (H. B. Brady), Gypsina globule (Reuss), Operculina gai- mairdi dOrbigny, Rectobolivina bifrons (H. B. Brady) var. striatule (Cushman), and Textularia sagittule Defrance var. fistulosa (H. B. Brady). Bryozoa (quadrate types), ostracodes, and molluscan fragments are common and all show considerable attrition. YONABARU MEMBER OF SHIMAJIRI FORMATION (360-1,900 FT.) Foraminifera contained in these deposits are similar to those of the Nomion nicobarense-Cibicides macneili fauna as developed in the upper part (0-1,250 ft.) of the Yonabaru well. The faunal and lithological boundary F14 between the Chinen and the Yonabaru is sharp, distinct, and represents a major unconformity that accounts for the absence of @loborotalia punctulate fauna (Shin- zato) and the Logostomum pacificum fauna. CORRELATION SUMMARY OF YONABARU AND KATCHIN HANTO WELLS Yonabaru 1 is located approximately 12 miles south- west of Katchin Hanto 1 (fig. 1). Correlations between the two wells (fig. 4), based on lithological and micro- paleontological data from controlled 10-foot cuttings, are given as follows. Yonabaru | Katchin 1 (feet) | Hanto 1 (feet) Hoeglundina elegans______________________ 200 645 Schenckiella communis____________________ 290 760 Uvigerina peregrina var. dirupta (top) ...... 1, 060 1, 450 Uvigerina peregrina var. dirupta (base)______ 1, 250 1, 675 Base sandstone A________________________ 1, 400 1, 800 The Naha Limestone and Chinen Sand which were penetrated between 0 and 360 feet in Katchin Hanto 1 are absent in the Yonabaru well. The author be- lieves that Katchin Hanto 1 did not penetrate strati- graphically lower than a horizon approximately 1,500 feet below the top of Yonabaru 1. GENERAL COMMENTS ON THE OKINAWAN AND SOUTH PACIFIC MIDDLE AND LATE TERTIARY MICROFAUNAS Many of the Foraminifera of the southern Okinawan Tertiary section have been described from Recent and middle to late Tertiary deposits of the Central and South Pacific and Indonesian regions. Brief comments on the affinities of some of these assemblages to those in the Naha, Chinen, Shinzato, and Yonabaru deposits are given here. The more common Foraminifera of the Naha Limestone include AmpAhistegina madagascariensis d'Orbigny, Buliminoides williomsonianus (H. B. Brady), Eponides praecintus (Karrer), E. subornatus (Cushman), Z. margaeritiferus (Cushman), Planor- bulinella larvata (Parker and Jones), and Siphogen- erina raphanus (Parker and Jones). These species are common in the late Tertiary to Recent warm reef lime- stones of the South and Central Pacific region. The fauna of the Chinen Sand contains many species that have been recorded in the late Tertiary and Recent deposits of the South and Central Pacific region. It includes such forms as AmpAistegina madagascariensis d'Orbigny, Hyalinee balthicae (Schroeter), Buli- minoides williamsonianus (H. B. Brady), Bolivina hantkeniana H. B. Brady, B. robusta H. B. Brady, Can- deina nitida d'Orbigny, Calcarina rustica Todd and Post, C. spengleri (Gmelin), Eponides praecintus (Karrer), £. subornatus (Cushman), Elphidium jen- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY seni (Cushman), Operculina gaimairdi d'Orbigny, and Rectobolivina bifrons (H. B. Brady) var. striactule (Cushman). Shinzato faunas are rather uniform in both genera and species and are related closely to those described by LeRoy (1941) from the late Tertiary (Miocene or Pliocene) of the Sangkoelirang Bay area of East Borneo. Koch (1926) recorded a similar fauna from the middle Tertiary of Bulongan, East Borneo. Asso- ciated with Koch's fauna, however, were the orbitoides, Lepidocyclina cf. L. angulosa Provale and Miogypsina cf. M. thecideaeformis Rutten, which placed the fauna within the Tertiary f (Miocene) according to Indo- nesian chronology. LeRoy (1944) recorded a Miocene assemblage from west Java in which many species were common to the Shinzato but which contained Lepidocyclina. A late Tertiary foraminiferal fauna described (LeRoy, 1941) from Siberoet Island, off the west coast of Sumatra, has much in common with Shinzato assemblages. Schwager's (1866) Kar Nicobar fauna, considered as Pliocene by some workers and as Miocene by others, shows a decided affinity to that of the Shinzato. Many species in the Shinzato were reported by Boom- gaart (1949) from the Miocene and Pliocene deposits of Bodjonegoro (Java). Caudri (1934), in her work on the late Tertiary Foraminifera of Soemba, listed several species that occur in common with those from the Shinzato. Brady (1884) and Cushman (1910-17, 1921) recorded many species from the Recent deposits of the Indo- Pacific and Philippine Sea areas that occur in the Okinawan section. Cushman and others (1954) reported many Oki- nawan species from Recent deposits of Bikini and nearby atolls. The Lozostomum pacificum fauna of the Yonabaru Member is a shallow-neritic warm-water assemblage, many species of which have been checklisted from late and middle Tertiary deposits of the South and Central Pacific and adjacent regions. Several South and Central Pacific species occur in the Nonion micobarense-Cibicides macneili assemblage of the Yonabaru deposits. That part of the Yonabaru between 2,450 and 4,036 feet in the Yonabaru well and characterized by a predominantly arenaceous micro- fauna cannot be compared by the writer with any known total assemblage of the Indonesian region, al- though a few species of this interval have been re- corded in Tertiary and Recent deposits of this part of the world. Based on foraminiferal studies of the central Suma- tran section and on other investigations of Indonesian FORAMINIFERA FROM TERTIARY OF OKINAWA microfaunas, it is believed that the oldest Yonabaru fauna (in Yonabaru 1 at 4,036 ft.) is younger than the pre-Orbulina Telisa fauna (Tertiary e-f) of central Sumatra (LeRoy, 1944). Chang (1954a) listed 47 species from the lower Oligocene of Taiwan (Formosa) including @lobigerina dissimilis Cushman and Bermudez. This species is common in the upper Oligocene of the West Indies. Since Chang did not observe Orbuling universe d'Orbigny, his assemblage is probably older than any fauna thus far found in the southern Okinawan Tertiary. Todd and others (1954) reported an occurrence from southern Saipan of "an assemblage of smaller Fora- minifera that contains distinctive planktonic species in common with the @lobigerinatella insueta zone (late Oligocene) of the Caribbean Tertiary." This fauna should be considered older than any Tertiary fauna noted in southern Okinawa. BATHYMETRIC INTERPRETATION OF THE SOUTHERN OKINAWAN SECTION The bathymetric interpretation of the stratigraphic sequence of the southern Okinawan Tertiary, as based primarily on Foraminifera and lithology, is shown in figure 6. The writer makes no pretense that this in- terpretation is final as the data on which the study was made are considered incomplete. Only that part of the stratal sequence above the bottom (4,036 ft.) of the Yonabaru well is involved. Below this depth the paleobathymetry of the Tertiary section is not known. Deposits from the deepest water of the Tertiary see- tion that were studied occur in Yonabaru 1, between 2,450 and 4,036 feet. This inference is made on the basis of a predominantly shale section containing the arena- ceous Foraminifera Adercotrymae, Ammodiscus, Cy- clammina, Eggerella, Goesella, Miliammina, and Schenchkiella. Molluscan fragments and ostracodes were not observed. Above these deposits, both in the well and at the surface, a series of interbedded fine- to medium- grained sandstones and shales contain both shallow- and deep-neritic Foraminifera that constitute the Nomion nicobarense-Cibicides maecneili fauna. Overlying this assemblage and appearing to represent the youngest de- posits of the Yonabaru is the Lowostomum pacificum fauna, which includes such shallow-water subtropical to tropical genera as Amphistegina, Asterorotalic, Hanzawaia, Opereulina, and Planorbulinella. This en- vironment is supported also by the presence of abraded molluscan and bryozoan debris, ostracodes, and polished rock fragments. Following the deposition of the Lozostomum paci- ficwm fauna the area submerged and resulted in the accumulation of the medium- to deep-neritic sediments F15 and faunas of the Shinzato Member. Many species of Foraminifera within these sediments are South and Central Pacific warm-water types. After Shinzato deposition there was gradual shallow- ing during which time the Chinen Sand and the coral- algal limestones of the Naha, Yontan, and Machinato were laid down. In summary it may be said that following the deposi- tion of the arenaceous fauna (p. F7) and associated sediments of the Yonabaru, there was an overall progressive but interrupted shallowing of the Tertiary sea across southern Okinawa. The time of greatest shallowing occurred at the start of Chinen deposition. SYSTEMATIC DESCRIPTIONS Family RHIZAMMINIDAE Genus BATHYSIPHON M. Sars, 1872 Bathysiphon arenacea Cushman Plate 1, figure 7 Bathysiphon arenacea Cushman, 1927, Scripps Inst. Oceanog- raphy Bull., tech. ser., v. 1, no. 10, p. 120, pl. 1, fig. 2. Common in the lower part of the Yonabaru Member which is penetrated by Yonabaru 1 between 2,450 and 4,036 feet. In these deposits it is associated with Cyclammina, - Schenchkiella, Goesella, Sigmoilina, Eggerella, and Miliammina. Length 1.10 mm (incomplete). Family REOPHACIDAE Genus REOPHAX Montfort, 1808 Reophax agglutinatus Cushman Plate 3, figure 31 Reophaz agglutinatus Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 78, pl. 14, figs. 2a, b. Several specimens were recorded from the shallow- water facies (Lowostomum pacificum fauna) of the Yonabaru. Length 1.93 mm ; diameter 0.64 mm. Family AMMODISCIDAE Genus AMMODISCUS Reuss, 1861 Ammodiscus dominicensis var. deformis Bermidez Plate 1, figure 12 Ammodiscus dominicensis var. deformis Bermfdez, 1949, Cush- man Lab. Foram. Research Spec. Pub. 25, p. 48, pl. 1, figs. 51, 52. Occurs sporadically only below 2,450 feet in Yona- baru 1. Diameter 1.05 mm ; thickness 0.14 mm. Genus GLOMOSPIRA Rzehak, 1888 Glomospira glomerata Hoglund Plate 1, figure 24 Glomospira glomerata 1947, Upsala Univ., Zoology, v. 29, p. 130, pl. 3, figs. 8-10, text figure 104 on p. 111. F16 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FORMATION Littoral to shallow neritic Medium to deep neritic Deep neritic to shallow bathyal Machinato Limestone UNCONFORMITY Yontan Limestone UNCONFORMITY Naha Limestone Chinen Sand UNCONFORMITY Shinzato Member Tuffacéous shale and shaly tuff ® C O O 2 m 0 Q. © C @ O 9 a. @ ® 5 _ 5 o 5 9 .o ° o 3 - & E C E £ & n © O 0 3 UNCONFORMITY(?) Major foraminiferal change Yonabaru Member Shale and sandstone Majorforaminiferal change but less pronounced than at base of Shinzato Yonabaru Member Lower part of Yonabaru 1 section Essentially shale b Amphistegina spD Fauna similar to that of the Chinen Rotorbinella chinenensis Calcarina spp Globorotalia punctulata Lozostomum pacificum Nonion nicobarense Cibicides macneili Arenaceous fauna Adercotryma Schenckiella Cyclammina Goesella Glomospira, and others _________ a Figur 6.-Suggested bathymetric variations of the southern Okinawan section based on benthonic Foraminifera. FORAMINIFERA FROM TERTIARY OF OKINAWA This species is confined to the lower part of the Yona- baru and was found in Yonabaru 1 between 3,420 and 4,036 feet. Diameter 0.63 mm. Glomospira gordialis (Parker and Jones) var. diffundens Cushman and Renz Plate 1, figure 25 Glomospira gordialis (Parker and Jones) var. diffundens Cush- man and Renz, 1946, Cushman Lab. Foram. Research Spec. Pub. 18, p. 15, pl. 1, fig. 30. Several specimens of this species were observed in Yonabaru 1 below 3,420 feet. Diameter 0.40-0.57 mm. Family LITUOLIDAE Genus ADERCOTRYMA Loeblich and Tappan, 1952 Adercotryma glomerata (H. B. Brady) Plate 1, figure 82 Haplophragmium glomeratum H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 309, pl. 34, figs. 15-18. Common and persistent below 2,450 feet in Yonabaru 1. Most of the specimens are as highly distorted as the one figured. Diameter 1.00 mm ; thickness 0.87 mm. Genus AMMOBACULITES Cushman, 1910 Ammobaculites subagglutinans Bandy Plate 1, figures 3, 4 Ammobaculites - subagglutinans - Bandy, 1949, Bull. Paleontology, v. 32, no. 131, p. 27, pl. 3, figs. 5a, b. Specimens assignable to this species, originally described from Oligocene of Alabama, were noted occa- sionally in the Chinen and Shinzato. Length 1.44 mm ; width 0.64 mm. Ammobaculites aff. A. cylindricus Cushman Plate 1, figures 5, 6 Only one specimen having an affinity to A. cylindricus Cushman (1921, v. 4, p. 92, pl. 17, fig. 5) from the Shin- zato was noted. Cushman recorded the form from many dredge stations between 18 and 554 fathoms in the Philippine region. Length 1.60 mm ; width 0.67 mm. Ammobaculites sp. A. LeRoy Plate 1, figures 1, 2 Only one specimen of this form was recorded from the Chinen. It appears to be related to A. yumotoensis Asano but differs by being somewhat less compressed. Length 1.50 mm ; width 0.33 mm. Genus CYCLAMMINA H. B. Brady, 1876 Cyclammina sp. A. LeRoy Plate 13, figures 3, 4 Test small for the genus, much compressed, faintly umbilicate; chambers indistinct, 8-10 in last whorl; Am. F17 sutures almost radial, indistinct; periphery subacute, slightly lobulate; wall finely textured; color generally white. It may be a young form of C. ezoensis Asano; recorded only between 2,730 and 3,420 feet in Yona- baru 1. Diameter 0.65-0.84 mm; thickness 0.24 mm. Cyclammina ezoensis Asano Plate 13, figures 1, 2 Cyclammina ezoensis Asano, 1951, Inst. Geology and Pale- ontology, Tohoku Univ., (Short Papers), v. 3, p. 20, pl. 3, figs. 2a, b. Commonly occurs between 3,170 and 4,036 feet in Yonabaru 1; absent in the upper part of the Yonabaru Member and younger deposits. Diameter 1.30-1.70 mm ; thickness 0.78 mm. Family TEXTULARIIDAE Genus TEXTULARIA Defrance, 1824 Textularia acuta Reuss Plate 1, figures 33, 34 Textularia acute Reuss, 1850, Akad. Wiss. Wien, Math.-natur- wiss. KI., Denkschr., v. 1, p. 381, pl. 49, fig. 1. Only a few specimens showing an affinity to this species were recorded from the Shinzato assemblages. Length 0.90 mm; width 0.51 mm ; thickness 0.23 mm. Textularia candeiana d'Orbigny Plate 2, figures 5, 6 Teaxtularia candeiana d'Orbigny, 1839, in De la Sagra, Histoire, physique, politique et naturelle de lle de Cuba, Foraminiféres, p. 148, pl. 1, figs. 25-27. Scarce in Shinzato and Yonabaru assemblages. Length 0.76 mm; width 0.55 mm ; thickness 0.34 mm. Textularia sagittula Defrance var. fistulosa H. B. Brady Plate 1, figures 30, 31 Teaxtularia sagittule Defrance var. fistulosa H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 362, pl. 42, figs. 19-22. Seemingly limited to the lower part of the Chinen Sand. Length 1.90 mm; width 0.73 mm ; thickness 0.42 mm. Textularia bocki Hoglund Plate 2, figures 1, 2 Textularia bocki Hoglund, 1947, Upsala Univ., Zoology, v. 26, p. 171, pl. 12, fig. 6. Rare in Chinen, Shinzato, and Yonabaru as- semblages. Length 1.00 mm; width 0.62 mm ; thickness 0.42 mnm. Textularia lythostrota (Schwager) Plate 16, figure 16 Plecanium lythostrota Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 194, pl. 4, figs. 4a-c. F18 Recorded rarely in only the Nomion micobarense- Cibicides maceili fauna of the Y onabaru. Length 0.67 mm. Textularia mayeriana d'Orbigny Plate 16, figures 1, 2 Teaxtularia mayeriana d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 245, pl. 14, figs. 26-28. Was observed in the Chinen deposits only. Length 1.87 mm; width 0.92 mm; thickness 0.67 mm. Genus SIPHOTEXTULARIA Finlay, 1939 Siphotextularia flintii (Cushman) var. pacifica LeRoy, n. var. Plate 2, figures 3, 4 Differs from the type by showing more overlap of the chambers and by having more angularity of the peripheral margin. Common in the Shinzato and rare in the Yonabaru. Length 0.60-0.65 mm; width 0.58-0.62 mm; thickness 0.35-0.38 mm. Genus VULVULINA d'Orbigny, 1826 Vulvulina pacifica Cushman Plate 3, figures 9, 10 Vulvulina pacifica Cushman, 1932, Cushman Lab. Foram. Re- search Contr., v. 8, p. 78, pl. 10, figs. 8, 9. Recorded in restricted numbers in Shinzato as- semblages only. Length 0.98 mm; width 0.85 mm; thickness 0.50 mm. Family VERNEUILINIDAE Genus GAUDRYINA d'Orbigny, 1839 Gaudryina solida Schwager Plate 1, figures 28, 29 Gaudryina solida Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 199, pl. 4, fig. 11. Observed in limited numbers from the Yonabaru only. Length 2.00 mm ; width 0.96 mm. Gaudryina karreriana Cushman Plate 1, figures 26, 27 Gaudryina karreriana Cushman, 1936, Cushman Lab. Foram. Research Spec. Pub. 6, 8, pl. 1, fig. 18. Several specimens seemingly referable to this species were recorded from the Lozostomum pacificum fauna of the Yonabaru. Cushman's illustration of the type is more quadrate in apertural view than the Okinawan forms. Length 1.05 mm; width 0.71 mm. Gaudryina siphonifera (H. B. Brady) Plate 1, figure 21 Teaxtularia siphonifere H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 362. pl. 42, figs. 25-29. Gaudryina siphonifera (H. B. Brady). Cushman, 1937, Cush- man Lab. Foram. Research Spec. Pub. 7, p. 83, pl. 12, figs. 9, 10. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Several typical specimens were recorded from the Loxostomum - pacifieum fauna of the Yonabaru. Length 1.10 mm ; width 0.56 mm. Family VALVULINIDAE Genus CLAVULINA d'Orbigny, 1826 Clavulina yabei akiensis Asano Plate 1, figure 11 Clavulina yabei akiensis Asano, 1936, Geol. Soc. Japan Jour., v. 43, no. 519, p. 944, pl. 52, figs. 4, 5. Common in the Lozostomum pacificum fauna of the Yonabaru; rare in the Naha, Chinen, and Shinzato. Many specimens show a much larger early triangular stage than the one figured. Length 1.60 mm; diameter 0.35 mm. Genus EGGERELLA Cushman, 1933 Eggerella bradyi (Cushman) Plate 1, figures 13, 14 Verneuilina bradyi Cushman, 1911, U.S. Natl. Mus. Bull. 71, pt. 2, p. 54, figs. STa, b, Eggerella bradyi (Cushman), 1937, Cushman Lab. Foram. Re- search Spec. Pub. 8, p. 52, pl. 5, fig. 19. Common in Shinzato and Yonabaru assemblages but attains best development in the Yonabaru; widely recorded in the late Tertiary and Recent deposits of the Indo-Pacific region. Length 0.73 mm; width 0.52 mm. Genus TRITAXILINA Cushman, 1911 Tritaxilina caperata (H. B. Brady) Plate 16, figures 3, 4 Tritazia caperata H. B. Brady, 1884, Challenger Rept., Zoology, p. 390, pl. 49, figs. 1-17. Tritawilina caperata (H. B. Brady). Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 8, p. 159, pl. 19, figs. T-12. Only one specimen was recorded in the Chinen. Length 1.50 mm ; diameter 0.60 mm. Genus GOESELLA Cushman, 1983 Goesella schencki Asano Plate 1, figure 15 Goesella schencki Asano, 1950, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 4, p. 2, figs. 11-13. Observed in the Yonabaru 1 below 3,300 feet only. Length 2.10 mm ; diameter 0.93 mm. Genus KARRERIELLA Cushman, 1933 Karreriella bradyi (Cushman) Plate 1, figures 22, 23 Karreriella bradyi (Cushman), 1937, Cushman Lab. Foram. Research Spec. Pub. 8, p. 135, pl. 16, figs. 6-11. FORAMINIFERA FROM TERTIARY OF OKINAWA Common in Shinzato assemblages and rare in those of the Yonabaru. Length 0.62 mm ; width 0.40 mnm. Genus SCHENCKIELLA Thalmann, 1942 Schenckiella communis (d'Orbigny) hosoyaensis (Asano) Plate 1, figure 18 Martinottiella communis (d'Orbigny) hosoygaensis Asano, 1950, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 4, p. 3, figs. 18, 19. Persistent in and seemingly confined to the Nomion nicobarense-Cibicides macneili fauna of the Yonabaru. Length 1.58 mm; diameter 0.26 mm. Schenckiella communis (d'Orbigny) Plate 1, figure 17 Clavulina communis d'Orbigny, 1826, Annales sci. nat., v. 7, no. 4, p. 268. Listerella communis (d'Orbigny). Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 8, p. 148, pl. 17, figs. 4-9. Rare in Shinzato and Yonabaru assemblages. Length 2.26 mm ; diameter 0.56 mm. Schenckiella howchini (Cushman) Plate 1, figure 20 Listerella howchini Cushman, 1937, Cushman Lab. Foram. Re- search Spec. Pub. 8, p. 141, pl. 16, figs. 34, 35. One incomplete specimen was recorded in the Yona- baru. Length 1.40 mm ; diameter 0.37 mm. Schenckiella okinawaensis LeRoy, n. sp. Plate 1, figure 16 Test small for the genus, about four times as long as broad, triserial stage about one-fourth length of test; chambers in triserial part indistinct, only moderately distinct in uniserial stage and when chambers are slightly inflated ; sutures slightly depressed ; wall white, very fine textured; aperture at end of short slender tube. This species appears to be similar to 8. bradyana (Cushman) but differs primarily by being smaller, more compressed, and by having a finer textured sur- face. It was recorded sporadically below 2,775 feet in the Yonabaru well. Length 0.63-0.66 mm; diameter 0.17-0.20 mm. Schenckiella victoriensis (Cushman) Plate 1, figure 19 Listerella victoriensis Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 8, p. 146, pl. 16, fig. 25. A few specimens recorded from the Shinzato depos- its; best development in Yonabaru 1 between 3,690 and 3,860 feet. Length 2.20 mm; diameter 0.30-0.39 mm. F19 Family SILICINIDAE Genus MILIAMMINA Heron-Allen and Earland, 1930 Miliammina echigoensis Asano and Inomato Plate 5, figures 15, 16 Miliammina echigoensis Asano and Inomata, 1952, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Ter- tiary Smaller Foraminifera, supp. 1, p. 5, figs. 21-24. Restricted to the Yonabaru; penetrated by Yonabaru 1 below 3,850 feet. Length 0.49 mm; width 0.21 mm; thickness 0.10 mm. Family MILIOLIDAE Genus QUINQUELOCULINA d'Orbigny, 1826 Quinqueloculina tricarinata d'Orbigny Plate 12, figures 15, 16 Quinqueloculina tricarinate d'Orbigny, 1839, in De la Sagra, Histoire, physique, politique et naturelle de 1'Ile de Cuba, Foraminiféres, p. 187, pl. 11, figs. 7-9, 18. Several specimens referable to this species were noted in Chinen and Naha assemblages. Length 1.10 mm; width 0.71 mm; thickness 0.34 mm. Quinqueloculina carinata d'Orbigny Plate 12, figures 19, 20 Quingqueloculina carianta d'Orbigny, 1825, Annales sci. nat., p. 136, type figure by Fornasini, 1905, Mem. R. Accad. Sci. Inst. Bologna, ser. 6, v. 2, pl. 4, fig. 2. Occurs in limited numbers in Naha, Chinen, Shinzato, and Yonabaru assemblages. Length 0.70 mm; width 0.60 mm; thickness 0.40 mm. Quinqueloculina sagamiensis Asano Plate 12, figures 17, 18 Quingqueloculina sagamiensis Asano, 1936, Geol. Soc. Japan Jour., v. 43, no. 515, p. 612, pl. 30, figs. 5Sa-c. Scarce and in Naha and Chinen assemblages only. Length 1.50 mm; width 1.10 mm; thickness 0.71 mm. Quinqueliculina reticulata (d'Orbigny) Plate 12, figures 21, 22 Quingqueloculina reticulata (d'Orbigny). Cushman, 1917, U.S. Natl. Mus. Bull. 71, pt. 6, p. 55, pl. 16, figs. 1-3. Several specimens were recorded in the Lozostomum pacificum fauna of the Yonabaru. Length 0.84 mm; width 0.70 mm; thickness 0.42 mm. Quinqueloculina akneriana d'Orbigny Plate 12, figures 13, 14 Quingqueloculina akneriana d'Orbigny, 1846, Foraminiféres fos- siles du bassin tertiaire de Vienne, p. 290, pl. 18, figs. 16-21. Most common in Shinzato and Yonabaru assem- blages; rare in Naha and Chinen deposits. Length 0.82 mm; width 0.55 mm; thickness 0.42 mm. F20 Quinqueloculina contorta d'Orbigny Plate 12, figures 7, 8 Quinqueloculina contorta d'Orbigny, 1846, Foraminiféres fos- siles du bassin tertiaire de Vienne, p. 298, pl. 20, figs. 4-6. Several specimens of this species were recorded from the Shinzato. Length 1.00 mm; width 0.55 mm; thickness 0.35 mm. Quinqueloculina elongata Natland Plate 12, figures 11, 12 Quinqueloculina elongata Natland, 1938, Scripps Inst. Oceanog- raphy Bull. tech. ser., v. 4, (5), p. 141, pl. 4, fig. 5. Present in the upper part of the Chinen Sand. Length 0.37 mm; width 0.18 mm; thickness 0.12 mm. Quinqueloculina pygmea Reuss Plate 12, figures 9, 10 Quingqueloculina pygmea Reuss, 1859, Akad. Wiss. Wien, Math.- naturwiss. Kl., Denkschr., v. 1, p. 384, pl. 50, fig. 8. Several specimens occur frequently in some Naha and Chinen assemblages. Length 0.33 mm; width 0.13 mm; thickness 0.09 mm. Genus MASSILINA Schlumberger, 1893 Massilina fragilissima (H. B. Brady) Plate 12, figure 31 Spiroloculina fragilissima H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 149, pl. 9, figs. 12-14. Observed occasionally in Chinen assemblages only. Length 0.66 mm; width 0.64 mm; thickness 0.13 mm. Genus SPIROLO . LINA d'Orbigny, 1826 Spiroloculina circularis Cushman and Todd Plate 3, figures 23, 24 Apiroloculina circularis Cushman and Todd, 1944, Cushman Lab. Foram. Research Spec. Pub. 11, p. 49, pl. 7, figs. 15, 16. Observed rarely in the Nonion micobarense-Cibicides macneili deepwater assemblages of the Yonabaru. Length 0.55 mm; width 0.50 mm; thickness 0.19 mm. Spiroloculina penglaiensis Jacot Plate 3, figures 25, 26 Spiroloculina penglaiensis Jacot, 1925, North China Branch Royal Asiatic Soc. Jour., v. 56, p. 76-79, figs. 1, 2. Rare in the Yonabaru. Length 1.13 mm; width 1.00 mm; thickness 0.38 mm. Spiroloculina communis Cushman and Todd Plate 3, figures 27, 28 ; plate 16, figures 14, 15 Spiroloculina communis Cushman and Todd, 1944, Cushman Lab. Foram. Research Spec. Pub. 11, p. 63, pl. 9, figs. 4, 5, 7, 8. Several specimens of this species were recorded from the Chinen and Naha. The length to breadth ratio of the species varies considerably. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Length 0.85 mm; width 0.55 mm; thickness 0.26 mm (pl. 3, figs. 27,28). Length 0.92 mm ; thickness 0.23 mm (pl. 16, figs. 14, 15). Genus SIGMOILINA Schlumberger, 1887 Sigmoilina celata (Costa) Plate 3, figures 21, 22 Spiroloculina celata Costa, 1855, Mem. Acad. Sci. Napoli, v. 2, p. 126, pl. 1, fig. 14, (1857). Sigmoilina celate (Costa). Cushman, 1946, Cushman Lab. Foram. Research Contr., v. 22, pt. 2, p. 36, pl. 5, figs. 23-29. Several specimens assignable to this species were re- corded from the Shinzato deposits only. Length 0.80 mm; width 0.53 mm; thickness 0.32 mm. Sigmoilina miocenica Cushman Plate 3, figure 34 Sigmoilina miocenica Cushman, 1930, Cushman Lab. Foram. Research Contr., v. 5, p. 81, pl. 12, figs. 12-14. Very rare in Okinawan assemblages. Length 0.60 mm; width 0.33 mm; thickness 0.09 mm. Sigmoilina schlumbergeri A. Silvestri Not illustrated Sigmoilina schlumbergeri A. Silvestri, 1904, Mem. Pont. Accad. Nuovi Lincei, v. 22, p. 267. Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 449. Rare in the Nomion micobarense-Cibicides macneili fauna. Common in Yonabaru 1 below 3,410 feet; a few specimens in the Shinzato. USGS loc. £11531 (FSM-45, Yonabaru). USNM 625396 Sigmoilina tenuis (Czjzek) Plate 16, figures 32, 33 Bigmoilina tenuis (Czjzek). Cushman, 1946, Cushman Lab. Foram. Research Contr., v. 22, pt. 2, p. 32, pl. 5, figs. 13-15. Several specimens were observed in Shinzato assem- blages only. Length 0.42 mm ; thickness 0.07 mm. Genus TRILOCULINA d'Orbigny, 1826 Triloculina tricarinata d'Orbigny Plate 3, figures 32, 33 Triloculina tricarinate d'Orbigny, 1826, Annales sci. nat., v. 7, p. 299; Modéles 94. Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 340, pl. 85, figs. 15, 16. Rather common in the Logostomum pacificum fauna of the Yonabaru ; rare in the Chinen. Length 0.60 mm ; width 0.37 mm. Triloculina trigonula (Lamarck) Plate 16, figures 30, 31 Triloculina trigonulae (Lamarck). Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 340, pl. 85, fig. 18. FORAMINIFERA FROM TERTIARY OF OKINAWA Very rare and recorded in the Chinen deposits only. Length 0.48 mm ; width 0.37 mm. Genus CRUCILOCULINA d'Orbigny, 1839 Cruciloculina striata Loeblich and Tappan Plate 12, figures 23, 24 Cruciloculina striata Loeblich and Tappan, 1957, U.S. Natl. Mus. Bull. 215, p. 234, pl. 74, figs. 13-16. Test small, roundly triangular in cross section, slightly longer than broad, sutures distinct; wall with many low closely spaced striae; aperture cruciform to dendritic. Observed in limited numbers in the Nomion micobe- rense-Cibicides macneili fauna of the Yonabaru. Length 0.70 mm; width 0.55 mm ; thickness 0.45 mm. Genus MILIOLINELLA Wiesner, 1931 Miliolinella inflata LeRoy, n. sp. Plate 12, figures 36, 37 Test broadly elliptical in apertural view, about as wide as long; chambers distinct, highly inflated and strongly overlapping; sutures distinct, slightly de- pressed; periphery broadly rounded; wall smooth; aperture crescent shaped, broad, with well-developed rim. Differs from M. australis (Parr) by exhibiting a broader and more rounded peripheral margin and by showing a thicker apertural rim. Very rare in Yonabaru assemblages. Length 0.50 mm ; width 0.47 mm ; thickness 0.40 mm. Miliolinella australis (Parr) Plate 12, figures 27, 28 Quingueloculina australis Part, 1932, Royal Soc. Victoria Proc., pt. 1, v. 44, p. 7, pl. 1, fig. 8. Observed in limited numbers in Yonabaru assem- blages only. Length 1.00 mm; width 1.00 mm; thickness 0.62 mm. Genus PYRGO Defrance, 1824 Pyrgo affinis (d'Orbigny) Plate 12, figures 25, 26 Biloculina affinis d'Orbigny, 1846, Foraminifdres fossiles du bassin tertiaire de Vienne, p. 265, pl. 16, figs. 1-3. Very rare in Chinen assemblages. Length 0.55 mm; width 0.41 mm; thickness 0.33 mm. Pyrgo depressa (d'Orbigny) Plate 12, figures 29, 30 Biloculina depressa d'Orbigny, 1826, Annales sci. nat., v. 7, p. 208. Modéles 94. Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 469, pl. 96, figs. 2a, b. 682-363 O-64-2 F21 Occurs in limited numbers in Shinzato and Yona- baru assemblages. Length 0.90 mm; width 0.90 mm ; thickness 0.42 mm. Pyrgo murrhina (Schwager) Plate 12, figures 82, 33 Biloculina murrhina Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 203, pl. 4, figs. 5Sa-c. Cushman, 1932, U.S. Natl. Mus. Bull. 161, pt. 1, p. 64, pl. 15, figs. 1-3. Rarely recorded in Chinen assemblages only. Length 0.47 mm; width 0.49; thickness 0.31 mm. Pyrgo subsphaerica (d'Orbigny) Plate 12, figures 34, 35 Biloculina subsphaerica d'Orbigny, 1839, in De la Sagra, His- toire, physique, politique et naturelle de l'le de Cuba, Foraminiféres, p. 162, pl. 8, figs. 25-27. Very scarce in Yonabaru assemblages. Length 0.95 mm; width 0.81 mm ; thickness 0.80 mm. Family OPHTHALMIDIIDAE Genus CORNUSPIRA Schultze, 1854 Cornuspira involvens (Reuss), var. Plate 1, figures 8, 9 Operculina involvens Reuss, 1849, Akad. Wiss. Wien, Math.- naturwiss. Kl., Denkschr. v. 1, p. 370, pl. 45, fig. 20. Cornuspirae involvens (Reuss). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 389, pl. 77, figs. 8, 4. This deeply depressed form is exceedingly rare in the Shinzato and Yonabaru. The specimens show con- siderable variation in the degree of inflation of the evolute tube. Diameter 0.71 mm. Family LAGENIDAE Genus ROBULUS Monfort, 1808 Robulus vortex (Fichtel and Moll) Plate 4, figures 7, 8 Nautilus vortex Fichtel and Moll, 1803, Testacea microscopia, p. 33, pl. 2, figs. ei. Cristellaria vortes (Fichtel and Moll). H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 548, pl. 69, figs. 14-16. Several specimens were observed in Yonabaru as- semblages only. Diameter 1.00 mm ; thickness 0.50 mm. Robulus yabei (Asano) Plate 4, figure 13 Planularia yabei Asano, 1988, Tohoku Imp. Univ. Sci. Repts., 2d ser., v. 19, pt. 2, p. 205, pl. 24, fig. 6. Very scarce in Chinen only. Diameter 0.90-1.45 mm ; thickness 0.53 mm. F22 Robulus costatus (Fichtel and Moll) Plate 4, figure 9, 10 Nautilus costata Fichtel and Moll, 1803, Testacea microscopia, p. 47, pl. 4, figs. g-i. Cristellaria costata (Fichtel and Moll). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 239, pl. 46, fig. 4; pl. 47, fig. 1. Noted in limited numbers and restricted to Shinzato assemblages. Diameter 0.70-1.00 mm; thickness 0.36 mm. Robulus costata (Fichtel and Moll) var. multicostatus (Cushman) Plate 4, figures 11, 12 Cristellaria costata (Fichtel and Moll) var. multicostata Cush- man, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 240, pl. 47, figs. 2, 8. One specimen referable to this species was recorded from the Shinzato. Diameter 0.92 mm ; thickness 0.48 mm. Robulus calcar (Linné) Plate 4, figures 14, 15 Nautilus calcar Linné, 1767, Syst. Nat., ed. 12, p. 1162, no. 272; (Gmelin's) ed. 13, p. $370, no. 2. Robulus calcar (Linné). Cushman, 1945, Cushman Lab. Foram. Research Spec. Pub. 15, p. 12, pl. 2, fig. 6. Several specimens recorded from the Shinzato and the shallow-water facies of the Yonabaru. Diameter 0.54 mm ; thickness 0.33 mm. Robulus sp. A LeRoy Plate 16, figures 23, 24 Very rare in the Shinzato; too few specimens to per- mit accurate identification or designation of a new species. Generally five noninflated chambers; sutures narrow, flush with surface, slightly curved; periphery with very narrow limbate keel. Diameter 0.87 mm ; thickness 0.50 mm. Robulus sp. B LeRoy Plate 16, figures 25, 26 Test compressed, somewhat uncoiled; generally 7-8 chambers, noninflated, enlarging only gradually as added; sutures flush or faintly recessed, slightly curved ; periphery with narrow flange. Diameter 0.90-1.20 mm. Robulus inornatus (d'Orbigny) Plate 16, figures 37, 38 Robulina inornata d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 102, pl. 4, figs. 25, 26. A few specimens were found in Shinzato and Yona- baru assemblages. Diameter 0.97 mm ; thickness 0.46 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Robulus polygonatus (Franke) Plate 16, figures 17, 18 Cristellaria (Lenticulina) polygonata Franke, 1936, Preuss. Geol. Landesanstalt, Abh., Berlin, new ser., No. 169, p. 118, pl12. figs. 1, 2, Several specimens referable to this species were recorded in the Shinzato deposits. Diameter 0.69-0.82 mm ; thickness 0.32 mm. Robulus himiensis Chiji and Nakaseko Plate 16, figures 12, 13 Robulus himiensis Chiji and Nakaseko, 1950, Geol. Soc. Japan Jour., pt. 3, v. 56, no. 663, text fig. on p. 520. Very rare in Shinzato and Yonabaru assemblages. Diameter 1.00 mm ; thickness 0.50 mm. Genus LENTICULINA Lamarck, 1804 Lenticulina peregrina (Schwager) Plate 4, figures 5, 6 Cristellaria peregrina Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 245, fig. 89. Very rare in the shallow-water deposits of the Yona- baru Length 1.20 mm ; width 0.83 mm ; thickness 0.53 mm. Genus MARGINULINOPSIS Silvestri, 1904 Marginulinopsis nozimaensis (Asano) Plate 5, figure 12 Marginulina nozimaensis Asano, 1938, Tohoku Imp. Univ. Sci. Repts., 2d ser., v. 19 (2), p. 210, pl. 28, figs. 19-21; pl. 30, figs. 18, 14. Recorded only in the Logostomum pacificum fauna of the Yonabaru in limited numbers. Length 2.30 mm (incomplete) ; width 0.71 mm. Marginulinopsis perprocera (Schwager) Plate 5, figure 10 Cristellaria perprocera Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 241, pl. 6, fig. 84. Marginulina perprocera (Schwager). Cushman and Todd, 1945, Cushman Lab. Foram. Research Spec. Pub. 15, p. 19, pl. 3, fig. 10. Found rarely in and restricted to Shinzato assem- blages. Length 1.50 mm (incomplete) ; width 0.27 mm. Genus MARGINULINA d'Orbigny, 1826 Marginulina striatula Cushman Plate 5, figure 11 Marginulina striatulae Cushman, 1913, U.S. Natl. Mus. Bull. 100, v. 4, p. 255, pl. 41, fig. 2. Very rare in Okinawa assemblages. Length 0.50 mm ; width 0.23 mm. FORAMINIFERA FROM TERTIARY OF OKINAWA Marginulina glabra d'Orbigny Plate 16, figure 29 Marginulina glabra d'Orbigny. H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 527, pl. 65, figs. 5, 6. Only rarely found in deepwater Yonabaru assem- blages. Length 1.00 mm. Genus DENTALINA d'Orbigny, 1826 Dentalina jarvisi Cushman and Todd Plate 15, figure 27 Dentalina jarvisi Cushman and Todd, 1945, Cushman Lab. Foram. Research Spec. Pub. 15, p. 22, pl. 3, fig. 22. Several specimens were observed in the upper part of the Yonabaru. Length 1.30 mm. Dentalina recta (Schwager) Plate 15, figure 30 Nodosaria recta Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 216, pl. 5, fig. 85. Rare in Shinzato and Yonabaru deposits. Length 1.87 mm (incomplete). Dentalina reussi Neugeboren Plate 15, figure 22 Dentalina reussi Neugeboren, 1856, K. Akad. Wiss., Math.-na- turwiss. KI., Abth. 2, v. 12, p. 85, pl. 3, figs. 6, 7, 17. Very rare and recorded only in Shinzato assem- blages. Length 1.20 mm. Dentalina advena (Cushman) Plate 15, figure 31 Nodosaria advena Cushman, 1923, U.S. Natl. Mus. Bull. 104, pt. 4, p. 79, pl. 14, fig. 12. Very rare and sporadic in Shinzato and Yonabaru assemblages. Length 1.70 mm. Dentalina obliqua (Linné) Plate 15, figure 19 Nodosaria oblique (Linné). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 210, pl. 38, fig. 1. Several specimens were recorded from the Shinzato only. It is common in Recent deposits of the Philippine Sea area. Length 1.78 mm. Dentalina semilaevis Hantken Plate 15, figure 32 Dentalina semilaevis Hantken. Bermudez, 1949, Cushman Lab. Foram. Research Spec. Pub. 25, p. 144, pl. 9, fig. 43. One specimen of this species was observed in the Shinzato. Seemingly not present in the Chinen or Yonabaru. Length 1.50 mm. F23 Dentalina communis d'Orbigny Plate 15, figure 28 Nodosaria (Dentalina) communis d'Orbigny, 1826, Annales sci. nat., v. 7, p. 254. Rare in Shinzato and Yonabaru assemblages. Length 2:10 mm. Dentalina emaciata Reuss Plate 15, figure 34 Dentalina emaciata Reuss, 1851, Deutsche geol. Gesell. Zeitschr., v. 3, p. 63, pl. 8, fig. 9. Noted in limited numbers from only the Shinzato. Length 2.82 nm. Genus RECTOGLANDULINA Loeblich and Tappan, 1955 Rectoglandulina radicula (Linné) Plate 15, figure 24 Nodosaria (Linné). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 190, pl. 84, fig. 4. Sporadic in Shinzato and Yonabaru assemblages. Length 1.05 mm. Rectoglandulina tornata (Schwager) Plate 15, figure 11 Nodosaria tornata Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 223, pl. 5, fig. 51. Several specimens assignable to this species were re- corded from the Shinzato. Length 0.95 mm. Rectoglandulina ambigua (Neugeboren) Plate 15, figure 8 Nodosaria ambigua Neugeboren, 1856, K. Akad. Wiss., Math.- naturwiss. Kl, Abth. 2, v. 12, p. 71, pl. 1, figs. 13-16. Recorded rarely from the Yonabaru only. Length 0.83 nm. Rectoglandulina laevigata (d'Orbigny) Plate 14, figures 29, 30 Nodosaria (Glandulina) laevigata d'Orbigny, 1826, Annales sci. nat., v. 7, p. 252, pl. 10, figs. 1-38. Rather common in the Shinzato and rare in the Yonabaru. Length 0.73 mm ; diameter 0.50 mm. Genus NODOSARIA Lamarck, 1812 Nodosaria tosta Schwager Plate 15, figure 1 Nodosaria tosta Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 219, pl. 5, fig. 42. Rare in the Shinzato but rather persistent in the Yonabaru. Length 2.50 mm. F24 Nodosaria acuminata Hantken var. uniforminata LeRoy Plate 15, figure 21 Nodosaria acuminata Hantken var. uniforminata LeRoy, 1944, Colorado School Mines Quart., v. 39, no. 3, p. 80, pl. 1, fig. 21. Scarce in Shinzato assemblages. Length 1.11 mm. Nodosaria crassitesta Schwager Plate 15, figure 25 Nodosaria crassitesta Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 224, pl. 5, fig. 55. A few specimens were recorded only from the Yona- baru Member. Length 1.80 mm. Nodosaria longiscata d'Orbigny Plate 15, figure 23 Nodosaria longiscata d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 32, pl. 1, figs. 10, 12. In limited numbers in Shinzato and Yonabaru assemblages. Length 2.54 mm. Nodosaria? aff. N.? exilis Schwager Plate 15, figure 2 Several specimens having an affinity to N. emilis Schwager (1866, pl. 5, p. 223, fig. 52) were recorded in Shinzato assemblages. Length 1.50 mm. Nodosaria hirsuta (d'Orbigny) Plate 15, figure 3 Nodosaria hirsuta d'Orbigny, 1826, Annales sci. nat., v. 7, p. 252. Observed in limited numbers only in Shinzato assemblages. Length 1.93 mm. Nodosaria subtertenuata Schwager Plate 15, figure 5 Nodosaria subtertenuata Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 235, pl. 6, fig. 74. Common in the upper part of the Yonabaru; very rare and sporadic in the Shinzato. Length 1.93 mm. Nodosaria hispidula Cushman Plate 15, figure 4 Nodosaria lepidula Schwager var. hispidula Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 203, pl. 36, fig. 7. Rare in Yonabaru and Shinzato assemblages. Length 1.44 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Nodosaria tympaniplectiformis Schwager Plate 15, figure 6 Nodosaria tympaniplectiformis Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 215, pl. 5, fig. 34. Several specimens were recorded from the Shinzato only. Length 0.60 mm. Nodosaria pupa Karrer Plate 15, figure 10 Nodosaria pupa Karrer, 1878, K. Gerold's Sohn, Wien, Osterreich, p. 89, pl. 5, fig. 9. Very rare and noted only in Yonabaru assemblages. Length 0.78 mm. Nodosaria hochstetteri Schwager Plate 15, figure T Nodosaria hochstetteri Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 214, pl. 5, fig. 82. Several specimens appearing to be typical of this species were recorded from the Shinzato. Length 1.45 mm. Nodosaria hochstetteri Schwager var. spinicosta Koch Plate 16, figure 5 Nodosaria hochstetteri Schwager var. spinicost@ Koch, 1923, Eclogae geol. Helvetiae, v. 18, no. 2, p. 351, fig. 5. Rare in Shinzato assemblages only. Length 1.30 mm (incomplete). Nodosaria fistuca Schwager Plate 15, figure 9 Nodosaria fistuce Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 216, pl. 5, fig. 36. Very rare in Shinzato and Yonabaru assemblages. Length 0.59 mm. Nodosaria insecta Schwager Plate 15, figure 14 Nodosaria insecta Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 224, figs. 53, 54. Rare in Shinzato and Yonabaru assemblages. Length 1.74 mm. Nodosaria spirostriolata Cushman Plate 15, figure 13 Nodosaria spirostriolate Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 212, pl. 38, fig. 4. Rare in Shinzato assemblages and occurs rather fre- quently in Yonabaru assemblages. Length 2.66 mm. Nodosaria pyrula d'Orbigny var; longi-costata Cushman Plate 15, figure 18 Nodosaria pyrule d'Orbigny var. longi-costat@e Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 188, pl. 33, figs. 8, 9. FORAMINIFERA FROM TERTIARY OF OKINAWA Rare and recorded in the Shinzato only. Length 1.34 mm (incomplete). Nodosaria vertebralis (Batsch) var. albatrossi Cushman Plate 15, figure 12 Nodosaria vertebralis (Batsch) var. albatrossi Cushman, 1923, U.S. Natl. Mus. Bull. 104, pt. 4, p. 87, pl. 15, fig. 1. A few specimens were noted in Naha, Chinen, Shin- zato, and Yonabaru assemblages. Length 2.38 mm. Nodosaria setosa Schwager Plate 15, figures 15, 16 Nodosaria setosa Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 218, pl. 5, fig. 40. Recorded only in Yonabaru assemblages in limited numbers. Length 1.52 mm (15) ; Length 1.25 mm (16). Nodosaria soluta (Reuss) Plate 15, figure 17 Nodosaria soluta (Reuss). Cushman, 1921, U.S. Natl. Mus Bull. 100, v. 4, p. 192, pl. 34, figs. 5, 6. Rare and scattered in the Chinen, Shinzato, and Yonabaru. Length 1.18 mm. Nodosaria scabriuscula Costa Plate 16, figure 6 Nodosaria scabriuscule Costa, 1856, Acad. Pont Napoli, Atti, v. 7, pt. 2, p. 140, pl. 16, fig. 1. A few specimens recorded in the deep-water faunas of the Yonabaru. Length 0.58 mm (incomplete). Genus SARACENARIA Defrance, 1824 Saracenaria latifrons (H. B. Brady) Plate 3, figure 36 Cristellaria latifrons H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 544, pl. 68, fig. 19. Very rare and recorded only from Shinzato assem- blages. Length 0.90 mm. Saracenaria italica Defrance Plate 3, figures 29, 30 Cristellaria italica (Defrance). H. B. Brady, 1884, Challenger Rept. Zoology, v. 9, p. 544, pl. 68, figs. 17, 18, 20-28. Scarce in Shinzato and Yonabaru assemblages. Length 1.07 mm. Saracenaria angularis Natland Plate 16, figures 19, 20 Saracenaria angularis Natland, 1938, Scripps Inst. Oceanography Bull., tech. ser., v. 4, no. 5, p. 143, pl. 5, figs. 1, 2. F25 Found in limited numbers in the Shinzato only. This form may be a variant of S. italica Defrance. Length 0.94 mm. Genus VAGINULINA d'Orbigny, 1826 Vaginulina tenuis (Bornemann) Plate 3, figure 13 Cristellaria tenuis Bornemann. H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 535, pl. 66, figs. 21-28. Observed rarely in Yonabaru assemblages only. Length 1.56 mm. Vaginulina yoshihamaensis Inoue and Nakaseko Plate 3, figures 11, 12 Vaginulina yoshthamaensis Inoue and Nakaseko, 1951, Geol. Soc. Japan Jour., v. 57, no. 664, p. 10, fig. 2. Seemingly restricted to the shallow-water Logosto- mum pacificum fauna of the Yonabaru. Length 1.40 mm ; width 0.53 mm ; thickness 0.43 mm. Genus LAGENA Walker and Jacob, 1798 Lagena sulcata (Walker and Jacob) var. spirata Bandy Plate 13, figures 32, 38 Lagena sulcata (Walter and Jacob) var. spirata Bandy, 1949, Bull. Am. Paleontology, v. 32, no. 131, p. 57, pl. 7, fig. 18. The Okinawan forms are closely related to this va- riety. There is considerable variation in outline and density of costae as shown by the figured specimens. Rare and found in Chinen assemblages only. Length 0.29 mm; diameter 0.16 mm (fig. 32). Length 0.50 mm ; diameter 0.34 mm (fig. 38). Lagena hystrix Reuss Plate 13, figure 47 Lagena hystriz Reuss, 1862, Akad. Wiss. Wien, Math.-naturwiss. KI., Denkschr., v. 46, Abt. 1, p. 335, pl. 6, figs. 80a, b. Very rare and noted in Shinzato assemblages only. Length 0.59 mm ; diameter 0.34 mm. Lagena striata (d'Orbigny) var. toddi LeRoy, n. var. Plate 13, figure 39 This variety differs from L. striate (d'Orbigny) var. intermedia Rzehak by lacking a basal spine and by being more spherical. It rarely occurs in the Okinawan as- semblages. This variety is named for Ruth Todd of the U.S. Geological Survey. Length 0.56-0.58 mm ; diameter 0.35-0.38 m. Lagena aspera Reuss Plate 13, figure 29 Lagena aspera Reuss. Cushman, 1913, U.S. Natl. Mus. Bull. 71, pt. 3, p. 16, pl. 16, fig. 1. This hispid species rarely occurs in the Yonabaru. Length 0.73 mm ; diameter 0.56 mm. F26 Lagena advena Cushman Plate 14, figure 1 Lagena advena Cushman, 1923, U.S. Natl. Mus. Bull. 104, pt. 4, p. 6, pl. 1, fig. 4. Several specimens were recorded from the Yonabaru only. The neck of the figured specimen is broken. Length 0.51 mm; diameter 0.36 mm. Lagena intermedia Hada Plate 13, figure 41 Lagena intermedia Hada, 1936, Sapporo Nat. Hist. Soc., Trans., Japan, v. 14, p. 244, fig. 4. Only one specimen assignable to this species was re- corded from the Yonabaru. Length 0.60 mm ; diameter 0.24 mm. Lagena laevis (Montagu) var. baggi Cushman and Gray Plate 13, figure 33 Lagena laevis (Montagu) var. baggi Cushman and Gray, 1946, Cushman Lab. Foram. Research Spec. Pub. 19, p. 18, pl. 8, figs. 26, 27. Noted in limited numbers only Chinen and Shinzato assemblages. Length 0.30 mm ; diameter 0.15 mm. Lagena williamsoni (Alcock) Plate 13, figure 40 Lagena williamsoni (Alcock). Cushman, 1923, U.S. Natl. Mus. Bull. 104, pt. 4, p. 61, pl. 11, figs. 8, 9. The Okinawan specimens appear identical to this spe- cies from the Atlantic as figured by Cushman. Very scarce in all the Okinawa assemblages. Length 0.31 mm ; diameter 0.21 mm. Lagena striata (d'Orbigny) var. semistriata Williamson Plate 13, figure 46 Lagena striata (d@'Orbigny) var. semistriata Williamson, 1848, London, Annals and Mag. Nat. History, ser. 2, v. 1, p. 14, pl. 1, figs. 9, 10. The Okinawan specimens show considerable variation in length. The figured specimen is more bulbous than the average but appears to be related to this species. Very rare and recorded only from the Shinzato. Length 0.27 mm ; diameter 0.22 mm. Lagena sulcata (Walker and Jacob) var. spicata Cushman and McCulloch Plate 13, figure 45 Lagena sulcata ((Walker and Jacob) var. spicat@e Cushman and McCulloch, 1950, Allan Hancock Pacific Exped., v. 6, no. 6, p. 360, pl. 48, figs. 3-7. The figured specimen is close to Cushman and Mc- Culloch's figure 6a, b. Both show several rings around the elongate neck. Rare and found only in Chinen assemblages. Length 0.25 mm ; diameter 0.17 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Lagena elongata (Ehrenberg) Plate 13, figure 36 Lagena elongata (Ehrenberg). Cushman, 1923, U.S. Natl. Bull. 104, pt. 4, p. 15, pl. 3, fig. 4. Recorded from the Chinen deposits in limited num- bers. Length 0.88 mm ; diameter 0.12 mm. Lagena distoma Parker and Jones Plate 13, figure 35 Lagena distoma Parker and Jones, 1864, Linnean Soc. London Trans., v. 24, pt. 3, p. 467, pl. 48, fig. 6. Very rare in Shinzato and Yonabaru assemblages. Length 0.74 mm ; diameter 0.13 mm. Lagena striato-punctata Parker and Jones var. bulbosa LeRoy, n. var. Plate 13, figure 34 Differs from the type by being more bulbous and by having a stout basal spine. It is easily identified by the many minute punctations along the base of the costae. Occurs only in the Shinzato assemblages in limited numbers. Length 0.47 mm ; diameter 0.28 mm. Genus OOLINA d'Orbigny, 1839 Oolina squamosa (Montagu) var. apiciglabra (Ten Dam and Reinhold) Plate 13, figure 42 Lagena squamosa (Montagu) var. apiciglabra ten Dam and Reinhold, 1941, Netherlands Geol. Stichting, Meded., Haarlem, ser. c, see. 5, no. 1, p. 48, pl. 2, fig. 11 ; pl. 6, fig. 5. Several specimens were recorded from the Chinen only. Length 0.27 mm ; diameter 0.19 mm. Oolina squamosa (Montagu) var. scalariformis (Williamson) Plate 13, figure 48 Entosolenia squamosa (Montagu) var. scalariformis (William- son), 1848, London, Annals and Mag. Nat. Hist., ser. 2, v. 1, pl. 2, figs. 21, 22. Very rare in Shinzato and Yonabaru assemblages. Length 0.29 mm ; diameter 0.23 mm. Oolina globosa (Montagu) var. setesa (Earland) Plate 13, figure 44 Lagena globosa (Montagu) var. setesa Earland, 1934, Univ. Press, Cambridge, England, v. 10, p. 150, pl. 6, fig. 52. Very scarce and occurs only in the Yonabaru deposits. Length 0.37 mm ; diameter 0.33 mm. Oolina gracilis Williamson var. meridionalis (Wiesner) Plate 13, figure 37 Lagena gracilis Williamson var. meridionalis Wiesner, 1931, Die Foraminiferen der deutschen - Sudpolar-Exped. FORAMINIFERA FROM TERTIARY OF OKINAWA 1901-03. Berlin u. Leipzig, Deutschland, de Gruyter, v. 20 (Zoology, v. 12), p. 117, pl. 18, fig. 211. Scarce in Shinzato assemblages only. Length 0.35 mm ; diameter 0.13 mm. Oolina trigona-pulchella (Balkwill and Millett) Plate 13, figures 30, 31 Lagena trigona-puilchella Balkwill and Millett, 1884, London, Micr. Nat. Sci. Jour., v. 3, p. 81, 87, pl. 3, fig. 11. Recorded rarely in the Chinen deposits only. Length 0.22 mm ; diameter 0.15 mm. Genus LAGENONODOSARIA Silvestri, 1900 Lagenonodosaria scalaris (Batsch) Plate 15, figures 20, 29 Nodosaria scaltaris (Batsch). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 199, pl. 35, fig. 6. Rare in Chinen, Shinzato, and Yonabaru assem- blages. Length 0.77 mm; diameter 0.56 mm (fig. 20). Length 0.98 mm; diameter 0.43 mm (fig. 29). Genus HEMICRISTELLARIA Stache, 1864 Hemicristellaria japonica (Asano) Plate 5, figure 17 Lenticulina japonica Asano, 1936, Japanese Jour. Geology and Geography, v. 13, nos. 3, 4, p. 828, pl. 37, figs. Ta, b. Very rare in Shinzato assemblages; common in the Pliocene of Japan according to Asano. Length 1.18 mm; width 0.74 mm; thickness 0.20 mm. Family POLYMORPHINIDAE Genus GUTTULINA d'Orbigny, 1839 Guttulina orientalis Cushman and Ozawa Plate 11, figures 28, 24 Guttulina orientalis Cushman and Ozawa, 1929, Cushman Lab. Foram. Research Contr., v. 4, p. 15, pl. 2, fig. 1. The figured specimen appears to be within the range of this species that was recorded in limited numbers in Chinen assemblages only. Length 0.54 mm. Guttulina pusilla Stache Plate 11, figures 30, 31 Guttulina pusilla Stache, 1865, Novara-Exped., Geol. Theil, v. 1, Abt. 2, p. 264, pl. 24, fig. 12. Noted in limited numbers in the Logostomum pacifi- cum fauna of the Yonabaru only. Length 0.75 mm. Guttulina pacifica (Cushman and Ozawa) Plate 11, figures 25, 26 Nigmoidella pacifica Cushman and Ozawa, 1929, Cushman Lab. Foram. Research Contr., v. 4, p. 19, pl. 2, fig. 13. F27 Several specimens closely allied to this species were recorded from the Yonabaru. Length 0.74 mm. Genus RAMULINA Rupert Jones, 1875 Ramulina globulifera H. B. Brady Plate 14, figure 2 Ramulina globulifera H. B. Brady, 1884, Challenger Rept., Zool- ogy, v. 9, p. 587, pl. 76, figs. 22-28. Several specimens closely allied to this species were observed in the Chinen and Shinzato deposits. Diameter 0.45 mm. Genus PYRULINA d'Orbigny, 1839 Pyrulina fusiformis (Romer) Plate 5, figure 26 Pyrulina fusiformis (Romer), Cushman and Ozawa, i930, U.S. Natl. Mus. Proc., v. 77, p. 54, pl. 13, figs. 3-8. Only one specimen showing an affinity to this species was noted in the Yonabaru. Length 0.8% mm; width 0.40 mm ; thickness 0.35 mm. Family NONIONIDAE Genus NONION Montfort, 1808 Nonion japonicum Asano Plate 10,_ figures 12, 13 Nonion japonicum Asano, 1938, Geol, Soc. Japan Jour., v. 45, no. 538, p. 593, pl. 15, figs. 1a, b ; 2a, b. Several specimens closely related to this species were recorded from the Chinen Sand. Diameter 0.45-0.58 mm ; thickness 0.24 mm. Nonion pompilioides (Fichtel and Moll) Plate 10, figures 10, 11 Nautilus pompilioides Fichtel and Moll, 1798, Testacea micro- scopica, p. 31, pl. 2, figs. a-c. Nonion pompilioides (Fichtel and Moll). Cushman, 1939, U.S. Geol. Survey Prof. Paper 191, p. 19, pl. 5, figs. 9-12. Rare in Shinzato and Yonabaru assemblages; com- mon in the Pliocene of Japan. Diameter 0.44-0.52 mm ; thickness 0.31 nm. Nonion pompilioides (Fichtel and Moll) var. okinawaense LeRoy, n. var. Plate 10, figures 18, 19 Differs from the type by having a very irregular and deep umbilical depression and by being somewhat thicker; recorded in Shinzato assemblages only. Diameter 0.49-0.56 mm; thickness 0.40-0.42 mm. Nonion nicobarense Cushman Plate 10, figures 14, 15 Nomon nicobarense Cushman, 1936, Lab. Foram. Research Contr., v. 12, p. 67, pl. 12, figs. 9a,b. F28 Common in Yonabaru assemblages; very rare in the Shinzato deposits. Diameter 0.36-0.43 mm ; thickness 0.17 mm. Nonion akitaense Asano Plate 10, figures 16, 17 Nonion a@kitaense Asano, 1950, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 1, p. 1, figs. 1, 2. Recorded in Chinen assemblages only. Diameter 0.18-0.21 mm ; thickness 0.10 mm. Nonion manpukujiense Otsuka Plate 10, figures 22, 23 Nonion manpukujiense Otsuka, 1932 Geol. Soc. Japan Jour., v. 39, no. 467, p. 654, fig. 1. Typical specimens of this species were observed in limited numbers in Yonabaru assemblages only. Diameter 0.43-0.62 mm ; thickness 0.36 mm. Nonion novozealandicum Cushman Plate 10, figures 20, 21 Nonion novozealandicum Cushman, 1936, Cushman Lab. Foram. Research Contr., v. 12, p. 66, pl. 12, figs. 6a, b. Common in the Shinzato; rare in the Yonabaru and Chinen. Diameter 0.55-0.64 mm ; thickness 0.85 mm. Genus ASTRONONION Cushman and Edwards, 1937 Astrononion sp. A LeRoy Plate 6, figures 6, 7 Occurs in limited numbers in Naha assemblages only. Structurally shows an affinity to A. italioum Cushman and Edwards (Cushman, 1939 a, p. 37) but is much smaller. Genus ELPHIDIUM Montfort, 1808 Elphidium poeyanum (d'Orbigny) Plate 9, figures 37, 38 Polystomella poeyana d'Orbigny, 1839, in De la Sagra, His- toire physique, politique et naturelle de l'lHe du Cuba, Foraminiféres, p. 55, pl. 6, figs. 25, 26. Elphidium peoyanum (@'Orbigny). Cushman, 1930, U.S. Natl. Mus. Bull. 104, pt. 7, p. 25, pl. 10, figs. 4, 5. Recorded rarely in Chinen assemblages only. Diameter 0.26 mm ; thickness 0.12 mm. Elphidium simaense Makiyama and Nakagawa Plate 9, figure 30, 31 Elphidium simaense Makiyama and Nakagawa, 1940, Geol. Soc. Japan Jour., v. 48, no. 572, p. 241, fig. 2. Rare in Chinen assemblages only; characterized by its coarse surface texture. Diameter 0.52 mm ; thickness 0.32 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Elphidium tikutoense Nakamura Plate 10, figures 3, 4 Elphidium tikutoensis Nakamura, 1937, Japanese Jour. Geology and Geography Trans. [abs.], v. 14, p. 139, pl. 11, figs. 10a, b. Very scarce in the Naha and Chinen deposits. Diameter 0.26 mm; thickness 0.12 mm. Elphidium advena (Cushman) var. depressula (Cushman) Plate 10, figures 6, 7 Elphidium advenum (Cushman) var. depressulum Cushman, 1933, U.S. Natl. Mus. Bull. 161, pt. 2, p. 51, pl. 12, fig. 4. Occurs in limited numbers in the Chinen. Diameter 0.27 mm; thickness 0.11 mm. Elphidium fax barbarense Nicol Plate 10, figures 1, 2 Elphidium fax barbarense Nicol, 1944, Jour. Paleontology, v. 18, no. 2, p. 178, pl. 29, figs. 10-12. This subspecies was recorded occasionally in the Naha, Chinen, Shinzato, and Yonabaru. Diameter 0.51 mm ; thickness 0.23 mm. Elphidium jenseni (Cushman) Plate 10, figures 8, 9 Elphidium jenseni (Cushman), 1983, U.S. Natl. Mus. Bull. 161, pt. 2, p. 48, pl. 11, figs. 6, 7. Common in the Chinen Sand ; rare in the upper part of the Yonabaru deposits. Diameter 0.32-0.42 mm ; thickness 0.14 mm. Elphidium taiwanum Nakamura Plate 10, figure 5 Elphidium taiwanum Nakamura, 1987, Japanese Jour. Geology and Geography Trans. [abs.], v. 14, nos. 3-4, p. 139, pl. 11, figs. 9a, b. Recorded in limited numbers from the Naha and Chinen only. Diameter 0.88 mm; thickness 0.40 muni. Family CAMERINIDAE Genus OPERCULINA d'Orbigny, 1826 Operculina gaimairdi d'Orbigny Plate 5, figures 13, 14 Operculina gaimairdi d'Orbigny, 1826, Annales sci. nat., v. 7, no. 5, p. 281. Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 375. Rare in the basal part of the Chinen and in the Lozostomum pacificum fauna of the Yonabaru. Diameter 0.85-1.10 mm ; thickness 0.31 mm. Family PENEROPLIDAE Genus PENEROPLIS Montfort, 1808 Peneroplis pertusus (Forskal) Plate 5, figure 20 Peneroplis pertusus (Forskal). Cushman, 1930, U.S. Natl, Mus. Bull. 104, pt. 7, p. 35, pl. 12, figs. 3-6. FORAMINIFERA FROM TERTIARY OF OKINAWA Only several specimens were observed in the shallow- water facies of the Yonabaru. Length 0.64 mm; width 0.48 mm ; thickness 0.23 mm. Family HETEROHELICIDAE Genus BOLIVINOPSIS Yakovlev, 1891 Bolivinopsis hiratai Uchio Plate 1, figure 10 Bolivinopsis hiratai Uchio, 1958, Japanese Jour. Geology and Geography, v. 23, p. 153, pl. 14, fig. 5. Common in limited numbers in the Nomion mico- barense-Cibicides macneili fauna of the Yonabaru. A few specimens having a very fine textured calcareous wall were noted from the Shinzato. Length 0.60 mm ; width 0.14 mm ; thickness 0.08 mm. Genus BOLIVINITA Cushman, 1927 Bolivinita quadrilatera (Schwager) Plate 2, figures 37, 38 Textularia quadrilatera Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 253, p. 7, fig. 10. Bolivinita quadrilatera (Schwager). Cushman, 1942, U.S. Natl. Mus. Bull. 161, pt. 3, p. 2, pl. 1, figs. 1-4. This species, originally described from the "Pliocene" of Kar Nicobar, is common in Shinzato assemblages and scarce in Yonabaru. Forms in the Yonabaru are generally smaller than those in the Shinzato. The spe- cies is widely recorded from the Indo-Pacific region. Length 1.00 mm; width 0.41 mm ; thickness 0.28 mm. Genus PLECTOFRONDICULARIA Liebus, 1903 Plectofrondicularia interrupta (Karrer) Plate 5, figure 25 Frondicularia interrupta Karrer. H. B. Brady, 1884, Chal- lenger Rept., Zoology, v. 9, p. 5283, pl. 66, figs. 6, 7. Very scarce and observed in the Shinzato Member only. Length 0.79 mm; width 0.16 mm. Plectofrondicularia sp. A. LeRoy Plate 5, figure 23 Test strongly compressed, periphery acute, initial end with short spine; chambers distinct, rather uniform in shape, gradually increasing in size as added; sutures distinct, slightly depressed, somewhat extended toward apertural end along medial axis; wall smooth, then finely perforate ; aperture terminal. One specimen of this form was noted from the Shin- zato only. Length 1.30 mm ; width 0.72 mm. Plectofrondicularia foliacea (Schwager) Plate 11, figure 18 Frondicularia foliacea Schwager, 1866. N ovara-Exped., Geol. Theil, v. 2, p. 236, pl. 6, fig. 76. F29 Very rare in Shinzato and Yonabaru assemblages. Length 1.01 mm; width (max.) 0.68 mm. Plectofrondicularia inaequalis (Costa) Plate 11, figure 12 Frondicularia inaequalis Costa, 1855, Mem. Acad. Sci. Napoli, v. 2, p. 372, pl. 3, fig. 8. Several specimens referable to this species were re- corded from the Shinzato and Yonabaru only. Length 1.25 mm; width (max.) 0.50 mm. Plectofrondicularia totomiensis Makiyama Plate 5, figures 18, 19 Plectofrondicularia totomiensis Makiyama, 1931, Kyoto Imp. Univ., Coll. Sci., Mem., ser. B, v. 7, no. 1, p. 51, pl. 2. Several specimens were noted only in the Nonmion nicobarense-Cibicides macneili fauna of the Yonabaru. This species appears to be closely related to P. califor- nica Cushman and Stewart. Length 1.30 mm; width 0.25 mm; thickness 0.12 mm. Genus ORTHOMORPHINA Stainforth, 1952 Orthomorphina challengeriana (Thalmann) Plate 15, figure 26 Nodosaria perversa H. B. Brady [not Schwager], 1884, Chal- lenger Rept., Zoology, v. 9, pl. 64, figs. 25-27. Nodogenerina challengeriana Thalmann, 1937, Eclogae geol. Helvetiae, v. 30, p. 341 (H. B. Brady, 1884, pl. 64, figs. 25-27). Common in deepwater Yonabaru assemblages; rare in the Shinzato. Length 0.82 mm. Family BULILMINIDAE Genus BULIMINOIDES Cushman, 1911 Buliminoides williamsonianus (H. B. Brady) Plate 11, figure 11 Bulimina williamsoniana H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 408, pl. 51, figs. 16, 17. Buliminoides williamsoniana (H. B. Brady). Cushman, 1911, U.S. Natl. Mus. Bull. 71, pt. 2, p. 90, fig. 144. Occurs most frequently in the Chinen ; absent in Shin- zato and Yonabaru; widespread in the late Tertiary and Recent deposits of the Indo-Pacific region. Length 0.53 mm ; diameter 0.21 mm. Genus ROBERTINA d'Orbigny, 1846 Robertina subteres (H. B. Brady) Plate 3, figures 15, 16 Bulimina subteres H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 403, pl. 50, figs. 17, 18. Scarce and recorded in Shinzato assemblages only. Length 0.54 mm; diameter 0.35 mm. F30 Genus BULIMINA d'Orbigny, 1826 Bulimina marginata d'Orbigny Plate 11, figure 2 Bulimina marginata d'Orbigny, 1826, Annales sci. nat., v. 7, p. 269, pl. 12, figs. 10-12. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 119, pl. 28, figs. 5, 6. Occurs in limited numbers in the Naha, Chinen, and Shinzato. Length 0.25 mm; diameter 0.14 mm. Bulimina yonabaruensis LeRoy, n. sp. Plate 11, figure 1 Test about twice as long as broad, last three or four chambers making up three-fourths of the test; sutures distinct, depressed; chambers slightly inflated, finely punctate, smooth, with minute spines on lower margins. This species differs from B. pyrulze d'Orbigny var. spinescens H. B. Brady by the chambers being more elongate. Occurs most commonly in the Yonabarw. Length 0.70 mm; width 0.32 mm. Bulimina subaffinis Cushman Plate 11, figure 3 Buliminae subafinis Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 166, figs. Ta, b. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 126, pl. 29, fig. 7. Rare in the Yonabaru and Shinzato ; widely recorded from late Tertiary and Recent deposits of the South Pacific region. Length 0.50 mm; diameter 0.30 mm. Bulimina inflata Seguenza Plate 11, figure 6 Bulimina inflata Seguenza, 1861, Atti. Accad. Gioen., Sci. Nat. ser. 2, v. 17, p. 25, fig. 10. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 118, pl. 27, figs. 16, 17. Common in both the Shinzato and Yonabaru ; widely recorded in late Tertiary and Recent deposits of the Tropical Pacific. Length 0.55 mm; diameter 0.39 mm. Bulimina aculeata d'Orbigny Plate 11, figure 7 Bulimina aculeata d'Orbigny, 1826, Annales sci. nat., v. 7, p. 269. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 120, pl. 28, figs. 8-11. Recorded in limited numbers from the Shinzato deposits only; common in the Recent deposits of the Indo-Pacific region and in the Miocene and Pliocene formations of Japan. Length 0.40 mm ; diameter 0.25 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Bulimina pupoides d'Orbigny Plate 11, figures 4, 5 Bulimina pupoides d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 185, pl. 11, figs. 11, 12. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 105, pl. 25, figs. 8-7. Rare and sporadic in the Yonabaru and Shinzato. The species exhibits considerable variation in the length-width ratio. Length 0.73 mm; diameter 0.38 mm (fig. 4). Length 0.79 mm ; diameter 0.35 mm (fig. 5). Bulimina subcalva Cushman and K. E. Stewart Plate 11, figure 8 Bulimina subcalva Cushman and K. E. Stewart. Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 116, pl. 27, fig. 5. The figured specimen is from the Logzostomum pa- cificum fauna of the Yonabaru and seems to be closely related to the type originally described from the Pli- ocene of California; occurs in the Pliocene of Japan. Length 0.81 mm ; diameter 0.54 mm. Bulimina microlongistriata LeRoy Plate 11, figure 9 Bulimina microlongistriata LeRoy, 1941, Colorado School of Mines Quart., v. 36, no. 1, p. 32, pl. 1, figs. 97, 98. Extremely rare in the Yonabaru and Shinzato assem- blages ; described originally from the Miocene of central Sumatra. Length 0.78 mm ; diameter 0.42 mm. Bulimina gutta Chapman and Parr Plate 11, figure 10 Bulimina buchiane d'Orbigny var. gutte Chapman and Part, 1937, Australasian Antarctic Exped., ser. c, v. 1, pt. 2, p. 86, pl. 8, fig. 4. | Cushman and Parker, 1947, U.S. Geol. Survey Prof. Paper 210-D, p. 127, pl. 29, fig. 16. This costate species, more elongate than B. rostrata H. B. Brady, is common in the Yonabaru; few speci- mens were recorded from the Shinzato. Length 0.30 mm ; diameter 0.12 mm. Genus GLOBOBULIMINA Cushman, 1927 G@lobobulimina pacifica Cushman Plate 14, figure 3 Globobulimina pacifica Cushman, 1927, Cushman Lab. Foram. Research Contr., v. 3, p. 67, pl. 14, fig. 12. A few specimens recorded in Shinzato assemblages only. Length 0.92 mm ; diameter 0.64 mm. FORAMINIFERA FROM TERTIARY OF OKINAWA Globobulimina globosa LeRoy Plate 14, figure 4 G@lobobulimina globose LeRoy, 1944, Colorado School of Mines Quart., v. 39, no. 3, pt. 1, p. 27, pl. 1, fig. 3; pl. 5, fig. 18. Several specimens referable to this species described originally from the Miocene of central Sumatra were recorded in the Chinen. Length 0.57 mm ; diameter 0.40 mm. Genus BOLIVINA d'Orbigny, 1839 Bolivina albatrossi Cushman Plate 2, figure 15 Bolivina albatrossi Cushman, 1937, Cushman Lab. Foram. Re- search Spec. Pub. 9, p. 153, pl. 18, figs. 22-24. This small form is common in the Shinzato and rare in the Chinen ; not observed in the Yonabaru. Length 0.41 mm; width 0.19 mm; thickness 0.12 mm. Bolivina alata (Seguenza) Plate 2, figure 12 Vulvulina alata Seguenza, 1861, Atti. Acead. Gioen. Sci. Nat. ser. 2, v. 18, p. 115, pl. 2, figs. 5, ba. Bolivina alate (Seguenza). Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 106, pl. 13, figs. 3-11. Recorded in limited numbers from the Chinen and Shinzato only; common in late Tertiary and Recent deposits of the Tropical Pacific region. Length 0.70 mm; width 0.38 mm; thickness 0.22 mm. Bolivina hantkeniana H. B. Brady Plate 2, figure 14 Bolivina hantkeniana H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 424, pl. 52, figs. 16-18. Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 132, pl. 27, fig. 2. Very rare and recorded in the Shinzato only; com- mon in Recent deposits of the Philippine Sea and abundant in the Pliocene of Japan. Length 1.10 mm; width 0.57 mm; thickness 0.26 mm. Bolivina subreticulata Parr Plate 2, figure 16 Bolivina subreticulata Parr, 1932, Royal Soc. Victoria Proc., v. 14, pl. 12, pl. 1, figs. 2la, b. Noted only sporadically and in limited numbers from the Shinzato and from the upper part of the Yona- baru; recorded in Recent deposits of the Tropical Pacific. Length 0.44 mm; width 0.24 mm; thickness 0.16 mm. Bolivina robusta H. B. Brady Plate 2, figure 13 Bolivina robusta H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 421, pl. 53, figs. 7-9. Occurs rather frequently in the Yonabaru and Shin- F31l zato; widely recorded from late Tertiary and Recent deposits of the Indo-Pacific region ; common in the Plio- cene of Japan. Length 1.00 mm; width 0.48 mm; thickness 0.32 mm. Bolivina plano-convexa Cushman and Todd Plate 2, figure 7 Bolivina plano-convezsa Cushman and Todd, 1945, Cushman Lab. Foram. Research Spec. Pub. 15, p. 48, pl. 7, fig. 16. Originally described from the Miocene of Jamaica; observed in limited numbers in the Nomion micobarense- Cibicides maeneili fauna of the Y onabaru only. Length 0.97 mm; width 0.54 mm; thickness 0.30 mm. Bolivina subangularis H. B. Brady var. agasaensis Asano Plate 2, figures 24, 25 Bolivina subangularis H. B. Brady var. agasaensis Asano, 1936, Japanese Jour. Geology and Geography, v. 13, figs. 3, 4; p. 331, fig. 8. Occasionally present in the Chinen ; rare to common in the Pliocene of Japan. Length 0.63 mm; width 0.31 mm; thickness 0.25 mm. Bolivina striatula Cushman Plate 2, figure 8 Bolivina striatule Cushman, 1937, Cushman Lab. Foram. Re- search Spec. Pub. 9, p. 154, pl. 18, figs. 30, 31. Several typical specimens were recorded from the Naha and Chinen deposits only. Length 0.55 mm; width 0.16 mm; thickness 0.12 mm. Bolivina spinescens Cushman Plate 2, figure 21 Bolivina spinescens Cushman, 1937, Cushman Lab. Foram. Re- search Spec. Pub. 9, p. 142, pl. 18, figs. 17-19. Rarely found in Chinen assemblages only. Length 0.33 mm; width 0.14 mm; thickness 0.10 mm. Bolivina capitata Cushman Plate 2, figure 9 Bolivina capitate Cushman, 1933, Cushman Lab. Foram. Re search Spec. Pub: 9, p. 80, pl. 8, figs. 12a, b. Few specimens recorded from the Chinen deposits only. The type was described from Recent deposits off Levuka, Fiji. Length 0.66 mm; width 0.18 mm; thickness 0.12 mm. Bolivina chinenensis LeRoy, n. sp. Plate 2, figures 10, 11 Length about two times maximum width, broadens rather rapidly toward apertural end, moderately com- pressed; chambers distinct, noninflated; sutures dis- tinct, curved, and angle about 45° in upper half ; periph- ery sharply rounded with distinct blunt spines in lower half; wall minutely punctate, a few scattered minute F32 beads of clear shell material on surface; aperture elon- gate with faint rim. This species is closely allied to B. seranensis Ger- meraad, described from the Neogene of Ceram, Indo- nesia, but differs by being thicker and exhibiting more surface beads on the upper half of the test and by more peripheral irregularity. The peripheral spines and suture beads characterize the species which is named after the village of Chinen. It is rare and was found in the Chinen Sand only. Length .0.42-0.45 mm; width 0.17-0.20 mm; thickness 0.10-0.12 mm. Genus FISSURINA Reuss, 1850 Fissurina fasciata (Egger) var. spinosa (Sidebottom) Plate 13, figurgs 11,12 Lagena fasciata Egger var. spinosa Sidebottom, Quekett, 1912, Micr. Club Jour., ser. 2, v. 11, pl. 17, figs. 16a, b, 17. Observed in limited numbers from the Yonabaru only. Length 0.30 mm; width 0.24 mm; thickness 0.17 mm. Fissurina echigoensis (Asano and Inomata), var. Plate 13, figures 9, 10 Entosolenia echigoensis Asano and Inomata, 1952, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Ter- tiary Smaller Foraminifera, supp. 1, p. 7, figs. 35, 36. The Okinawan specimens, somewhat less elongate than the type, occurs rarely in Yonabaru assemblages only. Length 0.24 mm; width 0.23 mm; thickness 0.19 mm. Fissurina semiopaca (Wiesner) Plate 13, figures 19, 20 Lagena (Entosolenia) semiopaca Wiesner, 1931, Deutsche Sud- polar-Exped., Berlin u. Leipzig, v. 20 (Zoology), p. 120, pl. 19, fig. 223. Very rare in Chinen deposits only. Length 0.54 mm; width 0.49 mm; thickness 0.32 mm. Fissurina ventricosa (Silvestri) Plate 13, figures 13, 14 Lagena ventricosa Silvestri, 1904, R. Accad. Sci. Torino, Atti Italia, v. 39, p. 11, fig. 6. Only a few specimens were recorded from the Yonabaru. Length 0.45 mm; width 0.41 mm; thickness 0.33 mm. Fissurina aff. F. crebra (Matthes) Plate 13, figures 15, 16 Lagena crebra Matthes, 1939, Paleontography Stuttgart, v. 90, Abt. A, p. 72, pl. 5, figs. 66-70. Very rare in Chinen assemblages only. Length 0.21 mm; width 0.18 mm; thickness 0.11 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Fissurina crebra (Matthes) var. scissa (Matthes) Plate 13, figures 27, 28 Lagena crebra Matthes var. scissa Matthes, 1939, Paleontography Stuttgart, v. 90, Abt. A, p. 73, pl. 5, figs. 71-74. Very rare in the Chinen deposits. Length 0.25 mm; width 0.20 mm; thickness 0.14 mm. Fissurina lacunata (Burrows and Holland) Plate 13, figures 17, 18 Lagena lacunata Burrows and Holland, 1895, in Jones, Palaeont. Soc. Pub., p. 205, pl. 7, fig. 12. Fissurina lacunate (Burrows and Holland) Cushman, Todd, and Post. 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 351, pl. 87, fig. 28. A few specimens were noted from the Chinen only. Length 0.29 mm; width 0.24 mm; thickness 0.12 mm. Fissurina radiato-marginata (Parker and Jones) Plate 13, figures 5, 6 Lagena radiato-marginata Parker and Jones, Trans., v. 155, p. 355, pl. 18, fig. 3. Fissurina radiato-marginata (Parker and Jones),. Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 351, pl. 87, fig. 29. A few specimens were found in the Chinen deposits only. Length 0.37 mm; width 0.19 mm; thickness 0.10 mm. Fissurina castrensis (Schwager) var. pacifica LeRoy, n. var. Plate 13, figures 7, 8 Differs from the type described from the Pliocene of Kar Nicobar by having several low peripheral ridges between the two well-developed outer ones; noted rarely in the Shinzato. Length 0.60-0.62 mm; width 0.46-0.49 mm; thickness 0.32-0.36 mm. 1865, Philos. Fissurina lunata (Matthes) Plate 13, figures 21, 22 Lagena lunata Matthes, 1939, Paleontography Stuttgart, v. 90, Abt. A, p. 90, pl. 8, figs. 153, 154. The Okinawan specimens are very closely related to this species which occurs in limited numbers in Yona- baru assemblages only. Length 0.32 mm ; width 0.27 mm ; thickness 0.15 mm. Fissurina enderbiensis (Chapman) Plate 13, figures 23, 24 Lagena enderbiensis Chapman, 1909, Philosophical Canterbury, v. 1, p. 339, pl. 16, figs. la, b. Rarely found in the Shinzato only. Length 0.28 mm ; width 0.15 mm ; thickness 0.08 mm. Inst. Fissurina perforata LeRoy, n. sp. Plate 13, figures 25, 26 Test compressed, about twice as long as broad, base rounded and with spine; periphery subacute with blunt FORAMINIFERA FROM TERTIARY OF OKINAWA narrow rim; surface finely perforate; aperture ellipti- cal, at end of short neck. Similar to F. milletti Todd but differs by having a less extended neck, by possessing a blunt basal spine, and by showing finer perforations. Rare in Shinzato assemblages only. Length 040-042 mm; width 0.21-0.23 mm; thickness 0.10-0.13 mm. Genus VIRGULINA d'Orbigny, 1826 Virgulina schreibersiana Czjzek Plate 3, figure 14 Virgulina schreibersiana Czjzek. Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 13, pl. 2, figs. 11-20. Observed rarely in only Naha and Chinen deposits. Length 0.83 mm ; width 0.15 mm. Genus LOXOSTOMUM Ehrenberg, 1854 Loxostomum compressum LeRoy, n. sp. Plate 2, figures 29, 30 Test small for the genus, very compressed, sides sub- parallel; periphery acute with narrow flange; chambers enlarge rapidly, noninflated ; sutures distinct, angles at about 45°, flush with surface; wall smooth; aperture narrow with slight rim. This species is very similar to B. nitide Brady (1884) originally described as B. laevigata (1881). It differs, however, by showing a more pronounced peripheral flange and less depression of the sutures. Very rare in the Yonabaru. Length 0.42-0.44 mm; width 0.18-0.21 mm; thickness 0.50-0.07 nam. Loxostomum lobatum (H. B. Brady) Plate 2, figure 19 Bolivina lobata H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 425, pl. 53, figs. 22, 23. Lozostoma lobatum (H. B. Brady). Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 188, pl. 22, figs. 2-4. Few specimens observed in Chinen assemblages only. Length 0.30 mm ; width 0.11 mm ; thickness 0.08 mm. Loxostomum limbatum (H. B. Brady) var. costulatum (Cushman) Plate 2, figure 20 Logostoma limbatum (H. B. Brady) var. costulatum (Cush- man), 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 187, pl. 21, figs. 20, 21. Recorded in very limited numbers from Chinen de- posits only. Length 0.71 mm; width 0.25 mm; thickness 0.08 mm. Loxostomum karrerianum (H. B. Brady) Plate 2, figures 26, 27 Bolivina karrerianum H. B. Brady, 1884, Challenger Rept., Zool- ogy, v. 9, p. 424, pl. 53, figs. 19-21. F33 Lozostoma karrerianum (H. B. Brady). Cushman, 1937, Cush- man Lab. Foram. Research Spec. Pub. 9, p. 184, pl. 21, fig. 17. Recorded in Chinen assemblages and in limited numbers. Length 0.60 mm; width 0.21 mm ; thickness 0.14 mm. Loxostomum amygdalaeforme (H. B. Brady) var. iokiense Asano Plate 2, figures 22, 23 Lozostomum amygdalaeforme (H. B. Brady) var. iokiense Asano, 1938, Geol. Soc. Japan Jour., v. 45, no. 538, p. 605, pl. 16, figs. 3a, b. Present in limited numbers in the Chinen and Shin- zato, and in the upper part of the Yonabaru. Length 0.54 mm; width 0.22 mm ; thickness 0.15 mm. Loxostomum pacificum LeRoy, n. sp. Plate 2, figures 31, 32 Test two to three times as long as broad, thick, periph- ery broadly rounded, sides nearly parallel; chambers indistinct, only faintly inflated; sutures slightly de- pressed, somewhat crenulated, indistinct; wall with faint costae, which on some specimens are almost absent ; aperture elongate with low marginal rim. This species differs from L. limbatum (H. B. Brady) var. costulatum Cushman by being more robust, thicker, and by developing a more pronounced uniserial stage. In some respects it shows an affinity to L. digitale (d'Orbigny). The species appears to be restricted to the upper part of the Yonabaru and typifies the Lozostomum pacificum fauna. Length 0.97 mm; width 0.36 mm; thickness 0.25 mm. Loxostomum okinawaense LeRoy, n. sp. Plate 2, figures 17, 18 Test elongate, about five times as long as wide, twisted, gradually increasing in width toward apertural ex- tremity ; periphery broadly rounded ; chambers distinct, last two or three inflated ; sutures distinct, wide, nearly horizontal in early stage, up to 45° in later stage, flush to faintly raised; wall coarsely punctate; aperture elongate, comma shaped. This species is similar to L. cepitate (Cushman) described from Recent deposits off Levuka, Fiji, but differs by being more coarsely perforate and twisted. Recorded in limited numbers in Naha assemblages only. Length 0.4%-0.49 mm; width 0.12-0.15 mm; thickness 0.10-0.12 mm. F3A Genus RECTOBOLIVINA Cushman, 1927 Rectobolivina? virgula (H. B. Brady) Plate 3, figure 7 Sagrina virgula H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 583, pl. 66, figs. 4-10. Observed rarely in Chinen assemblages only. Length 0.47 mm ; diameter 0.11 mm. Rectobolivina dimorpha (Parker and Jones) Plate 3, figures 3, 4 Siphogenerina dimorpha (Parker and Jones). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 279, pl. 56, fig. 8. Very rarely found in Shinzato and Yonabaru assem- blages. Length 0.95 mm ; diameter 0.31 mm. Rectobolivina bifrons (H. B. Brady) Plate 3, figures 1, 2 Bagrina bifrons Brady, 1884, Challenger Rept., Zoology, v. 9, p. 582, pl. 75, figs. 18-20. Rectobolivina bifrons (H. B. Brady). Cushman, 1937, Cush- man Lab. Foram. Research Spec. Pub. 9, p. 204, pl. 23, figs. 13, 14. This species commonly occurs in Recent sediments of the South Pacific and in the late Tertiary of the Indo- Pacific. It was observed in limited numbers within the Shinzato and the Lozostomum pacificum fauna of the Yonabaru. The species is common in the Pliocene of Japan. Cushman recorded the species as common from the following depths: 19, 272, and 554 fathoms, off the Philippines. Length 0.97 mm. Rectobolivina bifrons (H. B. Brady) var. striatula (Cushman) Plate 3, figures 5, 6 Rectobolivina bifrons (H. B. Brady) var. striatulae (Cushman), 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 205, pl. 23, figs. 17, 18. Common in the shallow-water facies of the Yonabaru deposits; rare in the Shinzato. Length 0.96 mm ; width 0.28 mm. Genus REUSSELLA Galloway, 1933 Reussella spinulosa (Reuss) Plate 3, figure 19 Verneuilina spinulosa Reuss, 1850, Akad. Wiss. Wien, Math- naturwiss. Kl. Denkschr., v. 1, p. 374, pl. 47, fig. 12. Recorded rarely in the Naha and Chinen assemblages and in the Logostomum pacifcum fauna of the Yona- baru. Length 0.39 mm ; width (max.) 0.25 mm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Genus BITUBULOGENERINA Howe, 1934 Bitubulogenerina convallaria (Millett) Plate 2, figure 28 Bolivina convallaria Millett, 1900, Royal Micr. Soc. Jour., p. 544, pl. 4, figs. 6a, b. Lozostoma convallarium (Millett). Cushman, 1937, Cushman Lab. Foram. Research Spec. Pub. 9, p. 191, pl. 22, figs. 11-18. A few specimens referable to this species were re- corded in Chinen assemblages only. Length 0.39 mm; width 0.09 mm. Genus UVIGERINA d'Orbigny, 1826 Uvigerina striatella Reuss Plate 3, figure 42 Uvigerina striatelle Reuss, 1851, Deutsche geol. Gesell. Zeitschr., v. 3, p. 159, pl. 8, fig. 7. Rare in Shinzato and Yonabaru assemblages; most common in the shallow-water deposits of the Yonabaru. Length 0.90 mm. Uvigerina gemmaeformis Schwager Plate 3, figure 39 Uvigerina gemmaeformis Schwager, 1866, Novara-Exped., Geo. Theil, v. 2, p. 247, pl. 7, fig. 92. Recorded in limited numbers from the shallow- water deposits of the Yonabaru only. Length 1.07 mnm. Uvigerina hispida Schwager Plate 4, figures 2, 3 Uvigerina hispida Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 249, pl. 7, fig. 95. Rare in Shinzato and Yonabaru assemblages. Length 0.80-0.90 mm. Uvigerina aculeata d'Orbigny Plate 3, figures 40, 41 Uvigerina aculeate d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiare de Vienne, p. 191, pl. 11, figs. 27, 28. Occurs in limited numbers and is seemingly restricted to the Shinzato. Length 0.67 mm. Uvigerina peregrina Cushman var. dirupta Todd Plate 4, figure 4 Uvigerina peregrina Cushman var. dirupte Todd, 1948, Allan Hancock Pacific Exped., v. 6, no. 5, p. 267, pl. 34, fig. 3. Occurs in limited numbers in Shinzato and Yonabaru assemblages, particularly in the Yonabaru. Length 0.60 mm ; width 0.34 mm. FORAMINIFERA FROM TERTIARY OF OKINAWA Uvigerina hispido-costata Cushman and Todd Plate 16, figure 7 Uvigerina hispido-costate Cushman and Todd, 1945, Cushman Lab. Foram. Research Spec. Pub. 15, p. 51, pl. 7, figs. 27, 31. The Okinawan specimens, only occasionally found in the Nonion micobarense-Cibicides macneili fauna of the Yonabaru, tend to show less spinosity of the costae than the typical. The figured specimen may well be a varietal form of U. peregrina Cushman. Length 0.53 mm. Uvigerina crassicostata Schwager Plate 4, figure 1 Uvigerina crassicostata Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 248, pl. 7, fig. 94. Rare in Shinzato and Yonabaru assemblages. Length 1.16 mm. Uvigerina proboscidea Schwager Plate 16, figure 8 Uvigerina proboscidea Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 250, pl. 7, fig. 96. Rare in Shinzato and Yonabaru assemblages. Length 0.47 mm. Uvigerina proboscidea Schwager var. vadescens Cushman Plate 3, figure 38 Uvigerina proboscides Schwager var. vadescens Cushman, 1933, Cushman Lab. Foram. Research Contr., v. 9, p. 85, pl. 8, figs. 14, 15. Recorded in limited numbers in Chinen, Shinzato, and Yonabaru. Length 0.59 mm. Uvigerina nitidula Schwager Plate 3, figure 37 Uvigerina nitidula Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 248, pl. 7, fig. 93. Recorded in limited numbers in Shinzato assemblages only. Length 0.72 mnm. Genus RECTUVIGERINA Mathews, 1945 Rectuvigerina striata (Schwager) Plate 3, figure 8 Dimorpha striata Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 251, pl. 7, fig. 99. Biphogenerina striate (Schwager). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 280, pl. 56, fig. 5. Recorded in limited numbers in Shinzato assemblages only; widely recorded in late Tertiary deposits of In- donesia. Length 0.72 mm ; diameter 0.23 mm. F35 Genus SIPHOGENERINA Schlumberger, 1883 Siphogenerina raphanus (Parker and Jones) Plate 3, figure 35 ; plate 16, figure 9 Uvigerina (Sagrina) raphanus Parker and Jones, 1865, Philos. Trans., v. 155, p. 364, pl. 18, figs. 16, 17. Siphogenerina raphanus (Parker and Jones). Cushman, 1942, U.S. Natl. Mus. Bull. 161, pt. 3, p. 55, pl. 15, figs. 6-9. Common in the Lozostomum pacificum fauna of the Yonabaru; occasionally recorded in Naha, Chinen, and Shinzato. Length 1.10 mm. Genus STILOSTOMELLA, Guppy, 1894 Stilostomella lepidula (Schwager) Not illustrated Nodosaria lepidula Schwager, 1886, Novara-Exped., Theil, v. 2, p. 210, pl. 5, figs. 27, 28. Siphonodosaria lepidule (Schwager). Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 356, pl. 88, figs. 27, 28. Abundant in Shinzato and Yonabaru assemblages. Dimension : Length 0.73 mm. USGS locality : £11536 (WF-274, Yonabaru Member). USNM 625393. Stilostomella ketenziensis (Ishizaki) Plate 15, figure 33 Ellipsonodosaria ketenziensis (Ishizaki), 1948, Nat. Hist. Soc. Taiwan Trans., v. 33, p. 684, figs. 1, 6, 11. Rare in Shinzato assemblages; sporadic in the Yo- nabaru. Length 1.70 mm. Genus TRIFARINA Cushman, 1923 Trifarina bradyi Cushman Plate 3, figures 17, 18 Trifarina bradyi Cushman, 1923, U.S. Natl. Mus. Bull. 104, pt. 4, p. 99, pl. 22, figs. 3-9. Constantly recurring in limited numbers in Chinen, Shinzato, and Yonabaru; abundant in Recent deposits of the South Pacific. Length 0.36 mm ; width 0.16 mm. Genus ANGULOGERINA Cushman, 1927 Angulogerina japonica Asano Plate 5, figure 24 Geol. Angulogerina japonica Asano, 1938, Geol. Soc. Japan Jour., v. 45, no. 538, p. 615, pl. 17, fig. 17. Very rare in Shinzato and Yonabaru assemblages. Length 0.29 mm ; thickness 0.14 mm. Genus PATELLINELLA Cushman, 1928 Patellinella jugosa (H. B. Brady) Plate 2, figures 33, 34 Teatularia jugosa H. B. Brady, 1884, Challenger Rept., Zo- ology, v. 9, p. 358, pl. 42, figs. Ta, b. F36 A few specimens were recorded in the Chinen and Shinzato. Length 0.25 mm; width 0.21 mm; thickness 0.12 mm. Patellinella inconspicua (H. B. Brady) Plate 2, figures 35, 36 Teatularia inconspicua H. B. Brady, 1884, Challenger Rept., Zo- ology, v. 9, p. 357, pl. 42, figs. Ga, b. Discobolivina inconspicuae (H. B. Brady). Siboga-Exped., pt. 3, p. 431, fig. 296. This distinctive species, more circular in plan view than Brady's form, was recorded in limited numbers in the Chinen. Length 0.21 mm ; width 0.26 mm ; thickness 0.24 mm. Hofker, 1951, Family ELLIPSOIDINIDAE Genus PLEUROSTOMELLA Reuss, 1860 Pleurostomella alternans Schwager Plate 5, figure 5 Pleurostomella alternans Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 238, figs. 79, 80. Noted in restricted numbers in the Shinzato and in the upper part of the Yonabaru. Length 1.40 mm; width 0.27 mm; thickness 0.22 mm. Pleurostomella brevis Schwager Plate 5, figure 4 Pleurostomella brevis Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 239, pl. 6, fig. 81. Rare in Shinzato and Yonabaru assemblages. Length 0.60 mm; width 0.40 mm; thickness 0.37 mm. Family ROTALIIDAE Genus ROSALINA d'Orbigny, 1826 Rosalina isabelleana d'Orbigny Plate 7, figures 51, 52 Rosalina isabelleana d'Orbigny, 1839, Voyage dans l'Amerique Méridonale, v. 5, p. 43, figs. 10-12. Discorbis isabelleana (@'Orbigny). Cushman, 1915, U. S. Natl. Mus. Bull. 71, pt. 5, p. 15, pl. 6, fig. 1. This species was noted in limited numbers in the Chinen deposits. It ranges through the Miocene and Pliocene section of Japan. Diameter 0.24-0.29 mm; thickness 0.11 mm. Rosalina stacyi LeRoy, n. sp. Plate 7, figures 42-44 Test small for the genus, nearly equally biconvex; periphery slightly lobulate, subacute; chambers dis- tinct, generally five in last whorl, moderately inflated, particularly the last one; chambers gradually increase in size as added; sutures distinct, depressed, slightly curved; some specimens have umbilical plug of clear shell material; wall distinctly perforate; test is light SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY brown; aperture an elongate opening at base of last chamber. This distinctive species cannot be compared with any published form. It appears to be confined to the Chi- nen deposits The species is named for J. R. Stacy (scientific illustrator, U.S. Geol. Survey) who com- pleted most of the illustrations in this paper. Diameter 0.32-0.38 mm; thickness 0.14-0.16 mm. Genus NEOCONOBRINA Hofker, 1951 Neoconobrina nakamurai (Asano) Plate 7, figures 45-47 Discorbis nakamurai Asano, 1951, Inst. Geology and Paleon- tology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 14, p. 2, figs. 8-10. This distinctive species, originally described from the Pliocene of Japan, was recorded in restricted numbers from the Chinen deposits only. The species is easily identified by its peripheral spines, conical cross section, and granulosity near the center on the ventral side. Diameter 0.25-0.29 mm ; thickness 0.12 mm. Neoconobrina opercularis (d'Orbigny) Plate 9, figures 9, 10 Rosalina opercularis d'Orbigny, 1839, in De la Sagra, Histoire physique, politique et naturelle de l'le de Cuba, Fora- miniféres, p. 101, pl. 3, figs. 24, 25. Discorbis opercularis (@'Orbigny). Cushman, 1915, U.S. Natl. Mus. Bull. 71, pt. 5, p. 18, pl. 11, fig. 3. This species was observed in the Chinen only and in the Loxostomum pacifieum fauna of the Y onabaru. Its tubercled ventral side, strongly curved sutures, and coni- cal cross section distinguish the species. It is found frequently in the Pliocene of Japan. Diameter 0.28-0.36 mm; thickness 0.10 mm. Neoconobrina pacifica LeRoy, n. sp. Plate 4, figures 26-28 Test nearly circular in plan view, more convex dorsally than ventrally; generally five chambers in last whorl, noninflated; ventral sutures slightly depressed, slightly curved; dorsal sutures flush with surface, broad, strongly curved and oblique; wall coarsely punc- tate dorsally, finely punctate veritrally ; periphery sub- acute with narrow rim containing minute radiating pores ; aperture small at base of last chamber. Similar to but differs from Necoconobrina (Discorbis) australis (Parr) by being somewhat convex ventrally instead of being slightly concave. Diameter 0.43-0.47 mm; thickness 0.28-0.30 mm. Genus ROTORBINELLA Bandy, 1944 Rotorbinella chinenensis LeRoy, n. sp. Plate 7, figures 48-50 Test small for the genus, more convex dorsally than ventrally, nearly circular in plan view, periphery sub- FORAMINIFERA FROM TERTIARY OF OKINAWA acute, with narrow border of clear shell material ; cham- bers distinct, six to seven in last whorl, noninflated, enlarge very gradually as added ; sutures distinct, flush with surface and strongly oblique dorsally, slightly de- pressed radial and faintly curved ventrally; distinct ventral umbilical plug; wall finely perforate; aperture elongate at base of last chamber extending toward ven- tral umbilical plug. This species appears to be related to D. turbo (d'Orbigny) as figured by Brady (1884, p. 642, pl. 87, figs. Sa-c) but which shows broader ventral sutures and more convexity of dorsal side. The species commonly occurs in the Chinen assemblages. Diameter 0.24-0.28 mm ; thickness 0.12 mm. Genus LAMARCKINA Berthelin, 1881 Lamarckina ventricosa (H. B. Brady) Not illustrated Discorbina ventricose H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 654, pl. 91, figs. Ta, c. Several specimens closely related to this species were recorded in the Chinen deposits. Diameter 0.48-0.53 mm ; thickness 0.38 mm. USGS locality : £11541 (ME-21, Chinen formation). USNM 625391. Genus VALVULINERIA Cushman, 1926 Valvulineria laevigata Phleger and Parker Plate 16, figures 27, 28 Valvulineria laevigata Phleger and Parker, 1951, Geol. Soc. America Mem. 46, pt. 2, p. 25, pl. 13, figs. 11, 12. Observed in limited numbers in Yonabaru assem- blages only. Diameter 0.23-0.25 mm; thickness 0.16 mm. Genus GYROIDINA d'Orbigny, 1826 Gyroidina trincherasensis Bermudez Plate 7, figures 1-3 Gyroidina trincherasensis Bermudez, 1949, Cushman Lab. Foram. Research Spec. Pub. 25, p. 254, pl. 17, figs. 55-57. This form, having a concave dorsal side, is common in the Shinzato and Yonabaru. The dorsal sutures of the Okinawan specimens appear to be somewhat less curved than shown by the figure of the type. Diameter 0.51 mm; thickness 0.43 mm. Gyroidina cibacensis Bermidez Plate 7, figures 16-18 Gyroidina cibacensis Bermfdez, 1949, Cushman Lab. Foram. Research Spec. Pub. 25, p. 252, pl. 17, figs. 61-63. Most common in the Shinzato and rare in the Yona- baru. Diameter 0.40 mm ; thickness 0.27 mm. F37 Gyroidina neosoldanii Brotzen Plate 7, figures 4-6 Rotalia soldanii d Orbigny. H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 706, pl. 107, figs. 6, 7. Gyroidina neosoldanii Brotzen, 1936, Sweden, Sveriges geol. un- dersokning Avh., ser. 'C, no. 396, p. 158, pl. 107, figs. 6, 7 (of Brady). Recorded rarely in Yonabaru assemblages only. Most of the specimens exhibit a more rounded peripheral mar- gin than the one illustrated. Diameter 0.80 mm; thickness 0.58 mm. Gyroidina altispira Cushman and Stainforth Plate 7, figures 10-12 Gyroidina altispira Cushman and Stainforth, 1945, Cushman Lab. Foram. Research Spec. Pub. 14, p. 61, pl. 11, fig. 1. Several small specimens showing an affinity to this species were recorded from the Shinzato. Diameter 0.51 mm; thickness 0.38 mm. Gyroidina altiformis R. E. and K. E. Stewart Plate 7, figures 7-9 Gyroidina soldanii d'Orbigny var. altiformis R. E. and K. E. Stewart, 1938, Jour. Paleontology, v. 4, p. 67, pl. 9, fig. 2. Rare in the Shinzato and Yonabaru. The specimens are somewhat smaller than the type but are morphologi- cally similar. Diameter 0.50 mm; thickness 0.40 mm. Gyroidina nipponica Ishizaki Plate 7, figures 13-15 Gyroidina nipponica Ishizaki, 1944, Nat. Hist. Soc. Taiwan Trans., v. 34, no. 244, p. 102, pl. 3, fig. Sa-c. Seldom found in the Yonabaru only. Diameter 0.28 mm ; thickness 0.21 mm. Genus EPONIDES Montfort, 1808 Eponides margaritiferus (H. B. Brady) Plate 7, figures 19-21 Truncatulina margaritifera H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 667, pl. 96, figs. Za-c. This species was only noted from late Tertiary de- posits on Heanna Island off the east coast of Okinawa. It is a form widely recorded in late Tertiary and Recent sediments of the Indo-Pacific region. Diameter 0.89 mm ; thickness 0.50 mm. Eponides hyalinus (Hofker) Plate 7, figures 24-26 Cibicides hyalina Hofker, 1951, Siboga-Exped., pt. 3, p. 359, figs. 244, 245. Rather common in the Nomion nicobarense-Cibicides maecneili fauna of the Yonabaru. Diameter 0.37 mm ; thickness 0.21 mm. F38 Eponides praecintus (Karrer) Plate 7, figures 30-32 Rotalia praecinta Karrer, 1868, Akad, Wiss. Wien, Sitzungsber., v. 58, p. 189, pl. 5, fig. 7. Truncatulina praecint@e (Karrer). Cushman, 1915, U.S. Natl. Mus. Bull. 71, pt. 5, p. 39, pl. 26, fig. 2. Commonly occurs in the shallow-water deposits of the Naha, Chinen, and Yonabaru; rare in Shinzato assemblages. Diameter 0.81 mm ; thickness 0.48 mm. Eponides procerus (H. B. Brady) Plate 7, figures 22, 23 Pulvinulina procera H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 698, pl. 105, figs. Ta-c. Occurs frequently in the Lowzostomum pacificum fauna of the Yonabaru; common in the late Tertiary and Recent deposits of the Indo-Pacific region. Diameter 0.60 m ; thickness 0.53 mm. Eponides subornatus (Cushman) Plate 7, figures 27-29 Pulvinulina berthelotiana d'Orbigny var. suwbornate Cushman, 1931, U.S. Natl. Mus. Bull. 100, v. 4, p. 333, pl. 70, figs. la-c. Appears most frequently in the Lozostomum paci- ficwm fauna of the Yonabaru; only a few specimens were noted in the Shinzato and Chinen. Diameter 0.62 mm ; thickness 0.43 mm. Genus OSANGULARIA Brotzen, 1940 Osangularia bengalensis (Schwager) Plate 9, figures 32, 33 Anomalina bengalensis Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 259, pl. 7, fig. 111. Osangularia bengalensis (Schwager). Cushman, Todd, and Post, 1954. U.S. Geol. Survey Prof. Paper 260-H, p. 360. pl. 89. fig. 21. Schwager originally defined this species from the Pliocene of Kar Nicobar. It occurs in limited numbers in the Yonabaru and Shinzato; attains greater dimen- sions in the Shinzato. Diameter 0.67-0.75 mm ; thickness 0.46 mm. Genus STREBLUS Fischer, 1917 Streblus beccarii tepida (Cushman) Plate 4, figures 16, 17 Rotalia beccarii (Linné) var. tepida Cushman, 1931, U.S. Natl. Mus. Bull. 104, pt. 8, p. 61, pl. 13, figs. 3a-c. Present in limited numbers in the Naha and Chinen only. Diameter 0.60 mm ; thickness 0.30 nm. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Genus PARAROTALIA LeCalvez, 1949 Pararotalia yonabaruensis LeRoy, n. sp. Plate 4, figures 23-25 Test strongly convex ventrally, slightly convex dor- sally, irregularly umbilicate ventrally, frequently shows distinct, irregular ventral plug, periphery subacute, lobulate, with narrow flange and with blunt spines or slight protuberances; chambers distinct, 6 to 7 in last whorl, slightly inflated, enlarge only gradually as added ; ventral sutures deeply depressed, nearly straight but somewhat oblique, sometimes bordered with minute beads of clear shell material; dorsal sutures flush with surface, slightly oblique; aperture small at base of last chamber just below peripheral margin and opening into ventral umbilical region. Diameter 0.39-0.44 mm; thickness 0.25 mm. Genus ROTALIDIUM Asano, 1936 Rotalidium okinawaensis LeRoy, n. sp. Plate 4, figures 290-31 Test nearly equally biconvex, almost circular in plan view; chambers distinct, 7 to 10 in last whorl, enlarg- ing very gradually as added; dorsal sutures flush, straight to slightly curved ; ventral sutures slightly de- pressed, straight; periphery sharply rounded, faintly lobulate; ventral umbilical area raised and with irreg- ular mass of clear shell material; wall smooth and mi- nutely punctate; aperture small and at base of last chamber near peripheral margin. Differs from R. pacifcum Asano by showing more convexity of the dorsal side, thus more equally biconvex. Diameter 0.52 mm ; thickness 0.30 mm. Genus ROTALIA Lamarck, 1804 Rotalia stachi Asano Plate 16, figures 34-36 Rotalia stachi Asano, 1951, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 13, p. 14, figs. 10-12. Common in the basal part of the Chinen and rare in the Lozostomum pacificum fauna of the Yonabaru. Diameter 0.96 mm ; thickness 0.63 mm. Genus HOEGLUNDINA Brotzen, 1948 Hoeglundina elegans (d'Orbigny) Plate 6, figures 27, 28 Rotalia (Turbinulina) elegans d'Orbigny. 1826, Annales sci. nat., v. 7, p. 276. Hoeglundina elegans (d'Orbigny). Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 360, pl. 89, fig. 28. Common in the Shinzato and in the upper part of the Yonabaru. Diameter 1.22 mm ; thickness 0.60 mm. FORAMINIFERA FROM TERTIARY OF OKINAWA Genus POROEPONIDES Cushman, 1944 Poroeponides cribrorepandus Asano and Uchio Plate 9, figures 26, 27 Poeroeponides cribrorepandus Asano and Uchio, 1951, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 14, p. 18, figs. 134, 185. Recorded in limited numbers in the Naha and Chinen only. Diameter 0.62-0.77 mm; thickness 0.32 mm. Genus PSEUDOEPONIDES Uchio, 1950 Pseudoeponides japonicus Uchio Plate 9, figures 20-22 Pseudoeponides japonicus Uchio, 1950, Assoc. Petroleum Tech- nology Jour., v. 15(4) , p. 190, fig. 16. Scarce and sporadic in Shinzato assemblages. Diameter 0.23-0.30 mm ; thickness 0.15 mm. Pseudoeponides umbonatus (Reuss) Plate 7, figures 33-38 Rotalina umbonata Reuss, 1851, Deutsche geol. Gesell. Zeitschr., v. 3, p. 75, pl. 5, figs. S5a-c. Eponides umbonate (Reuss). Cushman, 1929, Cushman Lab. Foram. Research Contr., v. 5, p. 98, pl. 14, fig. 8. Occurs most frequently in the upper part of the Y ona- baru; few specimens were recorded from the Shinzato. Diameter 0.60 mm; thickness 0.38 mm (figs. 33-85). Diameter 0.63 mm; thickness 0.34 m (figs. 36-88). Genus SIPHONINA Reuss, 1850 Siphonina australis Cushman Plate 4, figures 20-22 Siphonina australis Cushman, 1927, U.S. Natl. Mus. Proc., v. 27, p. 8, pl. 2, figs. 6a-c ; pl. 3, figs. Ta-c. A few specimens were recorded in Shinzato and Yona- baru. Diameter 0.45 mm ; thickness 0.18 mm. Siphonina tubulosa Cushman Plate 16, figures 10, 11 Siphonina tubulosa Cushman, 1924, Carnegie Inst. Washington Pub. 342, p. 40, pl. 13, figs. 1, 2. Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 361, pl. 89, figs. 29, 30. Several typical specimens were recorded from the Chinen deposits only. Diameter 0.40 mm ; thickness 0.24 mm. Genus CANCRIS Montfort, 1808 Cancris auriculus (Fichtel and Moll) Plate 6, figures 23, 24 Canoris auricul@ (Fichtel and Moll). Cushman and Todd, 1942, Cushman Lab. Foram. Research Contr., v. 18, p. 74, pl. 18, figs. 1-11 ; pl. 23, fig. 6. F3Q Occurs most frequently in the Chinen; rare in the Shinzato. Length 0.40 mm; width 0.27 mm; thickness 0.19 mm. Cancris communis Cushman and Todd Plate 6, figures 25, 26 Cancris sagra (@'Orbigny) var. communis Cushman and Todd, 1942, Cushman Lab. Foram Research Contr., v. 18, p. 79, pl. 19, figs. 8-11 ; pl. 20, fig. 1. A few specimens referable to this species were noted in Naha and Chinen assemblages. Length 0.64 mm; width 0.43 mm; thickness 0.23 mm. Genus BAGGINA Cushman, 1926 Baggina totomiensis Makiyama Plate 6, figures 20-22 Baggina totomiensis Makiyama, 1931, Kyoto Imp. Univ., Coll. Sci. Mem., ser. B, v. 7, p. 42, fig. 4. Asano, 1951, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Smaller Foraminifera, pt. 14, p. 21, figs. 154, 155. Occurs rarely in the Lozostomum pacificum fauna of the Yonabaru. Several specimens were recorded from the Chinen but not in the Shinzato. Length 0.57 mm ; thickness 0.37 mm; width 0.35 mm. Genus ASTEROROTALIA Hofker, 1951 Asterorotalia trispinosa (Thalmann) Plate 6, figures 18, 19 Rotalia pulchella H. B. Brady (not d'Orbigny), 1884, Challenger Rept., Zoology, v. 9, p. 710, pl. 115, figs. 8a, b. Rotalia trispinosa Thalmann, 1933, Eclogae geol. Helvetiae, v. 26, p. 248. Observed in limited numbers in the Logzostomum pacificum fauna of the Yonabaru only. Diameter 0.48 mm ; thickness 0.17 mm. Family AMPHISTEGINIDAE Genus AMPHISTEGINA d'Orbigny, 1826 Amphistegina wanneriana Fischer Plate 6, figures 3-5 Amphistegina wanneriana Fischer, 1927, Paleontologie von Timor, Stuttgart, Deutschland, E. Schweizerbart, v. 15, p. 170, pl. 217, figs. 131a-c. This relatively compressed form described from Pliocene of Seran occurs frequently in the Logostomum pacificum fauna of the Y onabaru ; rare in the basal part of the Chinen. Diameter 0.97 mm ; thickness 0.43 mm. Amphistegina madagascariensis d'Orbigny Plate 6, figures 1, 2 Amphistegina madagascariensis d'Orbigny, 1826, Annales sci. nat., v. 7, no. 5, p. 304. Cushman, Todd, and Post, 1954, U.S. Geol. Survey Prof. Paper 260-H, p. 362, pl. 90, figs. 1, 2. FAQ Commonly occurs in the Naha Limestone and in the upper part of the Yonabaru deposits; scattered oc- currences noted in the Chinen. It is widely distributed in the recent shallow-water sediments of the Indo- Pacific region. Many workers have recorded this species as A. Zessoni d'Orbigny. Diameter 0.78 mm ; thickness 0.50 mm. Family CALCARINIDAE Genus CALCARINA d'Orbigny, 1826 Calcarina rustica Todd and Post Plate 5, figures 1, 2 Calcarina rustica Todd and Post, 1954, U.S. Geol. Survey Prof. Paper 260-N, p. 563, pl. 201, fig. 7. Occurs sporadically only in the basal part of the Chinen and in the Naha. Diameter 0.76 mm ; thickness 0.36 mm. Calcarina spengleri (Gmelin) Plate 5, figure 3 Calcarina spengleri (Gmelin). H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 712, pl. 108, figs. 5, 7. Associated with C. rustica Todd and Post, and is seemingly restricted to the basal part of the Chinen and Naha. Diameter 1.45 mm ; thickness 0.55 mm. Family CYMBALOPORIDAE Genus CYMBALOPORETTA Cushman, 1928 Cymbaloporetta bradyi (Cushman) Plate 5, figures 6, 7 Cymbaloporetta bradyi Cushman, 1924, Carnegie Inst. Wash- ington Pub. 342, p. 34, pl. 10, figs. 2-4. Noted from only the Chinen in limited numbers. Diameter 0.48 mm ; thickness 0.21 mm. Family CASSIDULINIDAE Genus CERATOBULIMINA Toula, 1915 Ceratobulimina pacifica Cushman and Harris Plate 9, figures 23, 24 Ceratobulimina pacifica Cushman and Harris, 1927, Cushman Lab. Foram. Research Contr., v. 3, p. 176, pl. 29, fig. 9. Rather common in restricted numbers in the Shin- zato and rare in Yonabaru assemblages. Length 0.67 mm; width 0.54 mm; thickness 0.32 mm. Genus CASSIDULINA d'Orbigny, 1826 Cassidulina inflata LeRoy Plate 11, figures 13, 14 Cassidulina inflata LeRoy, 1944, Colorado School of Mines Quart., v. 39, no. 3, p. 37, pl. 4, figs. 30, 81. This small form occurs frequently in the Nomion mi- cobarense-Cibicides macneili fauna of the Y onabaru and SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY also in Shinzato assemblages. Diameter 0.17-0.21 mm; thickness 0.15 mm. Cassidulina orientale Cushman Plate 11, figures 15, 16 Cassidulina orientale Cushman, 1925, Cushman Lab. Foram. Re- search Contr., v. 1, p. 37, pl. 7, figs. 6a, c. Common in the Shinzato deposits and rare in those of the Yonabaru. Specimens appear to be slightly thicker than the type. Diameter 0.17-0.23 mm ; thickness 0.10 mm. Cassidulina okinawaensis LeRoy, n. sp. Plate 11, figures 21, 22 Test small for the genus, moderately compressed, periphery sharply rounded, slightly lobulate; chambers distinct, seven to eight pairs in last whorl, noninflated, enlarge gradually and uniformly as added ; sutures dis- tinct, slightly curved, flush with surface; wall smooth ; aperture elongate. This species occurs rarely in the Chinen, Shinzato, and Yonabaru, and is smiliar to C. tortwose Cushman but much smaller. Diameter 0.33 mm ; thickness 0.20 mm. Cassidulina margareta Karrer Plate 11, figures 27, 28 Cassidulina margareta Karrer, 1877, K. K. Geol Reischsanst., Abh., Wien, Osterreich, v. 9, p. 386, pl. 16b, fig. 52. Several specimens closely resembling this species were recorded from the Chinen. Diameter 0.38 mm ; thickness 0.24 mm. Cassidulina subglobosa H. B. Brady Plate 11, figure 17 Cassidulina subglobosa H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 430, pl. 54, figs. 1Ta-c. Cushman, 1921, U. S. Natl. Mus. Bull. 100, v. 4, p. 171, pl. 32, fig. 2. Rare in Shinzato and Yonabaru assemblages. Diameter 0.51 mm; thickness 0.38 mm. Cassidulina asanoi Uchio Plate 11, figure 29 Cassidulina asanoi Uchio, 1950, Assoc. Petroleum Technology, v. 15, no. 4, p. 190, fig. 13. Very rare in the Shinzato and Yonabaru. Diameter 0.20 mm; thickness 0.06 mm. Cassidulina pacifica Cushman Plate 11, figures 19, 20 Cassidulina pacifica Cushman, 1925, Cushman Lab. Foram. Re- search Contr., v. 1, p. 53,.figs. 14-16. Common in the Shinzato assemblages and rare in the Yonabaru; abundant in the Miocene and Pliocene de- posits of Japan and in the late Tertiary and Recent FORAMINIFERA FROM TERTIARY OF OKINAWA sediments of the Indo-Pacific region. Diameter 0.33 mm; thickness 0.37 mm. Genus CASSIDULINOIDES Cushman, 1921 Cassidulinoides tenuis Phleger and Parker Plate 12, figures 1, 2 Cassidulinoides tenuis Phleger and Parker, 1951, Geol. Soc. America Mem. 46, p. 27, pl. 14, figs. 14-17. Several specimens were recorded from the Shinzato deposits only. Length 0.73 mm; width 0.27 mm; thickness 0.24 mm. Cassidulinoides bradyi (Norman) Plate 12, figures 5, 6 Cassidulina bradyi (Norman). H. B. Brady, 1884, Challenger Rept., v. 9, p. 431, pl. 54, figs. 6-10. Occasionally were noted from the Chinen only. Length 0.37 mm; width 0.19 mm; thickness 0.19 mm. Cassidulinoides braziliensis (Cushman) Plate 12, figures 3, 4 Cassidulina braziliensis Cushman, 1922, U. S. Natl. Mus. Bull. 104, p. 130, pl. 25, figs. 4, 5. Very rare in and restricted to the Shinzato. Length 0.34 mm; width 0.22 mm; thickness 0.16 mm. Genus EHRENBERGINA Reuss, 1850 Ehrenbergina bradyi Cushman Plate 5, figures 21, 22 Ehrenbergina serrata H. B. Brady (part) (not Reuss), 1884, Uhallenger Rept., Zoology, v. 9, p. 434, pl. 55, figs. 6, 7. Ehrenbergina bradyi Cushman, 1922, U.S. Natl. Mus. Bull. 104, pt. 3, p. 134, pl. 26, fig. 5. Occurs in limited numbers within the Shinzato and in the upper part of the Yonabaru. Length 0.56 mm; width 0.55 mm (max). Ehrenbergina bosoensis var. decorata Takayanagi Plate 5, figures 27, 28 Ehrenbergina bosoensis var. decorate Takayanagi, 1951, Pale- ont. Soc. Japan Trans. and Proc., v. 3, p. 89, fig. 9. This spinose species was found in limited numbers in the Chinen. Length 0.55 mm ; width 0.47 mm (max.). Family CHILOSTOMELLIDAE Genus CHILOSTOMELLA Cushman, 1926 Chilostomella oolina Schwager Plate 2, figure 39 Chilostomella oolina Schwager, 1878, Bol. Com. Geol., Italy, v. 9, p. 527, pl. 1, fig. 16. Cushman, 1925, Cushman Lab. Foram. Research Contr., v. 1, p. 74, pl. 11, figs. 3-10. A few specimens were recorded from the Logostomum pacificum fauna of the Yonabaru. F4l Length 0.85 mm ; diameter 0.39 mm. Genus SPHAEROIDINA d'Orbigny, 1826 Sphaeroidina bulloides d'Orbigny Plate 16, figures 21, 22 Aphaeroidina bulloides d'Orbigny, 1826, Annales sci. nat., v. 7, p. 267, Modéles no. 65. Common in the Shinzato and Yonabaru. Diameter 0.40 mm. Sphaeroidina haueri (Czjzek) Not illustrated Sphaeroidina haueri (Czjzek). Cushman and Todd, 1949, Cushman Lab. Foram. Research Contr., v. 25, pt. 1, p. 16, pl. 4, figs. 1, 2. Rare and sporadic in the Shinzato and Yonabaru. Diameter 0.35 mm. USGS locality : £11536 (WF-274, Yonabaru Member). USNM 625387. Genus PULLENIA Parker and Jones, 1862 Pullenia quadriloba Reuss Plate 10, figures 28, 29 Pullenia compressiuscule Reuss var. quadrilobe Reuss, 1867, Akad. Wiss. Wien, Sitzungsber. v. 55, p. 87, pl. 3, fig. 8. Pullenia quadriloba Reuss. Cushman and Todd, 1943, Cushman Lab. Foram. Research Contr., v. 19, pt. 1, p. 15, pl. 2, figs. 20, 21. Several specimens closely related to this species were recorded from the Yonabaru only. Diameter 0.45-0.55 mm ; thickness 0.38 mm. Pullenia miocenica Kleinpell Plate 10, figures 26, 27 Pullenia miocenica Kleinpell, 1943, Cushman Lab. Foram. Re- search Contr., v. 19, pt. 1, p. 17, pl. 3, figs. 3, 4. Very rare in Shinzato and Yonabaru assemblages. Diameter 0.44 mm ; thickness 0.40 mm. Pullenia bulloides (d'Orbigny) Plate 10, figures 30, 31 Nonionina bulloides d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 107, pl. 5, figs. 9, 10. Rare in both the Shinzato and Yonabaru. Diameter 0.32 mm ; thickness 0.30 mm. Pullenia salisburyi R. E. and K. E. Stewart Plate 10, figures 24, 25 Pullenmia salisburyi R. E. and K. E. Stewart, 1930, Jour. Paleon- tology, v. 4, p. 72, pl. 8, figs. 2a, b. Cushman and Todd, 1943, Cushman Lab. Foram. Research Contr., v. 19, pt. 1, p. 20, pl. 3, figs. 10, 11. Several specimens typical of this species were re- corded from the Shinzato only. Diameter 0.39 mm ; thickness 0.25 mm. FA42 Family GLOBIGERINIDAE Genus GLOBIGERINA d'Orbigny, 1826 Globigerina baroemoenensis LeRoy Plate 14, figures 9, 10 Globigerina baroemoenensis LeRoy, 1939, Natuurk. tijdschr. Ned. Indié, pt. 99, afi. 6, p. 263, pl. 6, figs. 1-2. Common in the Yonabaru and rare in the Shinzato. Diameter 0.42 mm. Globigerina bulloides d'Orbigny Plate 14, figure 11 G@lobigerina bulloides d'Orbigny, 1826, Annales sci. nat., v. 7, p. 277, Modéles 76. Cushman, Todd, and Post, 1954, U. S. Geol. Survey Prof. Paper 260-H, p. 368, pl. 91, fig. 2. Occurs in most of the Okinawa section, particularly in the Shinzato and Yonabaru. Diameter 0.29-0.39 mm. Globigerina dubia Egger Plate 14, figures 6-8 Globigerina dubia Egger, 1857, Neues Jahrb. Min. Geog. Petrif. Kunde Stuttgart, Deutschland, p. 281, pl. 9, figs. 7-9. Common in Shinzato and Yonabaru assemblages, particularly in the Shinzato. Diameter 0.47-0.55 mm. Genus GLOBIGERINOIDES Cushman, 1927 Globigerinoides triloba immatura LeRoy Plate 14, figure 16 G@lobigerinoides sacculifera (H. B. Brady) var. immatura Le- Roy, 1939, Natuurk, tijdschr. Ned.-Indié, pt. 99, aff. 6, p. 263, pl. 3, figs. 19-21. G@lobigerinoides triloba immatura LeRoy. Bolli, 1957, U.S. Natl. Mus. Bull. 215, p. 113, pl. 25, figs. S3a-4c. Common Shinzato, assemblages. Diameter 0.60 mm (max). in Chinen, and Yonabaru Globigerinoides triloba sacculifera (H. B. Brady) Plate 14, figure 18 Globigerina sacculifera H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 604, pl. 80, figs. 11-17; pl. 82, fig. 4. Globigerinoides triloba sacculifera (H. B. Brady). Bolli, 1957, U.S. Natl. Mus. Bull. 215, p. 113, pl. 25, figs. 5a, b. Common in Shinzato assemblages and rare in the Chinen and upper part of the Yonabaru. Diameter 0.67 mm (max). Globigerinoides triloba fistulosa (Schubert) Plate 14, figure 17 G@lobigerina fistulosa Schubert, 1910, Geol. Reichsanst. Verh., Wien., no. 14, p. 324, fig. 2. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Globigerinoides sacculifera (H.B. Brady) var. fistulosa (Schu- bert). Cushman, 1933, Cushman Lab. Foram. Research Spec. Pub. 5, p. 132, pl. 34, figs. 6a-c. Recorded in limited numbers from the Shinzato only. The figured specimen is in an early stage of develop- ment. Diameter 0.62 mm (max). Globigerinoides ruber (d'Orbigny) Plate 14, figure 14 G@lobigerina rubra d'Orbigny, 1839, in De la Sagra, Histoire physique, politique et naturelle de l'le de Cuba, Fora- miniféres, p. 82, pl. 4, figs. 12-14. Very common in the Shinzato; rare in the Chinen and in upper part of the Yonabaru. Length 0.58 mm. Globigerinoides mitra Todd Plate 14, figure 15 Globigerinoides mitra Todd, 1957, U.S. Geol. Survey Prof. Paper 280-H, p. 302, pl. 78, figs. 3, 6. This species, originally described from the Miocene of Saipan, was observed sparingly in the deepwater Yonabaru assemblages. Length 1.10 mm. Genus GLOBIGERINELLA Cushman, 1927 Globigerinella aequilateralis (H. B. Brady) Plate 14, figures 19, 20 Globigerina aequilateralis H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 605, pl. 80, figs. 18-21. Appears most commonly in Shinzato assemblages; rare in the Chinen and Yonabaru. Diameter 0.40-0.52 mm ; thickness 0.31 mm. Genus ORBULINA d'Orbigny, 1839 Orbulina universa d'Orbigny Plate 14, figure 5 Orbulina universa d'Orbigny, 1839, in De la Sagra, Histoire physique, politique et naturelle de l'le de Cuba, Fora- miniféres, p. 3, pl. 1, fig. 1. This planktonic species is scarce in the Chinen, com- mon to abundant in the Shinzato, and frequent through- out the Yonabaru. The Yonabaru forms are generally smaller than those in the Shinzato and probably reflect cooler surface waters. In the Yonabaru 1 the species appeared to extend to a total depth (4,036 ft). Diameter 0.46 mm. Genus PULLENIATINA Cushman, 1927 Pulleniatina obliquiloculata (Parker and Jones) Plate 14, figures 25-28 Pullenia obliguiloculata Parker and Jones, 1865, Philos, Trans., v. 155, p. 368, pl. 19, figs. 4a, b. FORAMINIFERA FROM TERTIARY OF OKINAWA This widely recorded species commonly occurs in the Shinzato and is rare in the Yonabaru. Diameter 0.47 mm ; height 0.40 mm (figs. 25, 26). Di- ameter 0.53 mm; height 0.53 mm (figs. 27, 28). Genus SPHAEROIDINELLA Cushman, 1927 Sphaeroidinella seminulina (Schwager) Plate 14, figures 23, 24 Globigerina seminulina Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 256, fig. 112. Occurs in the Shinzato and Yonabaru faunas in vary- ing numbers. Diameter 0.50-0.67 mm. Sphaeroidinella dehiscens (Parker and Jones) Plate 14, figures 21, 22 Sphaeroidina dehiscens Parker and Jones, 1865, Philos. Trans., v. 155, p. 369, pl. 19, figs. 5a, b. Sphaeroidinella dehiscens (Parker and Jones). Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 297. Common in the Shinzato and rare in the Yonabaru. Diameter 0.61-0.80 mm. Genus GLOBOQUADRINA Finlay, 1947 Globoquadrina altispira (Cushman and Jarvis) Plate 14, figures 12, 13 Globigerina altispira Cushman and Jarvis, 1936, Cushman Lab. Foram. Research Contr., v. 12, p. 5, pl. 1, figs. 13, 14. This species, originally described from the Miocene of Jamaica, occurs in appreciable numbers in the upper part of the Yonabaru and is rare in the Shinzato. Diameter 0.55 mm; height 0.47 mm. Genus CANDEINA d'Orbigny, 1839 Candeina nitida d'Orbigny Plate 6, figure 11 Candeina nitida d'Orbigny, 1839, in De la Sagra, Histoire phy- sique, politique et naturelle de l'le de Cuba, Foramini- féres, p. 108, pl. 2, figs. 27, 28. H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 622, pl. 82, figs. 13-20. This pelagic species was observed in limited num- bers in Shinzato assemblages only. According to Cushman it is extremely rare in Recent deposits of the South Pacific and Philippine region. Diameter 0.40 mm. Family GLOBOROTALIIDAE Genus GLOBOROTALIA Cushman, 1927 Globorotalia punctulata (d'Orbigny) Plate 9, figures 11-13 Globigerina punctulate d'Orbigny, 1826, Annales sci. nat., v. 7, p. 277, Fornasini, 1898, Paleontolographia Italico, v. 4, p. 210, text fig. 5. F43 Globorotalia punctulate (d'Orbigny), Phleger, Parker, and Pierson, 1947-48, Rept. Swedish Deep-sea Exped., v. 7, sediment cores, no. 1, p. 20-21, pl. 4, figs. 8-12. Common in the Shinzato and seemingly absent in Yonabaru. Diameter 0.36-0.43 mm; thickness 0.31 mm. Globorotalia praemenardii Cushman and Stainforth Plate 9, figures 14, 15 Globorotalia praemenardii Cushman and Stainforth, 1945, Cush- man Lab. Foram. Research Spec. Pub. 14, p. 70, pl. 13, fig. l14a-c. Rare in Shinzato and Yonabaru assemblages. Diameter 0.48-0.59 mm; thickness 0.16 mm. Globorotalia tumida (H. B. Brady) Plate 9, figures 18, 19 Pulvinulina tumida H. B. Brady, 1884, Challenger Rept., Zo- ology, v. 9, p. 692, pl. 103, figs. 4-6. Globorotalia tumida (H. B. Brady). Cushman, 1931, U.S. Natl. Mus. Bull. 104, pt. 8, p. 95, pl. 12, figs. 3a-c. Abundant in the Shinzato; rare to common in the Chinen and Yonabaru. Diameter 0.56-0.77 mm; thickness 0.20 mm. Globorotalia menardii multicamerata Cushman and Jarvis Plate 9, figures 16, 17 Globorotalia menardii (d'Orbigny) var. multicamerata Cush- man and Jarvis, 1930, Jour. Paleontology, v. 4, p. 867, pl. 34, fig. 8. Common in Shinzato assemblages and rare in the Chinen and Yonabaru. Typical G. menard# (d'Or- bigny) also occur in considerable numbers in the assemblages. Diameter 0.57-0.61 mm ; thickness 0.21 mm. Family ANOMALINIDAE Genus ANOMALINA d'Orbigny, 1826 Anomalina glabrata Cushman Plate 6, figures 8-10 Anomalina glabrata Cpshman, 1942, Carnegie Inst. Washington Pub. 342, p. 39, pl. 12, figs. 5-7. Asano, 1951, Inst. Geology and Paleontology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 13, p. 14, figs. 10-12. Common in late Tertiary and Recent deposits in the Indo-Pacific region and occurs rarely in the Chinen, Shinzato, and in the upper part of the Yonabaru; com- mon in late Tertiary deposits of Japan. Diameter 0.52-0.70 mm ; thickness 0.29 mm. Anomalina bradyi Said Plate 6, figures 12-14 Anomalina ammonoides H. B. Brady (not Reuss), 1884, Chal- lenger Rept., Zoology, v. 9, p. 672, pl. 94, figs. 2, 3. Anomalina bradyi Said, 1949, Cushman Lab. Foram. Research Spec. Pub. 26, p. 41, pl. 4, fig. 2. F44 Common in the Shinzato; rare in the Chinen and Yonabaru deposits; common in late Tertiary and Re- cent sediments of the Indo-Pacific region. Diameter 0.54-0.70 mm ; thickness 0.23 mm. Genus LATICARININA Galloway and Wissler, 1927 Laticarinina pauperata (Parker and Jones) Plate 9, figure 25 Laticarinina pauperate (Parker and Jones). Cushman and Todd, 1942, Cushman Lab. Foram. Research Contr., v. 18, p. 15, pl. 4, figs. 1-6. Rare in Shinzato and Yonabaru assemblages. Diameter 0.58-0.73 mm ; thickness 0.21 mm. Genus HYALINEA Hofker, 1951 Hyalina balthica (Schroeter) Plate 9, figures 34-36 Hyalinea balthica (Schroeter). Hofker, 1951, Siboga-Exped., pt. 3, p. 508, figs. 345-8348. Widely recorded in late Tertiary and Recent de- posits of the South Pacific and is seldom found in the Shinzato and Yonabaru. Diameter 0.33-0.39 mm ; thickness 0.11 mm. Genus ANOMALINELLA Cushman, 1927 Anomalinella rostrata (H. B. Brady) Plate 6, figures 15-17 Truncatulina rostrata H. B. Brady, 1884, Challenger Rept., Zo- ology, v. 9, p. 668, pl. 94, figs. 6a-c. Anomalinella rostrata (H. B. Brady). Cushman, 1928, Cush- man Lab. Foram. Research Spec. Pub. 1, p. $22, pl. 50, fig. 1. Rare in the Naha and Shinzato; widely recorded from late Tertiary and Recent shallow-water deposits of the Indo-Pacific region. Diameter 0.77-0.85 mm ; thickness 0.46 mm. Genus CIBICIDES Montfort, 1808 Cibicides tenuimargo (H. B. Brady) Plate 8, figures 30-32 Truncatulina tenuimargo H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 662, pl. 93, fig. 3. Recorded in limited numbers in the Shinzato and in the Logzostomum pacificum fauna of the Yonabaru. Diameter 0.59-0.63 mm; thickness 0.20 mm. Cibicides Macneili LeRoy, n. sp. Plate 9, figures 4-6 Test small for the genus, generally light amber, nearly circular in plan view, slightly more convex ventrally than dorsally; periphery sharp, faintly lobu- late; chambers distinct, seven to eight in last whorl, increase gradually in size as added; sutures distinct, slightly depressed dorsally, ventrally wide, somewhat SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY curved and widened toward umbilical area; wall more coarsely punctate on dorsal side; aperture peripheral, small. This species, except for reworked specimens, appears to be confined to the Yonabaru Member. No published species appears to be closely related to this form. It is named in honor of F. S. MacNeil of the U.S. Geo- logical Survey. Diameter 0.28-0.37 mm ; thickness 0.15 mm. Cibicides okinawaensis LeRoy, n. sp. Plate 9, figures 1-8 Test of medium size for the genus, slightly more con- vex ventrally than dorsally ; periphery subacute, slightly lobulate, with very narrow marginal chord; chambers distinct, 9 to 10 in last whorl, increasing gradually in size as added ; ventral sutures distinct, strongly curved, depressed between last two or three chambers; dorsal sutures obliquely curved, distinct, faintly depressed; ventral and dorsal surfaces perforate, more so dorsally ; aperture a small arch on the periphery extending slightly over peripheral margin and then along base of last two chambers on dorsal side. Appears to be confined to Shinzato assemblages. Diameter 0.60-0.75 mm ; thickness 0.25 mnm. Cibicides refulgens (Montfort) Plate 8, figures 22-24 Truncatulina refulgens (Montfort). H. B. Brady, 1884, Chal- lenger Rept., Zoology v. 9, p. 659, pl. 92, figs. 7-9. Occurs sporadically in the Logostomum pacificum fauna of the Yonabaru only. Diameter 0.32-0.38 mm ; thickness 0.19 mm. Cibicides shinzatoensis LeRoy, n. sp. Plate 8, figures 7-9 Test of medium size for the genus, slightly longer than broad, moderately compressed, dorsal side more convex than ventral side; periphery slightly lobulate, sharply rounded; chambers distinct, seven to eight in last whorl, enlarge gradually as added, last two or three rather strongly inflated on ventral side; dorsal sutures distinct, raised and reinforced with clear shell material, last one or two depressed, strongly curved; dorsal sutures distinct, broad, strongly curved, flush with surface; ventral surface rough, coarsely perforate, dorsal surface smooth, glassy; aperture peripheral, at base of last chamber and extends into dorsal umbilical area along base of last two chambers. This species occurs rarely in the Shinzato and Yona- baru. The ornamentation is similar to that of Planw- FORAMINIFERA FROM TERTIARY OF OKINAWA lina foveolate (H. B. Brady) which is more evolute and which fails to exhibit the inflation of the last two or three chambers. Diameter 0.38-0.49 mm ; thickness 0.20 mm. Cibicides lobatulus (d'Orbigny) Plate 8, figures 10-12 Truncatulina lobatule d'Orbigny, 1846, Foraminiféres fossiles du bassin tertiaire de Vienne, p. 168, pl. 9, figs. 18-23. Cibicides lobatulus (d@'Orbigny). Cushman, 1981, U.S. Natl Mus. Bull. 104, pt. 8, p. 118, pl. 21, figs. 3a-c. Rare in the Naha, Chinen, Shinzato, and Yonabaru. Diameter 0.46-0.57 mm ; thickness 0.23 mm. Cibicides haidingerii (d'Orbigny) var. pacificus (Cushman) Plate 8, figures 4-6 Truncatulina haidingerii d'Orbigny var. pacifica Cushman, 1924, Carnegie Inst. Washington Pub. 342, p. 39, pl. 12, fig. 1. Noted occasionally in Chinen assemblages only. Diameter 0.71-0.87 mm ; thickness 0.34 mm. Cibicides convexa (Takayanagi) Plate 9, figures 7, 8 Planulina conveze Takayanagi, 1953, Tohoku Univ., Inst. Geology and Paleontology (Short Papers), no. 5, p. 34, pl. 4, figs. l14a-c. This species was noted in limited numbers in the Shin- zato only. The specimens appear to have more suture limbosity than C. comverae as originally illustrated. Diameter 0.30-0.40 mm ; thickness 0.18 mm. Cibicides pseudoungerianus (Cushman) Plate 8, figures 13-15 Truncatulina pseudoungeriana Cushman, 1922, U.S. Geol. Sur- vey Prof. Paper 129, p. 97, pl. 20, fig. 9. Cibicides pseudoungeriana (Cushman), 1931, U.S. Natl. Mus. Bull. 104, pt. 8, p. 123, pl. 22, figs. 3-7. - Common in the Shinzato and Yonabaru. Diameter 0.50-0.60 mm ; thickness 0.24 mm. Cibicides cicatricosa (Schwager) Plate 8, figures 27-29 Anomalina cicatricosa Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 260, pl. 7, fig. 4. Rare in the Shinzato and Yonabaru. Diameter 0.59-0.72 mm ; thickness 0.33 mm. Cibicides wuellerstorf (Schwager) Plate 8, figures 25, 26 Anomalina wuellerstorfi Schwager, 1866, Novara-Exped., Geol. Theil, v. 2, p. 258, pl. 7, figs. 105, 107. Planulina wuellerstorfi (Schwager). Cushman, 1929, Cushman Lab. Foram. Research Contr., v. 5, p. 104, pl. 15, figs. 1, 2. Occurs in limited numbers in the Shinzato and Yonabaru. Frequently recorded in late Tertiary and Recent deposits of the Tropical Pacific. Diameter 0.58-0.78 mm ; thickness 0.25 mm. 682-363 O-64-3 FAL Cibicides fijiensis (Cushman) Plate 8, figures 16-18 Planulina fijiensis Cushman, 1934, B. P. Bishop Mus. Bull. 119, p. 136, pl. 18, figs. 4a-c. Appears to be confined to the Shinzato but has been recorded by several workers from late Tertiary and Recent deposits of the Indo-Pacific region. Diameter 0.90-1.35 mm ; thickness 0.43 mm. Cibicides circularis LeRoy, n. sp. Plate 7, figures 39-41 Test small for the genus, slightly more convex ventrally than dorsally, nearly circular in plan view; periphery subacute, lobulate, with narrow marginal flange; ventral umbilical area filled with clear glassy plug; chambers distinct, 7 or 8 in last whorl, enlarge gradually as added, last 2 or 3 slightly inflated ; ventral sutures distinct, faintly curved, radial; dorsal sutures strongly oblique, slightly curved, flush with surface; wall minutely perforate on the ventral side, coarsely perforate on the dorsal side; aperture small, at base of last chamber, with slight lip. This species is similar to C. punctatus (LeRoy) de- scribed from the Miocene and Pliocene of Sangkoeli- rang Bay, East Borneo, but differs by being less convex dorsally. Commonly occurs in Yonabaru assemblages and very rare in the younger part of the section. Diameter 0.48-0.50 mm ; thickness 0.18-0.21 mm. Cibicides ornatus (Cushman) Plate 8, figures 19-21 Truncatulina ungeriana (d'Orbigny) var. ornate Cushman, 1921, U.S. Natl. Mus. Bull. 100, v. 4, p. 317, fig. 12a, b. Cibicides dorsopustulosus LeRoy, 1939, Natuurk. tidjschr. Ned.- Indié, no. 6, pt. 99, p. 268, pl. 1, figs. 1-3. Observed most frequently in the Lozostomum pacif- cum fauna of the Yonabaru; widely recorded in the late Tertiary and Recent deposits of the Indo-Pacific region. Diameter 0.54-0.68 mm ; thickness 0.25 mm. Genus VAGOCIBICIDES Finlay, 1989 Vagocibicides nipponicus Uchio Plate 4, figures 18, 19 Vagocibicides mipponicus Uchio, 1951, Paleont. Soc. Japan Trans. and Proc. (new ser.), v. 2, p. 41, pl. 3, figs. Sa-c. Observed rarely in Shinzato assemblages only. Length 0.81 mm; width 0.41 mm; thickness 0.15 mm. Genus DISCANOMALINA Asano, 1951 Discanomalina japonica Asano Plate 8, figures i-3 Discanomalina japonica Asano, 1951, Inst. Geology and Paleon- tology, Illustrated Catalogue of Japanese Tertiary Smaller Foraminifera, pt. 13, p. 13, figs. 3-5. F46 This conspicuous species was defined originally from the Pliocene of Japan. In the Okinawan section it was observed in the Shinzato only. The thick, blunt peripheral spines and coarse punctations characterize the species. Diameter 0.71-0.92 mm ; thickness 0.53 mm. Genus HANZAWAIA Asano, 1944 Hanzawaia nipponica Asano Plate 9, figures 28, 29 Hanzawaia nipponica Asano, 1944, Geol. Soc. Japan Jour., v. 51, no. 606, p. 99, pl. 4, figs. la, b; 2a, b. This distinctive species occurs rather frequently in the Lozostomum pacificum fauna of the Yonabaru. It was originally described from the late Tertiary deposits of Japan. Diameter 0.64-0.77 mm ; thickness 0.30 mm. Family PLANORBULINIDAE Genus PLANORBULINELLA Cushman, 1927 Planorbulinella larvata (Parker and Jones) Plate 5, figures 8, 9 Planorbulinella larvata (Parker and Jones). Cushman, 1933, Cushman Lab. Foram. Research Spec. Pub. 4, p. 278, pl. 29, figs. Sa, b. This shallow-water tropical species is best daveloped in the Lozostomum pacificum fauna of the Yonabaru. Several specimens were observed in the Chinen and Naha deposits. Diameter 0.87 mm ; thickness 0.17 mm. Genus GYPSINA Carter, 1877 Gypsina globula (Reuss) Plate 3, figure 20 Ceriopora globulus Reuss, 1847, Haidinger's Nat. Abh., v. 2, p. 33, pl. 5, fig. 7. Gypsina globulus (Reuss). H. B. Brady, 1884, Challenger Rept., Zoology, v. 9, p. 717, pl. 101, fig. 8. Only a few specimens were observed in the Shinzato. Diameter 0.64 mm. DESCRIPTION OF SAMPLE LOCALITIES [Map sheets are pant of AMS series L791 (1: 50,000)] USGS £11507 (MD-149). Chinen Sand. Rotorbinella chinenen- sis fauna. In lower part of large road- cut at top of hill on Highway 31 about 0.3 mile northeast of the junction of Highways 8 and 31, Okinawa. USGS £11508 (FSM-27). Shinzato Member. G@loborotalia punc- tulata fauna. - Medium-gray sandy foraminiferal marl. In high roadcut along Highway 64 about 0.1 mile west of sharp bend in road about 0.3 mile east of Yashitomi (map sheet 862511, Tamagusuku NW), Okinawa. USGS £11500 (FSM-31). Shinzato Member. Globorotalia punc- tulata fauna. - Medium-gray sandy foraminiferal mudstone. In ditch 100 USGS f11510 (RS-314). USGS f115l1 (RS-321). USGS f11M12 (RS-822). USGS f11513 (RS-323). USGS f11514 (RS-824). USGS f11515 (RS-831). USGS f11516 (RS-339). USGS £11517 (RS-360). USGS £11518 (RS-366). SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY yd north of gap in limestone escarp- ment along Highway 17 and about 0.4 mile north of Maegawa (map sheet 362511, Itoman NE), Okinawa. Shinzato Member. Globorotalia punc- tulata fauna. Medium-gray slightly silty claystone. In roadcut on south side of Highway 137 and 0.5 mile southeast of Shinzato (map sheet 362511, Tamagusuku NW), Okinawa. Shinzato Member. G@loborotalia punc- tulata fauna. Grayish-white soft foraminiferal marl. In quarry at the north end of the Chinen Plateau and 0.7 mile southeast of Shinzato. Due east of loc. f11510 (RS-314) (map sheet 362511, Tamagusuku NW), Okinawa. Shinzato Member. @loborotalia punc- tulata fauna. Light-gray soft silty foraminiferal marl. Prominent out- crop of tuffaceous bed on edge of Chinen Plateau and 0.5 mile N. 80° E. of Yabiku (map sheet 36251, Yonabaru SW), Okinawa. Shinzato Member. Globorotalia punc- tulata fauna. Light-yellow soft silty marl. In small hill on the northeast end of the Chinen Plateau and 0.6 mile N. 80° E. of Yabiku (map sheet 36251, Yonabaru SW), Okinawa. 'Shinzato Member. @loborotalia punc- tulata fauna. Light-gray sandy to silty claystone. Outcrop at edge of Chinen Plateau and 0.33 mile east of Ibara (map sheet 36251, Yonabaru SW), Okinawa. Shinzato Member. @loborotalia punc- tulata fauna. Medium-gray soft silty claystone. In roadcut on Highway 64 on east edge of the Chinen Plateau and 0.1 mile northeast of junction of Highways 64 and 137 at Hiyakuna (map sheet 362511, Tamagusuku NW), Okinawa. Shinzato Member. @loborotalia punc- tulata fauna. Medium-gray soft silty claystone and clayey foraminiferal marl. Outcrop on slope 600 yd N. 45° E. of Yabiku (map sheet 36251, Yona- baru SW), Okinawa. Shinzato Member. G@loborotalia punc- tulata fauna. Medium-gray soft silty claystone. Outcrop in roadcut at bend on Highway 64 and 0.33 mile north- east of Horikawa (map sheet 362511, Tamagusuku NW), Okinawa. Shinzato Member. G@loborotalia punc- tulata fauna. Medium-gray soft silty foraminiferal mudstone. In low cut on secondary road and about 0.6 mile north of the junction of road with Highway 64 at Asato (map sheet 362511, Itoman NE), Okinawa. USGS £11519 (RS-372). USGS £11520 (RS-376). USGS f11521 (RS-377). USGS £11522 (RS-54). USGS £11523 (RS-149). USGS £11524 (RS-150). USGS £11525 (RS-152). USGS £11526 (RS-196). USGS f11527 (RS-197). FORAMINIFERA FROM TERTIARY OF OKINAWA Shinzato Member. @loborotalia punc- tulata fauna. Light- to medium-gray silty soft foraminiferal marl. Thin tuffaceous layer in low roadcut on east side of Highway 64 and about 0.6 mile west of the junction of High- ways 137 and 64 at Hiyakuna (map sheet 362511, Tamagusuku NW), Okinawa. Shinzato Member. @loborotalia punc- tulata - fauna. Medium-gray - soft claystone. Outcrop along Highway 54 and 0.33 mile southeast of junction with Highway 7 and near Arakaki (map sheet 3525III, Itoman NE), Okinawa. Shinzato Member. G@loborotalia punc- tulata fauna. Light-gray claystone. In low roadcut on west side of see- ondary road leading to Makabe to Highway 7 and 200 yds northeast of Makabe (map sheet 3625III, Itoman NE), Okinawa. Yonabaru Member. Logostomum pa- cificum fauna. Light-tan medium- grained sand. Molluscan fragments common. Exposure in roadbed pass- ing through limits of Kohatsu and about 0.25 mile southwest of Highway 38 (map sheet 36251, Yonabaru SW), Okinawa. Yonabaru Member. Lo@ostomum pa- cificum fauna. Medium-gray sandy clay. Outcrop on the north side of poor road between Bingusuku and Tohashima and 150 yds west of Bin- gusuku (map sheet 3625111, Itoman NE), Okinawa. Yonabaru Member. Lozostomum pa- cificum fauna. - Light-gray coarse grained conglomeratic sand containing many molluscan fragments. Outcrop along path leading upstream 0.2 mile southeast of Nesabu (map sheet 3625 IV, Naha SE), Okinawa. Yonabaru Member. Lozostomum pa- cificum fauna. Grayish-brown sandy claystone. In cut on very poor road 0.25 mile S. 35° E. of Gishi (map sheet 3625111, Itoman NE), Okinawa. Yonabaru Member. Lozostomum pa- cificum fauna. Medium-gray sandy to silty claystone. In low cut on side of promontory on top of a narrow ero- sional spur, about 0.5 mile north- northwest of the junction of Highways 13 and 46 at Iwa, Okinawa. Yonabaru Member. Log@gostomum pa- ciffcum fauna. Light-tan sandy clay- stone. Outcrop on ridge just north of Hirakawa (map sheet 3625IV, Naha SE), Okinawa. USGS £11528 (RS-198). USGS £11529 (FSM-41). USGS £11530 (FSM-44). USGS £11531 (FSM-45). USGS £11532 (FSM-47). USGS £11533 (RS-129). USGS £11534 (WF-272). USGS £11535 (WF-273). USGS £11536 (WF-274). USGS f11537 (MD-25). USGS £11538 (RS-350). F47 Yonabaru Member. Logostomum pa- cificum - fauna. Medium-gray - soft claystone. Outcrop on east end of ridge and 1.8 miles southeast of in- tersection of Highways 5 and 44 (map sheet 3625IV, Naha SE), Okinawa. Yonabaru Member. Nomion nicobar- ense-Cibicides macneili fauna. Me dium-gray claystone. On Highway 31 and about 0.6 mile north of Heanna (map sheet 36251, Yonabaru 36251, Yonabaru NE), Okinawa. Yonabaru Member. Nonion nicobar- ense-Cibicides macneili fauna. Me- dium-gray claystone. In Highway 16 and just west of junction with High- way 24, about 1 mile east of Chibana (map sheet 362611, Kin), Okinawa. Yonabaru Member. Nomion micobar- ense-Cibicides macneili fauna. Me- dium-gray claystone. On Highway 24 and about 0.8 mile northeast of junction with Highway 13. North- west of Awashi Airfield (map sheet 3626II, Kin), Okinawa. Yonabaru Member. Nomion nicobar- ense-Cibicides macneili fauna. Medi- um-gray claystone. On road to Yaji- banta and about 0.5 mile from inter- section with Highway 5 (map sheet 36251, Yonabaru NE), Okinawa. Yonabaru Member. Nomion nicobar- ense-Cibicides morneili fauna. Medi- um-gray claystone. Cut on north side of secondary road in Naha Air Base housing area and 0.6 mile west of Highways 3 and 60 junction (map sheet 3625IV, Naha SE), Okinawa. Yonabaru Member. Nonion nicobar- ense-Cibicides macneili fauna. Medi- um-gray claystone. On secondary road and 0.5 mile north of junction of Highways 30 and 132 (map sheet 36251, Yonabaru NE), Okinawa. Yonabaru Member. Nonion nicobar- ense-Cibicides macneili fauna. Medi- um-gray soft silty claystone. On Highway 5 at Nagata (map sheet 36251, Yonabaru NE), Okinawa. Yonabaru Member. Nonion nmicobar- ense-Cibicides macneili fauna. Medi- um-gray Claystone. On Highway 5 and about 0.3 mile northwest of junc- tion with Highway 30. West of Yona- baru Airfield, Okinawa. Chinen Sand (marl facies). Fine grained marly sand. Along east side of narrow ridge just north of High- way 8, about 0.25 mile east of inter- section of the junction of Highways 8 and 16, Okinawa. Chinen Sand. Rotorbinelle chinen- ensis fauna. Light-yellow foraminif- eral and molluscan marl. At base of F48 high limestone, sea cliff forming a headland about 0.8 mile southeast of Nakaza on Highway 64 (map sheet 3625III, Itoman NE), Okinawa. Shinzato Member. Globorotalia punctulata fauna. Medium-gray for- aminiferal claystone. In roadcut just below top of long hill on Highway 137 and about 0.3 mile south of Shinzato, Okinawa. USGS £11540 (TKRS-7). Chinen Sand. Bluish-gray tuffaceous clay. In low cliff 0.3 mile northeast of northwest tip of Heanza-Shisna, Okinawa Gunto. Chinen Sand. Rotorbinella chinen- ensis fauna. Near mouth of small stream emptying into Katena-ko di- rectly across road from Nakoshi Pri- mary School (map sheet 3726IV, Okinawa,). Naha Limestone (marl facies) (Nako- shi Sand). In cut on the north side of road 0.2 mile from Untenko LCT landing on the Unten Peninsula (map sheet 2727111, Unten), Okinawa. SELECTED BIBLIOGRAPHY Asano, Kiyoshi, 1936a, Fossil Foraminifera from the Kakegawa district, Totomi, Japan: Geol. Soc. Japan Jour., v. 43, no. 517, p. 739-757, pis. 36, 37. 1936b, New species of Foraminifera from Aki-gun, Tosa Province, Japan: Geol. Soc. 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Ishizaki, K., 1941, A brief note on the Foraminifera of the Byoritsu beds, Kotobukiyama, Takao, Taiwan: Taiwan Tigaku Kizi (Geol. Notes of Formosa), v. 12, no. 1, p. 5-9. 1942, G@lobigerina sediment from Zinkosi, Kosyun-gai, Kosyun-gun, Takao Prefecture, Formosa: Taiwan Tigaku Kizi (Geol. Notes of Formosa), v. 13, no. 1, p. 21-30. 1943, 1944, New species of Neogene, Pleistocene, and Re- cent Foraminifera of Japanese Empire. Part 1, v. 33, no. 233, p. 19-23, pl. 1, 1943. Part 2, v. 34, no. 244, p. 98-104, pl. 3, 1944: Nat. Hist. Soc. Taiwan (Formosa) Trans. Iwasa, Saburo, 1955, Biostratigraphy of the Isizawagawa group in Honjo and its environs, Akita Prefecture: Geol. Soc. Japan Jour., v. 61, no. 712, 18 p. Iwasa, Saburo, and Kikuchi, Yoshiki 1954, Foraminifera from the Sugota formation, Akita Prefecture, Japan: Paleont. Soc. Japan Trans. and Proc. (new ser.) no. 16, p. 183-194, 8 figs. Kleinpell, R. M., 1954, Neogene smaller Foraminifera from Lau, Fiji: B. P. Bishop Mus. Bull. 211, 96 p., 10 pls. Koch, R., 1923, Die jungtertiire Foraminiferen fauna von Kabu (Res. Surabaja, Java) : Eclogae geol. Helvetiae, v. 18, no. 2, p. 342-361. 1925, Eine jungtertiire Foraminiferen fauna aus Ost- Seran : Eclogae geol. Helvetiae, v. 19, no. 1, p. 207-213. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Koch, R., 1926, Mitteltertiire Foraminiferen aus Bulongan, Ost- Borneo: Eclogae geol. Helvetiae, v. 19, no. 3, p. 722-751. Ladd, H. S., 1936, Globigerina beds as depth indicators in the Tertiary sediments of Fiji: Science, ser. 2, v. 83, no. 2152, p. 301-302. Lalicker, C. G., and McCulloch, I., 1940, Some Textularidae of the Pacific Ocean: Allan Hancock Pacific Exped., v. 6, no. 2, p. 115-148, pls. 18-16. LeRoy, L. 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A Page Acknowledgments.... 220 Fi aculeata, Bulimina. .... - 6, 7, 9, 80, pl. 11 UDigerima. ccc. 6, 8, 9, 84, pl. 3 acuminata, Nodosaria........___________________ F4 acuminata uniforminata, Nodosaria 24, pl. 15 acuta, Textularia...._.....__. -- 17, pl. 1 AdETCOMYM@LLLL .cc uc ul cucu ll ll n 7, 15.17 glomerata. ... 7, 12, 17, pl. 1 advena, Dentalina...._.___________________ . 28, pl. 15 depressula, Elphidium... -- 28, pl. 10 - -- 26, pl. 14 Pict o e 23 aequilateralis, Globigerinella_..._.____. 6, 7, 8, 42, pl. 14 affinis, ._. 21 PYPQQ.. ccc ccc 21, pl. 12 agasaensis, Bolivina subangularis. - 81, pl. 2 agglutinans, Textularia______. ___ --- 9,13 agglutinatus, Reophaz .. _____________________ 15, pl. 13 akiensis, Clavulina yabei._.___________ 4, 6, 13, 18, pl. 1 akitaensis, Nomion. .._. _._________________ 9, 28, pl. 10 akneriana, Quingueloculina....._.- 4, 6, 9, 13, 19, pl. 12 alata, 81, pl. 2 31 albatrossi, Bolivina. ........._________. 6, 7, 8, $1, pl. 2 Nodosaria vertebralis.... .... ___. 25, pl. 15 alternans, Pleurostomella. altiformis, Gyroidina .. -- 6, 8, 86, pl. 5 ---- 4, 87, pl. 7 Gyroidima 37 altispira, Globigerima....._._____.__.______________ 48 Globoquadrina... -- 4, 6, 8, 45, pl. 14 Gyroidina ... 87, pl. 7 ambigua, Nodosaria . cll! 23 Rectoglanduling. 23, pl. 15 Ammobaculites cylindricus.... ._.____.________._ 17, pl. 1 subagglutinans .. .. .. 17, pl. 1 yumotoensis.... ..... 222 17 sp. A.._____ 17, pl. 1 15 AMIMOUISCM®L 222202222022, 22222 3, 7, 15 dominicensis, deformis . . ammonoides, Anomalina. . madagascariensis... ... 4, 6, 8, 9, 10, 13, 14, 89, pl. 6 20000. 4, 6, 8, 9, 89, pl. 6 39 amygdalaeformisiokense, Lozostomum.. 8, 9, 13, $3, pl. 2 angularis, 25, pl. 16 85 2222222222222 22 8, 55, pl. 5 angulosa, Lepidocyclina. .. 14 43 @mmonoides . 2 43 .... 38 4, 8, 9, 13, 48, pl. 6 wuellerstorfiL L 45 Anomalinella ..... 44 POSETOAML L2 222 cucu coco ucc sess 44, pl. 6 Anomalinidae..._....._._.___ 1200 48 apiciglabra, Lagena squamosa. .... ._____________ 26 Oolima ... ._________________ 26, pl. 13 arenacea, Bathysiphonm...__________________.__ 15, pl. 1 Arenaceous 3, 7, 10 asanoi, Cassidulina .. aspera, c222222222202. 25, pl. 13 IN DE X [Italic numbers indicate descriptions] Page A8terOrOb@lig L. 2222222222222 F15, 89 trispinosa . - 4, 6, 59, pl. 6 L 2222 es 28 SD, cocco locus ccc ssc ccc es 28, pl. 6 auriculus, 8, 89, pl. 6 australis, Miliotinella. ...... -- 21, pl. 12 Neoconobrina (Discorbis)..... .._... 36 QWinguelOCUILMQ. .... 21 8, 9, 59, pl. 4 B baggi, Lagena laevis. .. -- 26, pl. 13 BAQ@iM@L 89 totomiensi$ . 2 2222222222222 2222220002 4, 8, 9, $9, pl. 6 baithica, Hyalinea......._._....... 6, 8, 9, 13, 14, 44, pl. 9 barbarense, Elphidium faz... --- 4,6, 7,8, 9, 13, 28, pl. 10 baroemoenensis, Globigerina... ...... .. -- 42, pl. 14 15 2222 ucc clu coil csc esses 15, pl. 1 beccarii tepida, 38 tepida, Streblus ._.. 9, 13, 88, pl. 4 bengalensis, Anomalina.......__________________ 38 Osangularia. ..... ._____________ 6, 8, 58, pl. 9 berthelotiana subornata, Pulvinulina.... .. ..... - 38 bifrons, Rectobolivina......._.._..__________. 4, 84, pl. 3 striatula, Rectobolivina . . 6, 8, 9, 13, 14, $4, pl. 3 34 Biloculina affinis....... ..... - 21 L.. 22222222 cll ccc cc es 21 2222222222222 coc cc 21 subsphaerica...___..__________ 21 Biostratigraphy, Katchin Hanto 1.. 13 Yonabaru 1. 10 34 convallaria. ...... bocki, Textularia. BOliPim@. . e 81 L222 222 81, pl. 2 222 6,7, 8, $1, pl. 2 LL 2 22222 81, pl. 2 chinenensis -. $1, pl. 2 COMOAU@TIQL.. c coo 34 Rantkeni@ana...lllllllllllllllllllll 81, pl. 2 RATrEPI@GMUML . . . 22 33 . cc 2222 cc 33 lobata... - 33 Milic 2222 --- 33 6, 31, pl. 2 robusta... ... - 6,7, 13,14, 31, pl. 2 spinescens. striatula_.._.__________ subangularis agasaensis.._._._____________ 81, pl. 2 SUDrENICUIQLEQL .cc cl 81, pl. 2 Bolivinita........ 29 quadrilatera . 4, 6, 7, 8, 10, 29, pl. 2 BOliPimOD8i8..... ... 29 REPOLO .. 6,7, 10, 29, pl. 1 bosoensis decorata, Ehrenbergina......_.... 8,9, 41, pl. 5 bradyi, Anomalina............. 4, 6,7, 9, 43, pl. 6 Cassidulina .. -- 41 Cassidulinoides - 41, pl. 12 Cymbaloporetta_......._._______________ 9, 40, pl. 5 EggereUa......._.___________.. 4, 6, 7, 9, 10, 18, pl. 1 41, pl. 5 8, 9, 18, pl. 1 Trifarina ... -- 4,6, 8, 9,13, 35, pl. 3 18 Page braziliensis, Cassidulina.___________._________.. FAL Cassidulinoides.......___._______________ 41, pl. 12 -_ 8, 36, pl. 5 buchiana gutta, Bulimina....._.___________._._____ 30 bulbosa, Lagena striato-punctata_....._.._._.. 26, pl. 13 80 aculeata..__..... - 6,7, 9, 80, pl. 11 buchi@ana 30 JUL cll 6,10, $0, pl. 11 4, 6, 7, 8, 10, 80, pl. 11 marginata.. ..... 6,7, 8, 9, 13, 80, pl. 11 microlongistriata. 80, pl. 11 pupoides...... - 30, pl. 11 .c 2 22 ece} 30 6, 7, 8, 80, pl. 11 subcalva. -. 6,10, 30, pl. 11 L.. cll 29 yonabaruensis. 6, 80, pl. 11 29 Buliminoides . . . _ 29 williamsonianus.........._... 8, 9, 13, 14, 29, p11 bulloides, Globigerina. . - 4, 6, 7, 8, 9, 13, 42, pl. 14 ccc 41 4, 6, 8, 9, 41, pl. 10 Sphaeroidina..........______.___.. 4, 6, 9, 41, pl. 16 C Calear, 22 RODULULS . . . ___ 4, 22, pl. 4 Calcareous fung. ..______________________ Calcarina... .... fauna.. rustica . 8, 9, 14, 40, pl. 5 - 40 californica, Plectofrondicularia.. ..... - 29 Camerinidae............. - - 28 ccc -- 89 8, 89, pl. 6 COMMUMASL Lcc 9, 13, 39, pl. 6 sagra communis. - 39 C@MAGIML L.. - 48 mitida....... ooo 6, 7, 8, 14, 43, pl. 6 TetUI@PiQ. . .c 9, 17, pl. 2 caperata, Tritaziling......_.._..._cccclllllll 18, pl. 16 capitata, Bolivina... -_ $1, pl. 2 Lozostomum ... -- -- 33 carinata, Quinqueloculina ... - 4, 6, 9, 19, pl. 12 L. 40 8001.2 lll 40, pl. 11 bradyi... b inflata. ...... L 222222 40, pl. okinawaensis...._________________.. 4, 7, 40, pl. 11 orientale... - 6, 7, 8, 40, pl. 11 L 2 6, 7, 9, 40, pl. 11 8UDGLODO8Q.L L .... 7, 40, pl. 11 Cassidulinidae........_________________________. 40 Cassidulimoides ... . 41 bradyi... 41, pl. 12 ...l 41, pl. 12 HMAS c 22222 ccc coc 41, pl. 12 castrensis pacifica, Fissurina_....__..______.. 82, pl. 13 celata, 20, pl. 3 Ceratobulimina . . coll 40 pacifica......_... F54 Page Ceriopor@ gIODULS. . . . F4G challengeriana, Nodogenerina . 29 Orthomorphina. .. 29, pl. 15 ChilO8tOMeUMA..... c. cl 41 OOLMMQL ccc ull o coc cee. 6, 8, 41, pl. 2 41 Chinen Sand ...._.____..- --- 8, 8, 13 chinenensis, Bolivina .. _______________________ 81, pl. 2 Rotorbinella.... .. - 9, 13, 86, pl. 7 cibavensis, Gyroidima_.__._______._______. 6, 7, 87, pl. 7 .cc ccc cl ucc occ ese} 44 cicatricosa. . 45, pl. 8 222222222222 45, pl. 7 convera....... - 45, pl. 9 dorsOpUSEULOSU8 .. . ___.... . 45 6, 7, 9, 45, pl. 8 haidingerii pacificus.._.__________________ 45, pl. 8 RY@UM@L L 2222222222222 37 lobatulus - 7, 8, 9, 13, 45, pl. 8 22222222222 cc 4, 6, 44, pl. 9 okinawaensis. .. __ 6, 7, 44, pl. 9 OPROLSL ce olo cus ucc eee 45, pl. 8 haidingerii pacificus .. 6 pseudoungerianus . 4, 6, 7, 8, 9, 10, 45, pl. 8 45 PEJUIQ@M® .. . c 22 ccc clu 44, pl. 8 shinzatoenis .. - 6, 44, pl. 8 tenuimargo ... 8, 44, pl. 8 wuellerstorfi. . ... - 6, 7, 45, pl. 8 cicatricosa, 45 Cibicides...._._______._ sen nce se ces 45, pl. 8 cireularis, Cibicides..___.___________. -- 45, pl. 7 Spiroloculing. ..... 6, 20, pl. 3 CIDUIMQ~. 1 2222222 cocci cc css. 18 communis... ._. ... 19 yabei akiensis.. . _______________ 4, 6, 9, 13, 18, pl. 1 communis, 9, 89, pl. 6 Caneris sagrac...______.____.____ - 39 Clavulina.. .. -- 19 Dent@UM@. 2222222222222 23, pl. 15 19 Nodosaria (Dentalina)........____.__________. 28 Schenckiella .. - 4, 6, 14, 19, pl. 1 Spiroloculina........ .... - 4, 9, 20, pl. 3, 16 hosoyaensis, MartinottielUla................... 19 SchenckieUlu .._________._.__.- 6, 7, 10, 19, pl. 1 compressiuscula quadriloba, Pullenia 41 compressum, ..... ... - -- 88, pl. 2 contorta, Quingqueloculina.... 4, 20, pl. 12 convallaria, Bitubulogenerina........._...___.. 84, pl 2 BOlibiM@. ._ 22 222222222 ccc cc 34 convallarium, Lozostoma e 34 convera, Cibicides___. .... -- 45, pl. 9 Planulina. . - 45 COPMUSDIPQL 21 ... cc cc cc lloc 21, pl. 1 Correlation summary of Yonabaru and Katchin Hanto 14 costata, ._. 22 multicostata, CristeUlaria...._._.____________. 22 L222 222 cc l cus es 22 costatus, Robulus.. _...... 22, pl. 4 multicostatus, Robulus...._.____._.________ 22, pl. 4 costulatum, Luzostomum limbatum .._... _._. 33, pl. 2 crassicostata, Unvigerima_......_________..__ 4, 6, $5, pl. 4 crassitesta, Nodosaria~. ... .._.______.____. ___. 24, pl. 15 crebra, Fissurina. ..... -- $2, pl. 13 L@Q@MQL L222. 2222222000222 ccc 32 scissa, 82, pl. 13 32 cribrorepandus, ..... ..____.. ___ 89, pl. 9 Cristellaria costata........ ... 22 costata 22 HLCM. cc ll 22222 ccc ccc ccc cece cel ec 25 U@bifTOM® L 2 2 2222 22 ccc c ccc cscs 25 PeO@TIM@L L222 2222222222222 2222222222 i perprocera. .... . -- 22 HEUMAS.. cc lc 22 ucc ucc csc uso eee 25 UOTEER L2 22 clon ool usu ocus sconce ccc cece ce 21 (Lenticulina) polygonata......._.____._____.__ 22 INDEX Page CTUCIIOCULIM@L .. L_ cc cll lc F21 striata... -- 21, pl. 12 CyCl@MMIMQ . .. cc $, 7,12, 15, 17 €20°M818 2.2 2 2222 7,12, 17, pl. 18 SP, Acc ccc cl es 17, pl. 13 cylindricus, Ammobaculities......_.__..._.___._ 17, pl. 1 ...... .._... 40 DPAUYi Lcc cc eee 9, 40, pl. 5 CymbaloporidB@.......______._.ccccc2 40 D decorata, Ehrenbergina bosoensis....._...... 8, 9, 41, p1.5 deformis, Ammodiscus dominicensis....... 7,12, 15, pl.1 dehiscens, Sphaeroidina......._....._____._._.... 43 Sphaeroidinella .. -6, 8, 9, 48, pl. 14 28 cl cucu cul cc 28, pl. 15 COMMUMISL.2 ccc uc 23, pl. 15 222 co 23, pl. 15 jarpisi.. 28, pl. 15 ObliQU@. . . cc 22 clu clic 28, pl. 15 PECbL .cc lc ll usu c 28, pl. 15 PEUS&LL 2 2 cll occ cece. cons 28, pl. 15 .. ccc 28, pl. 15 (Dentalina) communis, Nodosaria. 23 depressa, 21 PYPGO .. c 2 c cll c 21, pl. 12 depressula, Elphidium advena-.._....._._.. 28, pl. 10 diffundens, Glomospira gordialis.........._.... 17, pl. 1 dimorpha, Rectobolivina. ...... . 6, 8, 84, pl. 3 .. _._. _ 34 Dimor pha 8tri@ta... ...... 35 dirupta, Uvigerina 6, 7, 10, 14, 84, pl. 4 45 japomica.....__.___... Discobolivina ..... 36 Discorbina ventricosa . .. 37 Discorbis isabelleana........____________________ 36 L Ll 22 eens 8, 36 opercularis. .cc cc olo (Discorbis) australis, Neoconobrina......._...... 36 dissimilis, Globigerina......_._.__________._.....- 15 distoma, L@GeM@L _._... 26, pl. 13 dominicensis deformis, Ammodiscus-_-- 7, 12, 15, pl. 1 dorsopustulosus, Cibicides...._...._______._...... 45 dubia, Globigerina...... ...-... 4, 6, 7, 8, 9, 13, 42, pl. 14 E echigoensis, Entosolenia.._..._________________. 32 FHSSUTIMQL. _. ccc 82, pl. 13 7, 12, 19, pl. 5 ._ _c cc cl ll 15,18 bradyi. .- - 4, 6, 7, 9, 10, 18, pl. 1 ERYERbETGIMQ. . .._. .c 22 41 bosoensis decorata_......_..._...._.- 8, 9, 41, pl. 5 DTAUYL .c ccc cc ces 41, pl. 5 Co eee 41 elegans, Hoeglundina. ...... .. 4, 6, 7, 8, 9, 10, 14, 88, pl. 6 Rotalia 38 Ellipsoidinidae .. 86 Ellipsonodosaria ___.. 35 elongata, 26, pl. 13 Quinqueloculina. - 9, 13, 20, pl. 12 .cc 28 advena depressula. ... .._ 28, pl. 10 fax .._... 4, 6, 7, 8, 9, 13, 28, pl. 10 8, 13, 14, 28, pl. 10 POEY@MUM.. L222 2222 lloc 28, pl. 9 ... 2. ccc 28, pl. 9 H@UDAMAUM 22222 2222 c ccc 28, pl. 10 HRUEOGMS@. ._ __. 28, pl. 10 emaciata, Dentalina..._._._._.______.______._- 28, pl. 15 enderbiensis, Fissurinal ___.. .__. ___________. 82, pl. 13 L@GOMQL L.. scc 32 Emtosolenia echigoensis........_______________.___ 32 squamosa scalariformis....._.....______...__ 26 (Emtosolenia) semiopaca, Lagena..._...___..... . 32 Page Eponides... FS7 6, 7, 87, pl. 7 9, 13, 14, 87, pl. 7 4, 6, 8, 9, 10, 13, 14, 88, pl. 7 uc 4, 6, 10, 88, pl. 7 subornatus.. . -- 4, 6, 8, 9, 13, 14, 88, pl. 7 UMDOMLLL l 39 exilis, 24, pl 15 ezoensis, Cyclammina______________... 7, 12, 17, pl. 18 F fasciata spinosa, Fissurina.. faz barbarense, Elphidium - 4, 6, 7, 8, 9, 13, 28, pl. 10 fijiensis, Cibicides......_______.____..~ 6, 7, 9, 46, pl. 8 PUQMUMQ.L . Fissurina........~ castrensis pacifica. crebra.c.......... 8CISSLL L . ccc 82, pl. 13 higoensis $2, pl. 13 EMAETDiGn8i8.. . cc 82, pl. 13 JSCiULQ $2, pl. 13 l t 82, pl. 13 esse $2, pl. 13 33 perforata. ...... $2, pl. 13 82, pl. 13 semiop 82, pl. 13 ee}. 82, pl. 13 24, pl. 15 fistulosa, Globigerina......... Globigerinoides life Teatularia sagittula . .. flinti pacifica, Siphoteztularia_.......... 6, 8, 9, pl. 2 foliace@, 29 Plectofrondicularia.... - 29, pl. 11 45 fragilissima, Massiling............_..........- 20, pl. 12 SDiTOLOCULIMQ. .. . ccc cesses e> 20 Frondicularia foliacea_............. 29 29 interrupta..... 20 Jfusiformi8, 27, pl. 5 G gaimairdi, Operculina.......... 4, 6, 9, 13, 14, 28, pl. 5 cll 18 18, pl. 1 siphonifera......... L.. 4, 18, pl. 1 solida. .._....__.....~ _._ 18, pl. 1 gemmaeformis, Uvigerina. - 4, 84, pl. 3 glabra, 23, pl. 16 glabrata, Anomalina............... 4, 8, 9, 13, 43, pl. 6 (Glandulina) laevigata, Nodosaria 23 GObiGeTiM@ . . . .cc 42 QI&DITQL .. . L ccc eee} 43 bar Me 42, pl. 14 bulloides...._.__.....__.- 4, 6, 7, 8, 9, 13, 42, pl. 14 GisgimiLs . . _ 20 s CWbiG. .. - 4, 6, 7, 8, 9, 13, 42, pl. 14 . .. 42 seminulina............ -- foe 43 Globigerinmatella < 15 Globigerinella.._........... 42 aequilateralis.............. _.. 6, 7, 8, 42, pl. 14 42 42 ._ .._.6, 7, 8, 42, pl. 14 PUDET L cl 7, 8, 9, 13, 42, pl. 14 lifera fistulosa 42 dMMMAUTQ... ccc 42 triloba fistulosa._...............~ 6, 7, 8, 9, 42, pl. 14 immatura.__..._...... 4, 6, 7, 8, 9, 13, 42, pl. 14 sacculifera........... -. 42, pl. 14 Globobulimina..........~ bess 80 globosa.................~ - 31, pl. 14 cc 6, 8, 80, pl. 14 Page GlObOQUAdrim . . ... F43 Q8SDIPALLLL L222 4, 6, 8, 43, pl. 14 GLObOPObIQ.. ...... 48 crassa fauna 48 menardii_ . ...... __13, 43 multicamerata - 4, 6, 7, 8, 9, 13, 43, pl. 9 3, 6, 8, 14, 46, 47 7, 43, pl. 9 punctulata.. .. --- 6, 7, 8, 9, 43, pl. 9 tumida.........~ 4, 6, 7, 8, 9, 10, 13, 43, pl. 9 Globorotaliid@e..........._____.________________- 43 globosa, Globobulimina..........._....._..... 31, pl. 14 #EtE8@, 26, pl. 13 26 globule, Gypsina...._.._____._._.______._ 8, 9, 13, 46, pl. 3 globulifera, Ramulima..........._.._.___.. 8, 27, pl. 14 globulus, 46 glomerata, Adercotryma........._....._. 7, 12, 17, pl. 1 Glomospira............... 7, 12, 15, pl. 1 glomeratum, Haplophragmium..............._.. 17 GIOMOSPiTAL.... .. __ 3, 7, 15 .L. 7 12, 15, pl. 1 gordialis diffundens.......______.______.___. 17, pl. 1 GOESOU..... .l 3,7, 15, 18 schencki_...__... -- 7,12, 18, pl.1 gordialis diffundens, Glomospira....._......... 17, pl. 1 gracilis meridionalis, Lagena....__....___..___... 26 meridionalis, Oolima............_______... 26, pl. 13 gutta, Bulimina_..._.... - 6,10, 80, pl. 11 Bulimina buchiana..............._._________- 30 GUMULMG 222222 lll lc 27 OPIEMEAN8. ._. 22222 27, pl. 11 PACC L 22222222 27, pl. 11 -_ 27, pl 11 _____ 46 8,9, 13, 46, pl. 3 GYTOIMWMQ... 2222 87 @HifOPMI® . . 2222 4,37, pl. 7 L ...l 87, pl. 7 cibaoemsis 6,7, 37, pl. 7 6, 10, 87, pl. 7 MMDDOMICQ ... ccc 87, pl. 7 soldanii 87 trincherasensis. . 6,7, 87, pl. 7 H haidingerii pacificus, Cibicides........_.__._.... 45, pl. 8 haidingeri pacificus, Truncatulina........__._.... 45 hantkeniana, Bolivina.............__.___.__.___. 81, pl. 2 Hanzawaia............. 4,9, 13, 46, p1.9 Haplophragmium glomeratum... ...... -- 17 haueri, Sphaeroidinma.........._________._.._______ 41 27 japonica. - 27, pl. 5 Heterohelicid@@.............._.__________________ 29 himiensis, 22, pl. 16 hiratai, Bolivinopsis........._._____.... 6,7, 10, 29, pl. 1 hirsuta, Nodosaria........____________________ 24. pl. 15 hispida, Uvigerina... - 6,7, 84, pl. 4 hispido-costata, Uvigerima.....__.._________.__. 85, pl. 3 hispidula, Nodosaria..._..._.._______________ 24, pl. 15 Nodosaria lepidula........__________._______._ 24 Rochstetteri, Nodosaria_. ... -_ 24, pl. 15 spinicosta, Nodosaria .. -- 24, pl. 16 38 elegans.... _______________ 4, 6, 7, 8,9, 10, 14, 88, pl. 6 Rosoyaensis, Martinottiella communis.......__... 19 Schenckiella communis .... 6,7, 10, 19, pl. 1 howehini, 19 . 19, pl. 1 hyalina, 37 . . ._ 44 balthical ... 6, 8,9, 13, 14, 44, pl.9 hyaltinus, Eponides......___..____________._ 6,7, 37, pl. 7 hystrix, 25, pl. 13 immatura, Globigerinoides sacculifera . ._. 42 Globigerinoides triloba_..__. .. 4, 6, 7, 8, 9, 13, 42, pl. 14 INDEX Page inaequalis, Frondiculcria...____________________. F29 Plectofrondicularia........_____.______.__.. 29, pl. 11 inconspicua, Discobolivina......._._.__.______.__.. 36 Patellinella.._...__. -. 13, 36, pl. 2 36 inflata, Bulimina.......______.____. 4, 6, 7, 8, 10, 30, pl. 11 . 222 4, 40, pL 11 MiliolMmeUQ@_. .. .c 21, pl. 12 inoratus, Robulus ...... insecta, Nodosaria...._____.___.___.. 4, 9, 10, 13, 24, pl. 15 insucta, Globigerinatella.._._........ 15 intermedia, Legend. 26, pl. 13 Lagent SEGA... _ 25 interrupta, Frondicularia_... Plectofrondicularia. ..... Introduction . __..___...._... involtens, 21, pl. 1 ODETCULMLLLLL 222 21 iokense, Clavulina yabei__........ cll 9 Lozostomum amygdalaeformis. 8, 9, 13, 83, pl. 2 isabelleana, Discorbis...___________________.____.. 36 ROSQLIM.... 222 86, pl. 7 italiea, 25 25, pl. 3 J japonica, Angulogerima........___.._________ 8, 85. pl. 5 6,7, 45, pl. 8 Flemicristellaria.........ccc2cllllllllllcll 27, pl. 5 Lenticulina. .... japonicum, Nonion . japonicus, Nonion . . 89, pl. 9 jarvist, Dentalina . 23, pl. 15 jenseni, Elphidium.............. 8, 13, 14, 28, pl. 10 jugosa, Patellinella_..._._........ - 8, 9, 13, $5, pl. 2 Textulariq......___________ __ 35 Kar Nicobar 14 karreriana, 18, pl. 1 karrerianum, 33 Lozostomum. Karreriella _.. DFAUYiL L. 2222 8, 9, 18, pl. 1 Katchin Hanto 1, stratigraphic summary......_ 12 ketnziensis, Ellipsonodosaria...__________________ 35 StHLO8EOMeUQL L... lll 85, pl. 15 lacunmata, 82, pl. 13 LMGENML ...ll 32 laevigata, Bolivina... 33 Nodosaria (Glanduling).......__._____.____. 23 Rectoglandulina......... 8, 23, pl. 14 Valvulineria. ... .. - 87, pl. 16 laevis baggi, 26, pl. 13 LMC... cee 13, 25 advena. -.. 26, pl. 14 USDETL L . c 25, pl. 13 CTEDT@L.. ccc 32 8CIBSQ. L 2 2 ccc loo 32 Ci8EOMQ . . 26, pl. 13 elongata .. - 26, pl. 13 32 globosa 26 gracilis meridionalis . intermedia. . 22 32 14.08 DAQQi~ . .cc 26, pl. 13 ...... - 32 radiato-marginata. ......._.______.___ 32 squamosa apiciglabra_...._..._.___... 26 striata 25 LLL .._ lc 26, pl. 13 - 25, pl. 13 striato-punctata bulbosa... .... - 26, pl. 13 sulcata spicata......._._... - 26, pl. 13 8PIPAbLL LLL 25, pl. 13 trigona-pulchella. . ....._...___________.______ 27 DERETICOBM L 2222 cocoon eee 32 F55 Lagena-Continued Page Willi@M&OMA... . 22 F2, pl. 13 (Emtosolenia) semiopaca . L222 82 Lagenida@.......__________._._._______ - 21 Lagenonodosaria . 27 8C@@ri8 . 4, 8, 9, 13, 27 pl. 15 87 ventricosa . ..... 37 larvata, PlamorbulinelUla...... 4, 6, 9, 10, 13, 14, 46, pl. 5 L@UGQTIMIMQL . .cc cc 44 Laticarinina pauperata_._._..___________._.__ 6, 44, pL. 9 latifrons, Cristellaria.......cccccccccllcccccclll 25 Saracenaria. .. 25, pl. 3 - 22 japonica . -_- 27 L_. 22, pl. 4 (Lenticulina) polygonata, Cristellaria....._...... 22 Lepidocycling.........____l_lllllllllll - 14 LL cc - 14 lepidula, Nodosaria...._...___.._.___.. - 35 hispidula, Nodosaria...._.......________._.__ 24 Siphonod08@ri@.. .... 35 StilostomeUla......._...____.._ 4, 6, 8, 9, 10, 13, 85 limbatum costulatum, Lozostomum ... 33, pl. 2 Listerella communis......___.___.... -- 19 ROWCRMH.L. 222 19 DiCtOMIGMSI8L .. 2222 lll 19 Lithostratigraphy, Katchin Hanto 1... 13 Yonabaru 10 17 lobata, Bolivina. . . ... 33 lobatula, 45 lobatulus, Cibicides.... --- 7, 8, 9, 13, 45, pl. 8 lobatum, 88, pl. 2 longi-costata, Nodosaria pyrula............... 24, pl. 15 longiscata, Nodosaria...._..._...... 9, 10, 13, 24, pl. 15 Loxzostoma convallarium......_.._._.____._._.___. 10 34 L222 33 amygdalaeformis iokense.. . . - 8, 9, 13, $3, pl. 2 Lcc 33 .. L 22 Lcc 38, pl. 33, pl. .. 33, pl. 2 2 limbatum costulatum . . ...... 2 -_ $3, pl. 2 2 2 _._. $3, pl. ...ll 4, 6, 33, pl. fAUNA......__________.- 3, 14, 15, 18, 22, 25, 27, 28, 30, 33, 36, 38, 39, 41, 44, 45, 46, 47 lunata, Fissuring........._cclccllllcclllllll 82, pl. 13 32 lythostrota, Textularia........_.._________.._._ 17, pl. 16 M Machinato Limestone®..........._._._.______._..... 3, 10 macneili, Cibicides._.._._..._.______._.__... 4, 6, 44, pl. 9 Nonion micobarense-Cibicides................ 14, 20 madagascariensis, Amphistegina..........___.... 4, 6, 8, 9, 10, 13, 14, 39, pl. 6 manpukujiense, Nomion......_._____.._____._.__ 28, pl. 10 margareta, Cassidulina..._..._____.______.____ 40, pl. 11 margaritifera, Truncatulima.........._..______._._- 87 margaritiferus, Eponides............. 9, 13, 14, 87, pl. 7 marginata, Bulimina. . 6, 7, 8, 9, 13, 30, pl. 11 22 c 23, pl. 16 .. .L Lc ccc 22, pl. 5 22 nozimaensis.. - 4, 22, pl. 5 PET DTOCETQ.. .. ccc 22, pl. 5 Martinottiella communis hosoyaensis.........._.. 19 mayeriana, Textularia. . menardii, 13, 48 multicamerata, Globorotalia................-~ 4, 6, 7, 8, 9, 13, 43, pl. 9 meridionalis, Legena gracilis.._____________.___.. 26 Oolina gracilis.._....... -- 26, pl. 13 microlongistriata, Buliminma.__..........._.__.. 80, pl. 11 3,7, 15, 19 echigo@n$i8.. . . 7,12, 19, pl. 5 F56 Page F1Q ...ll c 21 australis. - 21, pl. 12 inflata... .. - 21, pl. 12 milletti, Fissurina.. - 33 Miocene or Pli0cen@....___._________________._.- 7 miocemica, 41, pl. 10 Sigmoilima.._...__._..__.. -- 20, pl. 3 Miogypsina thecideaeformis ...... __ 14 mitra, Globigerimoides.............. 6,7, 8, 42, pl. 14 multicamerata, Globorotalia menardii...._.___.... 6,7, 8, 9, 13, 48, pL. 9 multicostata, Cristellaria costata.......... 22 multicostatus, Robulus costatus murrhina, Biloculina.........~ makamurai, 8, 36 13 Neoconobrina... 86, pl. 7 N@ULilU® .. 22 Lc c c neces neces- 22 UOPEEZL 1 2 ccc es 21 Neoconobina nakamurai..............____.____._. 9,13 opercularig.... .... MORGMUTOL .c 86, pl. 7 L.. cc 36, pl. 9 pacifica..........- -- 86, pl. 4 (Discorbis) australig....__.__________________. 36 meosoldanii, Gyroidina............___.... 6,10, 87, pl. 7 micobarense, Nomion....... .... 6,10, 27, pl. 10 micobarense-Cibicides macneili, Nonion........... 14, 20 mipponica, Gyroiding. 87, pl. 7 Hanzawaia........ - 4,9, 13, 46, pl. 9 mipponicus, Vagocibicides.. «--- 6,8, 45, pl. 4 mitida, BOHDIMGL . . 33 .. ._ 6, 7,8, 14, 48, pl. 6 nitidula, 8, 35, pl. 3 Nodogenerina challengeriana. ___ 29 Nodosaria_...............~ - 28, pl. 15 ACUMIMUIGL L ccc cl 4 uniforminata.. - 24, pl. 13 QAUVEMML. L2 ccc oo cece}. 23 ambigua .................................... 23 24, pl. 15 ......... 24, pl. 15 _________ 24, pl. 15 RETEUML L.. cc 24, pl. 15 RiSPidQUUQ. 222 24, pl. 15 ROCRSEUETH . . 24, pl. 15 8DMACO8EQL . L ._ 24, pl. 16 insecta.......... 4, 9, 10, 13, 24, pl. 15 ccc ll cesses 35 RiSPidUUQ. . . 22 24 longiscata.. .... 9, 10, 13, 24, pl. 15 perversa..... 20 ObliQUG... ccc cc ces.. 23 cus 24, pl. 15 pyrule longi-costata_~~.....______________ 24, pl. 15 radicula......_.... 23 recta... 28 8CADTIUSCUIQ ...ll 25, pl. 16 8CQIUTIS . . 2 .cc eee} 27 L c ccc uuu nece eee ee}. 25, pl. 15 ._.. spirostriolata.... subtertenuata. . EOTO 222 23 EOB cc c enc ence} 10, 23, pl. 15 tympaniplectiformis . --- 24, pl. 15 vertebralis........ albatrossi....... (Dentalina) communis......_____________.___ 23 (Glandulina) laevigata.._._......____.______. 23 INDEX Page NOMIOM. ...l. c F2? QRitACM818... .c ccc 9, 28, pl. 10 japonicum. .... 9, 13, 27, pl. 10 28, pl. 10 MHCODATERSEL. .... _ 6, 10, 27, pl. 10 micobarense-Cibicides macneili fauna. 3, 6, 8, 10, 12, 13, 14, 15, 18, 19, 20, 21, 29, 31, 35, 37, 40, 47. landicum ..... 28, pl. 10 pompiliOides. . ._. 8, 27, pl. 10 4, 8, 27 Nonionidae 27 IVY i 1 bulloides....... 41 landi , Nonio 28, pl. 10 nozimaensis, Marginulinopsis.............. 4, 22, pl. 5 0 obliqua, 23, pl. 15 Nodosaria..... ... 23 obliquiloculata, Pulleniatina._...... 6, 8, 9, 13, 42, pl. 14 okinawaense, Lozostomum.... -... 83, pl. 2 Nonion pompilicides . . . ... --- 4, 8, 27 okinawaensis, Cassidulina. 4, 7, 40, pl. 11 6,7, 44, pl. 9 4, 8, 9, 38, pl. 4 Schenckiella . c.. 7,12, 19, pl. 1 OOLMG.. .c cece ece 26 glObO8@ 8ELE8@. . ._ ___ 26, pl. 13 gracilis meridionalig...___.__.______..__... 26, pl. 13 squamosa apiciglabra._........._.......... 26, pl. 13 scalariformis .... trigona-pulchelUla_......._.___.._____..__. 27, pl. 13 oolina, Chilostomella_.......__.__.._.....~ 6, 8, 41, pl. 2 opercularis, Discorbis..._._..________.____.. Neoconobrina 36 15, 28 gaimairdi.....__....._. -- 4,6, 9, 13, 14, 28, pl. 5 cll 21 Ophthalmidiidac. . 21 OTDULMGLL. .. ccc} 7, 42 universa......____. 4, 6, 7, 8, 9, 10, 12, 13, 15, 42, pl. 14 orientale, Cassidulina. . --- 6,7, 8, 40, pl. 11 orientalis, Guttulina. .. .... _._. 27, pl. 11 ornata, Truncatulina ungeriana . -__- 45 ormatus, 45, pl. 8 OrthOMOPDRIMGLL.. . .cc l 29 challengeriana. - 29, pl. 15 Osangularia. --- 38 Den@@Llengi8. . . 6, 8, 38, pl. 9 P pacifica, Cassidulimna_......_____..._.. 6,7, 9, 40, pl. 11 6, 8, 30, pl. 14 27, pl. 11 Neoconobina Neoconobrina.. Sigmoidella . . ... Siphotextularia flinti......________.___.. 6,8, 9, pl. 2 6, 8, 9, 18, pl. 3 pacificum, Lozostomum. -- 4, 6, 33, pl. 2 ROLLidiWM. .. .c 38 Pacificus, 6,7 Cibicides haidimgerii_._.______._.______.___. 45, pl. 8 Truncatulina haidingeri....__.____________.. 45 Pararotalia......___...__... yonabaruensis . Patellinella......- 1NCORSDIGUAL L. . . 13, $6, pl. 2 JUJOBM .. c c 8, 9, 13, 35, pl. 2 pauperata, Laticarinina. -- 6, 44, pl. 9 Peneroplis........._...... --- 28 pertusus . . - 10, 28, pl. 5 Peneroplid@ . 28 penglaiensis, Spiroloculima........_....._._..- 20, pl. 3 peregrina, 22 dirupta, Uvigerina_...._._.--- 6, 7, 10, 14, 84, pl. 4 Page peregrina, Cristellaria-Continued o e F2, pl. 4 Uvigerina... perforata, Fissurina........_._____clclcccccl 82, pl. 13 perprocera, Cristellaria._.________________.______ 22 Marginulinopsis . . . -__ 22, pl. 5 pertusus, Peneroplis....________._________ 10, 28, pl. 5 perversa, 29 PI@MOTOUILIMEUQL .._. .. .l cc 15, 46 4, 6, 9, 10, 13, 14, 46, pl. 5 46 plano-conveza, Bolivina.........._...._..... 6, $1, pl. 2 Planularia yabei. _...... .._..- 21 PIQMULING CORDEZ@...._ __ __ 45 45 JODEOLMLQ. .. . .. L222 ll lc 45 WUEUMETSEOT L...... cl ul cc es 45 Plectofrondicularia..... .. .. 20 californica... .... ...- foliacea......... .. inaequalis. . Lc ccc ccc 29, pl. 5 .. ... cc 29, pl. 5 sp, A________._ - 29, pl. 5 PIGISEOC@NE .. ._.. econo- 10 Pleurostomella. ewe ae as asus use 86 LLL cl uc ccc 6, 8, 86, pl. 5 i O oe 8, 86, pl. 5 c. cll ece cence ce 8 Pliocene or MiOGC@N@_....__..______.______- ---. 7 Poeroeponides cribrorepandus - 39 poeyana, Polystomella_....._._________._._______... 28 pocyanum, Elphidium........____.._._.....- 28, pl. 9 polygonata Cristellaria (Lenticulina) polygonatus, Robulus.. . Severe Polystomella pocyana . . pompilioides, Nomion. .._...____._____..__.. 8, 27, pl. 10 okinawaense, Nomion.......__.______._. ___... 4, 8, 27 .... .. cone 89 Cribrorepandus. . .... 89, pl. 9 pragcinta, 38 L 22 2222222 coc, cocco eens 38 praecintus, Eponides.... 4, 6, 8, 9, 10, 13, 14, $8, pl. 7 praemenardii, Globorotalia.............._.. 7, 48, pl. 9 proboscidea, Uvigerina. 9, 85, pl. 3, 16 vadescens, Uvigerina. 6,7, 8,9, 10, 18, 85 rOGETA, L... 38 procerus, Eponides....._.____._._.....- 4, 6, 10, 88, pl. 7 PSEUdOEPORiGe®. .... . __ 89 cc ccc cc 89, pl. 9 UWIMDOMAAUSL .. cc o> 6, 7, 10, 89, pl. 7 pseudoungeriana, -- 45 pseudoungerianus, Cibicides...... 4, 6, 7, 8, 9, 10, 45, pl. 8 pulchella, Rotalia.... .. . 39 Pullenia... ..... 41 4, 6, 8, 9, 41, pl. 10 compressiuscula 41 Pullenia miocenica-...._._____________._._-.-- 41, pl. 10 quadriloba..... - 41, pl. 10 SQL8DUTYL Lc cues eee 41, pl. 10 Pullenia 41, pl. 10 L... 222222222222 cen 42 obliquiloculata_................- 6, 8, 9, 13, 42, pl. 14 Pulvinulina berthelotiana 38 . L.. c 2222 ccc ccc cece ce e> 38 43 punctatus, Cibicides... 45 punctulata, ...- 6, 7, 8, 9, 43 pl. 9 PUD4, L...... 24, pl. 15 pupoides, Bulimina........________._.___.... 80, pl. 11 pUSiQ, LL. o> 27, pl. 11 pygmea, Quinqueloculina....._........-.-..- 20, pl. 12 P§TQO . .. .cc ccc clo ese #1 affinis. - 21, pl. 12 CEDPES8Q.. L_ __ cc cc 21, pl. 12 murrhina. .. .. - 6, 8, 21, pl. 12 SUDSPRGETICQL..... __ 21, pl. 12 pyrula longi-costata, Nodosaria........ ...... 24, pl. 15 PYPUHMQL L 2222 2222222222 oc cesses 27 Page quadrilatera, Bolivinita... ..... .-. F4, 6, 7,8, 10, 29, pl. 2 29 quadriloba, Pullenia.. .-..... . 41, pl. 10 Pullenia compressiuscula - 41 Quingueloculina. ...... .._. 19 4, 6, 9, 13, 19, pl. 12 @MLSET@US L 2222222222220 2222 occ sco sc 21 carinata. 4, 6, 9, 19, pl. 12 contorba.._....._______. -.- 4,20, pl. 12 - 9, 13, 20, pl. 12 o e 20, pl. 12 PEAICUIAbQ.L.. L2 2222222222 19, pl. 12 sagamiensis.. .... _. ___ 19, pl. 12 22222222 19, pl. 12 R radiato-marginata, Fissurina........_._...__. 82, pl. 13 32 radicula, Nodosaria__........__._... 28 Rectoglandulina.........__._._______.____ 23 pl. 15 R@MULM@ 27 globulifera 8, 27, pl. 14 raphanus, Siphogenerina ...... - 4,6,9, 13, 35, pl. 3,16 Uvigerina (Sagrina) ...... 35 recta, Zip]. 15 NOGOS@TIQ ..... ccc 23 Rectobolivina .. $4 Dif OMS . . .... .cc 4, 34, pl. 3 striatula..._._____________ 6, 8,9, 13, 14, 34, pl. 3 dimorpha. .... 6,8, 34, pl. 3 222222222 llc cc 9, $4, pl. 3 Rectoglandulina. 23 @MDiGU@ L122 23, pl. 15 IGEDIGQQ ..... c ccc 8, 23, pl. 14 PAWICUIQ 23, pl. 15 HOPMOLQ 23, pl. 15 Rectuvigerina. 85 8ETHAEQL L2 6,8, $5, pl. 3 refulgens, Cibicides..._..________.____________. 44, pl. 8 Truncatulina. Reophacidae .. Reophaz........ agglutinatus -__ reticulata, Quingueloculina.........._....__._._ 19, pl. 12 REUSSEUQL .. 84 8DIMUIOSML . . 22 4,9, 13, $4, pl. 3 reussi, 23, pl. 15 15 Robertina....... 12200 29 subteres.._________ 29, pl. 3 RObDUMLSL . .c 21 CAICQT L Llc loco lloc 4, 22, pl. 4 COBHQLUS L c 222 ccc loll 22, pl. 4 . 22222 22, pl. 4 Réimiensi8 .. 22, pl. 16 inornatus.. .. - 22, pl. 16 polygOM@bS LL 22, pl. 16 2 22222222222 ccc 21, pl. 4 Y@b€1. c cll loll 21, pl. 4 SP2 Ac cc ccc 22, pl. 16 Sp. 22, pl. 16 robusta, Bolivina. . -- 6,7, 13, 14, 81, pl. 2 ROSQLMG .... .cc 86 isabelleana.......__... -. 86, pl. 7 ODETCUIATI8 . ...l lll 36 b ccc nll ccc noon 36 rostrata, AmomalineUla......._...__________.___ 44. pl 6 Bulimina......... 30 TrUMC@bULMQ. 44 Rotalia...._...._. 88 beccariitepida 38 praecinta . 38 PUCREUAL L . L 22222 lll 39 2 2 cll loll noc 87 stachi. ... 4, 9, 10, 13, 88, pl. 16 trispinosa. - 30 wmbonata_.........____.. - 30 (Turbinulina) 38 INDEX Page Robtalidiim . F38 okimawaensis..._______________.______ 4, 8, 9, 38, pl. 4 PACIfICUML.L 222222 38 Rotaliidae........ 86 RotOrbinella.... 36 9, 13, 36, pl. 7 3, 12, 46, 47, 48 ruber, ._.... ._.... 7, 8, 9, 13, 42, pl. 14 rustica, Calcarina... - 6, 8, 9, 10, 13, 14, 49, pl. 5 Ryukyu 3 S sacculifera, Globigerinoides triloba_..._________ 42, pl. 14 fistulosa, Globigerinoides__________________... 42 immatura, Globigerinoides._..._._._.____.... 42 sagamiensis, Quinqueloculimna_..______________ 19, pl. 12 sagittula, Textularia__._________________._____ 4, 9, pl. 1 fistulosa, Textularia._______________________. 13, 17 sagra communis, Sagrima bifrO8. _...... 34 ITG UIO. L2 22222 lo $4 (Sagrina) raphanus, Uvigerina___________________ 35 salisburyi, Pullemia . __ 41, pl. 10 SAPACEMATIQLL LL.. 2 22 25 @MguL@ri® L 25, pl. 16 HEQUC@L L222 2222222 25, pl. 3 . 2 2 22222222 c 25, pl. 3 scabriuscula, Nodosaria._..._.__._____________ 25, pl. 16 scalariformis, Entosolenia squamosa.__..__._____. 26 Oolima squamo$a....L.._________LL.______ 26, pl. 13 scalaris, Lagenonodosaria._. - 4,8, 9,13, 27, pl. 15 27 schencki, Goesella_._ -- 7,12, 18, pl.1 3,7, 15,19 COMMAITMS . 4, 6, 14, 19, pl. 1 hosoyaensis.... -- 6,7, 10, 19, pl. 1 ROUDCRHMA LL.. 19, pl. 1 okinawaensis.... .. -- 7,12, 19, pl l victoriensis . ___ 6,7, 8, 19, pl. 1 schlumbergeri, Sigmoilina_...._____.._. 4, 6, 7, 8, 9, 10, 20 schreibersiana, Virgulina.____________________ 33, pl. 3 scissa, Fissurina crebra_. ._ -_ 82, pl. 13 Lagema 32 semilaevis, Dentalina.....__________________. 28, pl. 15 seminulina, Globigerina..._._._________________ 43 Sphaeroidinella. . .. 4, 6, 7, 10, 48, pl. 14 semiopaca, Fissurina.. --- 82, pl. 13 Lagena (Entosolenia) . ______________________ 32 semistriata, Lagena striata. 26, pl. 13 serrata, Ehrenbergina......._____________________ 41 setesa, Lagena globosa.._._.____.______________._ 26 Oolina globosa.. ...... 26, pl. 13 setosa, Nodosaria.....___.. --- 25, pl. 15 Shimajiri 2222222222 8, 7 Yonabaru member.. _._____________________ 13 Shinzato member....___._.... h 7 shinzatoensis, Cibicides._.. ...... 6, 44, pl. 8 Sigmoidella pacifica. .... - 27 SigMOiliM@... ... 22222222 lc ccc c cc ens 15, 20 Sigmoilina celata. .._. 20, pl. 3 MAHOCEMACQL L L222 2222222222 20, pl. 3 schlumbergeri. 4, 6, 7, 8, 9, 10, 20 222222222222 2202222222222 2222 22 20, pl. 16 SilicIMId@@L 1 1 2.2 2222222222222 19 simaense, Elphidium. 28, pl. 9 Siphogenerina.... .. - 85 34 4, 6, 9, 13, 55, pl 3, 16 striata _...... .. 35 siphonifera, Gaudryima. -._.____________. 4, 18, pl. 1 Tertularia... .... ols 18 1222 89 australis 222222222 8, 9, 89 pl. 4 .. 222222 222222222222 89, pl. 16 Siphonodosaria lepidula......._________________. 35 Siphotertularia.... .. .. fintii pacifica .... soldanii altiformis, Gyroidina. . ROHL L 2 2 2 2222 cc seco 37 F57 Page solida, F18, pl. 1 soluta, ...... 25, pl. 15 spengleri, Calcarina. .. - 8, 9, 14, 40, pl. 5 ____________ 41 4, 6, 9, 41, pl. 16 ___ cl lloc 43 o e 41 Sphaeroidinella . 22200 48 dehiscens. .._... conn 6, 8 9, 48, pl. 14 seminulina. .... _.. - 4, 6, 7, 10, 48, pl. 14 spicata, Lagena sulcata....._____.______._._____ 26, pl. 13 spinescens, Bolivina. ..._._..__._____._._________ 7, pl. 2 spinicosta, Nodosaria ... 24, pl. 16 spinosa, Fissurina fasciata.. ._.. ._._.______. $2, pl. 13 spinulosa, Reussella. _._. 4, 9, 13, 84, pl. 3 VEPMEUIMQL.. . 2222 34 spirata, Lagena sulcata....._..___._______.«_ 25, pl. 13 SDirOIOCULIMGL . ... .. 2 20 circularis... --- 6, 20, pl. 3 communis... 4, 9, 20, pl. 3, 16 JTaQgili881MQL L222 2222222222222 20 penglaiensi8. .. 20, pl. 3 spirostriolata, Nodosaria .. . - 24, pl. 15 squamosa apiciglabra, Lagena.. -- 26 apiciglabra, Oolina..... ... - 26‘, pl. 13 scalariformis, Emtosolenia....._..._._...___. 26 OOHM@L L2 2222s ccc ic 26, pl. 13 stachi, Rotalia... 4, 9, 10, 13, 88, pl. 16 stacyi, Discorbis. - pl.? Rosalina... ... 36 striata, Rectuvigerina........__.._________ 6, 8 85 pl. 3 35 StilostomeUla... ._.. . ___.... __ 85 ketenziensis .. _._. 85, pl. 15 4,6, 8, 9, 10, 18, 85 Stratigraphic summary of Katchin Hanto 1..... 12 Stratigraphic summary of Yonabaru 1..._____.. 10 Stratigraphy .. __ 3 SHTODIUSL.. L.. 2222222222222 coco coc cece 88 beccarii tepida. 9, 13, 38, pl. 4 striata, 21, pl. 12 Dimorpha. . 35 intermedia, Lagena-........_.... 25 semistriata, Lagena.. ...... --- 26, pl. 13 toddi, Lagena.... ...... ---.. 25, pl. 13 striatella, Unvigerina....__________._____ 4, 9, 13, 34, pl. 3 striato-punctata bulbosa, Lagena-............. 26, pl. 18 striatula, 9, 81, pl. 2 Marginuling.. .. 22, pl. 5 Rectobolivina bifrons . 6, 8, 9, 13, 14, 54, pl. 3 subaffinis, Bulimina...........___.... 6, 7, 8, 80, pl. 11 subagglutinans, Ammobaculites. ._.... .._... 17, pl. 1 subangularis agasaensis, Bolivina......... .... 81, pl. 2 eubcalva, Bulimina.......____________- 6, 10, 30, pl. 11 subglobosa, Cassidulina................ -- 7, 40, pl. 11 subornata, Pulvinulina berthelotiana . . _._... ..... 38 subornatus, -- 4, 6, 8, 9, 13, 14, 88, pl. 7 subsphaerica, Biloculima.....____________________ 21 subreticulata, Bolivina......._______________._. 81, pl. 2 subsphaerica, Pyrgo......_._._______ccclcclll 21, pl. 12 subteres, 20 RObDETHM@L . ._.. ces 29, pl. 3 subtertenuata, ._. 6, 24, pl. 15 sulcata spicata, Lagena..._._________________ 26, pl. 13 spirata, 25, pl. 13 Systematic descriptions.........._._________..... 15 T taiwanmum, 28, pl. 10 tennis, 25 tenuimargo, Cibicides....___.... Truncatulina......_....... tenuis, Cassidulinoides.. Sigmoilina . Vaginulina ... tepida, Rotalia beccarii.. F58 Page 12.222 F1? 17, pl. 1 -- 9 -_ 17, pl. 2 22 9, 17, pl. 2 .cc cc 36 jugosa. .... -- 35 lythostrota..........._... - 17, pl. 16 mayeriana. - 18, pl. 16 ccc 29 Textularia sagittula........._.________.. 4, 9, pl. 1 fistulosa. .... ___ 13, 17 - 18 Textulariidae.... - 17 thecideaeformis, Miogypsina......_..._____._.___. 14 tikutoense, Elphidium. ..__________________.__ 28, pl. 10 toddi, Lagena striata... - 25, pl. 13 tornata, Nodosaria. . . ___ 23 Rectoglandulina. ___ 23, pl. 15 tosta, Nodosaria............___._..____._._. 10, 28, pl. 15 totomiensis, Baggina......._.______.____. 4,8, 9, 39, pl. 6 Plectofrondicularia......_..._.______.___... 29, pl. 5 tricarinata, Quinqueloculina. ... ___ 19, pl. 12 Triloculima............__... 4,9, 13, 20, pl. 3 TrIfQNIMQ. 85 4, 6, 8, 9, 13, 35, pl. 3 trigona-pulchella, Lagena .. 27 OOLMQL . ... 27, pl. 13 trigonula, Triloculina.......___._______._______ 20, pl. 16 triloba fistulosa, Globigerinoides..... 6, 7, 8, 9, 42, pl. 14 immatura, Globigerinoides....... 4, 6, 7, 8, 9, 13, 42 sacculifera, Globigerinoides......._._..... 42, pl. 14 TrilOCUIMG. 11. 20 HriG@rimab@. . ._ 4, 9, 13, 20, pl. 3 HTIGOMUQL . 22222 occ coon nn 20, pl. 16 trincherasensis, Gyroidina................ 6, 7, 87, pl. 7 trispinosa, Asterorotalia......... 4, 6, 89, pl. 6 RObAQL . .cc 39 18 caperata... - 18, pl. 16 Truncatulina haidingeri pacificus... - 45 - 45 ccc 37 L L 222 38 INDEX Truncatulina haidingeri pacificus-Continued _ Page p de iana F45 TOBETUIGL 1 ccc cece} 44 cc cll 44 45 c ccc 44 tubulosa, 89, pl. 16 tumida, Globorotalia.. 4, 6, 7, 8, 9, 10, 13, 48, pl. 9 Pulvinulina.......... 43 (Turbinulina) elegans, Rotalia. 110 38 tympaniplectiformis, Nodosaria_............. 24, pl. 15 U bonata, Eponides..... - 39 89 umbonatus, Pseudoeponides......_.... 6, 7, 10, 89, pl. 7 ungeriana ornata, Truncatulina. .. 45 uniforminata, Nodosaria acuminata.......... 24, pl. 15 universa, Orbulina.. 4, 6, 7, 8, 9, 10, 12, 138, 15, 42, pl. 14 ccc 34 ACUGUQLL.L c cll 6, 8, 9, $4, pl. 3 crassicostata. --- 4, 6, $5, pl. 4 G@MMACfOPMISL..L ccc 4, $4, pl. 3 . .c 6, 7, $4, pl. 4 hispido-costat 85, pl. 16 22222 ooo ono 8, 35, pl. 3 DEFEQTIMGL L . ... 4, 35 6, 7, 10, 14, 84, pl. 4 proboscidea_........._____._._.__.. 9, 13, $5, pls. 3, 16 vadescens - 6, 7, 8, 9, 10, 18, 85 striatella....__..__.. - 4, 9, 13, 84, pl. 3 (Sagrima) 35 v vadescens, Uvigerina proboscidea..... 6, 7, 8, 9, 10, 13, 85 Vaginulina........__...__. -- 25 tenuig._...._ -_ 25, pl. 3 4, 25, pl. 3 o 45 MDDOMICUSL . 222 6, 8, 45, pi. 4 V@DUIIMETIQL . . 2222 87 cll 87, pl. 16 18 Page ventricosa, Discorbima.........________________.. F37 Fissurina. ...... -. $2, pl. 13 ........ 32 ________ 87 Verneuilina bradyi._.....______lllllllllllllllll 18 8DHMULO8ML L. LLL L222 22 34 Verneuilinidae........~. 18 vertebralis, Nodosaria_...........______.______._.___ 4 albatrossi, Nodosaria.............__..._.. 25, pl. 15 victoriensis, ListereUla_._.._____.________________.. 19 Schenckiella.............._.... - 6,7,8, 19, pl. 1 virgula, Rectobolivina . --- 9, 34, pl. 3 34 83 schreibersiama.._........... -... 33, pl. 3 vortex, 21 Nautilus... .. col- 21 21, pl. 4 . . ccc 18 alata.... 31 6, 8, 9, 18, pl. 3 w wanneriana, Amphistegina............ 4, 6, 8, 9, 89, pl. 6 williamsoni, Lagena_._.......... -- 26, pl. 13 williamsonianus, Buliminoides. 8, 9, 13, 14, 29, pl. 11 wuellerstorfi, Amomalima......._____.___________ 45 Cibicide8. . 6,7, 45, pl. 8 PIQMRULIMG- .. 45 yabei, Planularia ~ 1200 21 Robulus......... -.. 21, pl. 4 akiensis, Clavulimnga._...____.____... 4, 6, 13, 18, pl. 1 iokense, CIDULIMG.._..._..____lcccllllllllll 9 Y Yonabaru member......._____.._________lllll___ 3 Shimaijiri formation.. -- 13 Yonabaru 1, stratigraphic summary.... ........ 10 yonabaruensis, Bulimi -- 6, 80, pl. 11 yonabaruensis, Pararotalia...__.._._.....__... 88, pl. 4 Yontan limestON@. ___... 3,10 yoshih is, Vaginuli -- 4, 25, pl. 3 y toensis, A baculites. ___.... a 17 PLATES 1-16 FigurEs 1, 2. 3, 4. 10. 11. 12. 13, 14. 15. 16. 17. 18. 19. 20. 21. 22, 23. 24. 25. 26, 27. 28, 29. 30, 31. 32. 33, 34. PLATE 1 Ammobaculites sp. A LeRoy (p. F17). USNM 625137, X 23; USGS loc. £11538 (RS-351, Chinen) ; 1, side view; 2, edge view. Ammobaculites subagglutinans Bandy (p. F17). USNM 625136, X 25; USGS loc. £11513 (RS-323, Shinzato) ; 3, apertural view; 4, side view. . Ammobaculites aff. A. cyclindricus Cushman (p. F17). USNM 625135, X 30; USGS loc. £11508 (FSM-27, Shinzato) ; 5, apertural view; 6, side view. Bathysiphon arenacea Cushman (p. F15). USNM 625322, X 30; Yonabaru 1-3,480 ft (Yonabaru) ; side view. . Cornuspira involvens (Reuss), var. (p. F21). USNM 625319, X 32; USGS loc. £11509 (FSM-31, Shinzato) ; 8, edge view; 9, side view. Bolivinopsis hiratai Uchio (p. F29). USNM 625307, X 72; USGS loc. £11528 (RS-198, Yonabaru) ; side view. Clavulina yabei akiensis Asano (p. F18). USNM 625321, X 23; USGS loc. £11537 (MD-25, Naha) ; side view. Ammodiscus dominicensis var. deformis Bermudez (p. F15). USNM 625258, X 22; Yonabaru 1-3,670 ft (Yonabaru) ; side view. Eggerella bradyi Cushman (p. F18). USNM 625139, x 38; USGS loc. £11533 (RS-129, Yonabaru) ; 13, apertural view; 14, side view. Goesella schencki Asano (p. F18). USNM 625279, X 14; Yonabaru 1-3,320 ft (Yonabaru) ; side view. Schenckiella okinawaensis LeRoy, n. sp. (p. F19). Holotype, USNM 625211, X 80; Yonabaru 1-3,440 ft (Yonabaru) ; side view. Schenckiella communis (d'Orbigny) (p. F19). USNM 625214, X 27; Yonabaru 1-1,190 ft (Yonabaru) ; side view. Schenckiella communis (d'Orbigny) hosoyaensis (Asano) (p. F19). USNM 625215, x 38; USGS loc. £11531 (FSM-45, Yonabaru); side view. Schenckiella victoriensis (Cushman) (p. F19). USNM 625213, x 23; USGS loc. £11529 (FSM-41, Yonabaru); side view. Schenckiella howchint (Cushman) (p. F19). USNM 625212, x 40; USGS loc. £11526 (RS-196, Yonabaru) ; side view. Gaudryina siphonifera (H. B. Brady) (p. F18). USNM 625256, x 40; USGS loc. £11526 (RS-196, Yonabaru) ; side view. Karreriella bradyi (Cushman) (p. F18). USNM 625273, X 65; USGS loc. £11539 (FSM-27, Shinzato) ; 22, apertural view; 23, side view. Glomospira glomerata Hoglund (p. F15). USNM 625275, x 38; Yonabaru 1-3,420 ft (Yonabaru) ; side view. Glomospira gordialis (Parker and Jones) var. diffundens Cushman and Renz (p. F17). USNM 625274, X 58; Yonabaru 1-3,480 ft (Yonabaru) ; side view. Gaudryina karreriana Cushman (p. F18). USNM 625255, X 38; USGS loc. £11526 (RS-196, Yonabaru) ; 26, apertural view; 27, side view. Gaudryina solida Schwager (p. F18). USNM 625257, x 26; Yonabaru 1-270 ft (Yonabaru) ; 28, apertural view; 29, side view. Textularia sagittula Defrance var. fistulosa H. B. Brady (p. F17). USNM 625361, x 30; USGS loc. £11538 (RS-351, Chinen) ; 30, apertural view; 31, side view. Adercotryma glomerata (H. B. Brady) (p. F17). USNM 625282, % 23; Yonabaru 1-3,000 ft (Yonabaru) ; side view of distorted specimen. Testularia acuta Reuss (p. F17). USNM 625363, x 39; USGS loc. £11518 (RS-366, Shinzato) ; 33, apertural view; 34, side view. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-F PLATE 1 SMALLER FORAMINIFERA FirgurEs 1, 2. 3, 4. 5, 6. 7. 8. 9. 10, 11. 12. 13. 14. 15. 16. 17, 18. 19. 20. 21. 22, 23. 24, 25. 26, 27. 28. 29, 30. 31, 32. 33, 34. 35, 36. 37, 38. 39. PLATE 2 Textularia bocki Héglund (p. F17). USNM 625359, x 40; USGS loc. £11509 (FSM-31, Shinzato) ; 1, apertural view; 2, side view. Siphotextularia flintii (Cushman) var. pacifica LeRoy, n. var. (p. F18). Holotype, USNM 625360, X 40; Yonabaru 1-3,250 ft (Yonabaru) ; 3, apertural view; 4, side view. Textularia candeiana d'Orbigny (p. F17). USNM 625362, x 38; USGS loc. £11529 (FSM-41, Yonabaru); 5, apertural view; 6, side view. Bolivina plano-conveza Cushman and Todd (p. F31). USNM 625153, X 36; USGS loc. £11536 (WF-274, Yonabaru) ; side view. Bolivina striatula Cushman (p. F31). USNM 625147, X 76; USGS loc. £11542 (ME-36, Naha); side view. Bolivina capitate Cushman (p. F31). USNM 625144, X 66; USGS loc. £11541 (ME-21, Chinen); side view. Bolivina chinenensis LeRoy, n. sp. (p. F31). Holotype, USNM 625143, X 108; Katchin Hanto 1-245 ft (Chinen); 10, apertural view; 11, side view. Bolivina alata (Seguenza) (p. F31). USNM 625151, x 72; USGS loc. f11541 (ME-21, Chinen); side view. Bolivina robusta (H. B. Brady) (p. F31). USNM 625145, x 37; USGS loc. £11529 (FSM-41, Yonabaru) ; side view. Bolivina hantkeniana H. B. Brady (p. F31). USNM 625152, x 35; USGS loc. f11512 (RS-322, Shinzato) ; side view. Bolivina albatrossi Cushman (p. F31). USNM 625149, x 122; USGS loc. £11512 (RS-322, Shinzato) ; side view., Bolivina subreticulata Parr (p. F31). USNM 625148, X 100; Yonabaru 1-90 ft (Yonabaru) ; side view. Loxzostomum okinawaense LeRoy, n. sp. (p. F338). Holotype, USNM 625290, X 78; USGS loc. £11542 (ME-36, Naha); 17, side view; 18, peripheral view. Loxzostomum lobatum (H. B. Brady) (p. F33). USNM 625133, x 163; USGS loc. £11541 (ME-21, Chinen); side view. Loxzostomum limbatum (H. B. Brady) var. costulatum (Cushman) (p. F338). USNM 625277, X 30; Katchin Hanto 1-295 ft (Chinen); side view. Bolivina spinescens Cushman (p. F31). USNM 625150, X 115; USGS loc. £11541 (ME-21, Chinen); side view. Lozostomum amygdalaeforme (H. B. Brady) var. iokiense Asano (p. F33). USNM 625134, % 80; USGS loc. £11541 (ME-21, Chinen); 22, side view; 23, peripheral view. Bolivina subangularis H. B. Brady var. agasaensis Asano (p. F31). USNM 625146, x 71; USGS loc. £11541 (ME-21, Chinen) ; 24, apertural view; 25, side view. Lozostomum karrerianum (H. B. Brady) (p. F33). USNM 625289, X 78; Katchin Hanto 1-265 ft (Chinen) ; 26, side view; 27, peripheral view. Bitubulogenerina convallaria (Millett) (p. F34). USNM 625166, X 118; USGS loc. f11541 (ME-21, Chinen); side view. Loxzostomum compressum LeRoy, n. sp. (p. F33). Holotype, USNM 625333, X 81; USGS loc. £11522 (RS-54, Yonabaru) ; 29, side view; 30, peripheral view. Lozostomum pacificum LeRoy, n. sp. (p. F33). Holotype, USNM 625132, X 39; USGS loc. £11525 (RS-152, Yonabaru); 31, peripheral view; 32, side view. Patellinella jugosa (H. B. Brady) (p. F35). USNM 625141, X 80; USGS loc. f11541 (ME-21, Chinen); 33, apertural view; 34, side view. Patellinella inconspicua (H. B. Brady) (p. F36). USNM 625142, % 101; USGS loc. £11541 (ME-21, Chinen) ; 35, apertural view; 36, side view. Bolivinita quadrilatera (Schwager) (p.F29). USNM 625164, x 39; USGS loc. £11510 (RS-314, Shinzato) ; 37, side view; 38, peripheral view. Chilostomella colina Schwager (p. F41). USNM 625320, X 37; Yonabaru 1-330 ft (Yonabaru) ; side view. GEOLOGICAL SURVEY SMALLER FORAMINIFERA FrGur®s 1, 2. 3, 4. 5, 6. 14. 15, 16. 17, 18. 19. 20. 21, 22. 23, 24. 25, 26. 27, 28. 29, 30. 31. 32, 33. 34. 35. 36. 37. 38. 39. 40, 41. 42. PLATE 3 Rectobolivina bifrons (H. B. Brady) (p. F34). USNM 625347, % 38; USGS loc. £11527 (RS-197, Yonabaru) ; 1, apertural view ; 2, side view. Rectobolivina dimorpha (Parker and Jones ) (p. F34). USNM 625349, X 38; USGS loc. £11521 (RS-377, Shinzato) ; 3, apertural view; 4, side view. Rectobolivina bifrons (H. B. Brady) var. striatula (Cushman) (p. F34). USNM 625348, x 43; USGS loc. £11523 (RS-149, Yonabaru) ; 5, apertural view; 6 side view. . Rectobolivina? virgula (H. B. Brady) (p. F34). USNM 625350, X 84; USGS loc. f11541 (ME-21, Chinen); side view. . Rectuvigerina striata (Schwager) (p. F35). USNM 625355, X 64; USGS loc. £11539 (FSM-12, Shinzato) ; side view. . Vulvulina pacifica Cushman (p. F18). USNM 625354, X 40; USGS loc. {11521 (RS-377, Shinzato) ; 9, apertural view; 10, side view. . Vaginulina yoshthamaensis Inoue and Nakaseko (p. F25). USNM 625340, x 28; USGS loc. £11524 (RS-150, Yonabaru) ; 11, apertural view; 12, side view. Vaginulina tenuis (Bornemann) (p. F25). USNM 625341, % 27; USGS loc. £11526 (RS-196, Yonabaru) ; side view. Virgulina schreibersiana Czjzek (p. F33). USNM 625335, X 62; USGS loc. £11542 (ME-36, Naha) ; side view. Robertina subteres (H. B. Brady) (p. F29). USNM 625338, X 63; USGS loc. f11511 (RS-321, Shinzato) ; 15, apertural view; 16, side view. Trifarina bradyi Cushman (p. F35). USNM 625334, X 113; USGS loc. £11541 (ME-21, Chinen); 17, apertural view; 18, side view. Reussella spinulosa (Reuss) (p. F34). USNM 625336, x 80; USGS loc. £11542 (ME-36, Naha); side view. Gypsina globula (Reuss) (p. F46). USNM 625352, X 40; USGS loc. {11513 (RS-323, Shinzato) ; side view. Sigmolina celata (Costa) (p. F20). USNM 625383, % 40; USGS loc. {11513 (RS-323, Shinzato) ; 21, apertural view; 22, side view. Spiroloculina circularis Cushman and Todd (p. F20). USNM 625346, x 42; USGS loc. £11529 (FSM-41, Yonabaru) ; 23, side view; 24, peripheral view. Spiroloculina penglaiensis Jacot (p. F20). USNM 625345, X 26; USGS loc. £11534 (WF-272, Yonabaru) ; 25, peripheral view; 26, side view. Spiroloculina communis Cushman and Todd (p. F20). USNM 625344, X 42; USGS loc. £11537 (MD-25, Chinen); 27, side view; 28, peripheral view. Saracenaria italica Defrance (p. F25). USNM 625380, x 28; USGS loc. £11529 (FSM-41, Yonabaru) ; 29, side view; 30, front view. Reophaz agglutinatus Cushman (p. F15). USNM 625351, x 28; USGS loc. £11526 (RS-196, Yonabaru) ; side view. Triloculina tricarinata d'Orbigny (p. F20). USNM 625343, X 60; USGS loc. f11541 (ME-21, Chinen) ; 32, apertural view; 33, side view. Sigmoilina miocenica Cushman (p. F20). USNM 625382, X 63; USGS loc. £11509 (FSM-31, Shinzato) ; side view. Siphogenerina raphanus (Parker and Jones) (p. F35). USNM 625386, X 39; USGS loc. £11537 (MD-25, Chinen); side view. Saracenaria latifrons (H. B. Brady) (p. F25). USNM 625381, X 37; USGS loc. f11517 (RS-360, Shinzato) ; side view. Uvigerina nitidula Schwager (p. F835). USNM 625365, X 36; USGS loc. f11511 (RS-321, Shinzato) ; side view. Uvigerina proboscidea Schwager var. vadescens Cushman (p. F35). USNM 625364, X 64; USGS loc. £11521 (RS-377, Shinzato) ; side view. Uvigerina gemmaeformis Schwager (p. F34). USNM 625372, X 28; Yonabaru 1-1,170 ft (Yonabaru) ; side view. Uvigerina aculeata d'Orbigny (p. F34). 40, USNM 625366; 41, USNM 625369, x 46; USGS loc. £11508 (FSM-27, Shinzato) ; side views. Uvigerina striatella Reuss (p. F34). USNM 625373, X 37; Yonabaru 1-850 ft (Yonabaru) ; side view. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-F PLATE 3 [s fl HWI a £ J T 1 [ TC LaF . a eo Jol foes SMALLER FORAMINIFERA Figures 1 2, 3. 4. 5, 6. 14, 15. 16, 17. 18, 19. 20-22 23-25 26-28 29-31 PLATE 4 . Uvigerina crassicostata Schwager (p. F35). USNM 625368, X 36; USGS loc. £11527 (RS-197, Yonabaru); side view. Uvigerina hispida Schwager (p. F34). 2, USNM 625370; 3, USNM 625371, % 45; USGS loc. £11521 (RS-377, Shinzato) ; side views. Uvigerina peregrina Cushman var. dirupta Todd (p. F34). USNM 625385, X 67; USGS loc. £11536 (WF-274, Yonabaru) ; side view. Lenticulina peregrina (Schwager) (p. F22). USNM 625379, x 30; USGS loc. £11526 (RS-196, Yonabaru) ; 5, side view; 6, peripheral view. . Robulus vortex (Fichtel and Moll) (p. F21). USNM 625376, X 30; USGS loc. £11526 (RS-196, Yonabaru) ; 7, side view; 8, peripheral view. . Robulus costatus (Fichtel and Moll) (p. F22). USNM 625377, % 30; USGS loc. f11515 (RS-331, Shinzato) ; 9, peripheral view; 10, side view. . Robulus costatus (Fichtel and Moll) var. multicostatus (Cushman) (p. F22). USNM 625375, x 29; USGS loc. 11513 (RS-323, Shinzato); 11, peripheral view; 12, side view. . Robulus yabei (Asano) (p. F21). USNM 625378, x 28; USGS loc. £11507 (MD-149, Chinen) ; side view. Robulus calcar (Linné) (p. F22). USNM 625374, X 48; USGS loc. £11539 (FSM-27, Shinzato) ; 14, peripheral view; 15, side view. Streblus beccarii tepida (Cushman) (p. F38). USNM 625337, X 42; USGS loc. £11542 (ME-36, Naha); 16, ventral view; 17, dorsal view. Vagocibicides nipponicus Uchio (p. F45). USNM 625339, x 41; USGS loc. £11520 (RS-376, Shinzato) ; 18, ventral view; 19, dorsal view. . Siphonina australis Cushman (p. F39). USNM 625342, X 68; USGS loc. £11509 (FSM-31, Yonabaru) ; 20, dorsal view; 21, peripheral view; 22, ventral view. . Pararotalia yonabaruensis LeRoy, n. sp. (p. F38). Holotype, USNM 625367, X 59; Yonabaru 1-650 ft (Yonabaru); 23, ventral view; 24, peripheral view; 25, dorsal view. . Neoconobrina pacifica LeRoy, n. sp. (p. F36). Holotype, USNM 625356, X 64; Yonabaru 1-830 ft (Yonabaru); 26, ventral view; 27, peripheral view; 28, dorsal view. . Rotalidium okinawaensis LeRoy, n. sp. (p. F38). Holotype, USNM 625384, X 66; Yonabaru 1-290 ft (Yonabaru); 29, ventral view; 30, peripheral view; 31, dorsal view. PROFESSIONAL PAPER 454-F PLATE 4 GEOLOGICAL SURVEY ots ¥ 14.8} yt $08 NN SMALLER FORAMINIFERA FraurEs 1, 2. 3. 4. 5. 6, 7. 10. 11. 12. 13, 14. 15, 16. 17. 18, 19. 20. 21, 22. 23. 24. 25. 26. 27, 28. PLATE 5 Calcarina rustica Todd and Post (p. F40). USNM 625308, X 42; USGS loc. £11537 (MD-25, Chinen); 1, ventral view; 2, dorsal view. Calcarina spengleri (Gmelin) (p. F40). USNM 625309, x 23; USGS loc. £11537 (MD-25, Chinen); ventral view. Pleurostomella brevis Schwager (p. F36). USNM 625300, X 67; Yonabaru 1-30 ft (Yonabaru) ; oblique side view. Pleurostomella alternans Schwager (p. F36). USNM 625301, X 40; USGS loc. £11529 (FSM-41, Yonabaru); side view. Cymbaloporetta bradyi (Cushman) (p. F40). USNM 625165, X 64; USGS loc. £11541 (ME-21, Chinen); opposite sides. . Planorbulinella larvata (Parker and Jones) (p. F46). USNM 625299, X 40; Yonabaru 1-230 ft (Yonabaru); opposite sides. Marginulinopsis perprocera (Schwager) (p. F22). USNM 625285, % 40; USGS loc. £11539 (FSM-27, Shinzato) ; side view. Marginulina striatulae Cushman (p. F22). USNM 625286, x 77; USGS loc. £11521 (RS-377, Shinzato) ; side view. Marginulinopsis nozimaensis Asano (p. F22). USNM 625284, X 14; USGS loc. £11524 (RS-150, Yonabaru); side view. Operculina gaimairdi d'Orbigny (p. F28). USNM 625304, X 26; USGS loc. £11524 (RS-150, Yonabaru); 13, side view; 14, peripheral view. Miliammina echigoensis Asano and Inomata (p. F19). USNM 625292, % 82; Yonabaru 1-3,830 ft; (Yonabaru); 15, peripheral view; 16, side view. Hemicristellaria japonica (Asano) (p. F27). USNM 625283, x 39; USGS loc. f11517 (RS-360, Shinzato) ; side view. Plectofrondicularia totomiensis' Makiyama (p. F29). USNM 625314, X 40; USGS loc. £11536 (WF-274), Yonabaru); 18, side view; 19, peripheral view. Peneroplis pertusus (Forskal) (p. F28). USNM 625298, X 70; Yonabaru 1-350 ft (Yonabaru); side view. Ehrenbergina bradyi Cushman (p. F41). USNM 625162, X 64; USGS loc. f11517 (RS-360, Shinzato) ; 21, 22, opposite views. Plectofrondicularia sp. A LeRoy (p. F29). USNM 625353, x 35; USGS loc. £11519 (WF-372, Shinzato) ; side view. Angulogerina japonica Asano (p. F35). USNM 625317, X 113; USGS loc. £11521 (RS-377, Shinzato); side view. Plectofrondicularia interrupta (Karrer) (p. F29). USNM 625318, X 65; USGS loc. £11509 (FSM-31, Shinzato) ; side view. Pyrulina fusiformis (Romer) (p. F27). USNM 625332, x37; USGS loc. £11524 (RS-150, Yonabaru); side view. Ehrenbergina bosoensis var. decorata Takayanagi (p. F41). USNM 625163, X 66; USGS loc. £11538 (RS-350, Chinen); opposite sides. PROFESSIONAL PAPER 454-F PLATE 5 GEOLOGICAL SURVEY o -I cer r- earner Jane ttt sul r awl 3] A4ALA u 4 ATi (Ebb E. 4 -a A pa ate esr . % - Apt.,

ATT] j Fo fi:: 21 I sages s o | I 5 ITI IT I \ I | POTTER | ute o | __ OLDHAM lE | carRsoNYE::!!: i I | | A l__ ___________ Jl Oérpirijlgi _______ ty > B I Areas in which Precambrian A ; . rocks are exposed : Cliffside Field l 1 t. g & TP I I %8 & A. I CA- “M I | z W%A‘“v I J,. P aet . o | TEXAS fe. "s , C h 0 50 100 MILES a | o‘lnta. | 1 I I 1 | R 54 \_J“J\\ ns | F Y FIGURE 1.-Index map showing location of Panhandle field and adjacent areas. URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS 1.-Wells shown on plate 1, listed numerically Abbreviation Company Olt BOV: 222: AXLE cock Cities Service Oil Co. H ie Colorado Interstate Gas Co. | of . deny 1 aran in Continental Oil Co. Gray Co. Gray County Producing Co. A202... Kerr-McGee Oil Industries Inc. LAL Ler weve. Magnolia Petroleum Co. Nat. GPA Natural Gas Pipeline Co. of America (formerly Texoma Natural Gas Co.) North; Northern Natural Gas Co. Pan Bie Sci- Ue Panhandle Eastern Pipe Line Co. -... Panhandle Oil Co. Pan. Prod. -... Panhandle Production Co. ) 4 peo anns bees dee anv Phillips Petroleum Co. BAR.ili ies ne cecreuasl Red River Oil Co. Shamrock Oil & Gas Corp. sri _C ALI ILL Sinclair Oil Corp. T APA E Texas Interstate Pipe Line Co. [Asterisk (*) indicates well is not shown on map] Map No. Company and name Map No. Company and name Peo Ph. Jover 1 iro... Ph. Laughter 1 fa **: Ph. Stocking 1 lca cls" Sham. Perky 1 (DE redken g lX Kermac. Zoeber 1 fees er. Kermac. Schroeter 1 20d: .. Sham. Johnson C-1 ide ccs Kermac. Elgin 1 ;...}, Sham. Atcheson 1 Teds ci toned Sham. Robertson E-1 Kermac. Reeves 1 arsenic cn aslan, Sham. Robertson C-4 52, “““““““““““ 11:3? affczwé 4 frass. lsc ls .e sel Sham. Breesford 1 ___________________ . Witherbee BAG 5h. Zcéeber 1 a Badru cn. A LOO Mag. Thompson 1 inc. Phillips A-1 y.. gi e is s on ato Sham. Johnson B-1 clo cus Sham. Anderson 1 $ coo tsl un Rejad at st cella s Sham. Robertson C-2 2a ______________ ihaméghélfge; 1 Pos o Sham. Robertson C-1 ___________________ ermac. Ph. Utey 1 Stein ei Huber Russell; Fuller 1 B s.. .. bs ee een ins a we aes Ph. Moore '66' 1 g ___________________ £1111 s 019m, © Icey Sham. Robertson B-4 ___________________ ell-Sine. Flynn 1 »" PK bos Soe eron dan naan la an Shell-Sinc. Russel 1 -_ : ~~. s- $ ftc. Mip fines fer. n.... Ph. Jones A-3 on 2d Ph. Sunray A-2 10}. cn ncs E. teu. Sham. Robertson D-3 Te e oe alee als Ph. Purdy 1 Pen l Jill {u ul. Shell-Sine. Miller A-1 iR Es- cresent Ph. Jones A-2 n. Kermac. Humphries 1 f -i cet Ph. Jones A-1 12s or LR ccc Shell-Sinc. Kraker 1 a) (foe _s Shell-Sinc. Longanbecker 1 Se ECE rea e= an Mag. Brltfan 5 BOY IL.. caeca Mag. Britian 1 Ph. Butler 1 Mag. Britian 2 I4» 2 Ph. Mills 1 STS LCI ALIN CE Ph. Donaldson 1 19 - non.. lg.. Shell-Sine. Dash 1 Bar ma- cee -case ss Ph. Glass 1 Sc .ll... Ph.-Kermac. Wells 1 Are in sr o s Shell-Sinc. Miller 1 Shell-Sinc. Bartlett 1 Ms atras . [. Ph. Kelly 1 Pray. scene nic Lo Ph. Box 1 30 Ph. Wilson 2 sly cnc Ph. Pittman 1 ._ ls ny Kermac. Flynn 1 fI t :en c 2... Ph.-Kermac. McDowell C-1 sven Ph. McDowell 1 .e. Ph.-Kermac. McDowell C-2 ~~}. Sinc. McDowell 1 SB. __.. est Ph. Ebling 12 BBA Ph. Ebling 1 r Ph. Estate 1 Bebus _ J- LL Sham. Stewart 10 O sell nl.l...... Sham. Robertson C-3 cr cout. Ph. Brumley 1 dA c cll :L _L Sham. Myers 1 10... /z. cuse lilies Sham. Brumley 3 G3 G4 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name 408... ce- chal Sham. Brumley A-1 ce. lel cet Shell-Sinc. Hill 1 Sham. Tays 1 Sham. Johnson 1 40g. Sham. Powell C-1 Mre: Pli se ie > Sham. Brumley-Golf 1 Maciek e Sham. McKee C-1 MDLLE L H. ean Sham. Brumley Ryan 1 MC. .E Shell-Sinc. Jones 1 Md. 2.2. IAL Sham. Jones A-1 42... rda s: wes Sham. Jones B-1 M9 LIL. i- + ear aa Sham. Jones C-1 ER ! cel os. Ph. Albert 1 n alle Kermac. Jones A-1 I. .J. _c: Ph. Richard A-1 fD oo. cli ax s Sham. Sharkey 1 A0 o. iene ces uue a Cont. Brown 1 Te rt ile Mag. Britian 6 CBr: i Mag. Britian 3 40 eel asa Mag. Britian 4 50 :: Ph.-Kermac. Donaldson 1 Mle 2 ALI Shell-Sine. Donaldson A-1 uu celled. Kermac. Donaldson 1 Brar. u.. sculls Cont. Wells 1 beer Ph. Guleke 1 Bde er oal ens deel Sham. McDowell 1 ltrs re. cl Shell Lucas 1 BOT LL:. Ph. Lucas 4 508: aro eck ws Sham. Logan "A" en Sham. Logan 1 Deen LE EE: Ph. Lucas 1 BSEE i reck s Sham. Powell 1 - Sham. Burnett 1 rie. le cs. Sham. Burnett et al. 1 BSC: ce- Sham. Brumley 2 Sham. Sunset Brumley 1 SSt rue secede Sham. Allen 1 Bgy. Sham. Powell- Magnolia 1 D02 ces ell e Sham. Rubert 1 60-2 r 2 GLE aa Ph. Reeder 1 6032: ce ren sd Sham. Jones-Ryan 1 Cle! .n - Ph. Reeder 2 bla: xss e ec a ad Ph. Jones 1 62. :e! nlcs cus Cont. Jones B-1 63. ster d Ph. Ozark 1 CL. cree eine eee Kermac. McDowell 2 boe nani lll Cont. McDowell 1 .A. aul Mag. Britian 8 67e e sa e o side . Ph. Bush 1 A. Cont. Bush 1 CY E EEC cc Ph. Nunley 1 TOL eee ner ases Shell-Sinc. Donelson B-1 TOR Shell-Sinc. Donelson C-1 Tra nline - Ph. Donelson 1 ascent a tle Kermac. A. Donaldson 1 Map No. Company and name Tok - eti eo a ate ano Ph. Flynn 1 TELCO EYE naa sas Shell-Sine. Guleke 1 vay cinta oie ales" a Ph. Powell 1 TC:. ANL: Adee Rubin Carver 327 Ti ss Rubin Barnhill 3 Bil < Rubin Barnhill 28 TOs e ible ate c Nat. G.P.A. Texas C-1 80}: 2. Sham. Pritchard 1 SLX: Wittenburg 1 B21 Huber B-4 8B... cence Huber Henderson 1 $4}. Ph. Coffee 1 S48 22 L eel Sham. Coffee A-1 elias es Sham. Hight 1 SAG Lu teen reali Sham. Luckhard 1 S4d-.::ce-sE CII Ph. Faye 1 Sic.. ss. Sham. Gearhart 1 85... LIL. Ph. Clark Gable 1 S0 Kermac. Burnett 1 l als Ph. Texas 1 ieee e cela die aie Ph. Sunray-Jones 1 BD: .: aisle tos Kermac. Avery 1 90... n Ncc Ph. Hub 1 01:0 nn eee died -. Shell-Sine. McDowell B-1 08.0. Kermac. McDowell 1 YJ .e ten (*) JL. _ 2. crece csa es aan Ph. Marguerite Ann 1 ed Sham. Wilson 1 Mag. Britain 7 $7... Ph. Britain 1 98.:; ... .LI N i Cont. Arnis 1 99 .- ... ee aan a ak Ph. Reuter 1 100: : Cont. Marsh 1 101 tes Kermac. Morton 3 Cont. Meier 1 108: coule reac vene Ph. Venable 1 Ph. Castleman B-1 . (*) 106: Ph. Spur 1 107-. cl Ph. Ada May 1 108; .. Wittenburg B-3 109. .-: Huber 1 110%. 00. Huber 12 cic. Huber 3 112.1000 00% , Sham. Dore 1 Sham. Householder 1 Sham. J. F. Ward 1 (12e: s s e Mir Ph. Ward 1 12d, ::: Ph. Kane 1 twist Sham. McKeig 1 112. ssa cl e cracls Sham. Mercer 1 119g. Sham. McDade 2 | 6 b nae e (oan i oe Ph. Claudine 1 114... cst. sk tne. Ph. Clarence 1 11Ma. Ph. Marsh 1 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G5 TABLE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name 115... ccc lossy Cont. Burnett 1 te: 4. Ph. Sturdy 1 M7... E ...l: s Shell-Sine. Jones 9-1 18: .:.: Kermac. Jones G-1-A Cont. Jones A-1 Kermac. Jacobson 1 >>All: Ph. O. E. McDowell 1 (1222 ccc n oc. Sham. Becker 1 12s: ed. oll cus. Sham. Zwack 1 1242. . 022020000 Sham. Olsson 1 (2b .J _L -: lo..... Kermac. Wilson A-1 fede. c sel Mag. Nelson 1 /i Ph. Nelson 1 128-2. icc Shell-Sine. Wilson 1 N20... Kermac. Morton A-1 130: Kermac. Morton 4 Ph. Castleman A-1 TIR P Ph. Spurlock 1 Huber B-1 fed rc UQ. Cont. Spurlock 1 fsb esc - AC. cc nt. Cont. H. W. Carver 1 . Cont. H. W. Carver 6 19A EAL IIA Sham. Schlee 1 Tova .l Ph. Melvin 1 Nat. G. P. A. Dore 1-G Ph. Emily Nell 1 ford -...C..._...l0"" Sham. McDade 1 (ore.. cla scn ick sed Sham. McDade 3 TSS eect: ee adul 2 Kermac. Sullivan 1 139 : __.... ul sass Kermac. Strunk 1 toda.. sl., Nat. G. P. A. Pythian 1-P 140.2 :L 0.00 Sham. Jones 1 141: ll Ph. Booker 1 112ic= P ._. Kermac. Jones M-1 ._ Sham. Meinhardt 1 Sham. Cox 1 145 c cil Kermac. Taylor A-1 PAG»... Mag. Herndon 1 4T enn L Ph. Winn 1 fas: 10... ; :... (®) 149.2 dll Shell-Sine. Lindsey 1 150 >.. Kermac. Wilbar 2 1512 .y Shell-Sine. Hohman 1 152.c2.cl. 000.000. Shell-Sine. Catlett 1 cc ct _._. Ph. Ledlow 1 154 el LL Le Ii de Ph. Kinney 1 155 cecil colts (*) 156.2022 .s (*) 157. nc 000 -e cL luer .. Cont. W. A. Carver 1 : po). eat ids Sham. Hatcher-Crosby 1 199 Ph. Vanta 1 Ph. O'Hearn 1 cl Ph. Ochsner 1 1396: c. Ph. Stigall 1 Ph. Gearhart 1 690-464 O-63--2 Map No. Company and name 150962 - Sham. Frank Smith 1 ccc Sham. Bates 1 1598............°cc- Sham. Thaten 1 L_ Sham. Van Order 1 160... Kermac. Breyfogle 1 101... Sham. Geary 1 102223 eca ccs. Sham. Fowlstone 1 1052... Sham. Kelly 1 164 Sham. Coffee 1 105... ...s vel Sham. Mary Smith 1 Kermac. Taylor C-1 107; . - sls Ph. Armi 1 Kermac. Taylor A-2 .s Ph. Stanhope 1 169.1. cc ll Kermac. Wilbar 3 iO: s: lc c.. Shell-Sinc. Wilbar 1 tiles c lii ak Ph. Balfield 1 T2. Cc: dan cn ee Huber Owens 1 . cinc. lel Shell-Sine. Munson 2 T4 ouly (*) TiB -...__.-._.. .t Ph. Knapp 1 TDR L crane gwen s Ph. Shelton 1 secs o. Ce Ph. Dalla 1 lcs die Sham. Dale Smith 1 ls Sham. Young 1 Adams Pool 1 PTA Xd sie bes Adams Love 1 cA. scr Nat. G.P.A. LaSalle 1 Tiss ocus Nat. G.P.A. Schlee 1 Ph. Ethelyn 1 Nat. G.P.A. Troutnam 1-SP 180.2: Nat. G.P.A. Foster 1-S 181: Nat. G.P.A. Foster 2-FO 182: cnn Ph. Hinkle 1 {B3 __: cnd Ph. Kell 1 Sd: _._: N Ph. Lore 1 T85.. .. li celcall. Nat. G.P.A. Taylor 1-P 180...... .s. nils Ph. Dardiff 1 187. c. Ph. Preston 1 BTA .t: crse Ph. Fields 1 (TBS -_ _ loc icv cn Ul ske Cont. Armstrong 1 - scc ens Kermac. Bridges 1 190-2 cle Cont. Shellberg 1 191... .:: Ph. Twill 1 192°: ls s: ls Pan. Prod. LaSater 1 193. -. o.... Huber E. Herring 1 Ph. Daisy 1 03. Ph. Ray 1 (95: Lecce o ley Nat. G.P.A. Williams 1-T 190 .n oo ol eel eee Ph. Stan 1 197 ...s: ll : cit.. Ph. Rorax 1 198 0 Nat. G.P.A. Taylor 3-G 22.00. Burrus 1 Nat. G.P.A. Taylor 1-G | eas aa e s ech. Ph. Vent E-1 G6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name 201: s 22 Sham. Zella 1 02 2C aes L heve Ph. Stem 1 !e las Ph. Longmack 1 rOL2 ...s ils Ph. Hagaman 1 205....._......._:=..Cont. Armstrong 200. si a Ph. Malcolm 1 ROT: _s cull lel Cont. Bricker 1 Ph. Bridges 1 209.::..:..::.:_..... Ph. Rubin 4 2098.....s.....t.... Ph. Harrington 6 csr Ph. Lackey 1 P1P; Skelly M. B. Armstrong 1 Plac cscs Skelly Armstrong 1 P19 Psi cle cues Gray Co. Prod. Herring 4 PME. eel li iet Gray Co. Prod. Herring 16 PIB l Adams Nevenheim 1 Sham. Huff C-1 P Sham. Huff 1 I0... carlin .s Kermac. Brady 1 If s esis .d. Ph. Fullingim 1 Adams Heck 1 PIBU LI- Ph. Julius 1 RIBA... ac: Mag. Hardwick 1 Ph. Kin 1 ida :c=_cl:..l..}.}. Ph. Hardwick 1 BIQb- " csc Sham. Simmons B-1 aad cls nett ases Sham. Yonque 1 P208. __ elo. Sham. Schlee A-1 alee il le Ph. Stallwitz 1 s esl one Sham. Fred Smith 1 P22 Ph. McDade 1 Unit 2.0. Kermac. Anderson 1 Mary enote o aree on Hina sante wd Sham. Fuqua 4 fr Nat. G.P.A. Powell 1-G ead suelta c en. Ph. Harrison 1 clt nolo, Nat. G.P.A. Coon 14-M D20..s cul Nat. G.P.A. Coon 13-M ncs e uou. Nat. G.P.A. Coon 9-M ne. Ph. Taylor 1 ase DESO SPAL Ph. Vent D-1 aJ. teles 2d Nat. G.P.A. Taylor 2 PadR. X : cn hey c Ph. Vent E-2 gO ck Pe. ells Nat. G.P.A. Gober 1-SP SIP Coll serv Ph. Vent A-1 cn 2 - ict. e Ph. Vent A-2 BELLE. IO d Ph. Matler 1 284: vo ell case Ph. Gob 1 R sn tect conga Sham. Phillips A-1 230. 000 Nat. G.P.A. Lucky Tiger A-1 P97" ss e esi a. Sham. Phillips 1 c Sham. Underwood B-1 rod.: Ph. Rubin 2 24g --' 'so. ~. "'' (*) P41 2 ~- _" cus Ph. Rubin 3 Pda: cle _ elec.ll.gcl. Barnsdall Harrington 4 Map No. Company and name (IB LCAT cle eher e Skelly M.B. Armstrong 12 244 _c _ Ph. Katherine 2 245: . eA .E LEL 2. Huber E. Herring 12 40: re co Pan. Prod. Herring 3 247: serre: Ad Z Pan. Prod. Herring 5 ESL. Skelly E. Herring A18 ca Ph. Adams Sones 1 Ph. Adams Appling 1 PDL. cel cea Ph. Adams Kilgore 1 200a..--:.rec0ceu.e . Ph. Rachel 1 ABI. LCL; AUE. Kermac. Arie 1 292. eu eae Kermac. Phillips 1 2080..cl de Ph. Drury 1 204... _ ' Ph. Ellie 1 205. k scc Ph. Thaten 1 P50. :r Ph. Love 1 BBT: rse nys Ph. Dollie 1 PBB... fect. Ph. Farbert 1 PBQ Sham. Coffee E-1 2060... --.-20E leak. Sham. Crump 1 201; Sham. Hastie 1 Ph. Augusta 1 208. 2 a Sham. Ansley 1 204 : . coas ees Ph. Alda 1 205. eset ule ao old Sham. Fuqua 1 200... sen ea ace Sham. Fuqua 3 207 lea icin as Sham. Fuqua 2 20B-c.l iet Ph. Coon 1 200. .s ceases dude ad Nat. G.P.A. Coon 28-M 2100: : ct s ol Nat. G.P.A. Coon 24-M suss un cst AL Nat. G.P.A. Coon 22-M 2a solis adv e o Nat. G.L.A. Coon 10-M 219: . Nat. G.P.A. Coon 12-M 2174: anl Nat. G.P.A. Coon 3-M Nat. G.P.A. Coon 25-M cites allie Nat. G.P.A. Coon 30-M ATT: naw Nat. G.P.A. Coon 19-M eus Nat. G.P.A. Coon-Sneed 12-M B10: :e: Nat. G.P.A. Coon-Sneed 8-M luke. Nat. G.P.A. Taylor 1-H PBL: >. cle ne ds Nat. G.P.A. Coon-Sneed 6-M INL Nat. G.P.A. Coon-Sneed 4-M PBS: _E Ph. Vent B-1 BSM: L: cL Nat. G.P.A. Gober 2-SP 280: s = Nat. G.P.A. Gober 3-SP P862 0s LV «-L dso Nat. G.P.A. Sneed 12 PST :c. Sham. Sneed 20 cll Ph. Vent A-4 o8J. uns Ph. Gober 1 Ph. Priscilla 1 200... 2 licence. Sham. Sneed 21 201. Ph. Zella A-1 202; :- pes. Nat. G.P.A. Haile 1-M 209... Ph. Zella A-3 20Ga . clan sel. Ph. Sneed H-1 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G7 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name 2042. cnl .g Nat. G.P.A. Haile 2-M L Ph. Sneed B-8 BIOL. 20. Sham. Stewart 1 Pde :c esl ai ad bos Ph. Gunter 1 . Sham. Kempson 1 200.1 L/: Ph. Need 1 200°. .l iin Ph. Need 2 SOL cle - Jiscl.....0.s Rubin Beard 1 sua E Rubin Beard A-1 3024-2... 0 Kermac. Sneed C-1 S03. : Skelly M.B. Armstrong 2 B04 _s Skelly M.B. Armstrong 14 SOB. Ph. Katherine 1 Huber-Texas W.E. Herring 2 BOT. Pan. Prod. Herring 7 308 Huber W.E. Herring 7 B09: :A Huber Hobbs-Allen 1 S10... :: Skelly-A8 It"s Adams Disbrow 1 il ie drei tl Ph. Adams-Ford 1 ece Bayou Herbert 1 : ug... Bayou Smith 1 $1D:s. : Ls} Ph. Marni 1 _E: Ph. Ola 1 Ph. Stockman 1 IB ec Ph. Clements A-1 l Kermac. Drucilla 1 nils Sham. Brown A-1 Bar. _c nue csi t ole Ph. Sallie 1 ICAI - Ph. Jameson 1 agile rele nel LEL Ph. Champ 1 rd ris ...ll. Ph. Colwell B apis Phl Colwell C S20. ___ Nat. G.P.A. Coon 20-M dara allo s, Nat. G. P.A. Coon 2-M ses: iit .it. Nat. G. P.A. Coon 31-M all Nat. G.P.A. Coon 1-M s Nat. G.P.A. Coon 18-M .l. cum Nat. G.P.A. Coon-Sneed 9-M nas Nat. G.P.A. Coon-Sneed 1-M Sara. s ool co Nat. G.P.A. Coon-Sneed 5-M D erd ls Nat. G.P.A. Sneed 20 sed- sri llc... Nat. G.P.A Sneed 16-SN Nat. G.P.A. Sneed 1 eGift Let _L 020" Nat. G.P.A. Sneed 1-P Gores ened n neue Ph. Zella A-2 Bast lll cal Ph. Zella A-4 badr .ll llc laos, Shell Kelly 1 rs ien Ph. Sneed G-1 B40. L: ss noo Pan. Oil Sneed 1 c.. Ph. Need 3 dI ILL oul Pan Oil Sneed A-4 dass s noes ety cul Pan. Oil Sneed A-1 lux c., Ph. James 2 ice. s J Ph. James 1 Map No. Company and name 3 | me oan Ls tte sous Ph. James 4 ° 3402. cle d. Ph. Byrd 2 Tes cles Ph. Byrd 3 Huber W. E. Herring 10 B49 _ Huber-Texas W. E. Herring 1 Mil puns tct ot arate Huber W. E. Herring 5 Soll"... t:. Huber W. E. Herring 5 I0. Huber W. E. Herring 12 SDS i lc cule asus y Ph. Bay 1 Spd c on clu lle. u Ph. Hollye 1 DDE LIL -e ack Ph. McLaughlin 1 550. 00. Ph. Emmett 1 .e aul. Ph. Joanna 1 S58 .es. tne c_ ul geons Ph. Modine 1 B0. Inno ee nel an ee Ph. Althouse 1 Ph. Collins 1 301. ys: Ph. Inez 1 S02 AQ. Ph. French 1 sl po 's Ph. Colson 1 3042 ELLIE Ph. Elise 1 S00 cC Ph. Daught 1 SONI -L Ph. Carver 1 LCE -le 2 Ph. Stencil 1 Sham. Brown 3 cll. Sham. Brown 2 BTO C nasi e Sham. Brown A-2 STL eo eus Fel nlc a eas Sham. Brown 1 STavllle lull ce Ph. Ingrid 1 Toei nen ee c es Ph. Hurwitz 1 TAU e lene een Sham. Brown 4 e icc llis. Ph. Finch 1 270-21 Ph. Mass 1 fg alo is duvide s Ph. Weidling 1 TBs ene Ph. Colwell A TONE eL I2. Ph. Chloe 1 }.. s. cus CLOs Ph. Japhet 1 BBIS CUI. GCU Ph. Biffle 1 Ph. Marvin 1 GBE. ild. Nat. G.P.A. Beauchamp 1-P Ssd- _ Nat. G.P.A. Coon 15-M AIE IIe. Nat. G.P.A. Coon 27-M .c ec ild ole.. Nat. G.P.A. Coon 5-M Nat. G.P.A. Coon 29-M GBB L Nat. G.P.A. Coon 26-M BsQ rec LLE C-. Nat. G.P.A. Coon 17-M 390.2}. Nat. G.P.A. Coon 32-M 301.) je wc r faun uo Nat. G.P.A. Coon 21-M C02. Degg eect e Nat. G.P.A. Coon 6-M B0B -E- eel tice Nat. G.P.A. Coon 23-M 0.0002... Nat. G.P.A. Coon-Sneed 11-M IC Nat. G.P.A. Coon-Sneed 13-M Nat. G.P.A. Jester 1-T QT :A. As Passaic Nat. G.P.A. Coon-Sneed 7-M BOB. 2:2 icc Ph. Vent C-1 309 Os Nat. G.P. A. Coon-Sneed 10-M G8 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaABu® 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name L0 Nat. G.P.A. Sneed18-P dQ: ser ict Nat. G.P.A. Sneed 7-P 4022: .us Nat. G.P.A. Sneed 9-SN 103k: Pan. E. Sneed 1-9 1041; cn crcl nse Pan. E. Sneed 1-26 105: : incus, Nat. G.P.A. Brown 2-G 100-2 c- eee eck Pan. E. Sneed 1 107. Nat. G.P.A. Brown 3-G 10SL s e ince cule Pan. E. Bennett 1-22 IOBac -. Ph. Zella A-5 109 cnc. Pan. E. Sneed 1-3 410.2 Ph. Zella A-6 ML: slc .d Ph. Sneed B-5 (12 .n n Ph. Sneed B-6 MP3: ia Ph. Sneed E-1 HS $i LC OAI Ph. Sneed B-4 ue s Ph. Zell 2 M15... nii is- 0... Ph. Zell 1 L6... 2 nil. Ph. Zell 3 __. Ph. Zell 4 } 2}. 2s uca. Rowland Humphries 1 Al- Skelly M. B. Armstrong 11 alfa Ph. Duboise 1 1B Pan. Oil Jameson-Dubois 1 #190 . Ph. Byrd 1 820. dire in. bolic cet Huber Reed 2 alee seca intel, Huber Reed 1 122 Ph. Burnett 1 1BB JLL L Skelly W. E. Herring 2 424 ._ Lr Huber W. E. Herring 3 Mabee c_l2 .e... sl Huber W. E. Herring 8 A20 eed l Huber W. E. Herring 4 2T eile cll cc. Skelly W. E. Herring 5 IPSec ce -l bert Skelly W. E. Herring 3 $a scl lll Skelly Yake C-1 EU PNA HEEL ue caw. Skelly W. E. Herring 1 {n itso A pov aagi stn d Huber W. E. Herring 2 Sas Cnet Huber Prewitt 2 195: Huber-Mag. Herring 1 194 ¢. c Huber-Mag. Herring 4 foes Ph. Constant 1. 43061 Ph. Petty 1 497... ics.. Ph. Bradie 1 1GB: Le.} el Ph. Temple 1 TSP .ac rial Ph. Rena 1 440 ccc cl _ Ph. Leslie 1 MMOD lea _c Ph. Eve 1 149: e Ph. Tooker 1 413-22. nlc uc, Ph. Bissell 1 M44: 0.0.22 Ph. Dona 1 MMD c_ cli Ph. Sunray-Feltz 1 n Ph. Teddy 1 447 . Ph. Josie 1 cin Ph. Dumas 1 49: r:. .n Ph. Tanner 1 Map No. Company and name 450-0 oo Ph. Tarris 1 rre tal cl Ph. Bri 1 452. Lic Ph. Vinson 1 4593 - Kermac. Estate 1 454. sl. JO lll. Ph. Dale 1 1459. Ph. Fuqua B-1 450. Ph. See 1 4508. clase, Ph. Arris 1 Abs. rna .ll tell.. Ph. Greiner 1 5B. Ler ect e Lc Ph. Hibbard 1 aby c_ e l ccie Ph. Drib 1 460: . Ph. Harbert 1 2 lise Ph. Massey 1 4062... .L. inn" Ph. Harb 1 Ph. Blanche 1 .c .c Ph. Jennie 1 405. _. .c coli. C. I. Bivins A-68 ADBA... L Kermac. Terry A-1 460- : ciel... Ph. Jen 1 107. coli Pan. E. Henneman 1-100 408: 1C seis Pan. E. Purvin 1-69 10-2 nc Nat. G.P.A. Coon 16-M 4702. ils iL . (*) ATA CINA rE ce cu Nat. G.P.A. Coon 7-M ATR nene as Nat. G.P.A. Thompson 9-TH TiB i eee Ph. Brent 3 afarc cml (®) ATB EIRE Nat. G.P.A. Thompson 6-TH MTO y nent .or. Nat. G.P.A. Coon 4-M ATT el nie Pan. E. Brown 1-104 ITB. .L cecal... Nat. G.P.A. Thompson 8-TH 4709.2. Nat. G.P.A. Coon 11-M 480: :~ Pan. E. Brown 1-64 ABLE Cc Pan. E. Jester 1-18 IB2 elo Nat. G.P.A. Sneed 2-P 483. .n Nat. G.P.A. Coon-Sneed 3-M ABL»: i einen, Pan. E. Sneed 1-20 IBD Lx ele c s Nat. G.P.A. Coon-Sneed 2-M 4860... s. deere Nat. G.P.A. Sneed 14-SN 487 LAC cls Nat. G.P.A. Sneed 8-SN 488. :. ucla a Ph. Sneed C-9 Arc true y Ph. Sneed C-7 490... :c Pan. E. Sneed 1-24 Pan. E. Walker 1-6 492... Pan. E. Sneed 1-25 499: L lge ise ae Nat. G.P.A. Sneed D-2-SP 494 i cde Pan. E. Walker 1-8 195. Nat. G.P. A. Sneed 30-P Nat. G.P.A. Sneed 1-P 490 .S.. (Suck ce Nat. G.P.A. Sneed 29-P 107 c l l Nat. G.P.A. Sneed 28-P 408. Nat. G.P.A. Sneed 27-P 499.2. Nat. G.P.A. Sneed 21-P 4998. . vr enlil. Nat. G.P.A. Sneed 25-P 500. Nat. G.P.A. Sneed 22-P URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G9 TaBuE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name .: Ph. Huckaby 1 OOL ce oo ce eee cca as. Ph. Sneed B-7 502. rc- Ph. Snow 4 503-20 l: call. Ph. Ingerton C-1 Ph. Cattle 1 COBE cX. Ph. Ingerton B-1 500.-._:.......-_..s Ph. Ingerton A-2 Skelly Yake A-1 ._ . Skelly Yake D-1 Skelly Yake B-1 610 Ph. Queen 1 Pll. Ph. Ina 4 12: ell Ph. Ina 2 S19. Ph. Terry 1 IGR. C .ll cle l C.I. Bivins A-76 cc.. Ph. Ina 3 $15 cc .._ Ph. Ina 1 O10: ec Ph. Ploner 1 M17 ills. Ph. Bissell 2 MB e ESL... -s Ph. Balfour 5 I9. ell ce Ph. Balfour 6 Ph. Balfour 4 baleen nls le «Ph. Ames 1 B22 aus angie nl.... Ph. Dudley A-1 Sas Solel ues Ph. Viola 1 Ph. Messenger 1 o Ph. Klatt 1 20>. cnc Ph. Arnella 1 Defe csr cc s Ph. Barre 1 basses ll d Sham. Brian 1 aden Ph. McFarlin 1 930 - Ph. Worsley 1 Ph. Lantz 1 Sham. Finley 1 bob: Kermac. Bergeson 1 Doan -ne . Sham. Davidson 1 mbes Ph. Elbert 1 n Nat. G.P.A. Moore 3-P Nat. G.P.A. Moore 2-M Pan. E. Kilgore 1-56 oa seria dine i a ene Sham. Kilgore 1-28 esr ia uel 00, Pan. E. Kilgore 1-29 . Pan. E. Kilgore 1-57 c: cen l C.I. Thompson B-4 Kermac. Terry B-1 dt cc Ict Nat. G.P.A. Thompson 7-TH .l. s..... C.I. Thompson B-5 S49: csc. . 020. Nat. G.P.A. Thompson 3-TH /C Pan. E. Thompson 1-25 45... _ c 2, cll Nat. G.P.A. Thompson 1-P Nat. G.P.A. Thompson 4 Nat. G.P.A. Thompson 2-TH Ph. Brent 1 c... Pan. E. Thompson 1-63 Pan. E. Brown 1-22 Map No. Company and name Soli Pan. E. Brown 1-34 re aree casin ne Nat. G.P.A. Sneed E-1-P BBS em elcid ae Pan. E. Sneed 1-33 B5 a sar lull Pan. E. Brown 1-36 Ph. Sneed A-2 0 Ph. Sneed A-1 Pan. E. Sneed 1-37 SSS. cee cnn see Nat. G.P.A. Sneed 17-SN .- Nat. G.P.A. Sneed 6-P Pan. E. Sneed 1-23-6T b6le_l.cclc cels Nat. G.P.A. Sneed 23-P 502. Ph. Sneed C-4 {02 Ph. Sneed C-11 Ph. Sneed C-5 505 _._ cc coc Pan. E. Sneed 1-28 500-22 cutanea ece ees Ph. Sneed C-8 o ive aan ae C.I. Sneed D-1 ccna neue Pan. E. Sneed 1-27 Kermac. Sneed B-2 B69 scl tivity Nat. G.P.A. Sneed 13-P T0 uus Nat. G.P.A. Sneed 5-P 5T ce esa ane seule Nat. G.P.A. Sneed 24-P ien insane awan Nat. G.P.A. Sneed 19-SN Messen eal. Nat. G.P.A. Sneed 10-P sll lute Nat. G.P.A. Sneed 26-P eeu con Ph. Sneed F-1 ctl nt Ph. Polly 1 $ ec tind Ph. Latin 1 -i. .C c_ Ph. Snow 6 sie Ph. Record 1 Nias so c Ph. Snow 3 diable Ph. Snow 5 Price ie cele Ph. Snow 2 'c. Bool annem aati. Ph. Wild Bill 1 rail Ph. Snow 1 80: rescence nll. Ph. Williams 1 BBI RECC Gallae Ph. Evelyn 1 Le tus Ph. Ingerton A-1 D83: Lue Ph. "Jay 1 cc. l _ Skelly Merchant 1 DSD elis nter ce aan Henderson Merchant 4 n Ph. Merchant 2 D80 c.... cinecan a. Henderson Merchant 1 ecus sie c cre Ph. Yake 2 $55: c ue iis seus a C.I. Bivins A-72 ley C.I. Bivins A-90 Ph. Bivins 1-GG Kermac. Berneta 4 _._ Kermac. Berneta 1 Kermac. Berneta 2 SSB: .. lec Kermac. Berneta 3 ece C.I. Bivins A-93 BBQ.. icc. .ll C.I. Bivins A-63 B§08: C.I. Bivins A-71 589DB. .-- all} C.I. Bivins A-9 G10 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name ckc. C.I. Bivins A-64 Sor. ccs C.I. Bivins A-56 3902 ey cind as Ph. Balfour 1-286-F Mec Ph. Gordon 1 504: .A. .eu icles ua Ph. Balfour 8 boda. Ph. Balfour 7 bobs boll Ph. Balfour 1-294-F 50ba ct cll cls eon en C.I. Bivins A-62 500 Je. Ph. Balfour 3 lls Ph. Dudley B-1 clr. clvlc.ccl Ph. Dudley C-1 500- cc 2.0 innit C.I. Bivins A-61 600: : ss 2 ICCC Kermac. Helt 286-G 60+. icy ulcers die Ph. Dudley D-1 6022: 22} v sek ce Ph. Pink St. 605°. LL Ph. McFarlin 2 604. Rubin Brown 2 605% c sf Rell. Ph. Ezelle 1 606: ::.: cdo. Fowlton-Coke 1 607): ...en. _ Ph. Victor 1 C. I. Kilgore A-10 ...ll. Nat. G.P.A. Kilgore 5-P 610 . Pan. E. Kilgore 1-10 C.I. Kilgore A-13 CLL cu.: c c felis. C.I. Kilgore A-5 M12 c:: Ll.. C.I. Kilgore A-6 013 .cc C.I. Kilgore A-12 lst Nat. G.P.A. Kilgore 3-G MP5 - _L en Ca Nat. G.P.A. Moore 1-P 610. elt C.I. Kilgore A-2 MT. l Pan E. Massay 1-15 MIS. .m Nat. G.P.A. Walters 1-PAR (lg.: }. . Nat. G.P.A. Kilgore 2-G 620: Pan. E. Kilgore 1-16 G21 ccs Nat. G.P.A. Kilgore 4-G CRH L Ha sees Nat. G.P.A. Haas 1 629. em. 0.0 cc no C.I. Thompson B-2 Cad eres Nat. G.P.A. Thompson 11-TH Cabin ede cle cl C.I. Thompson B-8 00m 00-002 Pan. E. Nield 1-18 627A ell be du cals Ph. Nield D-1 629.2: 0300.04 00 C.I. Thompson B-6 udon C.I. Thompson A-2 m Ph. Brent 2 63L C.I. Thompson A-1 632 fee o PU Nat. G.P.A. Thompson 5 BOP re Loca slie oe ane C.I. Thompson A-3 s. L Nat. C.P.A. Thompson 10 634 C.I. Thompson A-4 635.00. 0010.00 2. Pan. E. Sneed 1-50 630. s Ph. Sneed G-2 yoo alte C.I. Sneed A-1 CSTA: . C.I. Sneed A-4 638... Ph. Sneed C-10 630. _. stl. cig. Ph. Sneed C-6 Map No. Company and name 040 Pan. E. Sneed 1-48 6f1:: s C.I. Sneed A-3 E. Ph. Sneed C-3 s C.I. Sneed A-2 644.0 C.I. Sneed C-1 045 ..o. Pan. E. Zoffness 1-55 Pan. E. Sneed 1-45 ls dco y Pan. E. Sneed 1-44 b48.. L _:el cc cnd nl.. C.I. Read A-3 G49: .}. cc Pan. E. Sneed 1-43 cnn C.I. Read A-1 651°... dec Ph. Sneed B-1 Nat. G.P.A. Sneed 11-SN .- C.I. Masterson A-7 654 Nat. G.P.A. Sneed 15-SN 65524 cock nie ei Nat. G.P. A. Sneed 3-P 650... Nat. G.P.A. Sneed 2-P 65T: : ex r Nat. G.P.A. Sneed 4-P Ph. Sneed B-3 cl Ph. Sneed B-2 G5BaA.. Ph. Sneed J-1 6509: ALC e o. C.I. Bivins A-65 -..: .r cL aie - C.I. Bivins A-94 650b.. : C.I. Bivins A-11 600. »: lm Ph. Balfour 2 601: C.I. Bivins A-58 602. MRA ei- C.I. Bivins A-8 665... :f .? C.I. Bivins A-22 000.000, C.I. Bivins A-34 > C.I. Bivins A-59 665 :- ov (*) 600. cie nu}. C.I. Bivins A-60 607. cic leslie ind Ph. Helton 1 665. >: sls aoe. lice Rubin Brown 3 669:1. e Ph. Gasser 1 .-.. sA Ru: Rubin Brown 4 un, Loy Nunn Rubin Brown 1 612... 2000 de a nne Rubin Brown 5 Lestat Rubin Brown 6-B 674-.:2 mde ey Sham. Rubin-Brown 5-B 675... .. Ph. India 1 670. : cc ll ice oud Nat. G.P.A. Kilgore 6-P Poa isl. Pan. E. Kilgore 1-8 CTB... D ll .za 4. C.I. Kilgore A-4 679-8 -il s ad C.I. Kilgore A-1 680... 1. C.I. Kilgore A-3 681: :s Rc lee Nat. G.P.A. Johnson 1-P 682. .: Ls. e's C.I. Luberstadt A-1 c 0:.l...E ...e. Nat. G.P.A. Haas 2 C.I. Thompson B-10 683.1: .r. s C.I. Thompson B-1 6§4-.... sms C.I. Thompson A-5 . C.I. Thompson A-6 680:.. Le Aai vad C.I. Sneed A-7 688) ec lila. C.I. Sneed A-8 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G1 Map No. Company and name 680... c C.I. Sneed B-1 690. _ C.I. Sneed B-2 C.I. Sneed B-4 . s Pan. E. Zoffness 2-55 :c ely ct Ph. Sneed C-1 C.I. Read A-2 694.001.0001. 080000. C.I. Read A-5 695... mc Ll C.I. Masterson A-10 600... . . C.I. Fee A-1 Ce c R.R. Shelton A-3 ec R.R. Shelton A-5 699-2. cc LLL. NLC R.R. Shelton A-6 Nat. G.P.A. Lea 1 7002 ce R.R. Shelton A-7 T.IL.P.L. Bivins 1-633 C.I. Bivins B-2 dra. : clin. t": : C.I. Bivins B-5 for. sll . C.I. Bivings A-10 T cL cde. C.I. Bivins A-97 C.I. Bivins A-111 ..."... C.I. Bivins A-78 }.. C.I. Bivins A-77 T03e.:;:...z:il.lll.l . C.I. Bivins A-89 C.I. Bivins A-83 Q4: s: is ssc... C.I. Bivins A-7 l C.I. Bivins A-66 _I Rubin Brown 7-B clu. C.I. Bivins A-17 TOTa : C.I. Bivins A-82 Tos: _ C.I. Bivins A-67 _i. 02 C.I. Bivins A-6 c cle C.I. Bivins A-55 AE.... ._.: C.I. Bivins A-15 A2. 2s seu s .. C.1I. Kilgore A-7 Adan Cult t fors. C.I. Kilgore A-8 A4. ccc sto C.I. Kilgore A-9 Burnett & Smith Kane 1 (19s C.I. Bivins A-54 MAO 00 C.I. Baker A-1 TATE 2g? C.I. Bivins A-37 As- _c C.I. Cooper A-1 C.I. Kilgore A-11 mad C.I. Kilgore B-1 ales rest na Ops C.I. Bivins A-24 ass ee re ial a ull C.I. Seay A-1 o n .. C.I. Crawford C-1 adres eos - C.I. Bivins A-52 eous itn og .o C.I. Crawford A-1 Teds selon yest uc. C.I. Bivins A-21 l alco. C.I. Crawford A-2 ases nle sn L2 iet C.I. Masterson A-5 eel ol ca oil C.I. Thompson B-3 clo. ll ica C.I. Thompson B-9 oll... C.I. Masterson J-1 LU Leno.. C.I. Thompson B-7 Tapur 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name Teras ss ssl} C.I. Thompson C-1 eg:» ncn. Nal ll C.I. Masterson A-14 Ted. ssi lil NSK C C.I. Masterson A-6 cnc cl tn C.I. Masterson A-15 TsO cil cld: out C.I. Masterson A-22 Tree recs e a auld ous C.I. Masterson A-16 tcl fillo C.I. Sneed A-5 egs cls itly C.I. Masterson G-3 Tad ls 00 (*) AT SL... i ec Pan. E. Sneed 1-6 T Alas sss css cyl, C.I. Masterson A-18 42s: QL W 4.4L C.I. Sneed A-6 Adare tre tg C.I. Sneed B-3 Tad. f: iy C.I. Masterson M-3 T45....l .e c oct C.I. Masterson M-1 AOC. cnc ss C.I. Masterson M-2 AT-: UCs C.I. Read A-4 L C.I. Masterson A-21 AOI Pan. E. Masterson 1-38 C.1. Masterson B-30 indy o oy S te wild ma oes cen ania C.I. Masterson B-18 ToL: C.I. Masterson B-15 oars guy C.I. Read A-6 ICAI P30. C.I. Masterson A-20 dim C.I. Masterson A-4 uc. ctu tI C.I. Masterson A-17 l C.I. Masterson A-12 TdT is cau C.I. Masterson B-2 T n ce sli C.I. Masterson A-3 :lol. C.I. Masterson A-1 ? C.I. Masterson A-11 Ole EARL. C.I. Masterson A-2 IIL Ee oe ack C.I. Masterson B-1 (O9 rel oo bu C.I. Bivins A-29 TOL C.I. Bivins J-1 collide R.R. Shelton A-2 700 AL R.R. Shelton A-1 TOTE ells R.R. Shelton A-4 llis y. C.I. Warrick A-3 TOY .s _ C.I. Bivins H-1 TiO ene lg ls iA C.I. Bivins G-1 TIVE seals North Nat. Bivins 1 asec le C.I. Bivins I-1 TiB gee eeelude C.I. Warrick A-2 T&R Leia rat T.LP.L. Bost 1 cari R.R. Bivins Est. 1 TID eee idee C.I. Bivins B-6 eer ia. C.I. Bost A-1 sel ce nee C.I. Dunnaway A-1 T csc yn ue C.I. Dunnaway A-2 TTB cE AAAs io C.I. Bivins F-1 TQ cs esto se C.I. Bivins B-4 ri. | PMs eaten AVT C.I. Bivins B-1 TBL... .co lie. C.I. Bost C-1 TSla -s ALC OR-. (*) G12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 1.-Wells shown in plate 1, listed numerically-Continued Map No. Company and name Telb C.I. Dunnaway B-1 T C.I. Bost B-1 T Balsall els ic C.I. Johnson A-1 i Baas ert lise. tes oss Nat. G.P.A. Johnson 1 BE eta cta ane C.I. Bivins A-36 Soa: en ee cil as C.I. Bivins A-92 Tesh. sree liao... C.I. Bivins A-91 T . .... C.I. Bivins A-98 esd: l: C.I. Bivins A-109 Bse rlic C.I. Bivins A-26 T Sofece l C.I. Bivins A-106 TBogg. C.I. Bivins A-104 T SGn-.. ~ C.I. Bivins A-103 T l C.I. Bivins A-99 Saf elsie. d cu C.I. Bivins A-100 v3.4 mos al rere acai - C.I. Bivins A-35 TSD -c icle. C.I. Bivins A-83 T 8ba _ C.I. Bivins A-101 T Sob. l C.I. Bivins A-102 i eL LLL IC LOCC C.I. Bivins A-105 T Sbd ccc _s. l uC C.I. Bivins A-95 T C.I. Bivins A-5 Sese in iin ul C.I. Bivins A-14 BBU RUL Gees. C.I. Bivins E-1 SY Cel . C.I. Bivins A-48 IO. cll _ C.I. Bivins A-4 l: _ aie. C.I. Bivins A-82 52. pain e onl dure Chl C.I. Bivins A-31 YG niece ann C.I. Bivins A-2 TIGR. L2 C.I. Bivins A-27 TIZ cC een nece C.I. Bivins A-43 TIB: cits len oils. C.I. Bivins A-25 (00+. _ C.I. Coughlin A-1 TOT secs seus nelly C.I. Masterson A-13 TIB: - cee. ee eous C.1I. Crawford B-1 N00» ccs cline C.I. Masterson B-17 ...- C.I. Masterson B-21 S00 .-.:= C.I. Masterson B-16 C.I. Masterson B-22 S00 C.I. Masterson B-7 C.I. Masterson B-45 8004. C.I. Masterson B-40 C.I. Masterson K-1 C.I. Masterson G-5 S02 rer ul C.I. Masterson B-8 B03 cale C.I. Masterson B-10 -s ese C.I. Masterson B-9 C.I. Masterson B-41 T.LP.L. Masterson 1-606 BOB C.I. Masterson B-19 -:: ul.. f C.I. Masterson A-9 806 -- re T.ILP.L. Masterson 1-587 2 C.I. Masterson B-20 SOS: i...il..sl..0s, C.I. Masterson B-13 800: C.I. Masterson B-3 Map No. Company and name eee ara C.I. Masterson B-12 BIF... c_ C.I. Masterson B-11 S12 XQ RRI LOLs T.LP.L. McBride 100 SLG X caa enne anus C.I. Bivins A-45 S138... (*) C.I. Bivins A-42 C.I. Bivins A-44 C.I. Allison A-1 de e eric uss C.I. Warrick A-1 C.I. Warrick A-4 S18: cl. C.I. Bivins A-39 S19: R.R. Bivins A-1 C.I. Bivins B-3 cues Navajo Poling 2 $208. Navajo Poling 1 C.I. Poling A-1 $218... erases C.I. Bost C-2 S22. el eee ee ern as C.1I. Bost D-1 $20 tlle .o ned (*) 24. allso (®) scouse C.I. Bivins A-50 saba. C.I. Bivins A-88 c: cst c= len. C.I. Bivins A-107 $250: L ue C.I. Bivins A-108 llike C.I. Bivins A-129 $20... ie eee ls C.I. Bivins A-38 S27... -_ _ C.I. Bivins A-70 SATB. Lice cale C.I. Bivins A-96 yas. Loef sill C.I. Masterson A-19 S20 M. C.I. Crawford D-2 $80... .L i C.I. Crawford B-2 C.I. Masterson G-4 $82. LL C.I. Masterson B-61 S39... tr eus uide. C.I. Masterson E-2 $34: : i C.I. Masterson C-1 pBb r rll lil C.I. Masterson C-3 cde. C.I. Masterson B-4 0.0002 ec. C.I. Masterson J-2 SAT. ei dara ae sins C.I. Masterson B-5 S378... s ll ceeds anl C.I. Masterson B-42 SEBL. cL .L ea aa ae C.I. Masterson B-14 R30... slr T.ILP.L. McBride 1 $40: Pan. E. McBride 1 S11... T.LP.L. Rockwell 1 $42... LI C.I. Bivins A-47 $48. --:... icc 00 C.I. Bivins D-3 Sida) L n, C.I. Bivins A-46 $44... n C.I. Bivins A-40 §t5 _ 2.0. aeg te (®) _._ ices C.I. Bivins A-16 847 2. c e R.R. Bivins B-1 S48. loose R.R. Bivins A-7-728 §40>.. :. e_ llc R.R. Bivins A-2 R.R. Bivins A-3 SDL c rth R.R. Bivins A-4 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS TABLE 1.-Wells shown on plate 1, listed numerically-Continued Map No. Company and name BBR suo rs .se doll R.R. Poling 3 SDS. esl nL Ml ie.. R.R. Poling 4 isn. R.R. Deahl A-1 . R.R. Bennett A-1 Sods (*) B55. esis (*) (*) SoTL ne nen (*) BBSR Ecco oan. . C.1I. Sanford A-3 C.1I. Sanford A-4 2... 0.01. C.I. Sanford A-5 _...... C.I. Sanford A-1 l. cll... C.I.Bivins A-69 C.I. Bivins A-13 _._. C.I. Bivins A-110 C.I. Masterson A-23 S60d::...-.......... C.I. Masterson J-4 C.I. Bivins A-128 C.I. Masterson A-25 ln. C.1I. Bradley A-1 C.I. Masterson J-3 .ll _ .s __ C.1I. Crawford D-1 802A .u. lice C.I. Masterson B-44 . c. C.I. Masterson J-5 s0ac:..s. C.I. Masterson A-24 sbad......l....}....C White and Parks v2.2... ...r C.I. Masterson D-4 ice _ C.I. Masterson B-38 C.I. Masterson B-24 cc.. C.I. Masterson B-23 S60... C.I. Masterson B-25 Sores lit T.LP.L. Bivins 1-540 B08. 0.0.0 .._ C.I. Bivins A-49 recente C.I. Bivins C-4 C.I. Bivins A-51 STI. sec css lll C.1I. Bivins A-18 Tellin cele il C.I. Bivins A-41 .l dls en cnl. C.I. Bivins A-3 iA epee Llc C.I. Bivins A-19 issn dds sea al C.I. Bivins A-20 s tect. .to R.R. Bivins A-7 sore ers R.R. Bivins A-6 STi ees doa oe R.R. Bivins A-5 690-464 O-63--3 Company and name Map No. PTB Cit. Serv. Poling 1 S70 coas aces, R.R. Deahl B-1 880° R.R. Deahl B-2 cll nical cks (*) 0001.02.00. (*) SBS se sell cilia ens (*) S84... (*) Seb .._ crcl (*) S80 > C.I. Masterson G-2 C.I. Masterson B-39 BBT ACII Ll io raves C.I. Masterson H-1 SSA.» l ule C.I. Masterson B-36 BSS - cn. c . C.I. Masterson I-1 uns C.I. Masterson B-85 (*) C.I. Masterson B-6 C.I. Masterson B-33 801. ccc: C.I. Masterson F-1 .L ...l .cc oen. C.I. Masterson B-34 SYR Le Cole nsane C.I. Masterson L-1 C.I. Masterson N-1 SOB C.I. Masterson B-31 :..: C.I. Masterson B-82 SOC: :.:. C.I. Masterson B-37 ccs, C.I. Masterson B-28 C.I. Masterson B-29 C.I. Masterson B-55 ute. C.I. Masterson B-27 C.I. Masterson B-26 C.I. Bivins C-1 aa C.I. Bivins A-53 ©00 : rlic le C.I. Bivins A-74 901 <_. _......scnll. C.I. Bivins A-79 902. C.1I. Bivins A-80 .cd. C.I. Bivins A-84 0 C.I. Bivins A-85 0020. C.1I. Bivins A-87 90832: C.I. Bivins A-81 0038 -. chasis. C.1I. Bivins A-86 0042.20 e C.I. Bivins A-23 C.1I. Bivins A-57 C.I. Bivins A-73 905b. "_. .. cy alco. C.I. Bivins A-75 G13 G14 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaBLE 2.- Wells shown on plate 1, listed alphabetically by company and name Number Company and well (pl. 1) Adams, K. S., Jr., Co.: Disbrow 1-......--. 311 Heck 1;;...._.._._... 217a "c... 175f Nevenheim 1..-_-.-_. 215 Pool 175e Barnsdall Oil Co.: Harrington 4. .--... 242 Bayou Gas Co.: Herbert 1. :_.s=.... 313 Smith 314 Burnett & @mith Co.: Kane 1l:........... Tl4a Cities Service Co.: Poling 1.:........... 878 Colorado Interstate Gas Co.: Allison A-1_____.__._ 816 Baker A-L.::..._.. 716 Bivins A-2:........ 793 873 790 s 786 AOL. 709 A-1.;:. aind 704 A-5: : 662 589b 703 659a 860a A-14..0..01. 787 A-15.u....20 711 846 A-17....\ l-. TOT A=18.: ...... 871 A-19.._.... 874 A-20........ 875 726 A22 cs se. 663 A28. 904 721 795 783e A- 27. 793a 763 A-31....:2.. 792 A-82.2.2.02. 791 0. 785 664 A-85._....... 784 A<86....:1 12.0 783 us. 717 A-8B.....5-L 826 818 844 A-41........ 872 A-42.0..009. 814 A-4B.:.:....; 794 815 A-45........ 813 Company and well Colorado Interstate Gas Co.-Continued Bivins-Continued A-46._.:...... A47 :.:... A<50> -.. .L. A-51......:. A-52........ A-03.2 . A-54........ A-~05...s. .ll. A:56........ A-Bi...:.... :::..~l A-60......... A-01-....ull A-63._...... A041... A-05...1.... .::.... A'DbS........ A-00.-....-. A-i0 ...s... A-TL i..... MA- T2. A-7B......L A-80-.:0.... A-84.....:.2. A86: :_z.._.:. A-88 ¢.... A-50-:-.... A-90::...... A-02:. .°... Number (pl. 1) 843a 842 789 868 825 870 724 899 715 710 591 905 661 664a 666 599 595a 589 590 659 705 708 465 860 827 589a 588 905a 900 905b 513a 703d 703¢ 901 902 903 7O7a 703 902a 902b 903a 902¢ 825a 703e 588a T83b 783a 588g 659a 785d 827a and name-Continued Company and well Colorado Interstate Gas Co.-Continued Bivins-Continued A-103-.....-. A-104.......- A105.:.:....- A-106...>... A-107 _.._._._L A-108 ...... A-1090..--L.. A-H0..-.--.. A-ll1.:.....; B-2:..:.l...22 B<3 B-4: B-5:..-:.l.s. p-8......._. E-1._....... ml: J=1. . -d Bost A-1.::...oc.l-1 Bradley A-1:..:-_...- Cooper A-1........ Coughlin A-1._..._. Crawford A-2..1... B-1.\ ..:. D=1..:.:. D2::.:. Dunnaway A-1----. A-2..... B-1:.... Fee Johnson A-1........ Kilgore A-1..._.._.. N-8. 2.2.04, A-4:....c.~ A-D:......_.e A-6: AT: A-8: ..... A-9 : A-10....... Number (pl. 1) 783h 783g 785¢ 783 825b 825¢ 783d 860b 703b 860e 825d 780 702 819a T79 702a 776 898 869 843 788 778 770 769 T72 764 TT7 T81e 781 82la 822 861 718 796 725 Tat 798 $30 723 862 829 777a TT7b 781b 696 782 679 616 680 678 611 612 712 7185 714 608 719 Company and well TABLE 2.-Wells shown on plate 1, listed alphabetically by company Number (pl. 1) Colorado Interstate Gas Co.-Continued Kilgore-Continued A12 ::..: B-l:.;_.:}> ... Luberstadt A-1...--. Masterson A-1-___-. A-B.:!.c2 A<4..:2.. A5. ._. A-6.:-..10 Ad...... A-10._... A-11-.... A-13...«. A-14-...; A-15..... A-16..... A-18.:... A-19...-. A-20-.__. A-21.°-.. A-22_..__ A-23____. A-24____. _... Bl...... B-2.____. B-3:..... B-4....01 B-5...:0.. B-6.:.... P-5...... B-9_..... B-10.. .= p-11...- B-12.... B-13....- B-14-..: B-15.... B-16.... B-17.... _.. B-19. .~ B-20. .... B-21..". B-22.:..* B-23. ... B-24- ___ _.. B-26.... _.. _.. ._.. 613 610a 720 682 759 761 758 754 728 734 653 805a 695 760 756 797 733 735 TST. 755 T4la 828 753 748 736 860c 862¢ 860f 762 757 809 835a 837 890 800b 802 804 803 811 810 808 838 751 800 799 750 805 807 799a 800a 865 864 866 897 896 894 895 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS TaBL® 2.- Wells shown on plate 1, listed alphabetically by company and name-Continued Number Company and well (pl. 1) Colorado Interstate Gas Co.-Continued Masterson-Con. B-30-..-- 7492 B-31..__ 8932 B-32.__. 893b B-33_....- - 8902 B-34.___ 8912 B-35.... 888a B-36.... - 887a B-37..._ 898c¢ B-38-_._- 8632 B-39.___ 8862 B-40-_-- 800d B-41-___ _ 804a B-42.__- 8372 B-44.__- 862a B-45.__- 800e B-55-.__- - 8952 B-61.._. - 882 C-11_°<.. 834 C-S8.._.. 835 D4: :s. 863 F-2:.... 833 891 G-2.:.:L 886 (G-3._... 739 G-4_._.___ 831 G-5.2)._ 801a H-1.>.;; 887 888 I1 781 .C 836 I-83... 86l1a IJ-4:000., 860d l 862b Ke1.:.__ 801 892 M-1.2.:.. 745 M-2.:20. 746 M-§..>. 744 N-1..._. 893 Poling A-1...._.... 821 Read A-1....:..... 650 NRA COOL Iz 693 7, to: Hoare o oro 648 , of Arepas TAT 694 AzO.::: :c... 752 Sanford A-1____.__. 859 858 A-4:0:00.0_. 858a 858b Beay A-1..._______ 722 Sneed A-1..._...._.. 637 A=2 2 643 L0... 641 637a Company and well Colorado Interstate Gas Co.-Continued Sneed-Continued A=O: :.-....> AT- PELLE C-1.-.-.s.«:. Thompson A-1--_.. ___. A-51 __ __ A-61 ._ B-1 -... B-2..00. B-4..... B-5..... B-6:.... B-7..... B-9_.___. B-10-__. Warrick A-1-_______ Ar.. 20. N-3:.. zi. Continental Oil Co.: Armstrong. __-.-__.. Armstrong 1. ...... Arnis 1 Bricker 1..:..... .._; Brown Burnelt Push 1..>....c0..} Carver, H. W., 1____ Carver, W. A., Jones Bef McDowell 1. _...... Marsh 1 Shellberg 1 '.>._._. Spurlock: 1: >-... Wells Fowlton Co.: Coke 1} ../... _ s2.ll Gray County Produc- ing Co.: Herring 16. sl.: Number (pl. 1) 742 686 688 689 690 7483 690a 644 642 567 631 629 633 634 684 685 683 623 729 540 542 628 732 625 730 682b 732a 817 718 768 81 7a 205 188 98 207 46 115 68 135 136 157 119 62 65 100 102 190 134 52a 606 213 214 G15 TABLE 2.- Wells shown on plate 1, listed alphabetically by company and name-Continued Number Number Company and well (pl. 1) Company and well (pl. 1) Henderson, E. C., Co.: Kerr-McGee Oil Indus- Merchant 1__....-.. 586 tries, Inc.-Con. : ame m 585 Jones-Continued Huber Corp.: G-1-A. . _.«...: o. CHB Isere 109 McDowell 1__.___-. 92 SMI cpl pI 111 2 - ek sec 64 12... 230 suey 110 Morton 2: .:: 129 B= co Uiser aki. 133 BEC uce 101 02 82 BS 130 Henderson 1___._.... 83 Phillips 252 Herring, E.,. 1..-.... 193 Recves le 12.32% 245 Schrocter 1..:>-:.'.. le Herring, W. E., 2--- _ 431 Sneed 568a 424 8028 4.y . 426 Strunk 139 Suz 350 Sullivan 138 8:.. : 351 Taylor A-1L.:..~_--.. 145 72>. "808 167a 8... 425 166 10. . :~ Terry 40652 12. 352 540a Hobbs-Allen 1--___. 309 Wilbat 2:.-1.._i... 150 Huber-Mag. o p aia ka t al 169 Herring 1.....:.- 433 Wilson A-1.._.---_-. 1285 434 1b Huber Russell Magnolia Petroleum Co.: Fuller I...... 2: 5b Britian 29 Huber-Texas W. E.: Pic cdl . 30 Herring 1_...._.. 349 Beeck Lu 48 Ae 306 : Sep deepen ao 49 Oowens 1:..~..c._.. 172 28 Prewitt 2:::¢-l.._.-.. 432 6:8. 47 Reed 1....s-_-:L... 421 Teter Itz. 96 Pees eL 420 ceci. 66 Kerr-McGee Oil Indus- Hardwich 1-....._.: 218a tries, Inc.: Herndon t.:.:..::.:. 146 Anderson 1...._.... 222a Miller _...... 9 Arie 1. 251 Nelsom 126 Avery 89 Thompson 1..------ 22b Bergeson 531b | Natural Gas Pipeline Brady 216 Co. of America: Berneta 1.._........ 588d Beauchamp 1-P -__-. 383 ae suss... 588e Brown 2-G.________--__ 405 Balck 588f 407 48 irie 588c Coon 329 PBreyfogle 1:........ 160 : 28. 527 Bridges 1:_::.....-. 189 B-M..........: 274 Burnett 1. _.-...-.. 86 (ATO Creed 5 §-M::::.z...."--086 Donaldson, A., 1... ra . 802 Donaldson 1._.__... 52 ." 471 Prucilla 1..-....... 319 g-M..... _ 227 . ... 1d s. tof fistate 1 _.. -.._.... 453 479 Hlyna 36 2783 Helt 286-CG.__._.___. 600 226 Humphries 1-___.__. lla 925 Jacobson 1......._.. 120 1I5- M..... 854 Jones 44 16-M.......:. -. 469 142 . O89 G16 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaBLE 2.-Wells shown on plate 1, listed alphabetically by company and name-Continued Number Company and well Natural Gas Pipeline Co. of America-Con. Coon-Continued _ r0-M.:::::..:. g2-M.._.::._". 2s-M..... ..- 25-M._.:.....-. :.,: :... 28-M..... ..-. sSQ-M.:.:_.:.. :...... G2-M..:....... Coon-Sneed 1-M ._. 3-M.___. 4-M.__.. 5-M.__ 6-M.___. T-M._.. 8-M___. 9-M.... 10-M... 11-M._.. 12-M_.. 13-M._.. Dore Foster 1-8....__..._ 2-FO...: :... Gober 1-SP-.____-_. G-bP:...._.: flans I.......s....} eas Haile I-M..:...:-C 2-M..:...:...: Jester 1-T.-.._... _s. Johnson I1-P...-_. -. Kilgore 2-G.___.__. {>.: 2 .as. LaSalle I._..>c. l.. Lea 22 Lucky Tiger A-1-__. Moore 1=-P.-_........ Powell 1-G.._.___._ Pythian I-P..._.. -_. Schlee Sneed 1 Poitevent (pl. 1) 277 326 391 271 393 270 2175 388 385 269 387 276 328 390 332 485 483 282 332a 281 397 279 331 399 394 278 395 137b 180 181 230 284 285 622 682a 292 204 396 681 782a 619 614 621 609 176 699a 236 615 535 534 228a 139a 177 335 Company and well Number (pl. 1) Natural Gas Pipeline Co. of America-Con. Sneed 1-P T&NO Survey.... 1-P Jones Survey.._-- 2-P D&P Survey.... 2-P G&M Survey.... - Texas Thompson 1-F....-. 2~TH.... 11-TH__. Troutman 1-SP --- -- Walters 1-PAR-___. Williams 1-T.-_____- 336 495a 656 482 TABLE 2.- Wells shown on plate 1, listed alphabetically by company and name-Continued Company and well Navajo Co.: Poling I.._......... e clean-. Northern Natural Gas Co.: Bivins I...... "... Panhandle Eastern Pipe Line Co.: Bennett 1-22... Brown 1-22......._. 1-34: .020.02 1-36......L_ 1-64...:.... 1-104=:. :. Hanneman 1-100-__. Jester 1-18..._--._. Kilgore 1-8........ 1-16.:.....L 1-560..:..... McBride 1_........ Massay 1-15......-- Masterson 1-38... Nield I-15__....... Purvin 1-69..._.... Sneed 1-20......... ...... 1-23-6T.___. 1-24:...2...2 1-20........s 1-48! 1-50.......:. Sneed, A. R., 1-33... 1-37. Thompson 1-25... 1-68... Walker 1-6--------- Zoffness 2-55...c.2. Panhandle Oil Co.: Jameson-DuBois 1. Sneed 1..:.s........ AL iI via. Panhandle Production Co.: Herring B. a Number (pl. 1) 820a 820 T7L 408 550 551 554 480 477 467 481 677 610 620 538 536 539 840 617 749 626 468 409 TAl 403 484 406 560 490 492 404 568 565 649 647 646 640 635 553 557 544 549 491 494 645 691 418 340 342 341 246 247 dompany and well Panhandle Production Co.-Continued Herring-Continued fee case LaRater 1..__._.__._>. Phillips-Kerr- McGee Co.: Donaldson 1-...._._. McDowell C-1-____- C2: ua wells 1... STES Phillips Petroleum Co.: Ada. May 1-......_. Adams, K. S., Jr.: Appling 1._...... Ford 1.....l..~.t Kilgore 1......... Sones Albert Alda Althouse ...-... Ames Armi Arnella 1...._./....>.- Arris Augusta 1.......... Balfield 1._::-..-.... Balfour 1-286-F ___ 1-294-F___. Pay I..... c Beraw Biffe Bissell v fear raye Bivins 1-GG-_.___-.-. Blanche 1.......~-.. Booker Bradie 1........~.. Brent 1. {BH bridges 1..........; Britain 1... ..._-sc.-L Brumley 1--.-....._.- Burnett Burrus Bush Butler 02-2. Number (pl. 1) 807 192 50 19 19a 16 107 249a 312 250 249 43a 264 381 443 517 588b 463 141 17a 437 548 630 473 451 208 97 39 422 198a 67 13a 419 346 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS TABLE 2.-Wells shown on plate 1, listed alphabetically by company and name-Continued Company and well Phillips Petroleum Co.-Continued Byrd-Continued .o boss ak Cardiff 1.:..-.... ._ Carver 1......_.... Castleman A-1..___. B-1..._. Cattle 1.:-..:~..-... Champ 1..........._ Chlog1............ Clarence 1:.....___._ Clark Gable 1______ Claudine Clements A-1._____. Cloby I..:......_... Coffee Colling 1..._..._... Colson I...... Colwell A.:...:.._. Constant 1.__....__. Coon Daisy Dale Daught 1-._.....--_ Della I.:'.....<~:.. Dollie '. Dona Donaldson 1.___._._._. Donelson 1:........ Drury 1.:......:..... Dudley 9 Dumas Ebling 1:.:..._..... 12. onc dof Elbert 1: Elise1:............ Ellie t.....___._}... Emily Nell 1...___- Emmett 1..:.....__. Estate 1I.:....-_:.: Ethelyn 1.......... Eve'l:=cl..ls._ .ll}. Evelyn !...... .. Ezclle Farbert 1...:...__._. Faye Fields 1..........- Finch 1._...>.:.:_._ 1I-_.....__~.. French Fuller Fullingim .._. Number (pl. 1) 186 366 131 104 504 323 379 114 85 113 318 6 84 360 363 378 324 325 435 268 193a 454 365 175b 257 444 31 ral 459 253 417a 522 597 598 601 448 38a 38 533 364 254 137¢ 356 19¢ 178 441 581 605 258 84d 187a 375 73 362 5b 217 Company and well Phillips Petroleum Co.-Continued Fuqus B-1-......_. Gasser 1I:_....._... Gearhart 1_________ Glass Cob I-: Gober: Gordon 1>.':~.-..;} (reiner 1...: :-.2.} Guleke:1_........>. Gunter Hagaman 1-.._.... Harn 1:...:i.....}s Harbert I Hardwick 1.:.-.:.. Harrington 6. ...--. Harrison Helton Hibbard Hinkle Hub A:. Huckaby I...... Hurwitz Ingerton Ina 1....:. .tt uC Ingrid -1.........:~. James Jameson 1 ____.__-_- Japhet Jay ee Jen Jennie 1..-.._._~..:- Joannsg Jones dover Jullug Katherine 1. -__-. Kinfiey 1......../.; Number (pl. 1) 455 669 159d 32 234 289 593 457 53 297 204 462 460 219a 209a 224 667 458 182 354 90 5002 373 503 515 512 514 511 675 506 505 503 872 344 343 345 322 380 583 466 464 357 6la 27b 272 26a 447 1 218 112d 305 244 G17 TaBu® 2.-Wells shown on plate 1, listed alphabetically by company and name-Continued Company and well Phillips Petroleum Co.-Continued Klatt Knapp I....../.... Lackey 1.......:... Lants 1............ Latin Laughter Ledlow 1-_..:.>.... Lesglic Longmack 1........ Lore Love I.. .co. Lucas 1.......:.... 41.1. vedios McDade McDowell 1-._...___.. McDowell, O. E., 1_. McFarlin 1......~.. eens seus McLaughlin 1-_____ Malcolm 1_._. -..... Marguerite Ann Marni Marsh 1..-_.-....._. Marvin Mass 1.__ ..:... Massey 1_.._..-.... Matiecr 1:._.......~ Melvin 1 Merchant _. Messenger 1...-___. Mills 1.:......_.-.-. Modine Moore '60' 1_..:.._. Nelson Nield D-1.._..._.... Nunley 1...~....... Ochsner 1...._.._... O'MHearn Ola Ozark 1......_..__. Pelly 1.....-...... Pink St. 1.-~.....-. Pittman 1.;..-.-.-... Ploner 1. Polly Powell Preston 1.:.._.-_.. Priscilla 1.._._...._. Purdy 1..:.......... Queen Ray Record 1...._...... Reeder 1.:-..:....... Number (pl. 1) 525 175 210 531 575a 20b 153 440 203 184 256 57 56 222 57. 121 529 529 355 206 94 315 114a 382 376 461 283 137a 585a 524 14 358 25 69 159b 159a 316 63 436 602 18 516 575 75 187 289a 27 510 250a 194 577 60 Company and well Phillips Petroleum Co.-Continued Reeder-Continued al Rena Reuter Richard A-1....__._. Rorex Rubin Sallie 1... :...... See Shelton Sneed A-1-____.-__. B-1...is0... B-3.-..l.-.. B-6.:........ ~. AH Morante. Cb. Spurlock 1. Stallwits 1-..-=..L-. Stan Stanhope 1-....... stem I.: Stencil Stigalli.:....-.._..c Stocking 1.......... Stockman 1-.--..__.- Sturdy 1. >-....s_u. Bunray A-2-_--_.... Sunray-Feltz 1--_-. - Sunray-Jones 1__._..- Number (pl. 1) 61 439 99 44a 197 239 241 209 321 456 175a 556 555 651 658 657a 413 411 412 501 295 692 642 562 564 132 221 196 168 202 367 159¢ la 317 116 26b 445 88 G18 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 2.-Wells shown on plate 1, listed alphabetically by company and name-Continued Company and well Phillips Petroleum Co.-Continued Fanner 1:-_.-.__:... Tatrig L Taylor 1.-.......-. -.- Teddy 1::........ Terry Texas 1. 3}..0..2._... 'Mliaten 1I........_.~ Tooker >... Ufey 1-12>°.._..32.. ants 1.1.:..3.0-.0 Yenable 1. ...____.. Vent A-1..:=..... Victor 1..¢.-.......t Vinson Viola Wad l_-_:...-...-. Way 1-2... Weidling 1.._..:.:_. wild Bill:1'...:.... Williams 1° .___..__. Wilson 2.:........;.. Winn Witherbee 1. -_-... Worsley Yake 00.04 1-..-..L.._.: Bennett Bivings A-1-_______._ Deahl A-1---_____- Number (pl. 1) 449 450 227a 446 438 513 87 255 442 191 ba 159 103 231 232 288 283 398 228 200 2292 607 , 452 523 112¢ Sa 377 578 580 35 147 3 530 587 415 414 416 416a 291 337 293 sa 853b 819 849 850 851 Company and well Phillips Petroleum Co.-Continued Deahl1-Continued Shelton A-1-._____. A2: Rowland, A. H., Co.: Humphries 1----.--- Rubin, Dave, Oil Prop- erties: IVM PBeard A-1.. _ Carver Shamrock Oil and Gas Co.: KXllen Anderson 1.._...._.. Ansley 1. ...._..LL. Atcheson 1-.1_.. ._.. Dates Decker Breesford 1........_ Prian I_._..._l...C brown Brumley-Golf 1..--._. Brumley Ryan 1-_.. Brumley Sunset 1. Burnett 1....:-...l; etal i:..:.... Coffee: 0 Cox t.. Crump Davidson 1.;:.._..; Dore Ir...: Finley Number (pl. 1) 880 852 853 766 765 697 767 698 699 700 416b T7. 78 301 302 671 604 668 670 672 673 706 76 58f 22d 263 20e 159f 122 22a 528 371 369 368 374 320 370 58¢ 40 40a 41 41b 58d 58a 58b 164 84a 259 144 260 532 112 53l1a TaBu® 2.-Wells shown on plate 1, listed alphabetically by company and name-Continued Company and well Shamrock Oil and Gas Co.-Continued Fowlston 1. .._... Gearhart 1..._..____ Geary HasticI........_... Hatcher-Crosby 1... Hight: Householder 1... Hufft1T:_-'!<:.l:..... CA:. silks.. Johnson B1"; :.... CAM.. Jones-Ryan 1_..____. Kelly Kempson Kilgore 1-28--_____- Logan I._:.l......s A” _________ Luckhard 1.:........_. McDade 1.......--: McDowell 1_._....._. McKee McKeig 1° ._..:._.:. Meinhardt 1.__---_.- Mercer 1_....:....«. Myers I...:..}.:.... Olsson, M.; 1....:>. Porky .~. Phillips 1..._....... 20 Powell 1:..:-.¢..... C=1 ._ Powell- Magnolia 1___ Pritchard 1-....>_:. Read E-1.......... Robertson _- C-12:;:. C-2.2..0..: C-3.:.212 D-3..... B-1....:. Rubert 1:::.~.>...... Rubin-Brown 5-B__. Schlee4..........y. Number (pl. 1) 162 265 267 266 84e 161 261 158 84b 112a 215b 215a 40d 22¢ 20d 140 24 41d 42 43 60a 163 298 537 56b 56a 84c 1374 112g 137e 54 4la 112e 143 112f 4a 20a 124 20¢ 237 235 '~58 40e 58g 80 4 25a 23a 23 20 22 24a 10 21 59 674 137 Company and well Shamrock Oil and Gas Co.-Continued Schlee-Continued Aol... Sharkey _i Simmons B-1....--_. Smith, Dale, 1.._-_. Smith, Frank, 1.____ Smith, Fred, 1__.__._. Smith, Mary, Sneed a pies. Stewart 1. .._... 10°: a Tays Thaten Underwood B-1-___. Van Order 1.;:.._... Ward, J. F.; 1 Yonque Young Zella 1 Zwatk 1 _.. Shell Oil, Inc.: Kelly 1_.../:....2. Lucas 1... Shell-Sinclair Co.: Bartlelt 1.":..~_..... Catlett 1}....0....: Dash :c /s: Donaldson A-1-__-. Donelson B-1..s.. 00 Flynn Guleke 1:.__-._.>>: Hill 1°: 22... Mohman Jones: 1. s..: .L EKraker Lindsey 1-.:....... Longanbecker 1__.__. McDowell B-1-.____ Miller Miller Munson Russell -1..::....._.- Wilbar 1 __...=. "as Wilson: l- Sinclair Oil Corp.: McDowell 1.___.___ Phillips A-1......>> Skelly Oil Co.: Armstrong _- Armstrong, M. B., 1 __ 2:2 11. 12. 14. Number (pl. 1) 45 219b 175¢ 159e 221a 165 287 290 296 38b 40c¢ 159g 238 159h 112b 95 220 175d 201 123 339 55 53 152 15 51 70a 70 T 74 40b 151 4lc 117 12 149 13 91 17 11 173 8 170 128 19b 3b 212 211 303 417 243 304 TABLE 2.- Wellé shown on plate 1, listed alphabetically by company and name-Continued Number Number Company and well (pl. 1) Company and well (pl. 1) Skelly Oil Co.-Con. Texas Interstate Pipe- Herring A-8.______. 310 B'lifle (fie-5:40 t iving 1-540-_.___._._ sta- os t=653." -.. 701 Herring, W. E., 1... - 430 bost I:"... ._. n 2... 429 McBride 1_...._.~.:. 839 3... 428 100; -...: 812 5... 2497 Masterson 1—232 ners 8322 1- Pats _______ 4 2/1 83112“: er 5?) 2 | . ..... ..: g41 ~ 2 White and Parks Co____ 862d 509 | whittenburg Co.: 429 p lae __ 2". 81 cc:}. 508 108 Uraniferous asphaltite is sparsely disseminated throughout the cap rocks and, in places, occurs within the reservoir rocks of the field. Analyses of this mate- rial show that it contains from about 0.2 to 5 percent uranium. The discovery of the uraniferous asphaltite presented the problems of evaluating the processes that resulted in its formation and of determining the source of the uranium and other metals that have been con- centrated in the asphaltite. The concentration and dis- tribution of uranium and other metals, therefore, were investigated in the reservoir rocks, asphaltite, residual petroleum, crude oils, and brines. ACKNOWLEDGMENTS The investigation was made by the U.S. Geological Survey on behalf of the U.S. Atomic Energy Commission. The writers wish to acknowledge the cooperation of the following companies: Colorado Interstate Gas Co., Phillips Petroleum Co., Kerr-McGee Oil Industries, Inc., Natural Gas Pipeline Co. of America, Shamrock Oil and Gas Corp., Panhandle Eastern Pipe Line Co., Continental Oil Co., Shell Oil Co., Standard Oil and Gas Co., Skelly Oil Co., Texas Co., Red River Oil Co., Dave Rubin Oil Properties, Nabob Production Co., Cities Service Oil Co., Gray County Producing Co., Magnolia Petroleum Co., Northern Natural Gas Co., Panhandle Oil Co., and the Sinclair Oil Corp. The writers are particularly indebted to B. B. Mor- gan, G. H. Tomlinson, H. S. Carver, and R. Rogers of the Colorado ynterstate Gas Co.; R. K. Lanyon and H. B. Bishop of the Phillips Petroleum Co.; O. C. Barton of Kerr-McGee Oil Industries, Inc.; and G. Galloup of Natural Gas Pipeline Co. of America, whose time and assistance are greatly appreciated. They also wish to express their gratitude to H. Neal Dunning, E. M. Frost, G. B. Shelton, C. W. Seibel, C. C. Ander- 2% URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G19 son, W. M. Deaton, and other members of the U.S. Bureau of Mines for their interest and invaluable help. Special recognition is due the following members of the U.S. Geological Survey for their contributions to this investigation: C. Albert Horr, for the chemical analyses; A. Tennyson Myers and Pauline J. Dunton, for the spectrographic analyses; John N. Rosholt, Jr., and Sylvia Furman, for the radiometric determina- tions; A. J. Gude 3d and William F. Outerbridge, for the X-ray crystallographic determinations; and to A. Y. Sakakura, for discussions of the source of radon in the natural gas. GEOLOGY OF THE WESTERN PART OF THE PANHANDLE FIELD The dominant structural feature of the Panhandle field is the Amarillo-Wichita uplift, a northwest- trending geanticline between the Anadarko and Palo Duro basins, which extends over 200 miles from the Wichita Mountains of southwestern Oklahoma to the Dalhart basin (fig. 2). The basement complex of the western part of the Panhandle field is composed of granite, porphyritic rhyolite, and diabase. Of these rocks types, rhyolite is most commonly penetrated by drill holes in the base- ment rocks (pl. 2). Flawn (1954) assigned all the igneous rocks to the late Precambrian. According to - Flawn, the granite is part of the "Wichita igneous pro- vince" that constitutes the core of the Amarillo- Wichita uplift, and the rhyolite represents flows of late Pre- cambrian age which made up the "Panhandle volcanic terrane." Diabase dikes and sills penetrate the porphy- ritic rhyolite and are considered to be the youngest rock type of the Precambrian complex. The porphyritic rhyolite is a dull-red welded tuff composed of sodic plagioclase phenocrysts and some high-temperature quartz phenocrysts, in a microcrystal- line groundmass showing flow structure. The diabase which has intruded the rhyolite is composed of labra- dorite, augite, ilmenite-magnetite, chlorite, and serpen- tine relies after olivine. The granite is a coarse-grained pink variety composed of perthitic orthoclase, quartz, green hornblende, brown biotite, zircon, and apatite (petrographic description by Charles Milton, U.S. Geo- logical Survey, Washington, D.C.). The sedimentary rocks of the western part of the Panhandle field range from Virgil (Cisco Group) to early Leonard (Clear Fork Group) age, as shown in figure 3. The sequence is made up of "granite wash," arkose, arkosic limestone; white crystalline fossilifer- ous limestone locally known as the "Moore County lime" ; light brownish-gray fine- to medium-crystalline dolomite known as the "Brown dolomite"; light yel- G20 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY COLORADO sos cs Hugoton Pains [ O _-T—Keyes Field. '. s} I mI e..." | e ar C I iif ' O Is #C 3 |" ¢ 22 o! 3 ~ oI l?” N ......... y fill = Panhandle: @ Z tian f Efll a e e . I I o o ot 1 4) alo o 5 al ‘v ( Coca | T I $ X" T _ I | Cliffside Field i I 4A | ¥ I ° ' C I I TEXAS O Areas in which Precambrian heil ® Rex I (G rocks are exposed 0 QQ E I $0 p L170 0 1 '\\ b/ta ~ u ll Basin XJS & ntains U [1 KANSAS Q 50 100 MILES FIGURE 2.-Map showing major structural features of the Panhandle field and adjacent areas. lowish-brown to light olive-gray dense dolomite known as the "Panhandle lime"; and red siltstone and shale interbedded with white, gray, and brown anhydrite known as the "Red Cave." This stratigraphic sequence resembles the basin-mar- gin class of evaporites of Sloss (1953) and represents a shifting depositional environment that ranges from normal marine to penesaline, modified by the influx of coarse to fine clastics. The white crystalline limestone is typical of a normal marine environment in that it is light in color, ranges from fine to coarse crystalline in texture, and contains abundant fossils and fossil frag- URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS G21 N:O M EN CL A T UR E Group ECONOMIC TERM SERIES SYSTEM Feit ”ll pe: Gf aa. - | deans a. l Rocks of Leonard Age r "Panhandle lime" Wichita r>. "- // 2" / // // // Z / mrt Aai rr oo ae o Permian // na- A4 //— a_ mes / Z Z "Brown dolomite" Rocks 7 of A A aA % a Wolfcamp = ". Age // 4 4 chorpmmu w ~ i LQ "Granite wash" j of - Precambrian EXPLANATION ety E Z L- _] ey AJK 7 mith rns +s. { /Z b T 1 T $ {4.13 V. 200 - Porphyritic rhyolite... 0002 4.-Radium content and radon-emanating power of core samples from two wells in the Panhandle field [Samples collected by Phillips Petroleum Co. for G. E. Manger. Analyses for porosity and permeability by U.S. Bur. Mines, Franklin, Pa.; radium and radon analyses by F. J. Davis and A. F. Gabrysh, Oak Ridge National Laboratory] Core Ra Perme- | Radon Depth of | recov- | Part of core analyzed | content | Porosity | ability | emanat- core (feet)| ered | (percent) (10-% |ing power (feet) Ra per g) darcies) | (percent) Phillips Petroleum Co. Ola well 1, Moore County Tex. (No. 312 on fig. 2) 3530-3540 8 SUT sia rete. 2.97 7. 69 0.1 5.98 1.86 8. 62 4 5. 45 1.33 2.72 . 33 5.38 19 2.77 A 1.23 3574-3580 4 1. 58 6. 58 21 12. 39 3573-3577 1.5 1.36 12.07 61. 23 4.74 3577-3590 5.6 1.10 3.19 3 4. 44 3597-3607 5 . 92 22.22 66. 4 4. 57 3611-3613 1 1.05 7.27 &. 5. 91 Phillips Petroleum Co. Louise well 1, Sherman County, Tex. 2771-2778 |__.____.._ TOD M 0. 64 16.49 7. 11 8.10 ________ Bottom 1 ft.. A1 7.83 7.75 2773-2774 |..___._._ Middle 1 ft.. . 70 8.95 21. 39 5.65 ........ Bottom 1 ft... . 45 8. 99 6. 60 2777-2781 |..____.__ 'Toplift..... . 64 8.17 52 6.25 ________ Bottom 1 ft.. . 20 14. 63 34. 12 15.08 2781-2784 |________ Bottom 14 ft. 17 25. 47 1858. 0 14. 62 2785-2788 |._______ Topift..... 28 10.19 8. 25 12.16 2788-2702 |______.. TopTf..... ess 14 12.85 21. 04 7.79 ________ Bottom 1 f6.......... 10 9.86 3.09 6. 88 and 0.40 x 10-* g per g which is equivalent, respectively, to 4.0 and 1.1 ppm uranium in equilibrium with radium. Calibrated gamma-ray logs by Schlumberger Well Sur- veying Corp. show radioactivity equivalent to 2 to 3 ppm uranium in the gas-producing "Brown dolomite." Radiometric analyses of several hundred samples have shown that the equivalent uranium content of the reser- voir rocks is less than the measurable lower limit of 10 ppm, by the beta-gamma counting technique that was used. Sakakura and others (1959) concluded that radon concentrations of 23 to 522 micromicrocuries per G26 liter (STP, standard temperature and pressure) in gases from the field correspond to reservoir rocks con- taining from about 0.4 to 9 ppm uranium, respectively. The average radon content of gases in the Panhandle field is about 100 micromicrocuries per liter (STP) (pl. 1) which would correspond to about 2 ppm in the reservoir rock. In summary these data indicate that the mean uranium content of the reservoir rocks is from 2 to 4 ppm. The uranium content of the cap rocks (the upper part of the "Panhandle lime" and lower part of the Clear Fork Group) apparently is several times higher than the uranium content of the reservoir rocks. Radiomet- ric analyses of 335 percussion-drill samples of the up- per part of the "Panhandle lime" and lower part of the Clear Fork Group in 13 wells distributed over the Panhandle field, show an average equivalent uranium content of 20 ppm. The rocks represented by these samples have an average thickness of 260 feet. Gamma- ray logs calibrated by Schlumberger Well Surveying Corp. show an average radioactivity through the same rocks equivalent to 18 ppm uranium. Seventy-five uncalibrated gamma-ray logs, examples of which are given in plate 3, show that the radioactiv- ity of the asphaltite-bearing interval, after allowance is made for absorption by the casing, is about 5 times greater than the radioactivity of the underlying "Brown dolomite." The "Brown dolomite" has been estimated to contain from 1 to 4 ppm uranium (table 3) ; the uranium content of the upper part of the "Pan- handle lime" and basal part of the Clear Fork Group is, therefore, indicated to be in the range of 5 to 20 ppm if the radioactivity is due entirely to the presence of uranium and its decay products. The asphaltite is estimated, on the basis of the exami- nation of 500 mineralized drill samples, to compose on the average about 0.5 percent by weight of the samples. The average uranium content of the asphaltite is about 1 percent as indicated by spectrochemical analyses. The mean uranium content of the mineralized drill sam- ples is calculated at about 50 ppm. The distribution of mineralized drill samples is shown on plate 2. Each asphaltite nodule symbol rep- resents a 10-foot thickness of asphaltite-bearing rock. It is estimated that from one-third to one-half of the samples from the "Panhandle lime" and lower part of the Clear Fork Group contain asphaltite. These results indicate that, if no asphaltite has been lost during drill- ing, the average uranium content of the mineralized rocks is from about 15 to 25 ppm. Although this esti- mate has only semiquantitative significance, when con- sidered with the radiometric analyses discussed above, it suggests that the mean uranium content of a 200- to SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 300-foot-thick interval in the upper part of the "Pan- handle lime" and lower part of the Clear Fork Group is at least 10 ppm and perhaps is as much as 20 ppm. URANIUM AND OTHER METALS IN THE CRUDE OIL Semiquantitative spectrographic, radiometric, and chemical analyses of the ash of 26 crude oil samples from wells peripheral to the western part of the Pan- handle gas field (table 5) show that the metal content of the crude oil is low (table 6). Their uranium con- tent ranges from less than 1 to about 300 ppb. Many of the predominating elements, particularly sodium, potassium, calcium, magnesium, and strontium, are those elements that are normally most concentrated in the brine, and the presence of these elements in the oil may have resulted, therefore, from incomplete desalting of the samples. Uranium, nickel, vanadium, molybde- num, cobalt, and arsenic, however, are concentrated in the crude oil to a greater degree than can be explained by contamination of the oil sample by brine. This fact is illustrated in figure 5 by the comparison of the con- centrations of trace metals in the oil, brine, and asphal- tite. The data for the oil are from tables 5 and 6. The data for asphaltite nodules and brine are presented in a following part of this report (tables 8 and 14). Semi- quantitative spectrographic analyses of the salts of these brines used in preparing figure 5 are not presented elsewhere in this report. The possibility of the occurrence of discrete minerals in the crude oil was investigated by filtering the mate- rials in suspension from several samples and studying them under high magnification. Some of the sus- pended materials were concentrated by passing the crude oil through a bacteriological filter. Other smaller particles were obtained by diluting the filtered oil with benzene and passing it through a column of powdered aluminum chloride (Sanders, 1928). The column of aluminum chloride was dissolved in water to form a saturated solution from which the extremely fine parti- cles that had been adsorbed from the oil were collected. The materials separated by these means were examined under 1500 X magnification in diffuse reflected light. They consisted of abundant tiny fragments of carbon- ized organic material, some micron-sized globules of brassy minerals, and particles of a black pitchy mate- rial. All these materials were mounted on glass slides, coated with liquid nuclear emulsion, and exposed for 2 months, but they showed no significant alpha activity. The low alpha activity suggests that the relatively high uranium contents of the ashes of these crude oil samples (table 5) do not originate from suspended materials. The tiny brassy globules from less than a micron to as much as tens of microns in diameter are probably made Na Ca Fe Mg Si As Sr Ni Al Pb Cu Ti Ba Co Cr Yb Mo Ag URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS 26 crude oils 27 asphaltite nodules 30 connate brines -log (g per g) -log (g per g) -log (g per g) s /a 5 6:7. 'B 49 10 ~ I1 0 1 :t" s ° 4 5 -~6 3 4/5 7 9 10 T * -o |-ro L SCU Pile 4 fed SOs G27 a, + | C* b hull c Wieby 5) bc C99 Ay -| fo-) pice bor | nh _I FiGURE 5.-Concentrations of metals in crude oil, asphaltite nodules, and connate brine. G28 up of pyrite and chalcopyrite, and may contribute sig- nificantly to the iron, copper, and sulfur contents of the oil ash. Inasmuch as the crude oil samples prior to analysis were filtered through frits of about 50 microns pore diameter, the metallic particles must have been present in the ashes of the samples that were analyzed. An analysis of the material removed by filtering a Panhandle crude-oil sample (table 5, sample 25) shows that iron and copper are the most abundant heavy metals removed followed by chromium, manganese, nickel, tin, lead, vanadium, and a trace of silver. A sodium fluoride flux test for uranium was negative. All these metals are also present in the filtered oil (table 5, sample 24). In relation to the major constituents such as silicon and sodium, the filter held back more than half of the iron, potassium, magnesium, aluminum, tin, barium, boron, titanium, lead, chromium, strontium, and manganese, about one-tenth of the copper, calcium, and possibly silver, and only about one-hundredth of the vanadium and nickel. Cobalt and molybdenum were detected in the oil but not in the residues from filtration. It seems probable from these results that of all the metals present, vanadium and nickel and possi- bly cobalt and molybdenum occur chiefly as compounds soluble in the oil. Vanadium, iron, and nickel are the three major metals occurring in the ash of the Panhandle crude oil. Both vanadium and nickel have been shown to occur as porphyrin complexes soluble in petroleum (Dunning, Moore, and Myers, 1954). A sample of crude oil from the Panhandle field has been analyzed for its porphyrin content by H. N. Dunning and J. W. Moore of the U.S. Bureau of Mines. They found 8 ppm of "free" or non- polar porphyrins (Dunning, written communication, 1953). Quantitative spectrographic analyses of this oil showed that it has a nickel content of 1.2 ppm and a vanadium content of 1.0 ppm. The amount of porphy- rin present in the oil is sufficient to complex about one- half of the total vanadium and nickel present. A sample of oil from well 731 was passed through a large adsorbent candle filter of about 5 microns pore size and then diffused for 48 hours in a thermal diffu- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY sion column. The resulting fractions were analyzed for their metal contents. The data, listed in descending order in the diffusion column (table 7), show that dur- ing diffusion the metals concentrated towards the bot- tom of the column with the heavy asphaltic molecules of the crude oil. The extent to which the various met- als concentrated is also shown in table 7. Vanadium, which probably occurs in the oil as a soluble porphyrin complex, is concentrated to a much greater degree than are the other metals. Small amounts of lead are present in the crude oil of the Panhandle field and a large proportion of this metal may be of radiogenic origin. The radon concen- trations in the gases of the West Panhandle field are as much as 10* micromicrocuries per liter of pore space at reservoir temperature and pressure. Radon is highly soluble in oil, and calculation shows that petroleum saturating these rocks could have accumulated as much as 10% g Pb/206 per g oil since Permian time (250 million years) from decay of radon dissolved in it. In- asmuch as the actual lead content of the crude oil (table 6) ranges from only 10- to 10 g Pb per g oil, a major part of the lead could have been derived from decay of radon. RADIUM AND URANIUM IN THE BRINE The radium and uranium contents and the chemical compositions of brine samples collected from the Pan- handle field are presented by Rogers (table 8). The radium content of 75 brine samples ranges from 3 to 156010 g Ra®"" per liter, and the uranium content of 29 of these samples ranges from less than 0.1 to 13 X 10~ g U per liter. Calculation shows that the amount of uranium in the 29 samples analyzed is sufficient to support from less than 0.01 to 24 percent of the radium (Ra#"®) present in individual samples. The major part of the uranium from which the radium was derived must, therefore, be in the reservoir rocks. The chemical compositions of the Panhandle brines are portrayed graphically in figures 6 and 7, which TaBu® 7.-Metal concentrations, in parts per million, in thermodiffusion fractions of a sample of crude oil from well 731 [Spectrochemical analyses by A. T. Myers. Thermodiffusion separation, chemical uranium analyses, and ash determinations by C. A. Horr. - Fractions are listed in order of appearance in thermodiffusion column] Ash Fraction Description v Ni | Na | Mg Ba Pb U Ag | Cu | Ca Mo Co Al Ti Cr | Mn | Fe 533) Light paraffinic oil.......... 0.09 | 0.9 4 2 0.09 | 0.2 | 0.006 | 0.3 2 20 0.03 0.03 8s | 0.9 | 0.9 | 0.9 20 0. O11 --| Intermediate paraffinic oil... +4 3 6 3 14 .8 .036 | 1.4 3 30 14 .07 12 A114 +4 30 . 035 ..__| Intermediate asphaltic oil... 8 20 40 20 .8 .8 . 054 2 20 200 12 4 80 8 4 2 80 .105 -| Viscous asphaltic oil......... 40 80 170 80 4 8 .210 | 8 40 | 500 8 8 170 | 17 17 17 170 . 092 Ratio of fraction 4 to fraction 1............. 450 90 40 40 40 40 | 35 25 20 30 | 30 30 20 | 20 20 20 10 8. 4 'souy1q pjoy orpusqus4 Uf sof}¥1 01 ouyi0{yo pus tintsougeur 04 uinjoreo 04 pareduroo s1u03u09 £4fuf®s pus 'are} [ns tnjpred 'tunfpey-9 @HADI 2-08: 19 X yt ~- 'p-- _ & _ __ _ _ $_ _L_____- 0 e 7! 7 0 +4280 3+ 43W X -juasuad ore win tee" hais Tei cers Bine mice ae Sane meee Sait Sach Hun tas de use juesied 0'9T- -- ad 0% ZE - a1eJns wniojeo se Suluiguoo suot jo aBequasiaq - -juosuad oz -- --- ~ L_ ~- t ___._~\______xua:u O Auurjes jego 1 -- 99 10d 8 1'0 --- 1911] 10d ut ajeos jeipey x 0 ___.____Q.._._____. | | 1 | / | | d O 5 § 1 | 1 | I | I | — : I x (on - - - --- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaBus 8.-Radium content and chemical analyses of brine samples from Samples 1-30, 36-49, and 72-74 were collected and analyzed for their major con J. N. Rosholt, Jr., James McGurk, Jesse Meadows, W. J. Mountjoy, J. E. Wilson, and 75 were analyzed by Water Resources Laboratory, U.S. Geological Survey, tion of samples 31, 51-59, and 63, which were analyzed for radium content by J. N. Lake City, Utah. Analyses for arsenic, J. T. Slayback and R. R. Beins, U.S. Geo Total solids include some constituents that are not reported. Well Location Depth | Density Sample No. Name Company Land description Survey County State (feet) | (g per cc) (pl. 1) © Sec. Tones Phillips...-:-.:-..- 15 | T. 2N., R. 1746 Atkins B-1. d 32 | T.1N., R. 1315 Hitch R-1.. 35 | T. 1 N., R. 0514 Karel 1... 8 |T. 1 N., K. 1280 7. {T. 1323 Armonr 1...-0u0..-. 2 | T.1N., R. 1299 Mundy 1 13 | T.1 N., R. 1012 Borah 15 | T.1LN., R. 0996 Nichols A-1.. 11] T. IN., B. 0984 Wacker 26 |.T. LN., R. 0965 Waugh 31 1 N., R. 0186 '| Atkins C-1 26 6 1346 Ivens T-1.. Wild Bill 1...- Johnson EE 1. Eddie !:...... High 4:.....;. McDowell C-2.. Burnett Est. 1-G Urbanzyk 1-T .. McConnell B-1-T .. Cobb 1-G... Gill-Morrow 1.. Britton A-1.- McKnight 1 Hexter 3-E. Bivins F-1...._..._._\ Jessie pout Estate 1.._.0..:i...... Katherine 2..---.---- Way Luss ie Vilas 1. .- nia se Idell 1..... Ean: spas Drury 1.............. OIA 1. .c Vinson Barre Fuqua B-1........... Robertson B-3....-.- Robertson B-3....--- Robertson D-2.....-- Anderson 1.......---- : Drucilla 1....:._..._._ Estate Sullivan Wells 1-B.:.......... Sneed 5-P............ Taylor 1-G.._........ Bivins G-G.......... Jordan et al 1-T._...-- Schafer 9-8..........- McEwen 1........... Ledrick 1-8.~......... do il Nat. G.P.A....... » -| Kerr-McGee...--- & FF .| GH and H._______ CB and H......:: GH and H.. T and NO........ GHand GH and H.. T and NO.. T and NO.. Tand NO. ._:__... T and NO........ T and NO.. Hand TC....._..- Hand TC..:..... H and TC........ Hand TC........ Hand TC.......: Hand T and NO........ AB and M...... Dand P.......... Dand P.:...0.l.- Capitol Lands. .-. Capitol Lands. .-- I and GN.. Tand GN......... land GN_........ ..... do..... Hartley.------ obipiplibibl plfififipi i co # to o 3 «© EHEC (44 ia URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS some gas wells in the Panhandle and Hugoton fields, by A. S. Rogers stituents by Phillips Petroleum Co.; samples 31, 50-59, and 63, were analyzed by and C. A. Horr, U.S. Geological Survey, Denver, Colo.; samples 32-35, 60-62, 64-71, Washington, D. 'C.. Allradium analyses were made by A. S. Rogers, with the excep- Rosholt, Jr. Analyses for fluorine and boron, Chemlstry Dept., [ital] Univ., Salt logical Survey, Denver, Colo. G31 Milligrams per liter of brine Remarks; other analyses 55,778 | 1,565 613 20, 500 32,168 | 5,500 580 5, 750 22,811 | 3,700 900 3, 250 44,865 | 3,800 | 1,300 12, 250 14,202 | 1,600 240 3, 350 28, 468 | 1,400 270 9, 350 169,182 | 3,400 | 2,100 55, 000 165, 411 | 1,690 TTL 61, 600 113,585 | 5,160 | 2,470 34, 800 171,156 | 4,810 | 1,600 £8,300 1 000 (2.0... n. Total Ca Mg Na and (or) K Br I Cl SO« HCO; Cu Fe Mn: U solids | 231,034 | 49,913 1, 452 83,122 -| 140,064 1, 412 71 193 | 11 ppm F; 6.8 ppm B. 176,357 | 2,194 689 65, 516 -] 104,150 3, 7 0 (esos nl nne alen bane Lye 179 171,108 | 1,338 431 25, 692 A 39, 138 5,083 20 {+-- [on 42 9 175,084 | 1,183 584 65, 890 -| 99, 350 10, 092 21 | j 92 | 7 ppm F; 3.7 ppm B. 178, 286 937 500 My 207 (N0 (e occ ede ln es 99, 240 10, 277 T5 (r. vena elec Le Elles 119 171,019 844 475 64, 381 93, 442 11, 800 4 100 134, O11 898 494 48/914 : <--. c 10808 | ~ 19,200] 186. |... -.- 183 134, 018 907 628 49, 390 112 132,798 | 1,065 | 1,075 48, 371 150 30, 334 948 544 48,155 - | fcr coll en -< (08, TOT . [00 c 97 | 89 25, 361 | 1,628 342 7, 423 12 183,099 | 1,926 798 68, 218 163 111,583 | 1,970 | 1,121 39, 472 85 116, 397 1, 897 1, 657 M 27 181,904 | 9,490 | 2,032 58, 109 1, 060 153, 678 | 1,206 699 57, 280 100 135,868 | 1,055 705 50, 110 83 138, 342 937 612 51, 572 90 39,195 | 1,730 428 12, 480 34 173,797 | 4,406 | 2,189 59, 952 121 | 3 ppm F; 3.3 ppm B. 145,033 | 5,176 956 49, 719 206 127, 404 | 18,358 | 8,502 16, 886 123 | 9 ppm F; 4.4 ppm B. 71, 911 , 290 1,121 11, 763 171 | 7 ppm B; 7.0 ppm B . 536 | 1,538 205 , 34 5, 883 364 51 1, 798 17 28, 445 706 74 8, 520 13 69,902 | 1,911 671 24, 118 21 1,169 49 14 5 4 134,545 | 4,046 | 3,632 42, 683 127 138,398 | 2,045 | 2,595 47, 742 170 228,607 | 4,900 1, 600 71, 000 . 720 154,111 | 4,640 1, 470 51, 400 2, 240 0.76 | 0.0008 435 | 1.2 ppm A1; 4.0 ppm Zn. 161,178 | 3,440 | 4,220 53, 100 2, 490 21 | .0022 565 | 4.2 ppm Al; .0 ppm Zn. 205,190 | 5,860 | 1,370 55,100 2, 080 0023 575 154,189 | 5,110 | 1,270 54, 600 1, 850 97 | .0065 218 | 200 ppm A1; 10 ppm Zn. 5, 880 658 104 1202 HHE ANL Ress 2, 478 1, 087 6 45,047 | 1,230 320 15, 345 4, 924 15 | 7 ppm F; 7.0 ppm B. 128,201 | 12,232 | 5,776 28, 104 1, 008 120 | 7 ppm F; 7.0 ppm B. 6, 27 771 143 1,123 1, 966 4 246,963 | 1,175 566 94 556 4, 206 44 | 1 ppm F 1.8 ppm B. 7,623 | 11,236 356 894 1, 774 6 151, 202 , 647 | 3,798 44, 035 1, 369 318 | 6.0 ppm F; 14 ppm B. 8,247 | 1,045 222 1, 533 1, 866 3 106,533 | 2,621 1,116 36, 808 3, 827 289 103,773 | 5,262 1, 788 32, 090 2, 096 483 | 0.2 ppm As. 140,965 | 6,703 | 2,263 44, 503 86,110 | 3,792 | 1,084 27,787 238,347 | 1,989 | 1,248 69, 336 3.0 ppm As. 125,973 | 6,205 | 1,863 39, 708 121,303 | 1,110 684 44,700 1.5 ppm Al; 0.08 ppm Zn. 148,228 | 2,397 | 1,230 53, 800 182,233 | 4,606 | 2,047 63, 800 8.0 g per 1 sludge; 0.5 ppm U in sludge. 1.0 g per l sludge. 2.7 gtfer 1 sludge; 0.5 ppm U in 52 g per l sludge; 0.2 ppm U in sludge. 1.1 ppm U in heavy oil emulsion. 6.5 ppm Zn. 1.6 ppm Al; 4.9 ppm Zn. Oil well producing from "granite wash” 16.0 ppm A1; 3.8 ppm Zn. 195,151 | 8,704 | 2,634 lok (+ auroral menrace 1172000: 1 :> 4,743. n eos ece e een era . 005 724 261,984 | 14,500 | 18,800 | 57,700 | 1, 640 833 | 42 167, 000 6.8 | 510 21 . 010 147 | 33 ppm Al; 17 ppm Zn. 4, 246 813 162 419 19 4 . 57 1,130 1.0..| 31 .32 | .0005 7 | 29 ppm Al; 2.9 ppm Zm. 105,550 | 2,560 | 1,870 | 32,800 | 1,060 365 | 6.0 62, 300 2.5 | 96 . 60 |<. 0001 33 | 2.5 ppm Al; 4.7 ppm Zn. 241,706 | 3,220 | 5,400 | 88,100 | 2,330 692 | 9.8 | 139,000 4.5 | 53 1.4 . 0008 97 | 16 ppm Zn 235,044 | 2,360 | 8,400 | 69,500 | 2,210 853 | 20 144, 000 12 | 41 B . 0008 62 | 24 ppm Al; 5.0 ppm Zn. 247,708 | 1,670 863 | 88,000 | 2,310 146 | 17 151, 000 1.5 47 4 . 0006 227 | 11 ppm Al; 5.0 ppm Zn. 238,749 | 8,280 | 13,100 | 62,500 | 1,490 782 | 52 151, 000 22 | 275 8. 8 . 0025 150 | 22 ppm Al; 7.5 ppm Zn. 271,330 | 2,870 | 7,010 | 92,200 | 3,650 | 1,050 | 20 162, 000 5.4 27 06 | .0042 141 | 14 ppm Al; 17 ppm Zn. 152,114 | 7,823 | 1,844 4 92, 658 288 135,855 | 7,963 | 2,227 82, 270 550 | 4.0 ppm F; 12 ppm B. 258,706 | 1,650 | 1,589 155, 314 27 10,373 | 1,550 184 4, 350 48 ! 1 ppm Zn. *sout1q Pog orpuequeq ut sof}e1 uot}21}u00u0) ogeJns 04 ourioryo pus tnjsoussut 03 tnpored 01 poredtoo 4u07009 £1tures pus '0f§}{ns tunjpred Stnont .~. 0 m 09 poe , 90! xxlbiom jo adueyo | 1.____ =-- -z-- 99 180 8 2°0 -@- @ 8 ed o'T Q -----~----1u894 ¢ ———-®-—-— @ ~ Jug. +420 I pee tal 1009.00 0B) - 2.2 o - oe cl tage 8 © + {°W a1eJins wniojeo se Sujuiguod suo; 10 -- quasied 0'Z -- 0p Auuies ero | -- -- 99 10d 8 T' --- > quasiad 0'91- qussiad 0-392 -- 49d wniofeo jo ur ajeos jeipey Saab URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS show the radium, calcium, total salinity, and calcium sulphate contents of the individual brine samples as a function of their calcium to magnesium and chlo- rine to sulfate concentration (weight) ratios. The diagrams show that both radium and calcium are en- riched in brine samples having high chlorine to sulfate ratios and high salinities. The parallel enrichment of radium and calcium in these waters probably can be attributed to the fact that both elements, as members of the alkaline-earth family, have similar chemical prop- erties, are more soluble as the chloride than as the sul- fate, and may tend to form similar complex ions. Ion exchange reactions with interstitial clay, organic sub- stances, and other materials in the rocks may also have an important influence on the radium and calcium con- centrations in the waters. Inasmuch as calcium is a major constituent of the reservoir rock, the calcium con- tent of a brine is probably determined by the relative concentrations of other ions in solution,. In particular, the sulfate ion concentration seems to be important, and contouring of the analytical data suggests that the brines are saturated with calcium sulfate (fig. 7). This saturation would be expected because anhydrite is an abundant reservoir mineral that is probably always present in excess of the amount that could dissolve in the brine. The distribution of the radium in the brines (fig. 6) does not suggest the presence of reservoir rocks that are very highly enriched in uranium. Brines having ap- proximately the same chemical compositions also have radium concentrations that are to within one order of magnitude of one another, despite the fact the brine samples were taken from different wells. The sample with the highest radium concentration (156010 curies per liter) comes from a well where the reservoir rocks contain uraniferous asphaltite; however, the ra- dium content of this sample is only about five times that of brines of similar composition. Figures 6 and 7 show that the salinity of the brines decreases with an increasing calcium to magnesium ratio and decreasing chlorine to sulfate ratio. The de- crease in salinity probably is a result of dilution of highly saline connate brines either by encroaching ground water having low salinity, by condensation of water vapor in boreholes of the gas wells, or by leakage of artesian water from above the casing points of the wells. The highly saline brines of the Panhandle field are most likely derived from the evaporites of Leonard age, which overlie the oil and gas reservoir rocks. They may represent bitterns which were incorporated during deposition of the rocks and were released through subse- quent compaction of the thick shales that are inter- G33 bedded with the evaporites Or they may represent meteoric water which has percolated downward through the evaporite sequence prior to accumulation of the gases in the reservoir rocks. The radium data discussed above are analyses of Ra*"", a decay product in the uranium series that has a half life of 1620 years. There are three other naturally oc- curring radium isotopes in the Panhandle field brines: Ra®", Ra, and Ra has a half life of 11.7 days and is a decay product in the actinium series. Ra" and Ra®® have half lives of 3.64 days and 6.7 years, respec- tively, and are decay products in the thorium series. Analyses of these short-lived radium isotopes in brine samples from two wells (table 9) show that significant amounts of the radium isotopes are present in the waters. The uranium contents of these brines are in- sufficient to support the radium. The relative concen- trations of the radium isotopes consequently provide a basis for estimating the time that they have been in solu- tion. At radioactive equilibrium Ra? equals Ra*, and Ra#® equals Ra when expressed in "equivalent" units. (See headnote, table 9, for definition of equivalent units.) Calculation shows that for the brine from well 455 the disequilibrium age (the time since the isotopes were in equilibrium) of the Ra" and Ra" is about 5 days, and the age of the Ra#® and Ra* is about 4 days. Similarly the data for the brine from well 316 show a disequilibrium age of about 15 days for the and and 2 days for the Ra#® and Ra®. The samples were 1 day old when they were analyzed. Allowing for this time interval and the time required for the brines to flow from the reservoir rock into the boreholes (about 4 days), the results indicate that the radium isotopes were derived from parent radioelements existing in the rock pores in the immediate vicinity of the wells. TaBL® 9.-Isotopic composition of radium in brines from two wells in the Pandandle field [Analyses by J. N. Rosholt, Jr. The data are expressed in terms of the equivalent amounts of uranium and thorium that would be in equilibrium with the observed concentrations of their respective radium daughter products (Rosholt, 1954)]. Milligram equivalents per liter Isotope Well 455 _ Wel 816 Rath: clin ni roe Nid ened. ses 4. 23 0. 096 Rats.. c anu cenas seesen 5.1 . 04 Ras L bl eL NELL CRL - saan 1.7 . 037 RaML._L LL. cie AN ruil. al ces ive: . 026 The ratio of Ra and Ra is 0.40 for well 455 and 0.39 for well 316. These values should approximate the ratio of thorium to uranium at the source of the radium. URANIFEROUS ASPHALTITE The search for the parent radioelements of the radon and helium in the Panhandle field resulted in the dis— covery of a uranium-bearing carbonaceous material, G34 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY OKLAHOMA 91 P4" on R z'g k,s~ E pAL # 0 Duro I lud i matTADOR I | 0 _ Panhandle Field € UPLIFT | BAS Ya se~ UPLIET 50 MILES Ne peut d ~ EXPLANATION eral.. Outline of major uplift Location of wells in which uraniferous asphaltite is in rocks of Permian age Only part of the known occurrences in the western part of the Panhandle field have been plotted FIGURE 8.-Regional distribution of uraniferous asphaltite in the Texas Panhandle and adjacent areas. termed "asphaltite," in drill cuttings of the reservoir and cap rocks of the gas field. The asphaltite is a metalliferous carbonaceous min- eraloid that occurs as botryoidal nodules and impreg- nations filling secondary pore spaces and fractures. It is a black solid brittle, highly lustrous substance, com- bustible at high temperatures and insoluble in organic reagents. The hardness ranges from 4 to 5, the aver- age specific gravity is 1.3, and the index of refraction is about 1.7. The asphaltite is enriched with arsenic, uranium, cobalt, and nickel. Autoradiographs indicate that the uranium is rather evenly distributed throughout the asphaltite, whereas studies of polished surfaces indicate that the arsenic, cobalt, and nickel are present in min- eral inclusions finely disseminated within the asphaltite. X-ray analyses of the asphaltite have shown the pres- ence of uraninite, chloanthite-smaltite, xenotime, anhy- drite, pyrite, dolomite, celestite, quartz, and graphitic carbon. Erythrite, the hydrous cobalt arsenate "bloom," has been observed on one sample but it had evidently formed after the sample had been obtained from the well. Uranium-bearing asphaltite is present throughout the stratigraphic sequence studied as part of this investi- gation. It is sparsely disseminated throughout the URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS lower part of the "Brown dolomite," "Moore County lime," "granite wash," and fractured parts of the Pre- cambrian complex. - It is most abundant in drill cuttings from the "Red Cave" and the upper part of the "Pan- handle lime." Plate 2 illustrates the distribution of asphaltite in the western part of the Panhandle field. Uraniferous asphaltite has also been observed in these rocks where they are exposed along the north flank of the Wichita Mountains (fig. 8), in drill samples from numerous wells along the north side of the uplift, and from wells in the Palo Duro basin. Of possible genetic significance is weakly uraniferous organic material in oil-producing dolomites and shales of the upper part of the "Panhandle lime" in the Anton oil field in the Palo Duro basin (well 7, fig. 9). The dolomites and black shales contain graptolites and other fossil marine-plant remains throughout a thickness of 400 feet. Some samples of the plant remains contain as much as 30 ppm uranium. These organic materials have been deposited in the same carbonate-evaporite sequence in which the Panhandle asphaltite occurs and may represent the type of materials from which the asphaltite was derived. NOMENCLATURE A variety of names have been introduced into the literature dealing with the solid forms of carbonaceous substances, especially substances enriched in heavy met- als. Terms that have been used to describe carbona- ceous materials enriched in uranium are: "huminite," "thucholite," "carburan," "anthraxolite," "carbon," "hydrocarbon," "bitumen," "pyrobitumen," and "as- phaltite." Serious objections can be raised to the use of any of these terms. Use of the words "carbon" and "hydrocarbon" conflicts with their definitions in chem- ical terminology. The words "thucholite" and "car- buran" indicate a more specific association of elements than is present in many localities,. The generic terms "huminite," "anthraxolite," "bitumen," and "asphaltite" imply that the substances were derived from definite source materials, which has in no case been demon- strated. In addition to these terms, geographic and personal names have been applied to these types of sub- stances, such as: "albertite," "grahamite," "elaterite," and "gilsonite." No single convenient name embracing all these mate- rials has been widely accepted. The confusion of no- menclature results from the fact that little is known about the origin of these substances and the nature of the chemical compounds which compose them. Sys- tems of classification based upon their physiochemical properties and ultimate chemical compositions such as Abraham's (1945, p. 56-59) have, thus far, proved to be G35 inadequate. In a mineralogical sense, the substances can be grouped together as carbonaceous or organic "mineraloids." This term, revived by Levorsen (1954), was originally introduced by Rogers (19837, p. ix) who defined it as follows: "Naturally occurring amorphous substances with chemical compositions and physical properties less definite than those of crystalline miner- als are considered as mineraloids." It is informative when describing these types of ma- terials to modify the description with some petrologic term describing their shape or their relation to the host rock, Most solid carbonaceous mineraloids occur either as nodules, as vein or fracture fillings, as impregna- tions, or rarely as lenses, layers, or pseudomorphs. The nodular variety is the most characteristic form of oc- currence of the uranium-bearing carbonaceous miner- aloids. The nodules frequently possess a botryoidal or warty surface, and in the writers' experience no nod- ules of this kind have proved to be nonuraniferous. In the absence of detailed knowledge regarding the chemistry of these substances, some term of common usage is desirable. In this report, the word "asphaltite" is used as a general term embracing all solid amorphous dark, apparently homogeneous carbonaceous mineral- oids that are physically distinct from surrounding ma- terials. It is in this sense that "asphaltite" has been used as a mineralogic field term in a large volume of literature, and its continued use would appear to be justified. Although the word suggests an asphaitic or petroliferous source material, such a source is not in- consistent with the observations and conclusions con- cerning the materials described in this report. REVIEW OF THE LITERATURE Many occurrences of carbonaceous nodules that are enriched in different metals have been reported in the literature. The most unusual of these occurrences is, perhaps, the nodular thucholite found in pegmatites of Precambrian age of the Parry Sound area, Ontario, Canada. Ellsworth (19282) was the first to make a de- tailed study of these nodules. Analyses showed them to be enriched in thorium, uranium, vanadium, and rare earths; the chief organic constituents were carbon, oxy- gen, and hydrogen. On the basis of its chemical compo- sition, Ellsworth termed the substance composing the nodules "thucholite." Repeated analyses showed that the chemical composition was variable and that the ma- terial was not a single mineral but apparently a mixture of compounds. Because of the nature of its physical oc- currence, Ellsworth believed the thucholite to be a pri- mary mineraloid formed through reaction of uranium and thorium with carbonaceous gases escaping from a granite magma. However, a subsequent examination of SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY G36 'szoq3o pus [Teg oye poytpow) 'xo, '4junogy Aapyoof; 01 "xo.p, '44uno; TOI} OJ}JBWIUICISEI(-*6 ZUADLT (0§61) s1ayzo pue jeg saye paippop NVIddISSISSIW NVIOIAOGHO | NVINWATASNN3d NVIW43d ANVILY3L DISSVINL guoz jing} 1ofew pauayuj Js. dnog 1a8inquaj{3 papiaipup) toy. dnoig pusg umens dnog uofuegy ______dnoup casiq _ seuag dweo;joM dnoug eyyolm dnouy 4104 12919 auopspueg ojaS8uy ueg auo;sawn] saipuy ueg (papiaipun) ueiuiag go ued 1addp P E ene fn papiaipup papiaipup _ ALNNOQ AHTHXDOH A _ WU J/J Ari10juooun aofew pauajuj 2 NYIOIAOGHO z pes O? j Ld4174N Y¥OUVLYW aljeudse snowsyuein Auiuiojuoosip 10few paiiayu| \}\/\\I\ NOILY NYTA X3 yjim pozijeauiu sjeiaqu| S37IW ST OT § NISYA ound O1¥vd NVIHEWYVO3Hd I NYIOIAOQHO NVIddISSISSIW dnog umen$§ dnoig uofuegy dnoig oostq NYINYATASNN3G seuag dweo/oy dnoig eyyoim dnoug 4104 12919 ojeSuy ueg 1 jleqdweo arguing mig a 13431 ¥3S I 8 £ t yomyeq arquiny ALNNOD ALNNOQ TVH o queaied pz°z ~moys sey auojsawl7 seipuy ueg ueruuag Jo ued saddp OISSVIHL ANVILHTL () 4m a9ejing 5p 1 Auuepy og-y sumig 1 ojjuewy Aip sgid areis19uj ojop oop __ WHSN ALNNOD HHHSIMS ALNNOD OXLSYO op jussued 56'T keg/mobAerwn g AS é ALNNOY TIYVCNYH spaq jo aylus uo pajoslod ejep {|2M uonoas uo pazedo| eep wearer Poros v 9 NOILO3S 10 0 QONY S3ILNNOQ ONIMOHS X30NI I 311W 0G 6 xflmflnuion: 3 OOT gi=< -_ siv | BWV mm 002 (ya I uzzw ousts - [8 1333 mfl --L__ qpvany/wims svsa Ym (szflGm/fi iC H bees WEI nyiro ___ prory ajpueyuey g ¥ ) syxau_ _ gC __ N »°____ 3W0G0 HSNng 14740 -WNYO3 juajeainba dnoug uosduwilg 4 ALNNOY MHLLOd 0109 Hd > a 9 & o & ® ® w o £ D I /< -z ysng g-6 uosiarsepy _ V#-1W9A ALNNOYD URANIUM AND HELIUM IN THE one of the pegmatites of the Parry Sound area by Spence (1930) revealed the presence of petroleum and asphalt seeps within the dike. Spence noted that the thucholite in the dike was most abundant in proximity to cross-fractures containing the oil and asphalt seeps. The thucholite nodules were in many places associated with pockets of minerals containing uraninite and also occurred as pseudomorphs in which thucholite appeared to have replaced uraninite. Other relationships in- cluded veinlets of thucholite cutting fractured minerals. Spence suggested that the thucholite had been formed from petroleum which had seeped into the dike and had been polymerized by the effects of radiation from ura- nium and thorium minerals to form the nodules. Thucholite, apparently similar to that described by Ellsworth and Spence, has since been reported from a large number of localities on the Canadian shield. Ellsworth (1928a, b) originally reported thucholite from four widely separated localities in eastern Canada. A tabulation by Lang (1952) mentions the presence of thucholite in a number of uranium districts on the Ca- nadian shield of Saskatchewan and the Northwest Ter- ritories, Canada. The thucholite is reported to occur in quartz veins, frequently with pyrite and pitchblende; however, no detailed studies have been made of it in these areas. Uranium-bearing carbonaceous nodules similar to thucholite have also been reported in pegmatites of Karelia, Russia, where the material has been termed "carburan" (Labuntsov, 1939; Grigoriev, 1985). A "carbonaceous uraninite" from a granite pegmatite in Fukuoka prefecture, Japan, has also been described (Kimura and Iimuri, 1937). Uranium-bearing carbonaceous substances have been known for nearly a century in Sweden where they have been described by a number of investigators. A review of the data of this early literature is given by Davidson and Bowie (1951). Grip and Odman (1944) have described thucholite nodules in quartz lenses and veins in Precambrian anda- lusite rocks at Boliden, Sweden. Drill holes in the vicinity of the thucholite nodules discharge unusual amounts of helium-rich hydrocarbon gases. Analyses of the gases from a number of drill holes showed they contained from 2.3 to 5.4 percent helium, 22.9 to 36.6 percent nitrogen, 59.6 to 68.8 percent methane, and small amounts of carbon monoxide, carbon dioxide, hydrogen, and hydrogen sulfide. Grip and Odman proposed that the thucholite nodules had resulted from polymeriza- tion of the hydrocarbon gases by radiations from ura- nium minerals. The thucholite or uranium-bearing carbonaceous ma- terial in the Witwatersrand reefs of South Africa is eco- G37 nomically the most important deposit of this type known. A study of this material as well as of similar materials from several occurrences in Australia, Eng- land, and Canada was made by Davidson and Bowie (1951) , who concluded that the "hydrocarbon-uraninite complexes" had been formed as the result of polymeri- zation of hydrocarbon gases by radiation from previ- ously deposited uranium. Analysis of a gas from faults in underground workings in the Witwatersrand reefs showed 8.3 percent helium, 13.9 percent nitrogen, 76.6 percent methane, 0.5 percent argon, 0.2 percent oxygen, 0.4 percent carbon dioxide and 0.1 percent hydrogen (Bowie, 1958). Hess (1922) reported uranium-bearing nodules in sandstones of the San Rafael Swell, Utah, and regarded them as being of detrital origin. Later Gott and Erick- son (1952) suggested that the uranium and other metals present in these nodules had been introduced by petroleum. From a reconnaissance study of uranium and trace metals in crude oil, asphalt, and petroliferous rocks, Erickson and others (1954) showed that uranium and a characteristic suite of other trace metals, notably nick- el, vanadium, cobalt, copper, zinc, and lead, were con- sistently associated in the ashes of crude oil, asphalt, and asphaltite from many different localities. The greatest enrichment of these metals in the petroleum was found to be in the heavy surface-active fraction which adheres to the surface of the rock. The results suggested that petroleum might be an important agent in the formation of some types of uranium deposits, but the authors pointed out that further research on the nature of metallic compounds soluble in petroleum was required to evaluate the significance of petroleum as a possible transporting agent of these metals. Uraniferous, but noncarbonaceous, nodules that are similar in several respects to those occurring in red beds of the Texas Panhandle field have been found in red beds of Permian age of Great Britain, and have been studied by a number of investigators (Carter, 1931; Perutz, 1939; and Ponsford, 1954, 1955). As originally described by Carter (1931), these nodules occur in red marlstones, and consist of a hard, black nucleus sur- rounded by a bleached greenish-white halo. Concentric black bands are often present in the bleached area, and a photograph by Ponsford (1954) shows the presence of well-developed liesegang rings surrounding the nucleus of a nodule from a core sample. Analyses of these nod- ules (Carter, 1931) show that the black nucleus con- sists of a silty matrix that is enriched in vanadium, uranium, cobalt, and nickel. Niccolite (NiAs) was identified in the nucleus, and analyses of the red and white parts of the rock by Perutz (1939) indicated PANHANDLE GAS FIELD, TEXAS G38 - that ferric iron had been removed from the bleached halos and redeposited at their external boundaries. Uraniferous nodules that are similar to those de- scribed above also have been reported in red mudstones of the Sibley Series of Precambrian age in Canada (Tanton, 1948). Still another occurrence may be pres- ent in the red beds of Permian age of Saxony, Germany (Schreiter, 1925), although the presence of uranium was not investigated. These occurrences are of interest with respect to the uraniferous nodules described in this report in that they suggest that uranium, vanadium, nickel, cobalt, and arsenic may be deposited in red beds of lithology similar to those described here without the aid of an organic medium. PHYSICAL PROPERTIES The uraniferous asphaltite in the Panhandle field oc- curs in intergranular secondary pore spaces and frac- tures. Morphologically, two varieties of asphaltite are present: relatively large nodules as much as 1 inch in diameter characterized by irregular and botryoidal shapes, and small nodules that are characterized by high sphericity and are generally less than 0.1 mm in diameter. Nodules 1 to 3 mm in diameter constitute most (by volume) of the asphaltite seen in the drill cuttings (table 10). The most numerous nodules, how- ever, are less than 0.1 mm in diameter (table 11). TABLE 10.-Size distribution of asphaltite nodules from the reservoir and cap rocks of the western part of the Panhandle field Nodules Diameter (millimeters) Lithology Total | <1 1-2 | 2-3 | 3-4 | 4-5 Distribution (percent of total) Limestone, anhydrite, dolomite........... 324 93 3 3 1 0 Sandstone, siltstone............. 279 94 4 2 0 1 (ATROSE : u LUSI eL e eel noice recess eau ae 107 93 6 1 0 0 'Total or average............_....._L 710 94 4 2 1 1 Asphaitite ..:._.._...... volume percent..|........ 6 26 59 4 5 Tapur 11.-Fine-size distribution of asphaltite nodules from the reservoir and cap rocks of the western part of the Panhandle field Nodules Diameter (millimeters) Lithology Total | <0.1 | 0.1- | 0.2- | 0.3- | 0.4- | >0.5 0.2 | 0.3 | 0.4 | 0. Distribution (percent of total) Limestone, anhydrite, dolomite.... 302 43 19 12 6 6 14 Sandstone, siltstone................ 264 48 19 12 5 3 13 EEE TEAS. Pouce ee 101 41 17 15 12 6 9 4 No co: Mees seen pean Se Fell 667 45 19 12 7 5 12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY The large nodules are formed through intergrowth of many small ones as is shown by figures 10 and 11. The numerous small nodules are of approximately the same dimension as the pores of the rocks in which they occur. This similarity indicates that the asphaltite originated as dispersed globules or films of an organic fluid which had permeated these rocks. The veinlet type of asphaltite likewise consists of a series of small and closely packed nodules along the length of the veinlet (fig. 11). The specific gravity of the nodules ranges from 1.26 to 1.53 and averages about 1.3 (table 12). The range in specific gravity is due to variations in metal content. When the weight that can be attributed to the average metal content of the nodules is subtracted from their average specific gravity, a residual specific gravity of about 1.1 is obtained which probably represents the density of the organic phase. FicurE 10.-A, Dense anhydritic oolitic dolomite from the 'Red Cave" containing disseminated nodules of asphaltite, well 825a. X 9.8. B, Asphaltite nodule from the "Red Cave" showing botryoidal structure, well 832. X 5. * PANHANDLE GAS FIELD, TEXAS - FiGurRE 11.-Asphaltite in porous crystalline dolomite from a major gas-producing zone in the "Brown dolomite," well 623. A, Veinlets filled with closely packed asphal. tite nodules. radon emanated from the pores. Polished-section studies indicate that the asphaltite has a variable hardness ranging from 4 to 5 on Mohs scale. Most of the nodules break with a conchoidal or platy fracture, but some fracture along radial or con- centric lines. The carbonaceous matrix of the nodules is neutral gray in reflected light, slightly pleochroic in reflected polarized light, and moderately anisotropic. Amber-colored internal reflections originating from metallic minerals buried just below the plane of the polished surface are common within the carbonaceous matrix. When finely powdered, the material transmits amber light at thicknesses of less than 2 microns, and the index of refraction averages about 1.7. COMPOSITION AND MINERALOGY Approximately 90 percent of the uraniferous as- phaltite is composed of carbon, hydrogen, and oxygen ; the remainder consists chiefly of metals, notably arsen- ic, uranium, nickel, cobalt, and iron. X 4.9, B, Autoradiograph of A on alpha-sensitive film. Sharply bounded black areas are due to uraniferous asphaltite, and diffuse areas are due to (Exposure time 8 weeks.) C, An enlarged part of A showing relation of asphaltite (as) to residual oil. part of A show ing apparent replacement of chert (c) and dolomite (d) by asphaltite (as). X 12.6. D, An enlarged X 12.6. Tasos 12.-Specific gravity and size of some asphaltite nodules from drill cuttings, western part of the Panhandle field Nodules Well (pl. 1) Specific Mean Weight | gravity in | diameter (mg) toluine at (mm) 0. 279 | 1. 3340.02 0. 67 . 389 | 1. 3340.02 74 .812 | 1. 5840.02 1.09 1.231 | 1. 3040.02 1. 37 1.815 | 1. 2640.02 1. 68 . 634 | 1. 3440.02 |_____._.__._. 198. 1. 32-£0.09 Organic analyses show the asphaltite to be made up of 78 to 80 percent carbon, 3 to 6 percent hydrogen, more than 3 percent oxygen, and as much as 0.43 per- cent nitrogen (table 13). The presence of oxygen and nitrogen suggests that the organic source material of the asphaltite consisted in part of complex organic compounds as well as hydrocarbons. The most prob- G40 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TaBu® 13.-Organic analyses, in percent, of asphaltite nodules from the western part of the Panhandle field [Analyses by Clark Microanalytical Laboratory, Urbana, I11.] Elevation Sample | of sample Hydro- Well (pl. 1) (table 14) igtel‘val Stratigraphic unit Lithology of host rock Ash Carbon gen Oxygen | Sulfur | Nitrogen above sea level (feet) .- el 3 | 1492-1462 | "Red Cave"..._____.. Siltstone cemented with second- 5.39 77.63 3.59 3. 41 0. 00 TE. ary anhydrite. 18 | 1292-1262 | "Panhandlelime".._.| Medium-grained oolitic dolomite 10. 93 79. 86 |L o Voort gexfiented with secondary anhy- rite. LN CUs Cen en 'Red Cave".......... Shales 0.044 s 10. 97 79. 88 5: BL |- neces ol dvs . 43 able source of oxygen- and nitrogen-bearing compounds are asphaltenes, resins, and organic acids found in petroleum and associated brine. Petrographic and X-ray studies suggest that the uraniferous asphaltite has formed from a nonuranifer- ous red organic material with which it sometimes oc- curs. The spatial relation of these two materials is shown on figure 124 where a veinlet of the red organic material, which is highly fluorescent, grades into urani- ferous asphaltite. Secondary anhydrite occurs inter- stitially with uraniferous asphaltite but not with the red organic material. The paragenetic sequence sug- gests that the asphaltite has formed from the red or- ganic material and implies that the uranium was intro- duced by the aqueous solutions from which the anhy- drite was deposited. The manner in which the red organic material occurs suggests that it was adsorbed from oil or precipitated from brine that permeated the rock. A study of its chemical properties by X-ray diffraction and infrared spectroscopy indicates that it is related to the uranifer- ous asphaltite. X-ray studies of both the red organic material and the uraniferous asphaltite show the diffuse halo pat- terns characteristic of armorphous: carbonaceous sub- stances. Two sets of diffraction halos are present in X-ray powder patterns of both materials. One set of halos has "d" spacings of 3.4 and 2.0 angstroms and is attributed to graphitic carbon (for example, see Clark, 1955). The other set of halos have "d" spacings of about 4.8 and 2.2 angstroms that correspond to the ex- pected spacings for halos produced by aliphatic C-C bonds with lengths of 1.54 angstroms (for example, see Simard and Warren, 1936). This set of halos is more intense in the red organic material than in the uranifer- ous asphaltite ; the relation suggests that these structures have been partially destroyed by radiation damage dur- ing conversion to asphaltite. Infrared analyses of the uraniferous asphaltite and the red organic material also indicate the presence of aliphatic structures (Pierce, Mytton, and Barnett, 1958). Both materials contain infrared absorption bands that are due to aliphatic carbon-hydrogen groups. A possibly significant feature of the infrared patterns is the presence in both materials of weak carbonyl absorption bands which suggests that the materials may have been derived in part from organic acids or esters occurring in the petroleum and petro- leum brine. These types of compounds often possess strong polarities and are attracted to oil-water and oil- mineral interfaces (for example, see Bartell and Nieder- hauser, 1946). Significant concentrations of arsenic, uranium, cobalt, nickel, and iron occur in the asphaltite (table 14). Cop- per, silver, lead, vanadium, bismuth, molybdenum, and rare earths are enriched to a lesser degree. X-ray crystallographic identifications show that the asphaltite contains anhydrite, dolomite, celestite, quartz, uraninite, chloanthite-smaltite, xenotime, pyrite, and graphitic carbon. (See table 14.) The identifications conform well with the spectrographic data inasmuch as the most frequently occurring metals in the asphaltite constitute the minerals identified. Other metallic min- erals that have been observed in intimate association with, but not as inclusions in, the asphaltite, are galena, sphalerite, chalcopyrite, and native copper. A few nodules from the "Red Cave" are composed largely of smaltite-chloanthite with minor amounts of asphaltite. Tiny isolated cubes of skutterudite ((Co,Ni) As,) were found in one core sample of hematitic shale from the "Red Cave." URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS GHA1 FIGURE 12.-Relation of anhydrite and nodular asphaltite to red organic material in oolitic dolomite from the "Panhandle lime," well 825a. A, White-light photograph of anhydrite (An) and nodular asphaltite (As) in oolitic dolomite. X 11.7. B, Ultraviolet light photograph of specimen A showing asphaltite (As), anhydrite (An), and fluorescent red organic material (white). X 10.7. C G42 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 14.-Spectrographic, radiometric, and X-ray crystallographic [ Spectrographic analyses by A. T. Myers and P. J. Dunton, radiometric analyses by J. N. Rosholt, Jr.; X-ray crystallographic analyses by W. F. Outerbridge and Evelyn Cisney, all with the U.S. Geological Survey. 'The elements are arranged according to their periodic chemical families (Moellar, 1952). Elements which were detected , but not listed in the table are: 0.0x- Gd and 0.000x- Be in sample 4; trace of Nb in sample 11; 0.0x Ge in sample 26; 0.0x Zn, 0.00% Sn, and 0.000x Ga in sample 27; and 0.000x+ Ga in sample 28. The analyses were made with substandard amounts of sample. eU, equivalent uranium, is defined as "the ratio of the net counting rate of Sample interval Sample Well | (elevation Stratigraphic unit Na K Cu Ag Ca Mg Sr Ba Se Al B Ti (pl. 1) | above sea level, in feet) 231 | 1338-1328 | "Red Cave"..____._.____... 0 0 0.0x+ | 0.000x- | x.+* 0. x 0.00x | 0. x- 0 x. 0 0.0x- 751 |+1 1629-1609 |----- 10. . .cc seee dene ades 0 0 .Ox .000x- | x. 0 00x | 0 'X 0 .00x+ 825a | 1492-1462 |----. AO: aso * 0 . 00x+ | .000x~ +X {X= .000x | .00x+| .000x+ %* 0 L= 887a | 1408-1398 |----- (10. ec ee eee 's 4 .xt 1... 0% .0000x+ | . x- x* .00x- | . Ox . 00x x~ .00x+ | . x+ 487 | 1 1499-1169 “Ifged pave,” "Panhandle | .x- | 0 .0x% | 1 Tr. xz Ko < .0x- . Ox+ .00x- o < Ir. .Ox ime." 699a | 1 1445-1275 0 .Ox Tr. x: -X .00x 00x | 0 .Ox 0 Ox 739 | 1 1565-1385 0 . Ox+ .000x+ | x. . X+ .00x .00x | 0 -K 0 0x~ 815 | 1 1441-1081 0 . Ox .000x+ | x. x~ 0 | :0 +K 0 0x 871 | 1 1412-1142 0 :% .00x Xx. x- .0x~ .00x+ | 0 +X . 00x Ox+ 890a | 1535-1345 ) 1%" 0 Xx. X 0 00x | 0 JX 0 0x- 20b 677-667 0 0x~ 000x- . 00x 000x | 0 . 00x . 00x .0x- .00X~ | s. x~ 736 987-977 0 . 00x 000x . Ox .00x | 0 .000x | 0 . Ox 0 . 000% 736 | 1 1097-907 0 . 00x 000x x. * < .Ox .Ox 0 ~a . 00x .00x 748 1542-1532 0 .00x | 0 .X .Ox 00x .00x | 0 . Ox 0 . 00x 814 1199-1189 0 . 00x 000x X .0x 0x .00x | 0 .Ox 0 . 00x 814 | 1 1480-1389 0 .Ox 0 x. + -X 0 .00x- | 0 * < 0 Ox+ 818 | 1 1477-1367 0 .Ox .000x- | xx. «K .0x .Ox+ | 0 o 0 0x- 825a | 1292-1262 0 .Ox .000x+ | x.~ "& .00x+ | .00x+| Tr. 0 .Ox 843a | 1 1446-1206 0 O0x+ .000%- | xx. . 00x .00x | 0 .X 0 .Ox 874 | 1 1269-1220 0 Jxt .000x+ | x x+ 0 .00x~ | 0 0 . 0x 894 | 1 1461-1361 0 x." .000x+ | xx. x. . Ox+ | 0 X . 00x . Ox 806 | 1268-1258 0 . Ox . 000% x. D 3 .Ox .00x | 0 Xx Tr. . 0x 897 1408-1398 0 . Ox+ .000x- | x. X Ox+ .Ox+ | 0 w < 0 . Ox 897 | 1388-1378 |----- 10.2. s 0 0 .00x | 0 x: Ox * x 0 Ox 0 . 00x 748 | 11542-1052 | "Panhandle lime," "Brown | 0 0 . Ox 0 x.~ x+ O0x+ Ox 0 »Kt 0 . 00x+ dolomite." 487 899-889 | "Brown dolomite"......---- 0 0 0 0 X. '0x~ 0x~ .000x | 0 .Ox- .00x+ | . 00x $90 1 « |. 20 -case ener steven t IS . Ox Tr. %: %. +X x. . 00% x. 0 +X 231 | 1628-378 | "Brown dolomite," "Moore | .Xx* | x.~ .00x+| .000x-~ | xx. xx. .0x- ;0x" .000x+ | x.+ .Ox- «Xt County lime." 1Composite sample. 2 Consists of heavy asphaltic coatings. The X-ray diffraction films of 17 asphaltite samples and the trace metal content of the samples indicate that chloanthite-smaltite and possibly uraninite are consist- ently present as mineral inclusions, but in variable crystal sizes and amounts. Both the crystal sizes and the concentration of the crystals limit the intensity of the diffraction pattern recorded. - Mineralographic studies indicate that the crystals range gradationally from approximately 2 microns to a dimension below the resolving power of the microscope. Measurements of the uraninite lattice constants in several X-ray diffraction patterns of the asphaltites all gave cell edges of 5.46 angstroms; this measurement corresponds to uraninite composed of pure uranium oxide (UO;) (Katz and Rabinovitch, 1951). Three varieties of dispersed metallic mineral inclu- sions are seen in polished surfaces of the asphaltite nod- ules. The most abundant of these mineral dispersions generally form "nebular" patterns concentric to the center of the asphaltite nodule as is shown in figure 13. The individual crystals, probably chloanthite-smaltite, have a brassy luster and range in diameter from 1 to 2 microns to a dimension below the resolving power of the microscope. Exposure of the polished surfaces of the nodules to nuclear emulsions shows that the areas of these dispersions are less radioactive than the rest of the nodule. Figure 134 shows a sample containing a high concentration of the mineral inclusions. When this sample was coated with nuclear emulsion, almost no alpha tracks were recorded above the central metallic URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS aas analyses of asphaltite nodules from the western part of the Panhandle field a sample to the counting rate per percent of a uranium standard in equilibrium with all of its disintegration products, both 'measured' under similar geometry'" (Rosholt, 1954). Mineral identification was based upon X-ray diffraction patterns obtained from sample splits. x+., x., and x.~ means 4.64 to 10, 2.15 to 4.64, and 1.0 to 2.15 per- cent respectively; 0.x+, 0.x, and 0.x- means 0.464 to 1.0, 0.215 to 0.464, and 0.10 to 0.215 percent respectively, and so forth. p, present as indicated by uranium flux test, but in amounts too small to be detected spectrographically. Zr Si Pb v AS Bi Cr Mo Mn Fe Ni Co ¥ Yb U eU Minerals identified OyOK (- 0 x: x, 0.0x- | 0.00x- 0.0x- | 0.00% (2.3 0. x 0. x+ OK : p 0.15 Quartz. [ss. .Ox 0 K7 .00x+| .00x- 0 .00x+ .Ox K xf 0 0 p . 34 Submicrocrystalline carbon, quartz. O0x- x.0 . 03 0% -1 X.~ . 00x .000x+ | 0 . 00x+ .0x . Ox+ .Ox- . Ox . 00x vG 09 -se Uraninite, quartz. Ox x.t . Ox+ . Ox XXx . Ox+ . 00x .00x+ | . 00x+ xt {gt o 4 «K 10x a KEL Pec ous Chloanthite-smaltite, quartz, pyrite. .000x+ | x. 0x- x- xx: 0 0 .00x+ | .Ox- x~ x* x+ . Ox+ . 00x $0. Salmplés was not ana- yzed. 0 0 x. 0 0 Re Sul .00x- | x. x= . Ox+ . 00x Bus Mec Do. . Ox 0 x.= Ox .00x- 0 . 00x+ x~ 6 4 * .0x- .00x- p A1 Celestite, quartz. 0 0 X~ .00x+| .00x- .00x+ ) . 00x . Ox+* Fo 9 n 0 0 p .18 Quartz. .0x- | x.+ .Ox .000x . 00x . 00x +3 x. ~ to < . Ox+ .00x v* .21 Quartz, anhydrite. .Ox+ | 0 x; .0x .00x- 0 . 00x . Ox+ D sal Vx= B: . 00x Tr. 04 Quartz. . 00x 00x | xx. 0 .000x 0x .0x- i%- % «& . Ox .00x- §-10 : Sample was not ana- yze Os Cen Tr. 0 0 Tr. 0 0 00x Ox . 0x 00x | 0 0 2 Bc Do. 0 . 0 x . 00x . 000x Tr. .00x x . Ox . Ox 0 T. p . 01-0. 1 Do. 0 0 .00x | 0 0 . 00x 0x . Ox . Ox 0 0 p As.4 Do. 0 Tr. x .00x | 0 . 00x . 00x x -x .Ox .00x | 0 7 ay Do. 00x+ 0 x.~ 0x= .00x- 0 . 00x x- ag .0x+ | 0 0 . Ox 45 Quartz, anhydrite. 00x- 0 x* NU s .00x- .0% .00x+ x xt Kt x~ . 00x s 4 13 Submicrocrystalline carbon, quartz. . 00x+ x. 00x+| .00x- . 00x 0x~- SS . Ox+t 0x+ x* .0x- $. N1. ea Uraninite, quartz, chloanthite-smaltite. 0 0 x. «- .00x- Tr. .00x- x x+ . xf Ox .00x- Tr. 26 Uranintite, dolomite, quartz. of 0 .00x+ | x. + .Ox+ .00x- .00x+ | .00x+ %" x~ x+ 0x~ 00x- :g* 33 Chloanthite-smaltite, dolomite. 200X ._. .Ox- .00x | x JX: . 000x+ . 00x xe o. :% .Ox 00x- X 35 Dolomite. 0 da Fas sats | Tr. .Ox 0 . Ox . 00x x x to. 4 94 0 1.6 1.5 Salmplg was not ana- yzed. 200K {-~ 0 0 xx. ~Oxt. | .0x~ | .000x+ xs x.: . x+ . 00x+ x+ 45 Xenotime. 0 x. 00x | 0 x. . Ox 0 . 00x . 000x Ox x . Ox .Ox 2 2 Saimplg was not ana- yzed. s 0 0 + Ox: 00x- 0 .00x- xt «X~ . Ox+ .00x+| .000x+ | p 2 Dolomite. .000x+ Ox+ | 0 .0x 0 0 .00x 0 0 Ox+ | 0 0 0 (Peep / Naib Salmplg, was not ana- yzed. .00x x: . 00x .Ox 0 0 .Ox 0 .x xx. .Ox .Ox 00x | 0 pesce I Eels eve Do. »OK tics esen. 0x- .0x- | 0 0 .Ox 0x~ 0x= A .Ox .00x-| .00x 000% p . 019 Quartz, dolomite. part of the nodule, although numerous alpha tracks originated from the surrounding organic material. Another type of fine-sized mineral segregations in the nodules are patchy areas that appear to be made up largely of fine mineral-filled capillaries or pores (fig. 144, B). The capillaries are tubular in shape, about a micron in diameter, several microns in length and are systematically arranged. Minute metallic mineral fill- ings are visible in some of the capillaries, and scratches originating in the vicinity of these areas indicate that polishing has removed minerals from them. Nuclear emulsion exposures indicate that the metallic fillings are radioactive and may be uraninite. These areas re- semble the "fingerprint structure" of the nodular thu- cholite of Boliden, Sweden, described by Grip and Od- man (1944), and are similar to features noted by the writers in a botryoidal "thucholite" nodule obtained by Henry Faul from a diamond-drill core of rhyolite from the Sudbury district, Ontario, Canada (fig. 14 C, D). X-ray diffraction patterns of the Sudbury nodule indi- cate the mineral inclusions present in the capillary structures of this specimen to be composed of uraninite and coffinite. The capillary structures of the Sudbury nodule are more extensive than those in the Panhandle nodules and occupy nearly the entire volume of the nodule. The uranium content of the Sudbury nodule is also greater, being approximately 6 percent as com- pared to an uranium content of approximately 0.2 per- cent in the Panhandle nodules represented by figure 144, B. G44 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 13.-Polished sections of asphaltite nodules showing "nebular'' dispersions of smaltite-chloanthite(?). well 8252. A third type of mineral inclusion is crystal frag- ments of pyrite in the peripheral parts of some of the asphaltite nodules. The erystals were fractured and floated apart in the asphaltite prior to its solidification, as is shown on figure 15. The uraniferous asphaltite nearly always occurs in or is intimately associated with secondary cements in- cluding anhydrite, celestite, and to a lesser degree silica, pyrite, residual oil stains, and asphalt. It is most com- monly associated with secondary anhydrite which fills pores (fig. 164, B) or fractures (fig. 17) or which oc- curs as intergranular cement in siltstone (fig. 172). X 81. B, Nodule from "Panhandle lime," well 897. X 57.7. Dark field illumination. A, Nodule from "Red Cave," C, Enlargement of a part of B. X 94.5. The close association of nodular asphaltite with see- ondary anhydrite suggests that it was formed contem- poraneously with the introduction of sulfate-bearing solutions. Both asphaltite and anhydrite fill fractures and solution cavities and thus clearly formed after con- solidation of the rocks. Many of the asphaltite nodules appear to replace the host rock, particularly the dolomite (figs. 104, 11). The nodules may have formed by a process of molecular replacement of the surrounding rock but more prob- ably were deposited in a cavity that was continuously enlarged by solution around the periphery of the nod- URANIUM AND HELIUM IN THE «oren. F A, Nodule from the "Panhandle lime", well 897, showing "capillary" structure and shrinkage cracks. X 920. H | i I C P fi’l‘ £ C, Nodule from a drill core of rhyolite, Sudbury district, Ontario, Canada, showing*'capillary" structures and shrinkage cracks. X 920. G45 PANHANDLE GAS FIELD, TEXAS B, Nodule from the' Panhandle lime", well 897, showing systematic arrangement and tubular shapes of "capillary" structures. X 920. D, Nodule from a drill core of rhyolite, Sudbury district, Ontario, Canada, showing systematic arrangement and tubular shapes of capillary structures. X 920. FIGURE 14.-A comparison of "capillary" structures in asphaltite nodules from the west Panhandle field and the Sudbury district, Ontario. FIGURE 15.-Cataclastic pyrite crystals in an asphaltite nodule from the "Panhandle lime," well 897. Dark-field illumination. X 204.5. ule. Experiments by Royer (1930) have shown that crystals of dolomite, calcite, and calimine undergo cor- rosion in the presence of petroleum and several natural organic acids derived from petroleum including naph- thenic and phenolic acids. It seems possible that the replacement effects could be the result of a similar process. Many of the nodules that occur in the shale of the "Red Cave" are surrounded by green halos which con- trast sharply with the red shale (figs. 184, 2). The color change is evidently due to reduction of ferric oxides. Anhydrite nodules surrounded by green halos were also observed in red dolomitic siltstones of the "Red Cave." An X-ray analysis of one sample showed that the rock composing the halo consisted of quartz and clay minerals, whereas the rock beyond the halo con- tained major amounts of dolomite as well. A small amount of uraninite and uraniferous asphaltite occur at the boundary of the anhydrite nodule. The min- eralogic relations suggest that the uraninite and as- phaltite were deposited contemporaneously with the anhydrite from solutions that were dissolving dolomite. Figure 19 shows the association of uraniferous as- phaltite with fossiliferous chert. The sample at right contains chalcopyrite in contact with asphaltite and G46 FIGURE 16.-Association of asphaltite with secondary anhydrite in dolomite from the Panhandle lime," well 783a. A, Polished section of mottled gray dolomite con- taining asphaltite (black) nodules embedded in white crystalline anhydrite, X 12.1. B, Polished section of fine-grained dolomite showing asphaltite nodule (black) surrounded by secondary anhydrite (dark gray). X 17.6. the sample at left contains galena in contact with as- phaltite. Pyrite, native copper, and sphalerite are also associated with the asphaltite in these samples. ORIGIN OF THE ASPHALTITE The association of the asphaltite with secondary an- hydrite and celestite, its occurrence in fractures and solution cavities, its presence in stylolites, and its re- placement of the host rock show that the asphaltite is epigenetic. The similarity in physical and chemical properties between the asphaltite and petroleum deriva- tives as well as the association of the asphaltite with residual oil and natural gas in the Panhandle field sug- gests that the organic matrix of the asphaltite was SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 17.-Association of asphaltite with secondary anhydrite in samples from the "Red Cave," well 825a. A, Asphaltite (black) and anhydrite (gray) filling frac- tures in fine-grained dolomite. X 9.4. B, Asphaltite (black) and anhydrite (white) in siltstone (gray). derived from petroleum. The uranium and other met- als were probably largely introduced by aqueous solu- tions. The estimated average concentration of uranium and other metals in asphaltite, crude oil, and brine (table 15) and the ratio of percent metal (the percent of each metal among the sum of all the metals present) in the oil and asphaltite to percent metal in the brine (table 16) show that the asphaltite and the crude oil tend to be selectively enriched in the same group of metals with reference to the brine. Uranium, arsenic, and cobalt, however, are preferentially concentrated in the asphal- tite while vanadium is preferentially concentrated in the oil; for this reason the two organic materials, al- though probably of common origin, seem to have been segregated and mineralized separately. B # FiGUurE 18.-Asphaltite nodules surrounded by halos, in shale. A, Botryoidal nodule in "Red Cave" shale, well 832. X 5.6. B, Asphaltite nodules in shale samples from the "Panhandle lime," well 139. X 4.7. TABLE 15.-Estimated average concentration of metals in brine, crude oil, and asphaltite from the Panhandle field Concentration, in parts per million, in- Metal Brine Crude oil |_ Asphaltite (30 samples) | (25 samples) | (26 samples) 44, 000 10 3, 000 2, 760 4 30, 000 1, 340 . 5 4,000 470 .5 5,000 140 A 200 70 6 4,000 20 .8 4,000 15 .03 40 7T . O1 300 5 . 005 100 4 .8 3, 000 2 .06 300 2 . O1 200 2 . 005 20 1 +7 300 1 $4 3, 000 1 . 03 50 1 . 5 30, 000 .5 . O1 s. . 005 50 €.1 . 005 2, 000 . 0015 0015 4,000 G47 TaBu® 16. --Comparison of ratios of percent metal in crude oil and asphaltite to percent metal in brine from the Panhandle field Metal in | Metal in oil asphaltite Metal Metal in | Metal in brine brine 0.5 0.04 3 A7 10 1 2 2 5 6 7 6 5 10 5 20 100 30 10 30 30 30 100 40 100 200 100 3,000 200 200 300 400 400 3,000 2,000 >200 10, 000 2,000 20, 000 4,000 (1,000,000 Segregation of the asphaltite from petroleum may. have occurred in several ways. The asphaltite may rep- resent water-soluble organic material that was dissolved from petroleum or its source rocks by associated connate brines, and was later precipitated from saturated brines during cementation of the reservoir rocks. Or it may represent a surface-active fraction of petroleum that was adsorbed at oil-mineral and oil-water interfaces. Adsorption of metal-bearing fractions of petroleum at oil-water and oil-mineral interfaces has been demon- strated by Denekas, Carlson, Moore, and Dodd (1951) and by Dunning, Moore, and Denekas (1953). The transformation of the organic material into as- phaltite is probably the result of polymerization and dehydrogenation caused by radiations from decay of uranium and its daughter products. Lind (1928) and others have demonstrated experimentally that alpha bombardment of liquid and gaseous organic compounds converts them to insoluble solids. Such materials are highly crosslinked and may resemble synthetic ion ex- change resins in their ability to extract metals from solutions. It is possible that initial adsorption of small amounts of uranium by asphaltite may in time have enhanced its ability to pick up more. The relation of asphaltite to the host rocks show that it, as well as anhydrite, celestite, and rarely silica, is present as a secondary cement. The secondary anhy- drite characteristically replaces dolomite in samples of the carbonate rocks. Uranium and other metals in the asphaltite seem to have been derived from the same cementing solutions as the secondary anhydrite. The interval of rocks near the top of the "Panhandle lime" and the base of the "Red Cave" contains oolitic dolo- mites and siltstones that in many places are completely cemented with asphaltite-bearing anhydrite and have G48 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 19.-Fossiliferous chert containing disseminated asphaltite from the "Brown dolomite," well 825a. X 2.4. a uranium content of 20 to 200 ppm uranium, most of which is in the uraniferous asphaltite. Inasmuch as the rocks contain about 20 percent secondary anhydrite, the uranium content of the anhydrite plus asphaltite must be in the range of 100 to 1,000 ppm. The solubil- ity of calcium sulfate ranges from about 2 to 6 g per liter of water, depending on salinity (Seidell, 1940). The upper limit for the uranium content of the original cementing solutions must, therefore, have been about 0.2 to 6.0 ppm. It is known that concentrated, highly oxidized saline brines tend to be enriched in uranium relative to other natural waters (Bell, 1960.) It may be postulated that if such a brine migrated through the evaporite sequence into the underlying rocks where it was subjected to a reducing environment, the uranium and other metallic ions would be precipitated as stable minerals. The uranium may have been introduced into the Panhandle field in this manner. The abundance of hydrogen in the Panhandle field gases allows an ~estimate of the reducing potential. The partial pressure of hydrogen in the gasfield, as calcu- lated from the hydrogen contents, ranges from about 0.003 to 0.06 atmospheres, and the pH of the brines, as measured at the well head, ranges from 5 to 7 (A. S. Rogers, written communication, 1956). The Eh of the environment as calculated from the hydrogen half- cell reaction is, then, about -0.2 to -0.4 volts, and is sufficient to cause reduction of uranyl, arsenate, and sulfate ions, resulting in the formation of uraninite arsenides, and sulfides (for example, see Garrels, 1960). URANIUM AND HELIUM IN THE It has been noted that secondary anhydrite replaces dolomite in the carbonate rocks. This replacement and the fact that the rocks are part of an evaporite sequence indicate that the original cementing solutions were mildly acid magnesium sulfate bitterns and that the magnesium sulfate reacted with calcium carbonate in the original rock to form dolomite and calcium sulfate. As the calcium sulfate solubility product was exceeded, anhydrite was precipitated. Oxidation potentials may have been such that the change in pH due to the above reaction was sufficient to result in reduction of uranyl ions by organic materials that were already present in the rock pores. The evidence and assumptions discussed above sug- gest that asphaltite and secondary anhydrite deposition occurred under more oxidizing conditions than now exist in these rocks, but occurred later than lithification and fracturing. It is estimated on the basis of data ob- tained from sample logging that 10 to 30 percent com- paction of the shales and siltstones in "Red Cave" and "Panhandle lime" would release a sufficient volume of brine, saturated with magnesium sulfate, to explain the amounts of secondary anhydrite cement now present in the intervening and underlying carbonate rocks. Ac- cording to the density studies made by Athy (19302, b) of red beds of Permian age in the Garber, Okla., area, a 10- to 30-percent compaction of shale would occur by the time the thickness of overburden reached about a thou- sand feet. Inasmuch as 1,000 to 2,000 feet of Permian rocks overlie the "Red Cave," this process could have been completed by the end of Permian time. The uraniferous asphaltite in the lower part of the Clear Fork Group and the upper part of the "Panhan- dle lime" is distributed over such a large area that it seems probable that these rocks, particularly the red shales and siltstones among the evaporite beds, were syngenetically enriched in uranium. The arsenic, co- balt, and nickel that are enriched along with uranium in the asphaltite nodules were also probably derived from the same hematitic red shales and siltstones. Conspicu- ous concentrations of these elements, especially arsenic, are known to result from their coprecipitation with fer- ric hydroxide in oxidate sediments of evaporite deposits (Rankama and Sahama, 1950). In summary, it appears that uranium has been redis- tributed and concentrated within the interstices of rocks through which petroleum and brine have migrated or in which they have accumulated. The redistribution and concentration of uranium has been associated in time with structural and diagenetic events including compac- tion, fracturing and cementation of the rocks, and con- centration of metals in organic materials derived from petroleum or petroleum waters. The result has been G49 that uranium and its daughter products have been con- centrated in the pore spaces where they are easily ac- cessible to fluids and gases. PANHANDLE GAS FIELD, TEXAS RADON IN THE NATURAL GAS The radon content of the gas in the western part of the Panhandle field as measured by Henry Faul and others (pl. 1) ranges from less than 5 to 145010" curies per liter, and averages about 100 X 10-* curies per liter (STP). These measurements have been discussed previously by Faul and others (1954) and by Sakakura and others (1959). From the study made by Sakakura and others, the above radon concentrations can be ex- plained by reservoir rocks containing 0.1 to 30 ppm ura- nium and averaging about 2 ppm uranium., A contour map showing the relation of the radon and helium content of gas to structure (pl. 1) shows that there is no direct relation between the positions of the radon and helium anomalies. Radon in excess of 100 X 10 curies per liter is concentrated in the natural gas in an extensive area along the north flank of the uplift, and conforms roughly to the configuration of the structure contours. The extremely high, but isolated, radon anomalies are related to the structurally more complex areas on both the north and south flanks of the uplift. Because of its short half life, the occurrence of radon must correspond to the distribution of its source. The distribution of the uraniferous asphaltite and its associ- ation with radon in gas-producing rocks (pl. 2) show that concentrations of radon in excess of about 100 X 10~* curies Rn* per liter (STP) are restricted to gas wells in which the generalized interval of rock that is mineralized with uraniferous asphaltite overlaps the generalized interval of gas-producing rocks. This rela- tion indicates that the source of the anomalous radon is uraniferous asphaltite. HELIUM IN THE NATURAL GAS Few studies on the geologic occurrence of helium have been made since that of G. S. Rogers (1921). Since that time, the increasing volume of data accumulated on the radioactivity of rocks has resulted in the general acceptance of Rogers' assumption that most of the he- lium of natural gas is radiogenic, having been formed since the beginning of earth history. However, this assumption cannot be fully proved because escape of helium from the earth's atmosphere prevents an esti- mation of the primordial helium abundance in the earth. Next to hydrogen, helium is the most abundant cosmic element and large amounts of primordial helium could conceivably have been trapped in rocks of the earth's interior and crust. If so, we would expect he- G50 lium to be greatly enriched in the earth with respect to other inert gases. The available evidence, however, suggests that there is no such enrichment. For exam- ple, the cosmic-abundance ratio of helium to argon is about 10* (Green, 1959), whereas natural gas from rocks have a mean helium to argon ratio of about 10 (Pierce, 1955; see also data in Boone, 1958). This difference might be interpreted as the result of preferential loss of helium at the time of the earth's formation, but an alternate explanation of the proportions of helium to argon is suggested by a comparison of their ratio in natural gas with the amounts that would be formed in average rocks by nuclear processes. The calculated helium-4 to argon-40 ratios resulting from the decay of the uranium, thorium, and potassium present in average carbonate rock, shale, and sandstone are about 50, 7, and 1, respectively, on the basis of the geochemical data given by Green (1959). The ratio for an average igneous rock presumably is close to that of shale because of the similar uranium, thorium, and potassium contents. The helium to argon ratio of 10 to 20 in the gas of the Panhandle and Cliffside fields (table 17) is within the range of ratios calculated for the above rocks and suggests that the helium and argon are of radiogenic origin. The average ratio of the helium isotopes, He? to He', in the Panhandle field is about 1.5 X 10 (table 17), as compared to an average of 1.7 X10- for the helium in the natural gas fields that have been investigated (Al- drich and Nier, 1948) and to a calculated ratio of 2X10-* for helium originating from nuclear reactions TABLE 17.-Composition of natural gas from the western part of the Panhandle field, the Cliffside field, and the Quinduno field [Analyses by the U.S. Bureau of Mines (Boone, 1958)] Western part of Cliffside Quinduno Panhandle field field field ! Volume percent Methane...............- 71.6 67.1 80.2 Ethane............._. 5.4 3.6 7.7 Higher hydrocarbons. 4.3 2.8 5.5 Carbon dioxide. s .8 aT A Hydrogen.... h sist L 12 iP Nitrogen... .- sy yess 17.4 24.8 6.3 Argon...-. ¥kex .05-. 1 .1-.2 Tr. MeOH. cot 1.11 1.79 14 nere nbn annals nan Tr. Tr. Tr. Ratio Ho :A deco cen e suse 10 20 TIER oP Ancel Glb 1s bus chas eaves 21.73X10-' 31. 5X10-' 31. 5X10-" Pounds per square inch Tniticl presstire.....-l._.._.cclll.l..... 440 730 883 1 Average of analyses from 10 wells having highest helium content. * From Coon (1949). 3 From Aldrich and Nier (1948). SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY in rocks of the earth's crust (Morrison and Beard, 1949). The comparatively close agreement between the measured and calculated proportions of argon, helium- 3, and helium-4 that should be present in common rocks suggests that the major part of the helium in the gas of the Panhandle field is radiogenic. Radiogenic helium presents the problem of deter- mining the distribution of the uranium and (or) tho- rium sources,. The average helium content of the gas in the Panhandle field is about 0.5 percent. Calcula- tion shows that this amount of helium would be gen- erated since Permian time in reservoir rocks containing either 0.02 percent uranium or 0.1 percent thorium. Al- though uraniferous asphaltite has been observed in drill samples from the gas reservoir rocks, most of the sam- ples contain no uraniferous asphaltite, only from 2 to 4 ppm uranium, and probably not more than three times that amount of thorium. It is likely, therefore, that the helium was derived from an external source. An investigation of the isotopic composition of argon in gas from the western part of the Panhandle field by Wasserburg (1957) has shown it consists mainly of argon-40, the decay product of potassium-40. Explain- ing the radiogenic argon (0.1 percent by volume) in the Panhandle field presents a problem similar to that of helium. Calculation shows that the reservoir rock would have to be about 100 percent potassium to supply the argon present ; the argon, therefore, also must have been derived from an external source. The distribution and concentration of helium in the Panhandle field are indicative of the direction from which the helium-rich gas has migrated (pl. 1; fig. 20). The helium content increases from about 0.1 percent in the gas along the eastern end of the field to about 1.9 percent in the zone of en echelon faults which in general constitute the southwestern boundary of commercial gas production. The helium content of gas from approxi- mately the same stratigraphic units continues to in- crease southward 20 miles beyond the boundaries of the field and reaches a maximum of 2.24 percent (figs. 9,20). Northward in the Anadarko basin the gas from the "Brown dolomite" in the Quinduno field, however, con- tains only about 0.15 percent helium (fig. 20). The res- ervoir pressure in the Quinduno field is about 885 psi and the pressure in the Cliffside field is about 730 psi; the Panhandle field, which has an initial pressure of only 440 psi, is therefore, a "pressure sink" into which gases of the Anadarko and Palo Duro basins can migrate. The Panhandle field is at about one-third the normal hydrostatic pressure gradient for a field of its depth, but is at nearly normal hydrostatic pressure with re- spect to the ground-water table in the Wichita Moun- G51 URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS & ; (geet 'soufpy Jo neomng 'g'n °g *p pus 'ggg1 'ouoog 'uosut pus uosiopuy wou; ors sesfreuy) . 'seore quoou{pe pus 'sexo.p, 'ploy o[pusQUueq oy} uf Jo I b I * I _ 1 S37IW OFE orA OI 0 TTI H a W 4 H | s L ¥ % g 0 4 T E X A S « W O 0 S d I T } syo01 Sutonpoid-se3 Jo £repunoq ajewtxoiddy e nn Seat hae ="" _ @ 4 ¥ L TI H 0 0 wv T7 I v C aqpnbapour s1 aaym porianb | | \\|N\o\| XR \ Ajoppmurxoadd» acaym pays» Gil 9 O |l///\I.\ as f wnifoy quaodead yjIm tuntJoy-OSI m [fl st 0 // vx Zar .r\\l|IrV.Q/|\ ( #. NOILYNYVTIA4X3 \ G52 tains where the igneous rocks of the Amarillo-Wichita uplift crop out (Levorsen, 1954). Deficient reservoir pressures also exist in satellitic oil and gas fields along both sides of the uplift, including the Cliffside and Quinduno fields. Interestingly, the latter fields, al- though deficient in pressure with respect to their depths, are at nearly normal hydrostatic pressure with respect to the water table of the vast Panhandle field. During Late Cretaceous time when the overlying surface was at or below sea level, the reservoir pressures of most of these gas fields were two or three times greater. Epeiro- genic uplifting since that time has been accompanied by erosion and drainage of waters from the elevated rocks and would have caused the reservoir volumes of the satellite fields (if they were filled with gas) to expand and to spill their excess gas into the structurally higher Panhandle field. The uplifting must also, because of lessening pressures, have been accompanied by a general degassing of formation waters throughout the rocks of the basins and uplifts, a process that is capable of sup- plying large quantities of gas and one which may still be going on. Such a process could result in mixing of gas migrating from either side of the uplift. The helium, nitrogen, and hydrocarbon content of the gas of the Panhandle field is intermediate to that of the Cliffside and Quinduno gas, as shown on figure 21, and thus can be explained as the result of mixing of gas de- rived from the Palo Duro and Anadarko basins. The relative amounts of other gas constituents in the Pan- handle field can also be explained as the products of mixing. For example, a mixture composed of 60 per- cent Cliffside-type gas (table 17) and 40 percent SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Quinduno-type gas (table 17) would contain about 72 percent methane, 5 percent ethane, 4 percent higher hydrocarbons, 17 percent nitrogen and 1.1 percent heli- um; this is the same as the actual composition of the helium-rich gas in the western Panhandle field (table 17). The average helium content of Panhandle field gas is about 0.5 percent and corresponds to a helium mixture composed of about one-fourth from Quinduno- type gas and three-fourths from Cliffside-type gas. Figure 21 shows that the overall helium-nitrogen- hydrocarbon distribution in the gas of these three fields could also be explained by systematic dilution of a nearly pure hydrocarbon gas with nonhydrocarbon gas, such as might be derived from basement rocks, contain- ing nitrogen and helium in proportions of about 10 to 1. A more detailed picture of the helium distribution in relation to the structure of the gas-producing rocks is shown in plate 1. The highest helium concentration of 1.9 percent occurs structurally in the lowest part of the field and indicates that helium is actively flowing into the gas field at this point. The helium source, therefore, must be either in the deep igneous and metamorphic rocks associated with the faults or in the downfaulted sedimentary formations to the south. These two pos- sible sources are discussed below. Little is known about the igneous and metamorphic rocks underlying the Panhandle field. Their uranium and thorium content, however, should be at least as great as that of the overlying sedimentary rocks and, because of their greater ages, their radiogenic helium content should be as large or larger. A part of their helium, however, must have been lost to the atmosphere EXPLANATION He =100 Area shown by figure 5 - 30 N, =100 Numbers are in volume percent 2 Gas sample aP § Cliffside Field Q7? Quindléno West Panhandle Field rJI—T Fiel R alves ——-—<'/ xg ty to-. 'e HM a- Line connecting average compositions O | re iet =- 1 1 1 I 0 5 10 15 20 25 30 Percent N2 FIGURE 21.-Graph of percent helium, nitrogen, and hydrocarbons in gas samples from the Panhandle, Cliffside, and Quinduno fields (data from Boone, 1958). URANIUM AND HELIUM IN THE PANHANDLE GAS FIELD, TEXAS before the uplift was finally covered by sediments dur- ing Late Pennsylvanian time. The Amarillo uplift, which underlies the principal helium accumulation in the western Panhandle field (see pl. 1), is about 40 miles long and 20 miles wide ; it has an average relief of about 2,000 feet and, in all, a volume of about 300 cubic miles. The igneous rocks of at least the upper part of the uplift are permeable and produce gas in some of the wells which penetrate them (pl. 2). The uplift was exposed to the atmosphere un- til it was covered by sediments during the Permian Period. If there is a mean uranium content of 4 ppm, a 50 percent retentivity, and a thorium to uranium ratio of 3.6, the total amount of helium generated in the uplift since Permian time would be about one- eighth of the amount that has accumulated in this part of the gas field. Calculations indicate that a compar- able amount of helium could have been generated by the "buried mountains" in Sherman, Carson, and Gray Counties where the reservoir rocks also contain anomal- ous concentrations of helium (fig. 20). If the helium was derived from igneous rocks, then, it seems likely that the main source would be deeper than the "buried mountains." Helium escaping from deep igneous rocks would probably tend to migrate up- ward through major tensional fault zones. The helium concentrated in gases along the Potter County fault zone (pl. 1) and in the adjacent Cliffside area (fig. 1) could have been derived from such a source. If it is assumed that the deep basement rocks in this fault zone are 10° years in age, contain 4 ppm uranium and have a thorium to uranium ratio of 3.6, and a helium retentiv- ity of 50 percent, then calculation shows that about 790 cubic miles of rock would be required to generate the helium of the Panhandle field. This amount of rock would be equivalent, for example, to that in a fault zone 30 miles long, 15 miles deep, and about 9,000 feet wide. Very little is known about the nature of such deep fault zones and whether the effective porosity and perme- ability necessary to degas these rocks could exist under the high geostatic pressures in such a region. The hydrocarbon gas of the Panhandle field was probably derived from sedimentary rocks of the basins and probably migrated laterally into the reservoir rocks. The enormous quantity of gas in the field indi- cates that the sedimentary rocks from which it migrated must be very permeable. If these sedimentary forma- tions are also the helium source, the rocks extending downdip from the Amarillo uplift must contain quanti- ties of uranium and thorium capable of supplying the helium existing in the Panhandle area. It has previously been shown that the reservoir rocks in the Panhandle field contain from 2 to 4 ppm urani- (G53 um and probably not more than three times that amount of thorium. Data described elsewhere in this report (p. 26), however, indicate that the upper part of the "Panhandle lime" and the basal part of the Clear Fork Group contain from 10 to 20 ppm uranium through a 200- to 300-foot-thick interval. Most of the uranium in these rocks occurs in asphaltite. Exploratory holes drilled south of the Panhandle field have encountered limited volumes of natural gas in the uraniferous rocks that contain high concentrations of helium (pl. 3; figs. 9, 20). The uraniferous and helium-rich rocks have been faulted against the gas-producing formations along the south side of the Panhandle field. (See pl. 2, section between wells 825a and 825b.) The structure, therefore, is such that the gas can migrate from the most uraniferous rocks across the fault zone and into the gas reservoir. It would be informative, therefore, to examine the total volume of helium these rocks could supply. The potential "gathering area'" for the natural gas that has migrated into the Panhandle field can be esti- mated from the Tectonic Map of North America (Longwell, 1944) by drawing lines normal to the struc- ture contours that define the Amarillo uplift. When this is done, the potential "gathering area" extending eastward to the center of the Anadarko basin is about 6,000 square miles, while the potential "gathering area" extending south of the Panhandle field through the Palo Duro basin to the Midland basin is about 5,000 square miles. The most probable source rocks of gas from the Anadarko basin are those of Wolfcamp age, whereas the source rocks of gas from the Palo Duro basin are probably those of Leonard age, particularly the "Pan- handle lime" which is known to contain helium-rich gas in this area. (See fig. 9.) Average thicknesses of the potential gas-source rocks in these two areas can be estimated from isopach maps by Roth (1955). The average thickness of the rocks of Wolfcamp age in the Anadarko basin is about 3,000 feet, and the average thickness of the rocks of Leonard age in the area of the Palo Duro and Midland basins is about 2,000 feet. If it is assumed that the rocks are 250 million years in age, contain 4 ppm uranium, and have a thorium to uranium ratio of 3.6 and a helium retentiv- ity of 50 percent, then calculation shows that the rocks of Wolfcamp age in the Anadarko basin could supply about 10 X10*"* ce helium, whereas those of Leonard age in the Palo Duro basin could supply about 6 X 10" ce helium. In comparison, the amount of helium in the Panhandle field is about 4x10 ce, on the basis of an original gas reserve of 30 trillion cubic feet and an av- erage helium content of 0.5 percent. If it is assumed G54 that the average helium content represents a mixture (discussed above) composed of about one-fourth of the helium from the Anadarko basin and about three- fourths from the Palo Duro basin, the respective source rocks could have supplied 10 and 2 times the amounts of helium attributed to them. Although this calculation shows that sufficient radio- genic helium is potentially available, a further calcula- tion (given below) indicates that the partial pressure of helium generated in rocks with 4 ppm uranium may not be great enough to explain the observed partial pressures of helium in the Cliffside field and western part of the Panhandle field. Results of this calculation suggest that about 10 ppm uranium in the source rocks is necessary to account for the helium present in these areas. The helium partial pressure of a gas field can be esti- mated from the physical properties of the source rocks (Pierce, 1960). The pores of the helium source rocks, which extend downdip from the Amarillo uplift, are mainly filled with water. Because helium is only slight- ly soluble in water, the minute amounts of it that are slowly produced in the rock by radioactive decay and that escape into the water-filled pores will exert a sig- nificant partial pressure in associated gas fields. If it is assumed that the radiogenic helium in the source rocks can migrate into a gas field at a rate that is rapid enough to maintain an equilibrium concentration, then the partial pressure of the helium in the gas phase can be calculated from Henry's Law : PHe=Kw, where P;, is the partial pressure of the helium in the gas phase, XK is an equilibrium constant which varies with temperature, and # is the mole fraction of helium in solution. # can be calculated from average rock properties, and the expression for the helium partial pressure becomes : Pa (€*-1)+6R" (e¥'"*- 1)]g Where U is the uranium content of the source rock; f is the fraction of radiogenic helium that escapes into (and is retained by) the effective porosity; A, A', and A"" are the decay rates of U*, U*", and Th*, respec- tively ; R' is the present ratio of U* to U®"*; R"" is the ratio of Th®> to U* in the rock; d is the rock density ; w is the water content of the rock as calculated from the rock porosity (water saturated) ; ¢ is the absolute age of the rock; and X is the Henry's Law equilibrium constant.. Typical values for these parameters as ap- plied to the possible helium source rocks (discussed above) of the Panhandle field are as follows: SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY U=1-4 ppm=0.4-1.7X10~8 moles per g rock for '"'Brown dolomite" source rocks in the Anadarko basin U=10-20 ppm=4.3-8.5X10~8 moles per g rock for "Panhandle lime" and basal part of the Clear Fork source rocks in the Palo Duro basin K=1.9%X10° psia f=0.50 A=1.54 X10-" per yr N=9.72 %\ 10~- per yr \''=0.49 X10-" per yr t=250 X 10° yrs R'=0.0071 R''=0 A0 d=2.6 g rock per ce rock w=0.050 ce pores (water saturated) per ce rock =2.75%X 107 moles H,O per ce rock The value of X, the equilibrium constant, is taken from the work of Pray and others (1952). The value of this constant does not vary greatly in the range of 32° to 200° F, and the value adopted is an average of those given. The value for f, the fraction of radiogenic helium that escapes into (and is retained by) the rock pores, is estimated to be 50 percent after Hurley (1954). The value for ¢ is the absolute age for early Permian rocks as given by the time scale prepared by Kulp (1959). The value for R' is a constant in nature. The value for R"" is based on the isotopic composition of radium in brines from wells (table 9). The value for w is calculated on the basis of rock porosities (water saturated) from the extensive study made by Katz and others (1952) of the properties of the gas-producing dolomites in Sherman County, Tex., immediately north of the area covered by this report. The value of 5 per- cent porosity corresponds to a permeability of about 0.02 millidarcy on the empirical porosity-permeability diagram given by Katz and others, and represents the average lower limit of porosity of the gas-producing dolomites which contain the gas reservoir. As applied to the Panhandle field, calculation shows that the helium partial pressures that would exist in gas originating from the assumed source rocks are: Px,.=1 to 5 psi for helium in gas migrating from the "Brown dolomite" in the Anadarko basin P4,.=10 to 30 psi for helium in gas migrating from the "Panhandle lime" and basal part of the Clear Fork in the Palo Duro basin As compared with these calculated pressures, the initial maximum partial pressure of helium in the Panhandle field was about 8.2 psi, that in the Cliffside field was URANIUM AND HELIUM IN THE about 13.0 psi, and that in the Quinduno field was about 1.4 psi. In summary, the helium partial pressure in the Quin- duno field could be explained by rocks containing nor- mal amounts of uranium, but the helium partial pres- sures in the Cliffside field-nearly 10 times that in the Quinduno field-would require source rocks having either a higher uranium content (as was assumed in the above calculation), lower helium retentivity, lower porosity, a greater age, or a combination of these fac- tors. It has already been shown that the "Panhandle lime" and the basal part of the Clear Fork probably contain from 10 to 20 ppm uranium through a 200- to 300-foot-thick interval. Much of the uranium in these rocks may be present in uraniferous asphaltite. The asphaltite, because of its amorphous structure, probably has a negligible helium retentivity and is a more effective helium source than would be an equiva- lent amount of uranium distributed through the crystal lattices of rock-forming minerals. CONCLUSIONS Studies and calculations indicate that the sedimen- tary rocks could be the source of the helium in the Pan- handle gas field. An undetermined part of the argon and helium in the gas may have been added from igne- ous rocks associated with the deeper parts of the fault zones bounding the uplift, but the decrease in perme- ability with depth due to the high geostatic pressures may be a limiting factor. In contrast to the igneous rocks, most of the possible sedimentary source rocks have relatively high perme- ability and their structure is such that the helium gen- erated in them can migrate into the gas field. These rocks also occur at comparatively shallow depths and their formation waters have been subject to extensive degassing as the result of greatly lessened hydrostatic pressures due to post-Cretaceous uplifting, erosion, and drainage of overlying rocks. The major sources in sed- imentary rocks from which gas could migrate into the uplift are in the Anadarko and Palo Duro basins. Data on the distribution and composition of the nat- ural gas suggest that about three-fourths of the helium in the Panhandle field was derived from helium-rich hydrocarbon gas that has migrated into the field from sources in the Palo Duro basin. The relation of the helium accumulation to the geologic structure and to the distribution of known uranium-bearing material suggests that the helium in this gas was derived from uraniferous rocks that are faulted against the gas- producing reservoir rocks along the western boundary of the Panhandle field. Available information about these rocks indicates that uranium was remobilized and G55 deposited with asphaltic residues in the interstices of the rocks where it is accessible to migrating fluids and gases. Helium generated under these circumstances would have easy access to the gas field. The low solu- bility and high diffusivity of the gases in the formation water, together with decrease of pressure during uplift, probably explain the migration of the helium and other inert gases into the gas field. About one-fourth of the helium in the Panhandle field appears to have been derived from the relatively low concentrations of helium present in the large vol- umes of hydrocarbon gas that have migrated into the Panhandle field from sedimentary rocks of the Ana- darko basin. The helium in this gas was probably de- rived from traces of uranium and thorium inherent in the same rocks as gave rise to the hydrocarbon gas. PANHANDLE GAS FIELD, TEXAS SELECTED BIBLIOGRAPHY Abraham, Herbert, 1945, Asphalts and allied substances: New York, D, Van Nostrand Co., v. 1, 887 p. Adams, J. E., 1932, Anbydrite and associated inclusions in the Permian limestones of west Texas: Jour. Geology, v. 40, no. 1, p. 30-45. Aldrich, L. T., and Nier, A. 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PANHANDLE GAS FIELD, TEXAS U.S. GOVERNMENT PRINTING OFFICE: 1964 - O-690-464 Midas 4 Nau PROFESSIONAL PAPER 454-G PLATE 1 101°30' 101°40' {01°35 } 101 °50" Xt £ la C| taq f i- 36°00" 101°45" Sunray) 102°00' UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY 2*10 102°05" lei} 192" 15 10220" EXPLANATIO N # U cn mee a 4, D ~--—___—fl’ Inferred fault ; 400 to 500 U, upthrown side; D, downthrown side 593 | | | | It39 | | ] | | .69 | | | | Neti te SNe -o 2 SHN t te netics atea ten len ees 8 Gas well and index number Slant number is radon content in micromicrocuries per liter at STP, More than 500 *=average value. Red number is Radon content, in micromicrocuries | percent helium in natural gas per liter at STP. Boundaries dashed | where approximately located -- --- s /’\\ Oil well ‘O' k\___/ Dry hole Areas that have produced oil e " Sood. aioe" * ~A Structure contour on top Major pipeline of "Brown dolomite" Contour interval 50 feet. Datum is j mean sea level. Dashed where , 1 | approximately located Carbon-black plant ) : 35°55" o e i n n U Anas. mam ao "* - | § <= & E| f Helium contour 4 - - Contour interval 0.1 percent. Dashed + where approximately located 3 / Fence lines and property - * boundaries | | Meare keer F | f | | to | i | 107 | | 144 | | Ephemeral pond p : tsk ; 2 | 175; | rf | °C a | * 7 14} / 205 a . Dumas Ss.. 100 to 200 7 2222 f f f ; 219 | 220 yi 4 3 X | 51 200 to 300 | 969} [mf \ } v MAP OF TEXAS SHOWING LOCATION ; *" i ; OF AREA OF REPORT || 0 000 ( Life- 3 [17 F . sare) 35°50 7 a I I XTL (- . 300 to 400 Lg.. \ 5 a 1 "y ys _o" . 306 \\ £208 33309 \,¢ {t> ..... (side 35°45" [-x ---~{-~-- - ~~~ month | corm illiterate yI PINTS I tg ¥ _ < Ais A 7 fg orl | Eh tol om mies pim i oal f regen mye {| C -Small auta oa ... . Rar . t | k“? ¢ 90 ~ [a a yJ CQ ~- | y* | | | / | X. \ 01°40" 101 101 °30' INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-62411 Compiled by G. B. Gott and J. W. Mytton, 1955. 'Well evaluations furnished by Colorado Interstate Gas Co. and Phillips Petroleum Co. Helium values furnished by Radon measurements by Henry Faul, Allan Tanner, Allen | ) y § U.S. Bureau of Mines. Rogers, Rosemary Staatz, and Betty Skipp 101 °45" 36° e Ligs SCALE 1:125 000 5 MILES MAP OF THE WESTERN PART OF THE PANHANDLE FIELD, TEXAS, SHOWING STRUCTURE CONTOURS, AND RADON AND HELIUM CONTENT IN GAS WELLS 102°20" © Base compiled by Rosemary Staatz from aerial photographs without ground control, s 1952 El & o 2 € 11 '% ._ 0 1 & 3 4 EA-EE ~F I 3 F t 5 6 1 2 3 4 5 KILOMETERS ECH =i ' I - j APPROXIMATE MEAN DECLINATION, 1963 UNITED STATES DEPARTMENT OF THE INTERIOR Calculated concentration of metals, in parts per million, in samples of crude oil from the Panhandle field PROFESSIONAL PAPER 454-G TABLE 6 2 A0 Us. ~ GEOLOGICAL SURVEY | s [Ths concentration of the metals is calculated from Lol percent 331333315 (table 5) X percent 88h, y 1, x. and x - mean 4.64 to 10, 2.15 to 4.64, and 1.0 to 2.15 respectively; 0.X+, 0.x, and 0.x- means 0.460 to 1.0, 0.215 to 0.464, and 0.10 to 0.215 respectively, and so forth] << well Location Producing Ash Concentration of metals a is Interval (percent > € (depth, Stratographic Unit 0 Name 5 Company tS_ec- Block Survey 091112378 in in feet) sample)] Na K Cu Ag Ca Mg Sr Be Ba Zn Al Ga B Ti Zr Si Sn Pb v As Cr Mo Mn Fe Ni Co La U ion Puc. ::.. Mudget 1.__ Phillips Petroleum...._....__....._ 85 «40 | H and TC...1.._.____.__._.l_ Hutchinson...| 2080-2085 | "Panhandle lime"....| 0.084 | xx.~ | 0 0. 0x 0 x. 0.x+ 0x 0 0.00x | 0 0.x 0 0 0.00x | 0.0x- | 0.x 0 0 x.- 0 0.00x | 0 0 0.x- 0.x 0 0 0.336 $ Oct 1 ol aaa tne 85 46 2080-2085 |___... 10.» . 0086 | x.+ 0 r w Tr «x+ Fo .< x" .000x- | .Ox- x.+ x" .00x- | 0 Ox .Ox- .X .Ox- .X xx 0 .00x .00x .0x x.+ x: .00x 0 . 0705 8 Yake T...... 16. .... ool. nc Asl eee cc cee 35 47 2835-2850 |___... O- .143 | xxx.~ | 0 h 0 xx. x. -X 0 .000x- | .x :t 0 .0x 0 .Ox At 0 0 x. 0 .000x- | 0 0 x. x." -.10 0 . 014 Mitchell 2. . Kerr-McGee Oil Industries.. 76 46 2812-2884 | "Panhandle lime" !...] .344 | XXXX.| XX.~ 0 *xx~ | xx.+ Ax" 0 .00x+ | 0 x. 0 .Ox+ xT .Ox+ x. 0 0 x+ 0 .Ox- 0 0 x.~ %. .Ox .0x- . 034 Childers Phillips Petroleum................. §W[.:i.l..._ T. C: 3040-3110 | "Panhandle lime"....| .026 | xx.+ | 0 .Ox+ 0 xx.* x* xt 0 .00x 0 .x+ 0 .0x+ .00x+ | .Ox- x. 0 0 x.- 0 .00x+ | .o0x- | 0 lx+ x.- .000x+ | 0 . 003 6:2 ico. Wittenberg 32. .... Kerr-McGee Oil Industries.....__. 12 X02 | fand 2930-2065 | "Panhandle lime" or | .005 | x. 0 Ox. 0 -X .Ox+ .Ox- 0 .000x+ | 0 K 0 0 .0x .00x xA .00x .Ox x X .00x .000x+ | 0 x+ .X .0x 0 . 001 "Brown dolomite" 7 858b | Sanford A-5.....-_ Colorado Interstate Gas..__....... 8 3 Carson........ 2778 "Brown dolomite"....} .170 | xx. x~ .Ox+ 0 xx.+ xx. -& 0 -K 0 x.+ .00% .0x+ .x- .0x+ xx.+ 0 .0x+ x.+ 0 .0x 0 .x xx.+ x. 00x+ | 0 .o17 8 Phillips Petroleum.... st 46 Hutchinson...| 2843-2860 |.... O-. -.- .206 | x.~ 0 .Ox- 0 -X x~ 0 0 x~ 0 x" 0 0 0 0 '% 0 0 .X 0 .0x- 0 0 xz x 0 0 . 062 9 Kerr-McGee Oil Industries -| - 14 B3 2780-2880 | "Brown dolomite" !...} .015 | x.+ X* Res 0 x. * .Ox+ 0 .000x+ | .Ox J 00x .Ox+ .Ox .0x x+ ** O0x+ x+ 0 .0x- .00x+ | .x xx.+ x+ .0x 0 . 002 10 PIBES 10.....0. -. _ HO: ree bee ou 7 M2l 3035-3058 |.... O:: e .004 | x. 0 x~ 0 X iX . Ox 0 .Ox -X F 4 0 0 .x .003 x+ .x .x .X 0 .00x .000x+ | .Ox x. x .00x .x- <. 001 1 1: Jasper %{. les. (10 A... nl eX acess 24 M23 3142-3185 |_____ 0s. seu. e .016 | xx. . Xt x. .000x+ | x.+ x: %. 0 :00x+ | . x~ .X .000x+ | 0 .Ox+ .Ox- B*, .Ox+ '% ix K .0x .00x .Oa+ .xxt | x.~ .x 0 . 002 Wittenberg A-12...| Stanley K. Feinberg. % 2 J Unknown |.... .005 | xx. 0 00x | 0 x.= x~ >. w 0 00x x "x= 0 .Ox- 0x 00x «x~ 0 0 'X 0 .00x .000x | 0 x- & .00x 0 <. 001 B-2 . ifl3c 2. a 2 J Unknown |_... OTE ne. 511 | XXX 0 AX 0 xX; xx.". .| x. 0 .Ox 0 xs 0 0 0 0 &. 0 0 % 0 .0x 0 0 $x.* x- 0 0 . 035 rel ce nen he cece 2 J Unknown |.... do...: -| .0006 | x. 0 .000x | 0 Ox+ .Ox~ 0 .000x+ | 0 .0x- 0 .000x | .000x- | .000x+ | .Ox 0 0 .0x 0 .000x- | .000x | 0 0x- 0x- .000x- | 0 . 0002 Gaty 4...........2 Phillips Petrolenm._....._...... ._ 26 M2 | 3240-3270 | "Brown dolomite"....} .008 | x. 0 .0x- 0 Ag x'; t Tl 0 .00x 0 A l 0 .00x- | .00x 0x- iK 0 .000Xx+ | .x 0 .00x .00x- | .00x x.~ x+ .00%x 0 . 001 Hasel 2. ...... gee Nor. ed ecole Nee en 4 X02 | H and 2055-3040 |.... do. c .003 | xx.~ | 0 .Ox 0 x. x+ .Ox+ 0 .00x- | 0 xz 0 .00x- | .00x+ | .00x+ x~ 0 :00x~ -| x- 0 .00x- | 0 :'00x- "|_ :x* x~ .000x+ | .00x <. 001 Ryan A-1..________ Kerr-McGee Oil Industries........ 1 MMT Tand 3195-3226 | "Brown dolomite" _.] .101 | 0 0 .Ox 0 * 4 .00x 0 0 .Ox+ 0 Ox 0 0 .Ox 0 x~ 0 0 .x 0 0 0 0 .x .x 0 0 . 010 Lucas 2... Phillips Petroleum...._... a beeen reece N34 112 acres J. W. Swisher 3202-3250 | ''Brown dolomite"....} .001 | x.+ 0 .000x+ | 0 Izy .Ox+ .000x+ | 0 000x- | 0 .Ox~ 0 0 .000x- | .000x+ | .00x+ | 0 0 .00x- | 0 .000x- |.0000x+ | 0 .0x- .0x- |.0000x- | 0 <. 001 Ebling 10. -le «[.. 18 | < MIO | -AB shd 3178-3205 |.... do...... .005 | xx. 0 Ox- 0 x* (X= Ox 0 .Ox- 0 & .00x- | 0 .Ox- Oxz x~ O0x- 0 x* 0 .0x- 0 x- *r~ | x~ .00x 0 . 001 Wells 1-B.__..._... Kerr-McGee Oil Industries...... 153 ahd Moore...... Unknown | Unknown............. 10. 0 XXXX X%X. "{ Xxx. 0 xxx. | *xx.~ | 0 xt 0 XXX,." | .X 0 x* -X X«Xxx.t| 1%. x- 0 *x.~ x- xxx. |xXxXxXXX | xx.- x.- PRA: .... 3 21 623 | Thompson B-2._._| Colorado Interstate Gas_._.__..... 17 444 -H and -., fo.. 2845-3115 | "Brown dolomite"....| 3. 0 Xx.+ xx.+ x; 0 XXXX." |*xxx.- | .x 0 x. 0 xx .+ 0 & X.+ .x *xa.~"[ 0 xt .x+ 0 .x+ 0 xx. xxXx.+ | x+ .x 0 .9 22 Johnson T-1.. Phillips Petroleum.... 8 [:.. cae Rockwell, School lands 2575-2010 |___. do....._.s.: . 0011 | .x* .Ox .00x+ | Tr & x: 00xt . | Ir 00x- /| 0x- x .000x- | .00x .0x- .00x Fa .000x~ | .Ox o %d 0 .00x- | .00x- | .00x .X .X .00x+ | 0 . 0004 29 Les 10.....".::. Z Kerr-McGee Oil Industries...... 72 $8 | GH and H.......2.......s.l Unknown | 12 XXx."i x" 0 xx.= x+ x." .00x Tr 0 .% 0 0 .00x 0 & 0 .0x- X 0 .00x 0 0 .X x+ .00x 0. "I2 032008 24 588d | Berneta 1._________\.____ do. ALIA. insitu ied 20 21] CBS ALL scr Hartley.... 5714-5728 | "Granite wash"....... L001 T x.+ 0 .Ox- |.0000x- | x- :0x~ .Ox+ 0 .000x+ | 0 .Ox- 0 .00x+ | .Ox+ .000x- | .x+ <.000x-| .000x- | .Ox+ 0 .000x+ | .000x- | .00x+ | .Ox- .0x- .00x+ | 0 <. 001 ARB e acc (10.2... ien se. ef l Ma 29 TL OBA: cello 5714-5728 |_____ Q- ewe 1... . lee. {co- |e cane |- aie aes [6a c =a oe {Wee never (FUL as s eH ta nah (a= #> 26002 a uk ahl ane Fea ae lank bs an olite bane us (o's ne u ans [s ded ak ad Ian Sie as a (us c eeece Is on ae leben tie a [e een ber oles ch docu Tee ae aa ae Tae ae ana lae e o an ee Ne ee Pe dee An cen 2 cie ce w o . . Son noe stie, . Io. Aided 26 b680.| Bernota 4........._|..__. ALL ILA iaa iX s 20 s.. naa iet tel 5770-5778 |...... 22. .0039 | x.~ «X+ X* .000x- | x.~ x. .Ox+ - |.0000x+ | .Ox- .Ox+ .X 0 .00x+ | .Ox- .00x x~ .00x+ ;) .x= Xz 0 .00x+ | 0 .0x x.+ :X .00x+ | .00x- . 0006 Ric ececlcsl. oc. omc e.. 10 ecs stn ai. conan v 20 SU 000! clase ae cess onne do.:....... 5782-5788 |___... ... AL... .0028 | x.+ '% .Ox+ Tr -% "Xz Kt Tr .000x+ | .Ox J& Tr AD .Ox- 00x x .00x Xt 0 .00x <1 00x] x~ A .00x 0 0058 28 588b | Bivins 1-GG__...._| Phillips Petroleum........__...... 29 ZL [NC BSL 02. onde nu e e aie nalwa ie (6.;.....s% 5716-5860 |___... 000000 .0007 | .x 0 .Ox+ |.0000x- | .x * 00x 0 .Ox- Ox+ xz 0 00x .00x 000% .: 1.02. cued Ox. .0x Xt X .000x | .000x+ | .00x+ | .x ix .00x 9; - ! May or niay mot be the correct stratigraphic unit; is either "Panhandle lime" or "Brown dolomite." 2 Collected from sludge pit. 3 Oil extracted from composite sample of drill cuttings with soxlet extractor. The sampling interval does not represent the gas-producing interval. + Residues from filtration of sample 24. 690-464 O - 64 (In pocket) UNITED STATES DEPARIMENT OF THE INTERIOR PROFESSION.L PAPER 454-G > ©000000 ©0000 co 000 o 00 o co nap mI GEOLOGICL SURVEY PLITE 3 SsoUTH NORTH @ © © @ © 6 ® HUMBLE T. V. CARTER SUPERIOR Well 825b Well 825¢ Well 860b Well 736 Leftwich 1 Currie 1 Gray 54-9 - 1% - $s 2 ---=188 £ i= 8 8 e o Clear Fork Group ("Red Cave") 00 00 000 0 0 000 n0 0000 ©00 000 00 000 000 |.__ | | | | | | | | | | | | | | | | | | | | | [ EXPLANATION Mottled anhydtic dolomite No samples Samples were examined for asphaltite but not logged for lithology Inferred disconformity e Uraniferous asphaltite x~. Gas-producing interval p 0 Oil stains | | | | I | g | |$ | | | | | | | | | | N PEET 400 - 300 - 0 S Shinee WM | | | | Datum is top of "Panhandle lime". Gamma-ray logs by Lane Wells Co lHocklenyubbock] erie tig d o > a maas s/ Cole- 0 [# CO7 ts = 8 PG Si #1 e mera. 0 000 000 00 o Wichita Group ("Panhandle lime") "Brown dolomite" 0 50 EXPLANATION Se Location and index number of wells on gamma-ray correlation diagram Outline of major structural basins and uplifts INDEX MAP SHOWING MAJOR STRUCTURAL BASINS AND UPLIFTS. COUNTIES, AND LINE OF SECTION CORRELATION OF GAMMA-RAY LOGS AND THE PALO DURO BASIN, TEXAS WITH URANIFEROUS ASPHALTITE IN SOME WELLS IN THE PANHANDLE FIELD 690-464 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Spectrographic and chemical analyses, in percent of the ash of samples of crude oil from the Panhandle field Spect hic analyses by A. T. Myers and P.J. Dunton; chemical analyses by C. A. Horr. The elements are arranged according to their peiodic chemical families (Moellar, 1952). Elements which were detected, but not listed in the table are: 0.x- Ce, 0.x- Nd . p50] 52552512113 Wis inst guril'lg a‘Shing because of. it's volatilityy. eU (equivalent uranium) is defined as "the ratio of the net counting rate of a sampl to the counting rate per percent of a uranium standard in equilibrium with all of its disintegration products, both measure , and 0.00x- Y in sample 10; 0.00x- Y in 19 and 21; 0.000x- Sc in 22; 0.0x Ce, 0.0x- Nd, and 0.000% Sc in 27; and 0.000x- d under similar geometry" (Rosholt, 1954). x.+, x., and x.- mean 4.64 to 10, 2.15 to 4.64, and 1.0 to 2.15 respectively; PROFESSIONAL PAPER 454-G TABLE 5 Sc in 28. Arsenic was detected in only three samples, although it probably was present in 0.x+, 0.x, and 0.x- mean 0.460 to 1.0, 0.215 to 0.464, and 0.10 to 0.215 respectively, and so forth.] 5 Spectrographic analyses Chemical Location Well ocati Croduting Ash ot S interval Sratographic unit . | (percent # arln- (depth in of . . ; xs No Name Company Sec- | Block Survey County in feet) sample) Na K Cu Ag Ca Mg Sr Be Ba Zn Al Ga B Ti Zr Si Sn Pb v As Cr Mo Mn Fe Ni Co La U eU K (pl. 1) tion Texas Mudget 1 Phillips Petroleum..__________.._. 85 «6 [+m sud TC..:....2.....3.2 Hutchinson... 2980-2085 | '"Pmhandle lime"._..| 0.084 | X.~ 0 0.00x 0 -X 0.0x+ 0.0x- 0 0.000x . | 0 0.0x 0 0 0.000x | 0.00x- | 0.0x 0 0 0.x- 0 0.000x | 0 W 0.0x- 0.0x 0 M 0.0400 | 0.024 do. 2. dow... fs 85 46-1 H and. TC. n. _ 2080-2085 |___... cento rege 0086 | x.+ 0 -x r x+ -X x~ .000x- | .Ox- x* XT .00x- 0 .Ox- .Ox- .% Ox- & x~ 0 .00x .00x .0x x.+ x.- .00x 0 ; 0880 :t Yake Te.. de iil: .. 40 ... nl o [| 35 <] H andfor UL... do... 2835-2850 |___. dos; 143 | x+ 0 .0x- 0 «- % Ox- 0 .000x .Ox- Ox 0 d0x- >| 0 .00x- .x 0 0 .x- 0 .000x - |.0 0 x- j0x+ 0 0 .oo14 . 008 Mitche-ll- 2 kerrMcGee Oil Industries Inc...! 76 «6 and co.: 2812-2884 | ''Panhandle lime" 1___| .344 | XX -X 00x 0 x. x.~ X 0 .000x- | 0 .Ox+ 0 .00x- 00x .00x- X= 0 0 X~ 0 .000x 0 0 .0x .0x+ .000x+ .00x 1.2 Childers 2.._____ Phillips 014 .s o. c. cesses. o- 3040-3110 | "Panhandle lime"._..| .026 | XXx.~ 0 .Ox- 0 x. x., x~ 0 .000x+ | 0 x~ 0 0x .00x- .00x+ % 0 0 A 0 .00x- .000x 0 .x- lx .000x- | 0 . 0010 .002 Wittenberg 32.._| Kerr-McGee Oil Industries Inc....\ 12 |_ X02 | H and TC._________________|.___ uce 2030-2965 | Panhandle lime" or | .005 | x.+ 0 .Ox+ 0 x+ x~ Ox 0 .00x- 0 x+ 0 0 .Ox+ .00x+ x. .00x+ .Ox+ xt x+. .00x+ .00x- 0 x.- x+ .0x+ 0 .*: '* Brown dolomite". « ite" - .Ox+ .00x 0 x. *.* .Ox- 0 Ox- 0 iX .000x- .00x .Ox+ .00x %. 0 .00x o 4 0 .00x- 0 .0x- x. 5 .000x 0 Sanford A-5.._.. Colorado Interstate Gas.._.______. 8 $,) AB and Carson.... ... 2778 'Brown dolomite".._.| .170 | x. Dugan Phillips Petroleum._._____________ 72 16 [-Hand TC....:0..2005...0. Hutchinson..) 2843-2860 |_____ Ins.... .206 | .Ox 0 .00x 0 .00x- .000x 0 0 00x 0 00x 0 0 0 0 .Ox- 0 0 Ox- 0 .000x 0 M .00x .0x- 0 0 . 0028 . 003 Cockereli 9 Kerr-McGee Oil Industries Inc 14 B3 2780-2880 | "Brown dolomite" 1... .015 x. X x 0 x~ IX" .Ox 0 .000x .0Xx~ IX" .00x- Ox .0x- .0x~ x. "x+ .Ox .X 0 :0x= .00x x= 3x: he .Ox- 0 « Pilts 16/2. _2._'> do.. ers aa ie Ner s. 7 | Mai 3035-3058 |___. do...... .004 | x.+ 0 -x 0 x* xt .Ox+ 0 .Ox+ Xt x+ 0 0 .0x+ .00x+ x~ Fi x+ x+ 0 .00x+ .00x- .0x+ x+ x+ .00x+ lx 0010 2. Jasper 2. do.: Ass. o ine. 2% | M23 3142-3185 |.____ 1. il-. ser. 010 -| *%.~ X &:~ .000x x. x.~ *~ 0 .00x .Ox+ X* 0 0 .0x .00x+ .x Ox .xt x+ .x- .0x- .00x- .0x xx. x+ .x- 0 20010 Wittenberg A-13) Stanley K. Foinborg....._.._.... 2 $|IWwNG..::;:..!" :...} Unknown..]. .<, 200.4. .0..0.-. 022... 005 | xx. 0 .00x 0 x= %> x> 0 .00x "X x> 0 .0x- 00x "kf .x- 0 o .x o .00x .000x - | 0 .x- ix .00x 0 .oo08 | _. 005 B-2 2 F B2: 72.2 do.... dof"... st [*+ 0 .o0x+ _ | 0 .x - .0x- 0 000% _ | 0 Ox- 0 0 0 0 Ox 0 .0x- .0x o .o00x | 0 0 .x- ox- 0 0 .oo07 | _ .000 02— 2 J | TWNG.. : ust. cc 0. a s Leas. die cta nal. .0006 | xx. 0 .00x 0 x+ X~ 0 .000x+ 0 Az 0 .00x .00x- .00x+ & 0 0 x 0 .00x- .00x 0 x- x- .00x- 0 .0026 .002 Gary 4 oak Phillips Petroleum._.._...._.____ $6 |= Mas E 3240-3270 | "Brown dolomite"._..| .008 | xx. 0 .Ox- 0 x.* x.+* pg 0 00x 0 x~ 0 .00x= .00x .Ox- X 0 .000x & 0 .00x .00x- .00x x.- .x .00x 0 . 0010 . 003 16 Hazel 2 4 X02 | H and OB.... 2055-3040 |_____ lc caries .003 | xx. 0 .Ox+ 0 x* x.+* x~ 0 00x 0 -x 0 00x Ox= & 0 .00x :X 0 .00x 0 .00x x.- .x .00x- .00x+ 0010 "T:. 1 1.:.:" Ryan AP.: Kerr-McGee Oil Industries Inc.... 1-| ~M# |T and C..._.. 3195-3226 101 | 0 0 00x 0 Ox .000x 0 0 00x+ 0 00x 0 0 00x 0 x= 0 0 O8 0 0 0 0 .0x 0x 0 0 . 0011 . 007 18 i i Phillips Petroleum... -.. 20. .. N4 112 acres, J. W. Swisher. 3202-3250 001 | xx. 0 .00x+ 0 x., -X 00x 0 .00x- 0 x~ 0 0 .00x- 00x .Ox+ 0 0 .0x- 0 .00x- .000x 0 x- .x- .000x- | 0 . 0006 . 002 pipet. y.. "> gare a ta trg ast" if) Ain Apa . L. s. _s $178-3205. |__ _._. No...... .. A8 | xx. 0 .0x- 0 x.- .x- 0x 0 :0x= 0 #: .00x- 0 .Ox- x~ x. Ox- 0 x.+ 0 .O0x- 0 a xx.~ x- 00x 0 . 0010 . 006 £30 |-. Wells 1-B....._. Kerr-McGee Oil Industries Inc.....| 153 8 | TI -and Ast Unknown.! Unknown.........._.. 10.0 x~ K= Ox 0 x~ -X Ox- 0 .00x- 0 xt 00x 0 .00x+ .000x x~ Ox- .00x .00x- 0 .0x- .00x- .x xx. .0x- .00x- 0 g x14. $21 623 | Thompson B-2..| Colorado Interstate Gas_.________. 17 «4 ...s... 2845-3115 | "Brown dolomite".._.| 3.0 X y Ox- 0 x* ** 00x 0 .00x+ 0 -x 0 .00x- Ox .00x- x* 0 .00x 00x 0 .00x 0 .x- x. .00x .00x+ 0 ~0os0 1.22... $9 l.;. icy Johnson T-1..._| Phillips Petroleum._..______._____ Bi.. Rockwell School lands.. .___ 2575-2610 |___. OR- .0011 | x.+ -& .Ox+ .000x x. x.~ .Ox+ 000x- Ox- x~ x* .00x- Ox *% Ox X; .00x- A x- 0 .0x- .0x- .0x x. x. .0x+ 0 Loose 1. 23 Lea 10 ___.] Kerr-McGee Oil Industries...... 72 8s |- OH and Unknown.! Unknown.....________ 125 | xx. X~ x.- Ox- 0 «x+ x~ .000x Tr 0 Ox 0 0 .00x 0 X 0 .00x- .0x 0 .000x 0 0 .0x .0x+ .000x 0 gak t cols sor 24 | 5884 | Berneta 1.______ do so l" "aml ess *... Hartley. ___... 5714-5728 | " Granite wash".______ l001 | xx. 0 x- 000x- | xx- | x- .x 0 .o0x+ | 0 x- o 0x+ 0 ~| Lox o00x- | x. ooox- | .oox- -| lox 0 o0x+ -| .oox- | .oox+ | x- .x- 0x ( room.. %.." 125 . vedo aan sal esa " g m fess [ lca. Lars do.* 2. sma-szag |... 2. Mo olen rans xx. .x . Ox Ts. x+ x; ix= 0 .00x 0 ix 0 0x 0x 0 o0x- | .oox- | .o00x+ | 0 .00x 0 pos: -| x~ : * To 0 $ 's. 4 2%. 3 g ® + s .000x- .Ox i%" x+ Tr .Ox- .Ox .00x+ x. .00x+ X ols 0 0x- 00x Ox+ xx.~ x+ Dx .0x- ;: -... z.. _________ db 25.0 Aai n aco "9p 2 | OBL: ALL. LTE esen Oe.. -|. {cc ece. 0089 | AX. x: & .00x x. x* x 00( (2 j L 2 x is Ct Berg?” je: dz 29 BTT Becll l do..s.l.sst 5782-5788 |_____ col- .0028 | xx. xx -X Tr. x.~ x+ x~ Ox .Ox- x.~ Ir, .Ox+ .Ox+ .Ox- XA .00x+ xt xt 0 .0x- .00x+ .0x X.+ x.- .0x- 0 por0 [c: 28 "£555- _i3_i_v_ins_ir(-}-G_:_: Phillips 29 BT | CBS... red egen be Po loan ne do 5716-5860 |___. tors.... els .0007 | x. 0 xt .000x- | x. x.~ Ox 0 x~ x* x.~ 0 Ox .Ox s .OS ade As 6 *. x, .00x .00x+ .0x+ x. x.- .0x> 0 >: spr eae cts * May or may not be the correct stratigraphic unit; is either "Panhandle lime" or "Brown dolomite." 2 Collected from sludge pit. 3 Oil extracted from composite sample of drill cuttings with soxlet extractor. The sampling interval does not represent the gas-producing interval. + Residues from filtration of sample 24. 690-464 O - 64 (In pocket) ED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY 588b 783e % Pco 589 661 FEET . 16007 14007 1200-7 1000-7 800 - 6007 400- 200-7 A R ey A s* 0 VERTICAL EXAGGERATION X 8 516 Top of panel! is 1600 feet above m Pc ean sea level SEA LEVEL 316 20b 0 0 o So» $... 0 503.0 9 0 56.5 ssstes C‘ 0 2C 0 0 0 0 o I o 0/0 0 ce 08% eo o 209 > £ > V OI8 : yi St oy A y on pa. <*> v B a wt Ty a se a be £ vor 'v 3 .f 3 x b<4(""n £ V 4 n € © AVJJ £ % a by a v 7 ¥ ~ > A < A € 3 yn NOBl «by 4 y* 7 % < 7. <1 k (6L 9 A 3:7" Ax Sn. a 9 v < al b < Al> A & ®. *+ ¥ «2.4.5 a 's a "@t ¥ * % 2 sin ge p:" r 4 ¥ ~ ZT T/, * FZ pou v . , al4 v 2% * L; > t Rs } 7" .y"".t F < 3 .+ 59 {113 A P7Aqv f 3 UK r v47(7(‘_ tie > SF 4. Vit * fuk 1.4: YE Each asphaltite nodule symbol represents a 10-foot thickness of asphaltite-bearing rock Asphaltite nodules Lower Permian 2 CCA. PROFESSIONAL PAPER 454-G EXPLANATION Pe | "Red Cave" Lower part of Clear Fork Group PI » "Panhandle lime Pb "Brown dolomite" Pm "Moore County lime" In part equivalent to the "Granite wash" PPg 64 » Granite wash Pc e N8) .... cenit y o, PENNSYL- PENNSYLVANIAN Cisco Group In part equivalent to the "Granite wash" J Diabase and gabbro Undivided rocks Names enclosed by quotation marks are economic terms /\\—/ Contact Dashed where inferred sithenmmess name (""*" Snaith meant * Fault Arrows show direction of movement. Dashed where inferred -_ t_ Inferred change in lithologic facies 3 Aes Je Inferred minor unconformity 7 Jene Law 23 “f Inferred major unconformity p 9 o o Generalized interval of occurrence of uraniferous asphaltite Generalized interval of gas- producing rocks 736 a a on s e en an ee a fi PERMIAN Gas-well index from well location map Heavy vertical bar denotes interval fram which drill samples were examined 69 ._. Numbers denote radon content of gas zones PLATE 2 AND PERMIAN VANIAN PRECAMBRIAN Petroleum-producing zone eA % Asphalt coating /H Residual petroleum stains in 10- ~ curies per liter (STP) Interval of gas-producing rocks Horizontal bars show major permeable gas-producing zones Number denotes average radon content of entire gas-producing interval in 10~ " curies per liter (STP) Horizontal control projected from well location map ISOMETRIC PANEL DIAGRAM SHOWING THE GEOLOGY AND THE SPATIAL DISTRIBUTION OF URANIFEROUS ASPHALTITE IN THE RESERVOIR ROCKS OF THE WESTERN PART OF THE PANHANDLE FIELD, TEXAS INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-62411 Compiled by A. P. Pierce, 1954 : Schumm-DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY-Geological Survey Professional Paper 454-H The Disparity Between Present Rates of Denudation and Orogeny GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-H $196 By- S 2 NOV 4 1963. < au <4?! ue The Disparity Between Present Rates of Denudation and Orogeny By S. A. SCHUMM SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-H Modern rates of denudation and orogeny are compared, and the geologic implications of the disparity between them are considered UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office ; Washington 25, D.C. CONTENTS Page Page - anaae oo sance s a H1 | Deductions from the comparison of rates of orogeny and introduction.. sec 1 ... sears acs. H7 1 The erosion Cy Cle .. . aes ell lern uus 7. Denudation ._. 1 0m DO L. 8 Large drainage 1 .... 9 Small drainage baging.--s.-s........._..._Ll...ll.. 8 Denudation and 9 Maximum denudation rates. __._.......__..__.._.._ 9 | cesses 12 The effect of changing relief on denudation... ¢ | References _ 12 Rates Of 4 T ILLUSTRATIONS Page Page Figur® 1. Relation of sediment yield rates to relief- Freur® 3. A, Hypothetical relation of rates of uplift and Ishgth rAbiQ.=e2 enn no noelle nne nen ae n H5 denudation (solid line) to time. B, Hypo- 2. Relation of denudation rates to relief- thetical relation of drainage-basin relief to length ratio and drainage basin relief. ___. 6 time as a function of the uplift and denuda- tion shown In H11 TABLE Page TaBL® 1. Denudation rates of drainage basing within the United States.________________________LL_LLLLL_LLLLL___ H2 IH SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY THE DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY By S. A. ABSTRACT Denudation rates are calculated for drainage basins, which average 1,500 square miles in area and which are underlain predominantly by sedimentary and metamorphic rocks. Aver- age denudation rates range from 0.1 to 0.3 feet per 1,000 years, whereas, an average of maximum denudation rates is about 3 feet per 1,000 years. Denudation rates are an exponential function of drainage-basin relief, indicating that denudation rates increase rapidly with uplift. Modern rates of orogeny are about 25 feet per 1,000 years, or about eight times greater than the average maximum denuda- tion rate. As a result of this disparity between rates of orogeny and denudation, it is concluded that hillslope form is more a function of the difference between the rates of hillslope erosion and stream incision than of rates of uplift. This difference also makes it unlikely that a balance between rates of uplift and denudation will yield time-independent landforms. Calculations of the time required for planation of 5,000 feet of relief suggest that ample time exists between orogenic periods for the development of peneplains. Rapid orogeny accompanied and followed by relatively slower denudation should cause epicycles of recurrent uplift owing to isostatic adjustment to denudation. These phases of recurrent uplift after the cessation of tectonism may partly explain the existence of multiple erosion surfaces and terraces as well as the isostatic anomalies associated with old mountain ranges. INTRODUCTION The statement is often made that the rate of denuda- tion for the entire United States approximates 1 foot in 10,000 years. It is difficult to grasp the significance of such a pronouncement, for when one considers the topographic and geologic variability of the continent, it is sure that no one rate of denudation is applicable to the whole. In addition, most geologic problems in- volve areas of less than continental extent, perhaps a mountain range or a section of a physiographic prov- ince. New data on sediment-yield rates from drainage basins of about 1,500 square miles in area or smaller, which are characterized by a variety of topographic, geologic, and climatic characteristics, permit calcula- tion of denudation rates for relatively small areas. Available data on recent rates of uplift afford an opportunity for consideration of the disparity between rates of mountain building and destruction. The ex- tension of present rates of denudation and orogeny into the past and into the future is valid 'only if the principle of uniformitarianism can be extended to rates as well as processes. At any given locality, denudation rates must have varied widely during the past; however, each time a mountain range existed in a given area, rates of denudation would have been high, and this in general should be true of the past as it is of the present. Gilluly (1955, p. 15) suggests that present rates of ero- sion are perhaps no greater than the average during the Cenozoic, and Menard (1961, p. 160) shows that denudation rates vary greatly, but "if mountain- building is random in time the rate of erosion of the whole world may be relatively constant when averaged for periods of 10-10® years." It is necessary to assume that present rates of denudation and orogeny are repre- sentative of past rates if there is to be any consideration of geologic and geomorphic problems with regard to the rates presented here. ACKNOWLEDGMENTS This paper was read by several people at one or an- other stage of its preparation. R. F. Hadley, G. C. Lusby, R. B. Raup, Jr., James Gilluly, and H. E. Malde of the U.S. Geological Survey and R. J. Chorley of Cambridge University all made suggestions which re- sulted in an improved manuscript. Dr. Gilluly's encouragement at a crucial stage in the preparation is deeply appreciated. The author also wishes to express his thanks to M. N. Christensen of the University of California at Berkeley for the time spent on a thorough reading and criticism of an early draft. DENUDATION RATES LARGE DRAINAGE BASINS In contrast to sediment yield rates, which are the weight or volume of sediment eroded from a unit area, denudation rates are generally expressed as a uniform lowering of the land surface in feet per 1,000 years or years per foot of denudation. Obviously, no surface is lowered uniformly in this manner, but it is a convenient way to treat the data. H1 H2 The denudation rates given in recent geologic publi- cations generally are those for large areas. For ex- ample, the rate for the Missouri River drainage basin is about 1 inch in 650 years or 1 foot in 7,800 years (Gil- luly, Waters, and Woodford, 1951, p. 185). The same authors state that the rate of denudation for the entire United States is about 1 foot in 9,000 years, and that if this rate could be maintained without isostatic compen- sation all the landmass would be eroded to sea level in about 23 million years. Russell (1909, p. 81-84) presents some data on 19th century attempts to calculate denudation rates. Those rates were uniformly high, for no consideration was given to the increase in volume involved in the conver- sion of rock to sediment. Early in this century, Dole and Stabler (1909) pre- sented calculations of rates of denudation for major river systems and geographic areas of the United States. Their rates of denudation for a few major rivers are as follows: Denudation rate Drainage area (feet per River (square miles) 1,000 years) MigslegIDDL _ 1, 265, 000 0.17 --. - C .- --- - ~a ms c coin tole a e meam mie dace 528, 000 . 13 COlOFAQO 230, 000 .19 Ohio 214, 000 17 Potomac ;...... 14, 300 . 09 Susquehanna 27, 400 . 10 These rates are calculated from data obtained on the dissolved and suspended loads of streams; bedload is not included in the calculations. Dole and Stabler considered that each 165 pounds of sediment in the stream was equivalent to the erosion of 1 cubic foot of rock; in this way they adjusted for the difference in weight and volume between rock and sediment. Again these values, though of considerable interest, were derived from large areas throughout which the topog- raphy, geology, and climate varied greatly. Their average for the entire United States is 8,800 years per foot or, if it is assumed that the closed drainage basins of the Great Basin yield no sediment, 9,120 years per foot. These data are probably the source of the denu- dation rates of 9,000 to 10,000 years per foot that have been so widely quoted. More recently the existing data have been reviewed, and two papers appeared almost simultaneously that af- ford new information on erosion from smaller areas (Langbein and Schumm, 1958; Corbel, 1959). Corbel has made a worldwide compilation of erosion rates, which for the most part include the total sediment load of streams. - His data were summarized on the basis of climate (Corbel, 1959, p. 15), and indicate that the highest rates of erosion occur in glacial and periglacial regions (2 feet per 1,000 years). Erosion was high SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY also in the high mountain chains having Mediterranean climate (1.5 feet per 1,000 years). In fact, one of the highest rates recorded in nonglacial regions was for the Durance River in southeastern France (1.7 feet per 1,000 years). Corbel's data reveal that denudation rates can be considerably in excess of those reported by Dole and Stabler (1909) ; this is true also of the Langbein-Schumm data for sediment yields within the United States. These data were averaged for cer- tain ranges of effective precipitation, that is, precipi- tation adjusted to that yielding equivalent runoff in regions having mean annual temperature of 50°F. The data show that sediment-yield rates are highest in semiarid regions (Langbein and Schumm, 1958, figs. 2 and 3). Average values for two sets of sediment-yield data are presented in table 1. The first set includes data from about 100 sediment- measuring stations main- tained by the Geological Survey. A variety of cli- matic, topographic, and geologic types are represented, and the drainage areas average 1,500 square miles. The measurements of sediment load at these stations include the dissolved and suspended load but not the bedload. The second set of data are sediment yields from drainage basins averaging 30 square miles in area. As the sediment yield was obtained by measuring sedi- ment accumulation in small reservoirs, these data represent an approach to total load, although small amounts of the suspended and dissolved material are probably lost through spillage of the reservoir. TABLE 1.-Denudation rates of drainage basins within the United Btates [From Langbein-Schumm data) 1 2 3 4 5 Mean Mean sedi- denuda- Mean Time required ment tion denuda- for planation Effective precipitation yield (feet tion of 5,000 feet (inches) (tons per (years of relief ! per f 1,000 per (millions of square years) foot) years) mile) Gaging-station data 670 0. 29 3, 400 85 780 .34 2, 900 75 550 | ! 24 4, 200 105 550 24 4, 200 105 400 ~A 5, 900 150 220 10 10,000 250 Reservoir data 1, 400 0.61 1, 600 40 1, 180 . 51 2,000 50 1, 500 . 65 1,500 40 1,130 .49 2,000 50 1, 430 . 62 1, 600 40 790 . 34 2, 900 75 560 .24 4,200 105 470 21 4, 800 120 440 19 5, 300 135 1 Assuming a 5Xisostatic adjustment, reduction of altitude by 1,000 feet requires 5,000 feet of denudation, that is, denudation rate of column 4 multiplied by 25,000. DISPARITY BETWEEN” PRESENT RATES OF DENUDATION AND OROGENY To convert the sediment-yield rates in tons per square mile to a denudation rate in years required to ~ remove 1 foot of material, it is first necessary to con- vert the sediment tonnage to cubic feet of rock. An average density of sediment was assumed to be 2.64, and the sediment yield in pounds per square mile was divided by 165 to yield the volume of the surface of the earth removed per square mile per year. Thus, the erosion of 1 ton of sediment per square mile equals the removal of 12.1 cubic feet of rock which is equiv- alent to 4.34 X10-" foot of denudation per year. The average denudation rates for the two sets of Langbein- Schumm data are listed in table 1. The rates are higher than those presented by Dole and Stabler (1909) and are similar to some of the average values presented by Corbel (1959) but do not approach his maximum values, for the sediment yield rates presented in table 1 are average values based on effective precipitation, and the range of individual values comprising each mean is great. SMALL DRAINAGE BASINS Even higher denudation rates occur in drainage basins smaller than 830 square miles; for example, a small drainage basin eroded into the sediments of the White River Group of Oligocene age in Nebraska yields 32 acre-feet of sediment per square mile annually (Schumm and Hadley, 1961, fig. 1). Denudation is occurring in this small basin at a rate of 24 feet per 1,000 years. The Halls Debris Basin in the San Gabriel Mountains of California trapped 29.95 tons of sediment per acre of drainage basin per year, between 1935 and 1954 (Flaxman and High, 1955). This mate- rial is eroded from an area of 1.06 square miles and at a rate of 8.5 feet per 1,000 years. The maximum sediment-yield rate recorded by the Federal Inter- agency River Basin Committee (1953, p. 14) is 97,740 tons per square mile for a small drainage basin located in the Loess Hills area of Iowa. The drainage area of this basin is 0.13 square mile. With a sediment yield of this magnitude, denudation will progress at a rate of 42 feet per 1,000 years. This high rate, however, is due to gullying in loess rather than erosion of bedrock. Obviously, the above rates are extreme, but one objec- tive of this report is to indicate that, in the light of recent studies of sediment-yield rates, our concepts of the time required for denudation of less than conti- nental areas should be revised downward. MAXIMUM DENUDATION RATES Denudation in large areas requires more time, and in general the sediment yield per unit area decreases at about the -0.15 power of drainage-basin area (Brune, H3 1948, figs. 6 and 7; Langbein and Schumm, 1958, p. 1079). Sediment from the upper part of the larger basins may be deposited, eroded, and redeposited sev- eral times before reaching the basin mouth, although very high denudation rates may pertain to headwater areas. In the smaller basins, steeper slopes allow rapid and generally efficient transport of sediment through and out of the system. For example, on the basis of Brune's (1948) relation between drainage area and sediment yield, it can be calculated that the maximum denudation rate from the Loess Hills area should de- crease from 24 to 10 feet per 1,000 years as the size of the drainage basin increases from 0.13 to 1500 square miles. In addition, the denudation rate of 8.5 feet per 1,000 years for the Halls Debris Basin, which has a drainage area of 1.06 square miles, would decrease to about 5 feet per 1,000 years in a 30-square-mile drain- age basin, and it would decrease to about 2.8 feet per 1,000 years in a 1,500-square-mile basin. This rate ap- proaches that of the Durance River mentioned by Cor- bel and other large drainage basins in mountainous areas. Can this denudation rate of about 3 feet per 1,000 years be considered an average maximum rate for drainage basins on the order of 1,500 square miles in area ? - It is instructive to compare this rate with rates of erosion in some major mountain ranges. Wegman (1957, p. 6) refers to some earlier work to show that the northern Alps are being lowered at a rate of about 2 feet per 1,000 years. Khosla (1953, p. 111) reports on the suspended sediment yield from the Kosi River above Barakshetra, Bihar, India, which has a drainage basin of 23,000 square miles. Within this basin lie the highest mountain peaks in the world, Mount Everest and Mount Kanchenjunga. The annual suspended sediment yield from this basin is 4.1 acre-feet per square mile which, when converted to a denudation rate and adjusted for change in volume, equals a denudation rate of 3.2 feet per 1,000 years. These limited data indicate that 3 feet per 1,000 years approximates an average maximum rate of denudation. The denudation rates as calculated here may be extremely high in comparison to those of the geologic past, for man's activities are known to have increased erosion rates many times in certain areas. Yet Gilluly (1949) estimates that 3 miles of denudation occurred in the Rocky Mountains during the Late Cretaceous. If the duration of the Late Cretaceous was 27 million years (Kulp, 1961), denudation occurred at a rate of 0.59 feet per 1,000 years which is almost twice the rate for the large drainage basins (table 1). Gilluly (1949, p. 570-571) also indicates that 5,000 feet of sediment were eroded from the Ventura Avenue anticline in H4 about 1 million years. This is a denudation rate of 5 feet per 1,000 years, a rate higher than the maximums calculated above. Thus, a denudation rate of 3 feet per 1,000 years may not be excessive during the early stages of the erosion cycle when relief is high. THE EFFECT OF CHANGING RELIEF ON DENUDATION The denudation rates presented in table 1 are average values which may be used to calculate the time required for peneplanation. It is well known, however, that the rates of denudation change with uplift or during an erosion cycle. Other factors remaining constant, de- nudation rates will be dependent on the relief of a drainage basin. Data are available on the sediment yields from drainage basins of about 1 square mile in area that are underlain by sandstone and shale in semi- arid regions of the western United States. When these data are plotted against the average slope or rela- tive relief of the drainage basin (relief of basin divided by basin length) in figure 1, sediment-yield rates are found to be an exponential function of this relief-length SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY about 0.05 during orogeny then, according to the rela- tion between relief-length ratio and sediment yield (fig. 1), such an increase in basin mean slope would increase sediment yield rates roughly tenfold. When this relationship is applied to the data of table 1, the gaging-station data yield a maximum rate of 3.4 feet per 1,000 years. - The maximum rate for the reservoir data is 6.7 feet per 1,000 years, but when this value for the small basins is extended to a 1,500-square-mile basin, it becomes 8.6 feet per 1,000 years. Therefore, as sug- gested previously, a value of about 3 feet per 1,000 years may approach the average maximum rate of de- nudation for mountainous areas. When this average maximum rate of denudation for drainage basins having an average relief-length ratio of 0.05 is plotted on figure 2, the point falls far to the left of curve 2. A curve drawn through this point (curve 1, fig. 2) may represent the maximum denuda- tion rates for a given relief-length ratio. Undoubtedly a family of curves would be required to show the rela- tion between denudation rates and relief-length ratio for varying lithology and climate. As rock resistance ratio (Schumm and Hadley, 1961). In log form the vegetative cover increase, the curve should shift to equation for the regression line of figure 1 is log 8S=27.35R-1.1870, (1) where S is sediment yield in acre-feet per square mile and R is relief-length ratio. - This relation is a straight line when plotted on semi-log paper. When plotted on arithmetic paper, the resulting curve shows clearly the rapid increase in sediment yield or denudation rates with the increase in relief-length ratio. This relation is shown on figure 2 (curve 2), where the sediment-yield rates have been converted to denudation rates for drainage basins 1,500 square miles in area and are plotted against relief-length ratio. Because basin length is constant, figure 2 can also show the increase in denudation rates as the relief of a drainage basin is increased to 30,000 feet. The equation for curve 2 in figure 2 is log D=26.866H-1.7238 where D is denudation in feet per 1,000 years and AZ is relief-length ratio. To return to the problem of maximum denudation rates for mountainous areas, it is now possible to adjust the data of Table 1 for an increase in relief. The data for the gaging stations on table 1 indicate that the maximum average rate occurs in a semiarid climate and is 0.34 feet per 1,000 years. As the slope or relief of the basins is increased, however, as it would with uplift, the sediment-yield rates will increase greatly. For example, when the average slope of a drainage basin or the ratio of relief to length increases from 0,005 to the right. Figure 2 may be viewed in another manner. If the curves can be considered the locus of points occupied by one drainage basin during a cycle of erosion (high relief is analogous to the geomorphic stage of youth), then the decrease in denudation rates with time during the erosion cycle is illustrated. In all the preceding discussion it should be remem- bered that the data on which figures 1 and 2 are based are representative of small drainage basins under a semiarid climate and underlain by sedimentary rocks. Therefore, only the general shape of the curves and the form of equation 1 may be considered as an approxima- tion to large-scale denudation. RATES OF OROGENY Before one can discuss the implications of the de- nudation rates presented here, consideration should be given to rates of orogeny. To be comparable to modern rates of denudation, the rates of orogeny should be modern measured rates rather than rates based on a study of the geologic history of an area. For example, Zeuner (1958, p. 360) presents data showing that uplift occurs at rates of a fraction of a millimeter per year when the age of a formation exposed in the Alps or Himalayas is divided by its present altitude. The rates obtained are only minimum values for the actual rate of uplift, which probably occurred during a rela- tively short time. DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY 1000 100 ESTE T Sediment yield (acre-feet per square mile) 675127-63--2 .02 .04 .06 .08 "10 Te. © Relief-length ratio FIGURE 1.-Relation of sediment-yield rates to relief-length ratio. H5 't oin@y uf umoys UopBJOI uo postq st z oan) '¢0°0 st opr yjSuat-JoroI uoum sreo4 QOQ'T dod joo; g Jo ore uoppepnuop oy}; uo postq SJ T JAIN) 'SofU arenbs 008'T yo stoue a@Bureip 0; pojSN[pPE ort sored 'JoIlOI put ope: 0; sojer uorpepnuop go Uo HUODLE ojyp1 - I" 80° 90° vo cO 0 (1991) sallaX | O00°'0¢ : 000 02 | v 000° 01 _ 6 ~ | SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY H6 (ses Je. < tel ee) o (s1D0a4 ooo; 12d 1981) uouuppnueg ol DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY Rates of orogeny being measured at the present in- stant of geologic time are far in excess of the minimum values obtained by geologic studies Gilluly (1949) lists some rates of uplift for areas in California in an effort to demonstrate that orogeny is an important as- pect of the present. The rates listed are as follows: Location Uplift (feet per 1,000 years) San: L0 c; 17 Buenat¥ists Hills..._._..___.M C_ Cel: i nL 42 Cajon {{ (I* __ (of' Aaye: t_ 20 Baldwin Mills. {L ~' 29 ZPIAIT .- 2 2. . -.. _. 2 _ 2 ..." 222 nnn e bub n ee nl anna n e daal 16 The average of these values is 25 feet per 1,000 years. All these rates of uplift are greatly in excess of the highest rates of denudation presented in table 1, but they are of the same order of magnitude as maximum rates of denudation for very small areas underlain by easily erodible materials, loess and shale. A recent report on rates of orogeny (Stone, 1961) from results of repeated precise leveling in the Los Angeles area reveal that some stations on the flanks of the Santa Monica Mountains are rising at a rate of 13 feet per 1,000 years. This rate applies also to some stations on the south flank of the San Jose Hills. Sta- tions on the south flank of the San Gabriel Mountains are rising at a rate of 20 feet per 1,000 years. Gutenberg (1941) has compiled information on post- glacial uplift in Fennoscandia and North America. Maximum uplift at the head of the Gulf of Bothnia is 110 centimeters per 100 years or 36 feet per 1,000 years. Geologic evidence indicates the total uplift during the past 7,000 years to be 100 meters or a rate of 48 feet per 1,000 years. Present rates of uplift in North America are 50 centimeters per 100 years to the north of Lake Superior, a rate of 16 feet per 1,000 years. Guten- berg (1941) estimates that present rates of uplift aver- age about half the average for the past 4,000 years. Uplift of about 500 meters has occurred and an addi- tional uplift of 200 meters is required to establish equilibrium. Because over two-thirds of the adjust- ment has been accomplished, the rates of uplift are slowing but still are high in comparison to rates of denudation. In contrast to uplift occurring as a result of de- crease of load, Lake Mead provides an example of rapid subsidence caused by the addition of 40 billion tons of water and 2 billion tons of sediment (Gould, 1960) to an area of 232 square miles (147 pounds per square inch). Subsidence is occurring at a rate of 40 feet per 1,000 years although total subsidence is expected to be only 10 inches (Longwell, 1960). Average rates of uplift measured on the eastern Eu- ropean plain of Russia range from 6.5 to 13 feet per 1,000 years (Mescheryakov, 1958) ; maximum rates are H7 83 feet per 1,000 years. Data presented by Tsuboi (1933) show an average rate of uplift for leveling sta- tions in Japan of 15 feet per 1,000 years and a range from 250 to 2.6 feet per 1,000 years. Lees (1955) re- ports rates of uplift in the Persian Gulf area at 33 and 10 feet per 1,000 years. The above rapid rates of uplift were measured in tectonically active areas or those adjusting to increase or decrease of load. On the other hand, data obtained on epeirogenic uplift along seacoasts (Cailleux, 1952) show that uplift is occurring at an average rate of only 3.2 feet per 1,000 years. The range is from 12 to 0.3 feet per 1,000 years. It is to be expected that slow rates of uplift will be measured even in tectonic areas, for the beginnings and end of orogeny are probably slow. Some data on present rates of orogeny indicate that these rates are very rapid. Although it is not certain that uplift will continue at these rates, it seems prob- able that the formation of mountain ranges occur at rates comparable to the rates measured in existing mountains. That is at a rate approaching 25 feet per 1,000 years. SUMMARY Calculations based on the best available recent data indicate that denudation will occur at the average maximum rate of 3 feet per 1,000 years in the early stage of the erosion cycle and that an average rate of denudation will be about 0.25 feet per 1,000 years when effective precipitation is less than 40 inches and drain- age area is 1,500 square miles. The relation of relief-length ratio to sediment yield shows that denudation rates will be an exponential function of drainage-basin slope or the relief of a drainage basin of constant size as it is raised by uplift or lowered by denudation. Modern rates of orogeny are about 25 feet per 1,000 years, or about 8 times greater than the average maximum rate of denudation. Existing data show a marked unbalance between the recent rates of orogeny and denudation. DEDUCTIONS FROM THE COMPARISON OF RATES OF ' OROGENY AND DENUDATION Based on the preceding conclusion that rates of orogeny are rapid in relation to maximum rates of denudation, it is possible to reconsider some classic geologic and geomorphic problems relative to hill- slopes, peneplains, and the effects of isostastic adjust- ment and denudation on landforms. THE EROSION CYCLE Davis' assumption of rapid uplift of mountain ranges, which allows little erosional modification of the area before the cessation of uplift, is supported to HS some extent by the disparity between rates of uplift and denudation. Depending on rock type, the rapidly uplifted block may either be little modified by stream incision or significantly modified by it. Nonetheless, when uplift stops, channel incision should be occurring at a maximum rate. The uplifted area, therefore, would be in a youthful stage of geomorphic develop- ment or in the beginning of the Davisian cycle. How- ever, if there is isostatic adjustment during the cycle of erosion, uplift will reoccur, perhaps intermittently, throughout much of the cycle. This will extend the duration of and complicate the cycle, but the basic principle of the evolution of landforms from a youth- ful topography is not changed. HILLSLOPES If channel incision is occurring at a rapid rate when uplift ceases, a hillslope profile will not reflect varying rates of diastrophism as suggested by Penck (1953), for long before the slope form could change from convex to concave in response to a waning of the en- dogenetic forces, uplift would have ceased. In spite of the fact that most rates of orogeny exceed maximum denudation rates, it is possible to conceive of extremely slow, perhaps epeirogenic, uplift. When uplift is slow in an area of high relief, denudation would be at a maximum, and the landforms would change in relation to the dominant factor of rapid denudation rather than from the effects of slow uplift. If the uplift were long-continued, however, the de- crease in the rate of denudation with reduction of relief might continue until it equalled the rate of slow uplift. It is difficult to visualize what effect this balance might have on landforms, but it has been suggested that when uplift and denudation are equal an equilibrium or time- independent landform develops (Penck, 1953, Weg- man, 1957, p. 5). If an area of low relief is slowly uplifted at rates equal to or less than the denudation rates, it would seem that little change in the landscape would occur and that again equilibrium landforms, whatever these might be, would be maintained. This conclusion is, I believe, incorrect and results from the fallacy of assuming that because denudation rates are calculated as a uniform lowering of a land surface that denudation, in fact, occurs in this manner. Obviously it does not, for the forces of denudation are composed of two parts, hillslope erosion and stream channel erosion. - Channel erosion may be rapid and in some cases approach the rate of uplift, but hillslope erosion is much less effective in lowering interfluve areas. A theoretically perfect balance between rates of uplift and denudation will, therefore, manifest itself by channel incision and extension of the drainage pat- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY tern. Mescheryakov (1959), for example, attributes recent channel erosion in the south Russian steppes to contemporary uplift. Attempts to relate hillslope form to the interaction of rates of uplift and denudation (Penck, 1953) seem misguided in view of the importance of factors other than orogeny in determining hillslope form. Varia- tions in hillslope form in areas of homogenous mate- rials can best be explained as the result of available relief (Glock, 1932; Schumm, 1956@) or the erosion process (Schumm, 19560). The data presented here show that uplift in orogenic areas will be rapid. In fact, figure 2 (curve 2) shows that maximum denudation rates do not reach the aver- age rate of uplift, 25 feet per 1,000 years, until relief is well above 20,000 feet. If so, differences in hillslope form should not be a result of the disparity between uplift and denudation, but probably are the result of the difference between the two components of denu- dation, rates of channel incision and hillslope erosion. For example, when rocks are very resistant, channel incision will be relatively much greater than hillslope erosion and a narrow canyon is formed. When the rock is less resistant, weathering and erosion on the upper slope form a convex profile. More easily eroded material will pass from an initially convex to a straight and then possibly to a concave profile in relatively rapid succession. This evolution has been noted in badlands (Schumm, 1956a, p. 635), where erosion in the channels and on the slopes proceeds at a rapid rate. Time-independent or equilibrium landforms probably cannot result from a theoretical balance be- tween uplift and denudation. If time-independent forms did develop, it would be as a result of rapid chan- nel incision in response to rapid uplift. For example, if uplift is rapid and of a large amount, initial channel incision will form convex hillslopes, but as channel deepening continues and if the rock is easily eroded, steep straight slopes will result which may be main- tained at an angle typical of this material (Strahler, 1950). Again such slopes have been observed in bad- land areas where channel incision and slope erosion is rapid (Schumm, 19560). In conclusion, although slow uplift cannot be ne- glected entirely, rapid uplift probably is the rule in orogenic areas, as the existence of mountains attest. If rates of uplift in orogenic regions always exceed denu- dation rates, then hillslope form will not reflect the relation between uplift and denudation. Further, a theoretical balance between rates of uplift and denuda- tion would be reflected in channel incision rather than by equilibrium landforms. DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY PENEPLANATION Some questions have been raised not only with regard to the cycle of erosion but also with regard to the pene- plain itself. For example, Gilluly's (1949) conclusion that diastrophism has not been periodic but was almost continuous through time has been used as evidence against the uninterrupted evolution of landforms through a cycle of erosion as deduced by Davis. This objection has also been leveled at the concept of pene- planation (Thornbury, 1954, p. 189). However, Gil- luly qualified the above statement to indicate that the location of diastrophic movements has continually changed. This shift in location is the crucial point in this connection, for when a period of stability occurs in a given tectonic area, a pediment or peneplain may form if the period of stability is long enough. Davis (1925) estimated 20 to 200 million years was required for the planation of fault-block mountains in Utah. If, as some assume (de Sitter, 1956, p. 471), there are periods of about 200 million years of "relative quiescence" following shorter periods of diastrophism, then the cycle of erosion must run its course and pene- planation must occur within 200 million years. The upper estimate of Davis is close to the maximum allow- able time, and the need for such long periods of sta- bility introduces an element of the implausible. Recent estimates of the time involved in peneplana- tion involve much shorter periods; without isostatic readjustment, the continental United States could be reduced to base level in about 10 million years (Gilluly, 1955, p. 15). This figure is only one-twentieth of the allowable time, but no correction for isostatic readjust- ment during erosion of this mass of rock has been made. This is an extremely important factor which may in- crease the time required for peneplanation by a factor of five or much more. For example, Holmes (1945, p. 190) considers that to reduce a land surface by 1,000 feet, erosion of 4,000 feet of material would be required ; that is, there would be 3,000 feet of isostatic adjustment to erosion. Gilluly (1955, p. 14) in his calculation of the time required for the planation of mountain areas, areas more than 0.2 kilometers in elevation, allows for the erosion of 5.5 times the volume of existing mountain areas owing to isostatic uplift. Considering this iso- static factor, Gilluly (1955) concludes that 33 million years are necessary for the planation. To use the denudation rates presented in table 1 and figure 2 to calculate time required for peneplanation, it is necessary to consider the 1,500 square mile areas as components of a larger area. It is possible to visu- alize a series of such basins alined and forming a mountain range. - Assuming our model mountain range is so composed and has 15,000 feet of relief then it HQ should be possible to calculate the time required for peneplanation using the changing rates of denudation shown in figure 2. However, it is difficult to know what amount of denudation is required for peneplanation. It appears that if a mountain block were uplifted 15,000 feet, denudation may need only remove about 5,000 feet of rock, for the adjacent lowlands are being built up by deposition of sediment as the mountains are eroded. This is a complication not shown in figure 2. Let us assume that 5,000 feet of rock must be eroded for peneplanation. If rates of denundation for the 1,500-square-mile drainage basins are average, all except the basins within the 40-60 inch range of effective pre- cipitation fall within the 200-million-year time limit for peneplanation (table 1, column 5). If less than 5,000 feet of denudation were required for peneplana- tion, then all would fall within the time limit. The smaller drainage basins (80 square miles) require much less time for planation as expected (table 1). From figure 2 (curve 1) it is possible to obtain denudation rates during the lowering of the mountain range 5,000 feet. At 15,000 feet on the maximum curve, denuda- tion is 2.6 feet per 1,000 years ; at 10,000 feet denudation is 1.1 feet per 1,000 years. If the denudation rate at 12,500 feet (1.6 feet per 1,000 years) is the average of these rates, 3 million years are required for the reduc- tion of 5,000 feet of relief. If isostatic compensation requires a 5-fold adjustment, then peneplanation will occur in 15 million years. On the curve obtained from sediment yields of small drainage basins (fig. 2, curve 2), the average denuda- tion rate between 15,000 and 10,000 feet is 0.23 feet per 1,000 years. At this rate peneplanation would require about 110 million years. These periods of time seem short enough to make peneplanation a distinct possi- bility in the geologic past. Much has been ignored in the above analysis, for example, the effects of uplift on the climate of the area and vegetative changes during geologic time. Never- theless, if denudation occurred at the maximum rate, (3 feet per 1,000 years), an area with 5,000 feet of relief would be reduced to base level in 10 million years. DENUDATION AND ISOSTASY Isostatic adjustment to erosion will occur continu- ously with denudation only if the earth's crust behaves as a fluid. The crust has considerable strength locally (Gunn, 1949, p. 267) ; before isostatic adjustment can occur, this strength should be exceeded by the removal of rock by denudation. Indeed, even when the strength is exceeded there may be a lag before isostatic adjust- ment occurs as that which allowed submergence of glaciated lands following the melting of the Pleistocene H10 ice sheets (Charlesworth, 1957, p. 1361). In addition, isostatic adjustment to the retreat of the Pleistocene ice sheets was episodic (Lougee, 1953). This adjustment may be explained most simply by assuming that iso- static adjustment accompanied periods of rapid melting of the ice and that no uplift occurred during pauses in deglaciation. However, one may object to this simple explanation on the grounds that pulses of rapid iso- static adjustment followed rapid melting with a lag of about 2,000 years (Charlesworth, 1957, p. 1345). Many field studies indicate that discontinuous epi- sodes of uplift occurred in most mountain ranges. For example, Wahlstrom (1947, p. 568) states that uplift of the Front Range in Colorado "to its present eleva- tion was not the result of a single upheaval. The presence of more or less poorly developed terraces in the canyons * * * and well-developed terraces in the valleys east of the mountains suggests intermittent uplifts." In general, a discussion of these multiple terraces and stepped erosion surfaces, when it is assumed that they have been formed by uplift alone, raises the subject of the role of isostatic adjustment to denudation as a factor in their formation. Whether isostatic adjust- ment to denudation will occur in a given area depends on the local strength of the earth's crust. Any one of three conditions for adjustment may prevail in a given area: mechanical equilibrium whereby a rigid crust is capable of supporting uncompensated loads; isobaric equilibrium whereby there is a regional compensation for loading or unloading; and isostatic equilibrium whereby a local compensation to loading or unloading occurs along fractures in the crust (Hsu, 1958). Com- pensation for deglaciation is isobaric, whereas compen- sation for denudation will generally be isostatic. The episodic nature of isostatic adjustment to de- glaciation and the disparity between rates of uplift and denudation in orogenic areas suggest that isostatic ad- justment to denudation will also be episodic. When initial diastrophism occurs, uplift will be relatively rapid until an equilibrium is approached. Orogeny will then cease, and denudation will proceed at a slower rate until the strength of the crust is exceeded, when rapid isostatic adjustment should occur. This relation is shown diagrammatically in figure 3. The orogeny raises the area 15,000 feet; during and following the orogeny, denudation rates increase to a maximum, to be followed by a decline as relief is lowered. This orderly sequence of events is interrupted by a short period of isostatic adjustment, during and following which denudation rates again increase to a maximum. Tf the result solely of isostasy, the succeeding uplifts will not reach the altitude of the initial uplift due to 'SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY mountain-building processes. If such a relation be- tween denudation and isostasy exists, the topographic form of many mountain ranges will be due to episodes of isostatic uplift as well as to the postorogenic uplift discussed by Pannekoek (1961). Depending on the strength of the crust in a given area, the recurrent isostatic adjustment may be long delayed and large, or more frequent and of smaller magnitude. Renewed tectonism can interrupt these epicycles of denudation and uplift but, if tectonism ceased after initial uplift, the sequence of erosion and isostatic ad- justment may be considered analogous to a positive feedback system. Initial uplift increases denudation rates which in turn increase the tendency for further uplift; when this removal of material per unit area is such that it exceeds the strength of the crust, isostatic adjustment occurs and the cyele begins again. These epicycles within the cycle of erosion occur because the components of the system, denudation and isostatic ad- justment, operate at greatly different rates. These epicycles, if real, may partly explain the occurrence of multiple terraces, multiple or warped erosion sur- faces, and piedmontreppen. For example, King (1955) and Pugh (1955) have attributed the multiple searps and erosion surfaces formed in western and southern Africa to periods of isostatic adjustment caused by the retreat of major scarps over long distances from the sea coast. With the preceding hypothesis in mind, it is instruc- tive to compare the condition of isostatic adjustment in young and old mountain ranges. Most of the younger mountain ranges (Rockies, Alps, Andes, Himalayas) have a deficiency of mass at depth, which causes a Bouguer anomaly of about -300 milligals (mgal). This deficiency compensates for the mass of the mountains above sea level, and the young moun- tains are in isostatic balance. The old, eroded moun- tain ranges (Appalachians), however, have a smaller deficiency of mass, and although the Bouguer anom- alies may be only 0 to 100 mgal, the mass deficiency is larger in many cases than is required for isostatic com- pensation. "As a result, isostatic anomalies of ap- proximately -50 mgal may be obtained, indicating that erosion and reduction in elevation in these areas has proceeded faster than the readjustment of the compen- sating mass at depth" (Jacobs, Russell and Wilson, 1959, p. 100). It would be possible to conclude from this quotation that denudation works faster than uplift, but the data just reviewed disprove this, even if (as figure 3 shows), during long periods of geologic time, denudation does continue while uplift is dormant. The isostatic anom- alies in old, eroded mountain ranges, therefore, seem DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY H11 Relief (feet) co Denudation and uplift _ > a . 5. a. :g (feet per 1000 years) O O e] O pra anale pel panne o easton Orogenic 'X 7 - Isostatic -- ) , 3 @ I -Ispstafic ; *~-- - 3 a- Isostatic ~- -> FicUrE 3.-A, Hypothetical relation of rates of uplift and denudation (solid line) to time. B, Hypothetical relation of drainage- basin relief to time as a function of uplift and denudation shown in 4. H12 to indicate that erosion, although considerable, is not enough to trigger another isostatic adjustment. The young mountain ranges, however, may not be signifi- cantly affected by denudation since the last isostatic adjustment, or these adjustments may occur more fre- quently in the younger ranges and prevent any major isostatic anomaly. Rapid denudation in the younger ranges of high relief make it likely that frequent ad- justments keep the young ranges almost in isostatic balance. Evidence of these epicycles should appear in the stratigraphic record. For example, in sediments derived from an area subjected to cyclic isostatic uplift, gravels might recur through a great thickness of sedi- ment. An example of this as cited by Gilluly (1945) is the Sespe Formation of Eocene and Oligocene age which represents a depositional period of 12 to 15 mil- lion years. The recurrent uplift proposed by Gilluly to explain the persistence of coarse sediments in the Sespe Formation may be partly the result of isostatic adjustment to denudation as discussed above. CONCLUSIONS Tentative conclusions based on present rates of denu- dation and uplift are presented as follows : 1. Rates of denudation for areas of about 1,500 square miles average 0.25 feet per 1,000 years and reach a maximum of 3 feet per 1,000 years. These rates are relatively rapid and are representative of areas for the most part underlain by sedimentary rocks in a semiarid climate. Denudation rates in humid regions are about four times slower. 2. Present rates of orogeny exceed rates of denudation significantly. An average maximum rate of orogeny is about 25 feet per 1,000 years. 3. The rapid rates of orogeny in contrast to denuda- tion and valley cutting make it unlikely that hill- slope form can be used to decipher the earth's recent diastrophic history. Rather the form of a hillslope profile in an area of high relief probably reflects the difference in rates of channel incision and hillslope erosion. 4. Because denudation has two components, channel and hillslope erosion, which operate at much different rates, a balance between rates of denudation and up- lift will not yield time-independent or equilibrium landforms. 5. Relatively rapid rates of denudation make pene- planation a very likely event under conditions which were probably common in the geologic past. Plana- tion of 5,000 feet of relief may require perhaps 15 to 110 million years. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 6. An erosion cycle will be interrupted by periods of rapid isostatic adjustment separated by longer stable periods of denudation. 7. The episodic recurrence of isostatic adjustment may partly explain the existence of multiple or warped erosion surfaces, the recurrence of coarse sediments through a thick sedimentary deposit, and isostatic anomalies in old mountain ranges. REFERENCES CITED Brune, G., 1948, Rates of sediment production in midwestern United States: Soil Conservation Service Tech. Pub. 65, 40 p. Cailleux, A., 1952, Récentes variations du niveau des mers et des terres: Geol. Soc. France, Bull. 6, v. 2, p. 135-144. Charlesworth, J. K., 1957, The Quaternary era : London, Edward Arnold, 2 v., 1700 p. Corbel, J., 1959, Vitesse de 1'Erosion : Zeitschr. Geomorph., v. 3, p. 1-28. Davis, W. M., 1925, The basin range problem : [U.S.] Natl. Acad. Sci. Proc., v. 11, p. 387-392. Dole, R. B., and Stabler, H., 1909, Denudation: U. S. Geol. Survey Water-Supply Paper 234, p. 78-93. Federal Inter-Agency River Basin Comm., 1953, Summary of reservoir sedimentation surveys for the United States through 1950: Subcomm. on Sedimentation, Sedimentation Bull. 5, 31 p. Flaxman, E. M., and High, R. D., 1955, Sedimentation in drainage basins of the Pacific Coast States: Soil Conservation Service, Portland [mimeographed]. \ Gilluly, James, 1949, Distribution of mountain building in geologic time: Geol. Soc. America Bull., v. 60, p. 561-590. 1955, Geologic contrasts between continents and ocean basins: Geol. Soc. America Special Paper 62, p. 7-18. Gilluly, J., Waters, A. C., and Woodford, A. O., 1951, Principles of geology : San Francisco, W. H. Freeman & Co., 631 p. Gould, H. R., 1961, Amount of sediment, in Smith, W. O., Vetter, C. P., Cummings, G. B., and others, Comprehensive survey of sedimentation in Lake Mead, 1948-49; U.S. Geol. Survey Prof. Paper 295, p. 195-200. Glock, W. S., 1932, Available relief as a factor of control in the profile of a landform : Jour. Geology, v. 40, p. 74-83. Gunn, R., 1949, Isostasy-extended : Jour. Geol., v. 57, p. 263- 279. Gutenberg, Beno, 1941, Changes in sea level, postglacial uplift, and mobility of the earth's interior: Geol. Soc. America Bull., v. 52, p. 721-772. Holmes, Arthur, 1945, Principles of physical geology : New York, Ronald Press, 532 p. Hsu, K. J., 1958, Isostasy and a theory for the origin of geosyn- clines : Am. Jour. Sci., v. 256, p. 305-327. Jacobs, J. A., Russell, R. D. and Wilson, J. T., 1959, Physics and geology: New York, McGraw-Hill Inc., 424 p. Khosla, A. N., 1953, Silting of reservoirs: Central Board of Irrigation and Power [India] Pub. 51, 203 p. King, L. C., 1956, Pediplanation and isostasy : An example from South Africa: Geol. Soc. London Quart. Jour., v. 111, p. 353-359. Kulp, J. L., 1961, Geologic time scale: Science, v. 133, p. 1105 1114. DISPARITY BETWEEN PRESENT RATES OF DENUDATION AND OROGENY Langbein, W. B., and Schumm, S. A., 1958, Yield of sediment in relation to mean annual precipitation: Am. Geophys. Union Trans., v. 39, p. 1076-1084. Lees, G. M., 1955, Recent earth movements in the Middle East: Geol. Rundschau, v. 43, p. 221-226. . Longwell, C. R., 1960, Interpretation of the leveling data: U.S. Geol. Survey Prof. Paper 295, p. 33-38. Lougee, R. J., 1953, A chronology of postglacial time in eastern North America: Scientific Monthly, v. 76, p. 259-276. Menard, H. W., 1961, Some rates of regional erosion: Jour. Geol., v. 69, p. 154-161. Meshcheryakov, Y. A., 1959, Contemporary movements in the earth's crust : Internat. Geol. Rev., v. 1, p. 40-51 (Translated by A. Navon from Sovremennyye dvizheniya zemnoy kory : Priroda, 1958, no. 9, p. 15-24). Pannekoek, A. J., 1961, Post-orgenic history of mountain ranges : Geol. Rundschau, v. 50, p. 259-273. Penck, W., 1953, Morphological analysis of landforms : (Trans- lated) London, Macmillan, 429 p. Pugh, J. C., 1955, Isostatic readjustment in the theory of pedi- planation : Geol. Soc. London Quart. Jour., v. 111, p. 861-369. Russell, I. C., 1909, Rivers of North America: New York, G. P. Putnam's Sons, 827 p. Schumm, S. A., 1956a, Evolution of drainage systems and slopes in badlands at Perth Amboy, New J ersey: Geol. Soc. America Bull., v. 67, p. 597-646. :% H13 1956b, The role of creep and rainwash on the retreat of badland slopes: Am. Jour. Sci., v. 254, p. 693-706. Schumm, S. A., and Hadley, R. F., 1961, Progress in the appli- cation of landform analysis in studies of semiarid erosion : U.S. Geol. Survey Circular 437, 14 p. Sitter, L. U. de, 1956, Structural geology: New York, McGraw- Hill, Inc., 552 p. Stone, Robert, 1961, Geologic and engineering significance of changes in elevation revealed by precise leveling, Los Angeles area, California [abs.]: Geol. Soc. America Spec. paper 68, p. 57-58. Strahler, A. N., 1950, Equilibrium theory of erosional slopes approached by frequency distribution analysis: Am. Jour. Sci., v. 248, p. 673-696, 800-814. Thornbury, W. D., 1954, Principles of geomorphology: New York, John Wiley & Sons, 618 p. Tsuboi, C., 1933, Investigation on the deformation of the Earth's crust found by precise geodetic means: Japanese Jour. Astronomy and Geophysics : v. 10, p. 93-248. Wahlstrom, EH. E., 1947, Cenozoic physiographic history of the Front Range, Colorado: Geol. Soc. Am. Bull., v. 58, p. 551-572. Wegman, E., 1957, Tectonique vivante, dénudation et phéno- méenes connexes: Rev. Géog. Physique et Géol. Dynamique, pt. 2, v. 1, p. 83-15. Zeuner, F. E., 1958, Dating the past: 4th ed., London, Methuen & Co., 516 p. U.S, GOVERNMENT PRINTING OFFICE:1963 Ia 7D 26 : _ Z4SZ /: Z 7" The Late Cretaceous Cephalopod Haresiceras Reeside and Its Possible Origin | GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-I The Late Cretaceous Cephalopod Haresiceras Reeside and Its Possible Origin By WILLIAM A. COBBAN SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-1 Haresiceras, which seems to have been derived from the scaphitid stock of ammonites, provides a means of correlating thin units of strata in the Western Interior region UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Page nl. .L. .D Ui ei. 11 | Sequence of fossils-Continued introduction cc _>. .L... cE 000 lay. 1 Buffalo area in north-central 19 Geographic distribution....._._.__......__....l....l. 1 Salt Creek oil field in east-central Wyoming_______. 9 Sequenceiof fossils. 1 Wind River Basin in west-central Wyoming_______. 9 Sweetgrass arch in northwestern Montana---______ 4 Green River area in east-central Utah_____________ 10 Mosby area in east-central Montana_-____________ 6 Summary of faunal sequences ___________________ 10 Porcupine dome ‘in east-central 6 ! Age of sg 00 11 Black Hills uplift in southeastern Montana and Origin of and evolution within Haresiceras . _ ___ ___ __ ___ 11 western South 6 id Lic d pt! [ Elk Basin area in southern Montana and northwest- d - . ol cuss -c ne em Wyoming... 9 { cited... oustees 18 Hardin area in south-central Montana_____________ 8 .. sl eca ses 21 ILLUSTRATIONS [Plates follow index] Page Prats 1. Desmoscaphites, Clioscaphites, Haresiceras, and Scaphites. 2. Haresiceras. 3. Haresiceras and Clioscaphites. Frounr 1? IndoX® MAD. --.... .... s 0 ols 22+ co as wie ae on a e mule kins mik n's ale BE blalm Bt ae minn ae tie an o a naw ain aln ak sine ank as I 2 2-4. Stratigraphic relations- 2. Between northwestern Montana and the Black 5 8. Botween EJK Basinand n L2 lulu an ar cles an man o nin aan kine mda ue nog eep eas 7. 4. Between the Wind River Basin and 10 5. Lineages of Clioscaphites, Desmoscaphites, and 12 6. Sutures of Clioscaphites, Desmoscaphites, and 00> 14 7. Cross sections of Haresiceras ssn nian ad annneanae we 15 TABLES Page TABLE 1. Localities at which fossils were 13 2. Possible correlation of the zones of Haresiceras to the late Santonian and early Campanian faunal zones in Europe. 11 IH SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY THE LATE CRETACEOUS CEPHALOPOD HARESICERAS REESIDE AND ITS POSSIBLE ORIGIN By Wiruran A. ComBax ABSTRACT The ammonite Haresiceras is known from 43 localities in the Western Interior of the conterminous United States. The genus is represented by at least four species, which are from oldest to youngest, Haresiceras mancosense (Reeside), H. montan- aense (Reeside), H. placentiforme Reeside, and H. natronense Reeside. A fifth form, H. fisheri Reeside, may be a variant of 'H. natronense. Haresiceras mancosense and H. montanaense are each represented by two forms, an early form and a late form. The older species of Haresiceras are stouter than the younger species and have less complex sutures. These older species have constrictions on the early juvenile whorls, arched to nearly flat venters, and ribbing differentiated into primaries and second- aries on the adult body chamber ; later species lack constrictions, possess flat to slightly concave venters, and have ribbing tending to be of uniform strength on the adult body chamber. The earliest species, Haresiceras mancosense, which com- bines characters of Clioscaphites, Desmoscaphites, and Hare- siceras, is assigned to a new subgenus Mancosiceras. Inasmuch as Haresiceras (Mancosiceras) mancosense is contemporane- ous with Desmoscaphites but younger than Clioscaphites, it probably was derived from some species of Clioscaphites that trended toward compression of the whorls and flattening of the venter. Clipscaphites platygastrus bridges the gap well between the stouter and more round-ventered species of Clioscaphites and the more slender H. (M.) mancosense. Haresiceras (Mancosiceras) mancosense is associated with Desmoscaphites, Uintacrinus, and Marsupites of late Santonian age. Haresiceres placentiforme, H. natronense, H. fisheri, and the late form of H. montanaense are found with Scaphites hippocrepis of early Campanian age. The early form of H. montanaense occurs in rocks older than those containing Scaphites hippocrepis and younger than those containing Des- moscaphites and free-swimming crinoids; a very early Cam- panian age seems to be the best choice. INTRODUCTION Haresiceras is a rare ammonite known only from the Western Interior of the conterminous United States. This genus, for C. J. Hares, was estab- lished by Reeside (19274, p. 17) to include small am- monites that have compressed whorls, very narrow umbilicus, flat venter bordered by small ventrolateral nodes, weak sigmoidal ribs that cross the venter with a forward arching, and sutures characterized by a long triangular first lateral lobe. Three species were de- scribed, H. placentiforme (genotype), H. natronense, and H. fisheri. Reeside, with some reservations, as- signed Haresiceras to the subfamily Hoplitinae of the family Cosmoceratidae [Kosmoceratidae] Haug. In addition to these species of Haresiceras, Reeside (19272, p. 15, 20) described two other ammonites, which he named Puzgosia (Latidorsella) mancosensis and Acan- thoceras? montanaense. These two ammonites are in- cluded in the present treatment because the writer believes they are early forms of Haresiceras. Since the publication of Reeside's important paper, new collections of fossils that include his species have been made from carefully measured stratigraphic see- tions by geologists of the U.S. Geological Survey and of oil companies. These collections have shed con- siderable light on the age relations of the various species of Haresiceras and on the possible origin of the genus. The present investigation was prompted by a need for close zoning of strata adjoining the boundary of the Colorado and Montana Groups. The presence of Haresiceras in rocks assigned to the Colorado Group as well as in rocks assigned to the Montana Group has been pointed out previously (Cobban and others, 1962). The figured specimens are in the U.S. National Mu- seum, Washington, D.C. R. E. Burkholder, of the Geological Survey, photographed the fossils. GEOGRAPHIC DISTRIBUTION Haresiceras is known from 48 localities in the West- ern Interior. The general position of each locality is shown in figure 1. Detailed data concerning the locali- ties, stratigraphic position, and collectors are given in table 1. SEQUENCE OF FOSSILS Reeside recognized as long ago as 1924 (p. 11, 12, pl. 3) a Telegraph Creek fauna and a younger Eagle fauna named for the two oldest formations of the Montana Group. Later, Desmoscaphites bassleri Reeside was designated the guide fossil for the Telegraph Creek fauna and Sceaphites hippocrepis (DeKay) the index I1 12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY $ ® Glaci ---: ace CANADA have pae ias - mcg" 40000 "Park - (2&2 dome UNITED STATES (* B I ) a S8 +4 1 ® Cg) “26,5 \l§ “é r; A Great Falls South Arch jel p> 5 [2 Mosbyo+\ E oe Porcupine § \ dome || , 8 , L———— *> 1‘ Billingso Hardin % $t sass s O + the I National ) £ 2 hast & ww ot ee nee ee tnd hane nove ein anat one | Ek #14 +18 ¥ o \ p Basin , *~. 18 33 m X ( \1Yellowstong 15-fi\ J 4 aP s I A" ; Elgin Creew"*~ - Buffalo ¥ -Rapid City I I o I +25 ; 26 \ a 27 0 ©, 23,24 * \ o 1 D A H O | - ghotgun Butte" \ 1 3 Conant Creek roi" ll , 28 ©~1£:29,30 Casper \ I I w - ¥ : :0 ¥ _ I y . C. z I I 23 sola |E , 31 Rawlins ff; 3 > I I Rock Springs O? 2 Z ~+ o SALT LAKE CITY _ 38 I *40 I al 37 341 DENVER 38+O+ 39 Green River Pueblo , 42 -- -—'_——___—_~____“+ ades _—-__—_——__________—A ARIZONA | s NEW MEXICO 3 | o 50 100 150 _ 200. MILES I | | | FicUrE 1.-Index map showing Haresiceras localities and the lines of sections of figures 2-4. Numbers refer to the detailed description of localities in table 1. CRETACEOUS CEPHALOPOD HARESICERAS TaBu® 1.-Localities at which fossils were collected 13 1.-Localities at which fossils were collected-Continued - .S. Geo- Locality UigéicGa‘io Collector and year of collection, description of locality, Locality Ulosgicafio Collector and year of collection, description of locality, on figure Survey and stratigraphic assignment on figure Survey and stratigraphic assignment 1 Mesozoic 1 Mesozoic locality locality 1x '-.. 11995 | A. J. Collier, 1923. Three miles northwest | 17._____ 21851 | J. B. Reeside, Jr., and D. A. Andrews, 1938. of Kevin, in see. 17, T. 35 N., R. 3 W., Sec. 16, T. 57 N., R. 98 W., Park County, Toole County, Mont. Marias River Wyo. From just below Elk Basin Sand- Shale, 20 ft below top. stone Member of Telegraph Creek Forma- l 21420 | W. A. Cobban, 1948. Eight miles west of tion. Shelby, in the NEM sec. 31, T. 32 N., | 18..____ 9740 | C. J. Hares, 1916. Six miles northwest of R. 3 W., Toole County, Mont. - Telegraph Lovell, north of Shoshone River, in T. Creek Formation, 24-35 ft above base. 57 N., R. 95 W., Big Horn County, Wyo. Byd... D696 | W. L. Rohrer, 1955. SMSWMNWM sec. Elk Basin Sandstone Member of Telegraph 31, T. 32 N., R. 3 W., Toole County, Creek Formation. Mont. Telegraph Creek Formation, 148 | 19._____ 22822 | R. K. Hose and W. J. Mapel, 1950. North ft above base. of Elgin Creek in the NEMZNWMH sec. 13, 4....~. 20774 | G. W. Beer, 1946. Sec. 19, T. 30 N., R. T. 49 N., R. 83 W., Johnson County, Wyo. 5 E., Liberty County, Mont. Telegraph Cody Shale, from limestone concretions Creek Formation, 49 ft above base. 748 ft below Shannon Sandstone Member. oA... 21405 | W. A. Cobban, 1948. About 3.4 miles east | 20-_____ 12730 | W. W. Rubey, 1924. SEV sec. 32, T. 49 N., of Mosby, in the SWMNEMSEM sec. 5, T. R. 66 W., Crook County, Wyo. From 14 N., R. 31 E., Garfield County, Mont. 175 ft above base of Gammon Ferruginous Gammon Shale, 45 ft above base. Member of Pierre Shale. Cel u. D3519 | J. R. Gill, 1961. Thirty-six miles west- | 21--___ 12054 W. W. Rubey, 1923. North of Mud Creek, northwest of Forsyth in the NWMNWM in the NW 14 sec. 30, T. 56 N., R. 67 W., see. 36, T. 12 N., R. 38 E., Rosebud Crook County, Wye. From limestone County, Mont. Gammon Shale, from at concretions in Gammon Ferruginous Mem- least 125 ft above base. ber of Pierre Shale. D3520 | W. A. Cobban, 1948. Thirty-seven miles | 22.____ 12714 W. W _ Rubey, 1924. See. 26, T. 58 N., R. west-northwest of Forsyth in the SEM 61 W., Crook County, Wyo. From 120 see. 27, T. 12 N., R. 38 E., Rosebud ft above base of Gammon Ferruginous County, Mont. From lower part of Member of Pierre Shale. Gammon Shale. 23... 23110 J. B. Reeside, Jr., and others, 1950. East 11208 | W. T. Thom, Jr., 1922. SWL see. 26, T. 1 Sheep Creek in the NWLHSEL{NEL4 sec. S., R. 27 E., Yellowstone County, Mont. 23, T. 6 N., R. 2 E., Fremont County, Telegraph Creek Formation. Wyo. Cody Shale, from about 1,275 ft 0:..-...- 9649 | C. J. Hares, 1916. Sec. 27, T. 7 S., R. below top. 28 E., Carbon County, Mont. From 150 | 24-____ 23112 M. L. Troyer, W. R. Keefer, and R. Burn- ft below Elk Basin Sandstone Member of side, 1950. East Sheep Creek in the Telegraph Creek Formation. see. 23, T. 6 N., R. 2 E., 10: .... . 10752 | T. W. Stanton and W. T. Thom, Jr., 1921. Fremont County, Wyo. Cody Shale, Between Shoulderblade Butte and St. from 550 ft below top. Xavier Mesa, near the south quarter | 25. -__ 9454 C. T. Lupton, 1915. Five miles southwest corner see. 27, T. 4 S., R. 33 E., Big Horn of junction of Buffalo and Nowood Creeks County, Mont. Near base of Telegraph in T. 44 N., R. 88 W., Washakie County, Creek Formation. Wyo. Cody Shale, from 250 ft below 11}. =_. 12631 | W. W. Rubey, 1924. Sec. 1, T. 9 S., R. 56 top. E., Carter County, Mont. From Gam- | 26-____ 23457 J. B. Reeside, Jr., and others, 1950. Along mon Ferruginous Member of Pierre Shale, ~ road to West Sussex oil field about 10 20 ft below Groat Sandstone Bed. miles southeast of Kaycee, Johnson 12... 12639 | W. W. Rubey, 1924. S%4 sec. 12. T. 8 S., County, Wyo. Cody Shale (Steele Shale R. 56 E., Carter County, Mont. - Gammon of former usage). Ferruginous Member of Pierre Shale, | 27..... 10701 J. B. Reeside, Jr., 1921. Half a mile west about 400 ft below Groat Sandstone Bed. 3 of Castle Rock in Salt Creek oil field, 18.....0 28477 | W. A. Cobban, 1941. Head of Owl Creek Natrona County, Wyo. Cody Shale in the NEMNEM sec. 13, T. 9 S., R. 61 (Steele Shale of former usage), 200 ft E., Carter County, Mont. From gray below Shannon Sandstone Member. limestone concretions in Gammon Ferru- | 9g_____ 21550 | J. B. Reeside, Jr., and others, 1949. _ NW 14 ginous Member of Pierre Shale, about 130 SW!4 sec. 4, T. 33 N., R. 98 W., Fremont ft below base of Groat Sandstone Bed. County, Wyo. Cody Shale, about 1,035 14}..... 9625 | C. J. Hares, 1916. Southwest side of Elk ft below top. - & A Basin in the NEM see. 25, T. 58 N., R. a i Ale 29.110 21536 G. N. Pipiringos and K. A. Y¥enne, 1949. 100 W., Park County, Wyo. Elk Basin ELINWIISE1z 7, T. $2 N.' B. 93 Sandstone Member of Telegraph Creek W/ZF s Amini. ars i an, Formation. ., Fremont County, Wyo. Cody Shale, 15t..... 9672 | C. J. Hares, 1916. Twelve miles west of about 1’069 ft PEIOW fop. y Lovell, in the EX T. 56 N., R. 98 W., | 30----- D1259 | R. A. MacDiarmid and P. E. Soister, 1956. Park County, Wyo. From Elk Basin Center of the NL&NI4N!4 sec. 19, T. 33 Sandstone Member of Telegraph Creek N., R. 91 W., Fremont County, Wyo. Formation. Cody Shale, upper part. 16::.:..: 17645 | D. A. Andrews, 1936. About 3 miles south- | 31.-____ 22102 L. A. Hale, 1950. Six miles northeast of west of Frannie in the SEM sec. 10, T. 57 Rock Springs, in sec. 14, T. 19 N., R. N., R. 98 W., Park County, Wyo. Basal 104 W., Sweetwater County, Wyo. Baxter part of Telegraph Creek Formation. Shale, from 785 ft below top. I4 TaBu® 1.-Localities at which fossils were collected-Continued U.S. Geo- logical Survey Mesozoic locality Collector and year of collection, description of locality, Locality and stratigraphic assignment on figure 1 32-.... D3053 | J. H. Smith, 1961. About 10 miles south of Rawlins, in the NW14 see. 14, T. 19 N., R. 88 W., Carbon County, Wyo. Steele Shale, from 1,468 ft above base. W. W. Rubey, 1924. W% sec. 11, T. 8 N., R. 5 E., Butte County, S. Dak. From 50 ft above base of Gammon Ferruginous Member of Pierre Shale. R. Gill, 1958. Three miles north of Bear Butte, in the NENE} sec. 6, T. 6 N., R. 6 E., Meade County, S. Dak. From lens of marlstone in lower part of Gammon Ferruginous Member of Pierre Shale. R. Gill, 1958. About 3.5 miles south of Alkali Creek, in the NW! sec. 9, T. 4 N., R. 8 E., Meade County, S. Dak. From lens of marlstone 50 ft above base of Gammon Ferruginous Member of Pierre Shale. A. D. Zapp and W. A. Cobban, 1961. see. 22, T. 3 N., R. 21 E., { Daggett County, Utah. Baxter Shale, from thin-bedded sandstone bed in upper part. W. A. Cobban, 1945. About 6.5 miles southeast of Jensen, in the S% sec. 12, T. 6 S., R. 23 E., Uintah County, Utah. Mancos Shale, from thin lens of sandstone 2,645 ft above base. E. M. Spieker and J. B. Reeside, Jr., 1925. One mile east of Desert, in the SEM S., R. 14 E., Emery County, Utah. Mancos Shale, from concretion 1,710 ft above base. D. J. Fisher, 1925. NW! sec. 18, T. 21 S., R. 18 E., Emery County, Utah. Mancos Shale, from 800 ft below top. J. B. Reeside, Jr., J. D. Sears, and W. H. Bradley, 1923. Near Vermilion Creek, in the NE} T. 10 N., R. 101 W., Moffat County, Colo. Mancos Shale, from 1,439 ft below top. G. R. Scott, 1960. Four miles north of Boulder, in the see. 1, T. 1 N., R. 71 W., Boulder County, Colo. Niobrara Formation, from chalky lime- stone 28 ft below top. G. R. Scott and W. A. Cobban, 1961. One mile east of Apishapa River, in the NEMSWMNWHM see. 23, T. 23 S., R. 59 W., Otero County, Colo. Niobrara For- mation, from chalky limestone 84 ft below top. 10142 | Harvey Bassler, 1917. West foot of Hog- back: Mountain, in sec. 32, T. 30 N., R. 16 W., San Juan County, N. Mex. Man- cos Shale, from 160 ft below top. 88... 12654 D1847 | J. 55.....; D1849 | J. 36..... D3420 87..... 23255 S8.:.... 13247 39;:.... 13340 40... .. 11948 41.1... D2827 42.___.| D3266 49..... fossil for the Eagle fauna (Reeside, 1944). In terms of the standard stages of the Upper Cretaceous Desmo- scaphites bassteri was assigned to the upper part of the Santonian and Seaphites hippocrepis was placed in the lower part of the Campanian (Reeside, 1927b, p. 28, 30; 1944). This usage of D. bassleri and 8. hippocrepis as zonal indices has continued to the present time. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Haresiceras, as defined by Reeside, has been placed in the Scaphites hippocrepis Range Zone and assigned an early Campanian age (Cobban and Reeside, 195%, p. 1019). Reeside's Puzosia (Latidorsella) mancosen- sis was placed originally in the Eagle fauna (Reeside, 1924, p. 12, pl. 3) but later its presence with Desmosec- phites bassleri was noted (Thom and others, 1985, p. 54-56). - Reeside's Acanthoceras? montanaense has been recorded only from below the Telegraph Creek Forma- tion at one locality (Reeside, 1927a, loc. 9649 on dis- tribution table). Collections of fossils made subsequent to the publi- cation of Reeside's monograph on the cephalopods of the Eagle Sandstone and related formations (19272) revealed the possibility of recognizing subzones within Reeside's zones of Desmoscaphites bassleri and Sea- phites hippocrepis. This refinement in zoning can be demonstrated best by considering the stratigraphic see- tions and fossil content in the following areas: (1) Sweetgrass arch in northwestern Montana, (2) vicinity of Mosby Post Office in east-central Montana, (3) Por- cupine dome farther east in east-central Montana, (4) Elk Basin oil field and surrounding area in southern Montana and northwestern Wyoming, (5) Hardin area in south-central Montana, (6) Buffalo area in north- central Wyoming, (7) Salt Creek oil field in east-central Wyoming, (8) Wind River Basin in west-central Wy- oming, and (9) Green River area in east-central Utah. SWEETGRASS ARCH IN NORTHWESTERN MONTANA The Sweetgrass arch (fig. 1) consists of a northern structural feature, the Kevin-Sunburst dome, and a southern feature, the South arch (Dobbin and Erd- mann, 1955). - High on the west flank of the Sweetgrass arch, rocks ranging in age from middle Santonian to early Campanian consist of the following units from oldest to youngest: Marias River Shale, Telegraph Creek Formation, Virgelle Sandstone, and lower part of the nonmarine Two Medicine Formation (Cobban, 1955, p. 111-116). Limestone concretions in the Marias River Shale contain many well-preserved fossils. The upper part of the formation, Kevin Shale Member, contains at least seven faunal zones of which only the upper three need be considered here (Cobban, 1951a, p. 2197). The oldest of these three is the CHoscaphites vermiformis Range Zone, which contains Znoceramus cordiformis Sowerby dating it as early middle Santonian (Seitz, 1956, p. 3, 4). This is succeeded by the Clioscaphites choteauensis Range Zone of probable late middle San- tonian age. The uppermost part of the Kevin Shale Member is characterized by the Desmoscaphites erd- manni Range Zone, which has the lowest occurrence of CRETACEOUS CEPHALOPOD HARESICERAS 15 Inoceramus patootensis de Loriol, Baculites thomi Ree- side. Scaphites leei Reeside, and the free-swimming crinoid Uintacrinus socialis Grinnell. This zone can be assigned to the early part of the late Santonian (Cob- ban, 1962, p. D140). In addition to these fossils, Col- lier (1929, p. 72, loc. 11995) collected a septate coil of an ammonite (pl. 1, figs. 25, 26) identified by Reeside as Puzgosia (Schlueteria) n. sp. from a limestone con- cretion "* * * 20 feet below the top of the Colorado Shale." The writer believes this specimen is a variant of the species described by Reeside as Puzosia (Lati- dorsella) mancosensis. Reeside's species is herein as- signed to Haresiceras owing to the similarity of the suture pattern, the type of ribbing, and the flattened venter on the adult whorl to those of other species of Haresiceras. The Telegraph Creek Formation contains Znoceramus patootensis, Baculites haresi Reeside, Desmoscaphites bassleri Reeside, Sceaphites leei, and a late form of Haresiceras mancosense (fig. 1, locs. 2, 3). The Inocer- amus patootensis and Sceaphites leei were originally listed as Zmoceramus lundbreckensis McLearn and Sea- phites cf. 8. hippocrepis (Cobban, 1950, p. 1900). The specimens recorded as Puzgosia (Latidorsella) manco- sensis Reeside differ from Reeside's types by having a flattened venter at an earlier diameter and are thus transitional to Reeside's Acanthoceras? montanaense. The Sweetgrass arch specimens may deserve separate species rank, but until larger collections of this form permit an evaluation of the amount of variation, the specimens at hand are treated as a late form of Reeside's Sweetgrass arch Disturbed _ West of belt Shelby 50 miles | East of Shelby 44 miles | 183 miles Clagett Shale @ sp ( Baculites sp. (smooth) Haresiceras natronense Haresiceras placentiforme Kevin Shale Member (part) Clioscaphites |: of Marias River Shale choteauensis C foscsph ites vermiformis species. They are assigned to HZaresiceras and placed in a new subgenus Mancosiceras. Fossils have not been found in the Virgelle Sand- stone on the east and west flanks of the Kevin-Sunburst dome which forms the northern part of the Sweetgrass arch in the Shelby area (fig. 1). West of Great Falls on the west flank of the South arch (fig. 1) and farther west, in the Disturbed belt near the east margin of the Rocky Mountain front, the Virgelle Sandstone is moderately fossiliferous and contains /moceramus pa- tootensis, Baculites haresi, and Desmoscaphites bassleri. The Virgelle Sandstone in these western areas is inter- preted as the time equivalent of the Telegraph Creek Formation farther east and higher up on the Sweet- grass arch (fig. 2). Likewise, the upper part of the Marias River Shale is older west of the Sweetgrass arch than it is high up on the arch. In the Disturbed belt southwest of the Sweetgrass arch, thin-bedded sandstone and siltstone of Telegraph Creek lithology contain CHoscaphites vermiformis. In summary, the ammonite sequence for the middle and late Santonian rocks on the Sweetgrass arch con- sists of the following, from oldest to youngest, (1) Clioscaphites vermiformis; (2) C. choteauensis; (3) Desmoscaphites erdmanni, Baculites thomi, and the early form of Haresiceras (Mancosiceras) mancosense; and (4) Desmoscaphites bassleri, Baculites haresi, and the late form of H. (M.) mancosense. Scaphites leei and patootensis are present in both Desmo- seaphites zones (3 and 4) and a free-swimming crinoid, Uintacrinus socialis, is known from the older zone (3). a' Mosby Porcupine Albion Rapid City dome area area + 47 miles 72 miles Sharon Member (lower part) Pierre Shale Member 5 _s, F r F y + u - f, l. i P }; ( |.. [; hm A WP $f f f. R l, ! F 3, st |_ F F WH J Phi t H ( F Mice wat nal malt coset ae th i ~- Niobrara Shale Member (part) -=- of Colorado Shale ; <-- {~~ he To to un- it PPM ahh ih" C H5 HH HF i a tile K1 FicurE 2.-Stratigraphic relations between the Disturbed belt in northwestern Montana and the east flank of the Black Hills uplift near Rapid City, S. Dak. numbers. this cross section are indicated by large black dots. Occurrences of Haresiceras are shown by circles enclosing their map locality Occurrences of guide fossils a little older or a little younger than Haresiceras that aided in constructing 16 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY MOSBY AREA IN EAST-CENTRAL MONTANA West of the Musselshell River in east-central Mon- tana, rocks equivalent to the Marias River Shale are included in the upper part of the Colorado Shale. Here the Colorado Shale is overlain by thin-bedded sandstone, siltstone, and shale of the Telegraph Creek Formation and this in turn by the Eagle Sandstone. The Tele- graph Creek Formation and Eagle Sandstone grade eastward into finer grained rocks, and the upper part of the underlying Colorado Shale becomes calcareous (fig. 2). East of the Musselshell River, in the vicinity of Mosby Post Office, the Telegraph Creek and Eagle are no longer identifiable but represented by a gray shale and mudstone unit that is in part sandy and con- tains beds of ferruginous concretions. This unit, rest- ing on the yellow- and orange-weathering Niobrara Shale Member of the Colorado Shale and underlying the dark-gray Claggett Shale, represents the northwest- ward extension of the Gammon Ferruginous Member of the Pierre Shale of the Black Hills region. In the Mosby area and eastward beyond Porcupine dome, this ferruginous unit is a distinct formation to which the name Gammon Shale is applicable. Near Mosby Post Office the Niobrara Member of the Colorado Shale consists of a lower noncalcareous shale unit that contains CHoscaphites vermiformis in its upper part and an upper and much thicker calcareous shale unit that has yielded, 50 feet below the top, Baculites thomi, Seaphites leei, Desmoscaphites sp., and small fragments of an Znoceramus that is probably I. patootensis. This collection may be from the Desmo- seaphites erdmanmi Range Zone. Limestone concretions 45 feet above the top of the Colorado Shale contain the round-ventered or early form of Haresiceras (Manco- siceras) mancosense associated with Baculites hares and Seaphites leei (fig. 1, loc. 5). The Haresiceras and scaphite were originally recorded as H. mnatronense, H. placentiforme var. parvum, and Seaphites hippocrepis (Cobban, 1953, p. 100). Higher in the Gammon Shale, about 150 feet above the base, limestone concretions con- tain Znoceramus patootensis, Baculites aquilaensis Ree- side, and Sceaphites hippocrepis (DeKay) var. tenuis Reeside. HZaresiceras and Seaphites were not observed higher in the Gammon; the upper part contains bacu- lites that have weak flank ribs. The dark-gray Claggett Shale, which overlies the lighter colored Gammon Shale, contains numerous beds of bentonite in the lower part. A weakly sculptured form of Baculites obtusus Meek is in the basal part, and a more strongly sculptured form (the typical late form) of B. obtusus is found a little higher in this bentonitic unit. In summary, the known faunal sequence in the Mosby area is, from oldest to youngest, (1) CHoscaphites vermiformis; (2) Desmoscaphites sp., Baculites thomi, and Sceaphites leci; (3) Haresiceras (Mancosiceras) mancosense, Baculites haresi, and Neaphites leeis (4) Sceaphites hippocrepis var. tenuis and Baculites aqui- laensis; (5) baculites with weak flank ribs; (6) an early form of Baculites obtusus; and (7) a late form of B. obtusus. - Inoceramus patootensis seems to have a range of from the second (2) to the fourth (4) of these zones. PORCUPINE DOME IN EAST-CENTRAL MONTANA North of Forsyth on the north flank of Porcupine dome (fig. 1) , about 55 miles east-southeast of the Mosby locality, Reeside's Acanthoceras? montanaense, here assigned to Haresiceras. is found in limestone concre- tions at least 125 feet above the base of the Gammon Shale (fig. 1, locs. 6, 7). Associated fossils include Baculites haresi and Seaphites leei. Collections made higher in the Gammon by J. R. Gill, of the Geological Survey, reveal the presence of dominantly smooth bacu- lites about 85 feet below the top of the formation and baculites that have weak flank ribs about 40 feet below the top. The lower 55 feet of the overlying Claggett Shale is characterized by numerous beds of bentonite. The weakly sculptured form of Baculites obtusus is present in the basal part of this bentonitic unit, whereas the more strongly sculptured form (the typical form) of this species is found higher in the unit. BLACK HILLS UPLIFT IN SOUTHEASTERN MONTANA AND WESTERN SOUTH DAKOTA Along the northeast flank of the Black Hills uplift, rocks of Santonian and Campanian age are represented by the Niobrara Formation and the overlying Pierre Shale. The lower part of the Pierre Shale consists of the Gammon Ferruginous Member and the younger Sharon Springs Member. About 10 miles southeast of Albion, near the common corner of Montana, South Dakota, and Wyoming (fig. 1), the Gammon attains a thickness of 785 feet. Here it is divided by the 45- foot Groat Sandstone Bed (fig. 2) into a lower part 580 feet thick and an upper part 160 feet thick. Haresiceras placentiforme was found in limestone con- cretions 130 feet below the base of the Groat Sandstone Bed (fig. 1, loc. 13). Associated fossils include numer- ous specimens of RBaculites aquilaensis and a single example of Scaphites aquisgranensis Schliiter [=S8. aquilaensis Reeside]. Higher in the Gammon, about 75 feet below the Groat Sandstone Bed, a specimen of the fine-ribbed form of 8. Aippocrepis was found with smooth or nearly smooth adult baculites. - Smooth adult baculites characterize the Groat Sandstone Bed and the lower part of the overlying Gammon. The juveniles of these baculites as well as the juveniles of the baculites CRETACEOUS CEPHALOPOD HARESICERAS T5 feet below the Groat have widely spaced broad lateral nodes. Sceaphites from the Groat are small flat- ventered undescribed forms entirely different from the slightly older S. Aippocrepis. The uppermost 85 feet of the Gammon is charaterized by baculites that have weak lateral ribs on the adults. The lower part of the Sharon Springs Member con- tains many layers of bentonite. A weakly sculptured form of Baculites obtusus is present in the basal part of this bentonitic sequence. Haresiceras natronense has been found at two local- ities 50-7O miles southeast of Albion (fig. 1 locs. 34, 35). Associated fossils include a fine-ribbed form of Seaphi- tes hippocrepis and smooth or nearly smooth baculites. 17 The fossils were found in lengthy lenses of marlstone, 50 feet above the base of the Gammon. The presence of these fossils so low in the Gammon can be explained by the southeastward replacement of noncalcareous Pierre lithology by calcareous Niobrara lithology (fig. 2). ELK BASIN AREA IN SOUTHERN MONTANA AND NORTHWESTERN WYOMING In the Elk Basin area in the northern part of the Bighorn Basin (fig. 1, loc. 14), rocks of Santonian and early Campanian age consist of the upper part of the Colorado Group (Niobrara and Carlile Shales), Tele- graph Creek Formation, and Eagle Sandstone (Dobbin and others, 1944). (See fig. 3.) A ridge-forming B Elk B‘asin } 116 miles Elgin Creek B' Albion area 142 miles, Claggett Formation (lower part) stone and shale) - H Z elle ~- -_-: Telegraph Creek Formati (@ Baculites obtusus (late form) ® Baculites obtusus 7 (early form) @ _ Baculites sp. (weakly ribbed) @ - Baculites sp. (smooth) O Haresiceras natronense Sharon Springs Shale Member (pia rt) ® ba ___ Gammon Ferruginous a O Haresiceras placentiforme O Haresiceras montanaense (late form) __| Haresiceras montanaense (early form) O Haresiceras mancosense (late form) O Haresiceras mancosense (early form) ® Clioscaphites choteauensis - (Sandstone and shale) $ IK Basin: Niobrara and Carlile Shales of Dobbin and others (1944) (part) ® Clioscaphites vermiformis FicUrE 3.-Stratigraphic relations between Elk Basin in the northern part of the Bighorn Basin and the Albion area on the northeast flank of the Black Hills. Occurrences of Haresiceras are shown by circles enclosing their map locality numbers. Occurrences of guide fossils a little older or a little younger than Haresiceras that aided in constructing this cross section are indicated by large black dots. 18 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY unit, the Elk Basin Sandstone Member, forms the base of the Telegraph Creek Formation. Calcareous con- cretions in the Elk Basin Sandstone Member have yielded many fossils including the type specimens of Reeside's FutrepAhoceras alcesense, Haresiceras placenti- forme, Seaphites levis, S. hippocrepis var. pusillus, S. aquilaensis var. nanus, and 8. aquilaensis var. costatus (Reeside, 19272, loc. 9625). Collections made recently from the upper part of the Elk Basin Sandstone Mem- ber by J. R. Gill include Znoceramus patootensis, one specimen of the fine-ribbed 8. Aippocrepis var. tenuis, and several examples of the coarse-ribbed var. crassus, including one individual that has well-defined rounded nodes and that is transitional to 8. Zee? (pl. 1, figs. 28-30). Collections made earlier from just below the Elk Basin Sandstone Member by Geological Survey personnel include a slender form of Haresiceras mon- tanaense (pl. 2, figs. 29, 30, 37, 38) associated with a coarse-ribbed form of 8. Aippocrepis (fig. 1, locs. 16, 17). The holotype of H. montanagense came from a lower stratigraphic position, 150 feet below the Elk Basin Sandstone Member about 12 miles north of the Elk Basin oil and gas field (fig. 1, loc. 9). The faunal sequence in the Elk Basin area seems to be, in ascending order, (1) the stout coarse-ribbed form of Haresiceras montanaense; (2) a slender or later form of H. montanaense associated with coarse-ribbed Sceaphites hippocrepis; and (3) H. placentiforme asso- ciated with Inoceramus patootensis and dominantly coarse ribbed forms of 8. Aippocrepis and 8. aquisgra- nensis Schliiter [-= 8. aquilaensis Reeside]. HARDIN AREA IN SOUTH-CENTRAL MONTANA In the area of its outcrop east and south of Hardin (fig. 1) in Big Horn County, the Telegraph Creek, originally defined as a formation (Thom and others, 1935, p. 53), is treated now as a member of the Cody Shale (Richards, 1955, p. 57). It overlies the Niobrara Shale Member which contains CHoscaphites vermi- formis within 32 feet of the top. The Eagle Sandstone, which is massive and cliff forming at Billings west of Hardin, grades eastward into gray shale and mudstone that contain beds of ferruginous concretions, and in its outcrop area east of Hardin, the name Gammon Ferruginous Member of the Cody Shale is applicable. Thom and others (1935, p. 54-56) recorded the occur- rence of Desmoscaphites bassleri from the base, middle, and top of their Telegraph Creek Formation and Haresiceras (Mancosiceras) mancosense at the top (fig 1, loc. 10) and in the "***middle rim-forming Elk Basin sandstone" (fig. 1, loc. 8). In addition they found Uintacrinus sp. at the base, Imnoceramus patootensis [as I. aff. I. lobatus Goldfuss]in the middle, and Marsupites sp. at the top. In the area 20 miles or more west of Hardin where the Eagle Sandstone occurs, Thom and others (1935, p. 54) give a thickness of 320 feet for the underlying Telegraph Creek Formation. East of Har- din, where the Eagle Sandstone is absent owing to its passage into Gammon lithology, the most convenient boundary between the Telegraph Creek and Gammon Members is at a much higher stratigraphic level than farther west, and a thickness of 867 feet has been as- signed to the Telegraph Creek by the writer (in Richards, 1955, p. 57, 58). In this thick section of Telegraph Creek, Scaphites hippocrepis var. tenuis was collected 122 feet below the top, and Baculites aqui- laensis was found about 70 feet below the top. The lower part of the Gammon Ferruginous Member has not yielded megafossils in its area of outcrop east of Hardin, but a 6-foot sandy unit 162 feet above the base of the member contains Seaphites Aippocrepis and S. aquisgranensis Schliiter [as 8. aquilaensis Reeside] (Richards, 1955, p. 60). Most of the specimens have fine dense ribbing (pl. 1, figs. 33-36) in contrast to the dominantly coarse ribbed forms known from the Elk Basin Sandstone Member of the Telegraph Creek For- mation of Elk Basin (pl. 1, figs. 28-30). The fine tibbed scaphites in the Hardin area are associated with Glyptozoceras rubeyi (Reeside) and baculites with very weak lateral ribs. The 51 feet of shale immediately overlying the 6-foot sandy unit (Richards, 1955, p. 59) is characterized by smooth or nearly smooth baculites which represent the type of baculite found in part of the Gammon Shale on Porcupine dome. The rest of the Gammon (155 ft) contains baculites that have weak flank ribs like those in the uppermost part of the Gammon on Porcupine dome. The basal few feet of the overlying Claggett Shale Member contains a weakly ribbed early form of B. obtusus; the more strongly sculptured typical form of this species is found about TO feet above the base. The known sequence of fossils from rocks of middle Santonian to early Campanian age in the Hardin area can be summarized as follows: (1) CHoscaphites vermi- formis, (2) Desmoscaphites bassleri and Haresiceras (Mancosiceras) mancosense associated with Inoceramus patootensis and Marsupites sp., (3) Scaphites hippo- crepis var. tenuis and Baculites aquilaensis, (4) domi- nantly fine ribbed forms of 8. Aippocrepis and 8. aquis- gramensis associated with @lyptomoceras rubeyi and very weakly ribbed baculites, (5) smooth baculites, (6) weakly ribbed baculites, (7) weakly ribbed early form of Baculites obtusus, and (8) more strongly sculptured late form of B. obtusus. CRETACEOUS CEPHALOPOD HARESICERAS I9 BUFFALO AREA IN NORTH-CENTRAL WYOMING Hose (1955, p. 93-99) described a thick section of the Cody Shale exposed along Elgin Creek, 10 miles southwest of Buffalo in Johnson County (fig. 1, loc. 19). He found Haresiceras montanaense associated with Baculites aquilaensis and dominantly coarse ribbed forms of Seaphites hippocrepis and 8. aquisgranensis [as 8. aquilaensis] in limestone concretions in the Cody Shale, 748 feet below the Shannon Sandstone Member of the Cody Shale (fig. 1, loc. 19; also see fig. 3). The specimens of Haresiceras were first identified by the writer as H. placentiforme. They are a little more slender than the specimens of H. montanaense associ- ated with Seaphites leei on Porcupine dome (fig. 1, loc. 6-7) and are transitional to H. placentiforme. Much higher in the Cody Shale, from 75-382 feet below the Shannon Sandstone Member, Hose collected fine-ribbed forms of 8. Aippocrepis and S. aquisgranensis. Smooth baculites were found in the Shannon Sandstone Member. SALT CREEK OIL FIELD IN EAST-CENTRAL WYOMING In the Salt Creek area in Natrona County (fig. 1, loc. 27), Wegemann (1918, p. 19,20) recognized a calcareous unit which he called Niobrara Shale overlain by a non- calcareous gray unit which he called Steele Shale. Two sandstone units were noted in the Steele Shale, a lower thin fishtooth conglomeratic sandstone and an upper and thicker Shannon Sandstone Member. In recent years the name Steele has been restricted and not used in the Salt Creek area, and the name Cody has been applied. A third sandstone, the Sussex Sandstone Member of the Cody Shale, is recognized about 400 feet above the Shannon (Wilson, 1951). The type specimen of Haresiceras natronense Reeside came from the Cody Shale, 200 feet below the Shannon Sandstone Member (Reeside, 19272, loc. 10701). J. R. Gill carefully measured the Cody Shale at Salt Creek and collected many fossils. He found that about 600 feet of shale separates the unit locally known as the Fish-tooth sandstone from the Shannon Sandstone Member. Fine-ribbed forms of Seaphites hippocrepis were collected from 35 feet below the Fish-tooth sand- stone to about 385 feet above it (210 ft below the Shan- non). @lyptoxoceras rubeyi was found in the upper part of this range, although Reeside (1927a, locs. 10701-10703) recorded it on up into the Shannon Sand- stone Member. Gill collected Baculites aquilaensis from 150 feet below the Fish-tooth sandstone to about 385 feet above it, a more weakly ribbed form of baculite in the next 65 feet of shale, and smooth baculites in the Shannon Sandstone Member. In the Sussex Sandstone Member and in the shale separating it from the Shannon 686-600 O-64--2 Sandstone Member, Gill found baculites that have weak flank ribs. Immediately above the Sussex, Gill meas- ured 90-130 feet of bentonite-bearing shale that con- tains an early form of Baculites obtusus (weakly ribbed) in the lower part of the shale and the late or typical form (strongly ribbed) in the upper part. WIND RIVER BASIN IN WEST-CENTRAL WYOMING Haresiceras has been found in three areas in the Wind River Basin: (1) near Shotgun Butte on the northwest side of the Basin (fig. 1, locs. 23, 24), (2) near Lander on the southwest side (fig. 1, loc. 28), and (3) near Conant Creek on the south side (fig. 1, locs. 29, 80). The localities near Shotgun Butte and Conant Creek provide the most data concerning stratigraphic relations (fig. 4). Keefer and Troyer (1956) measured a detailed section of the Cody Shale near Shotgun Butte on the north side of the Wind River Basin. Here the Cody Shale con- sists of a lower shaly member 1,560 feet thick and an upper sandy member 2,190 feet thick. Keefer and Troyer found Cléioscaphites vermiformis 330 feet above the base of the sandy member and Haresiceras (Man- cosiceras) mancosense, Desmoscaphites bassler:, and Seaphites leei, associated with the free-swimming cri- noids Uintacrinus and Marsupites, 900 feet above the base (fig. 1, loc. 23). At 1,660 feet above the base (fig. 1, loc. 24), they found Haresiceras montanaense (orig- inally identified by the writer as H. placentiforme) and the septate coils of Sceaphites hippocrepis and 8. aquis- granensis [as S. aquilaensis]. At 2,120 feet above the base of the sandy member (75 ft below the top), Keefer and Troyer collected ZInmoceramus patootensis [as I. lundbreckensis], Baculites aquilaensis, and the coarse- ribbed Scaphites hippocrepis var. crassus Reeside. Near Conant Creek, about 60 miles southeast of Shot- gun Butte, Yenne and Pipiringos (1954) found Hare- siceras montanaense (identified by the writer as Puzosia mancosensis Reeside) associated with Seaphites hippo- crepis var. tenuis in the middle part of the sandy mem- ber of the Cody Shale (fig. 1, loc. 29). Higher in the sandy member, Y¥enne and Pipiringos found fine-ribbed forms of 8. Ahippocrepis and S. aquisgranensis [as S. aquilaensis] and, more recently, Haresiceras natronense and @lyptozoceras rubeyi have been found apparently in this part of the Cody (fig. 1, loc. 30). The overlying Mesaverde Formation is split into a lower and an upper part by a tongue of marine shale. Baculites from the lower part of the Mesaverde consist of noded juveniles and smooth adults that were identified originally by the writer as B. asper Morton, B. minerensis Landes, and B. Aharesi Reeside; these are interpreted now as representing various growth stages of the smooth species 110 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY C Shotgun Butte 58 miles Conant Creek 90 miles @Baculites obtusus (late form) @Baculites obtusus (early form) I oa > @ Baculites sp. (weakly ribbed) W/ @ Baculites sp. (smooth) O Haresiceras natronense O Haresiceras placentiforme O Haresiceras montanaense (late form) (Marine shale) 62 O Haresiceras montanaense Cody Shale (early form) O Haresiceras mancosense (upper part) (late form) O Haresiceras mancosense ® (early form) @ Clioscaphites choteauensis @ Clioscaphites vermiformis © ‘ ~in Niobrara Fornjgtlin' =f ~-: (part) 1-4-1 FIGURE 4.-Stratigraphic relations between part of the Santonian and Campanian rocks of the Wind River Basin (Shotgun Butte and Conant Creek) and the time-equivalent rocks near Rawlins. Occurrences of Haresiceras are shown by circles enclosing their map locality numbers. Occurrences of guide fossils a little older or a little younger than Haresiceras that aided in constructing this cross section are indicated by large black dots. that characterizes the Shannon Sandstone Member of the Cody Shale and Groat Sandstone Bed of the Pierre Shale and equivalent rocks. The small undescribed flat-ventered scaphite known from the Groat (p. 17) has been found near Conant Creek in the lower part of the Mesaverde. GREEN RIVER AREA IN EAST-CENTRAL UTAH In the belt of Mancos Shale cropping out between the town of Green River and the Book Cliffs (fig. 1), Fisher and others (1960, pl. 10) found Clioscaphites vermiformis 1,350-1,525 feet above the base of the Man- cos Shale, Desmoscaphites bassleri 1,i10-1,920 feet above the base, and Sceaphites Ahippocrepis about 2,800- 3,200 feet above the base. Haresiceras (Mancosiceras) mancosense was found with D. bassleri and Inoceramus patootensis 1,i10 feet above the base of the Mancos Shale (fig. 1, loc..38) , and Haresiceras fisheri was found with 8. Aippocrepis about 2,800 feet above the base (fig. 1, loc. 39). SUMMARY OF FAUNAL SEQUENCES By combining the data provided by each of the selected sequences of fossils, the following succession of forms, from youngest to oldest, is apparent from rocks of middle Santonian to early Campanian age. Baculites obtusus (late or strongly ribbed form) obtusus (early or weakly ribbed form) sp. (adults with weak flank ribs) sp. (adults smooth) Dominantly fine ribbed forms of Scaphites hippocrepis and S. aquisgranensis associated with Haresiceras natronense, H. fisheri, Glyptoxoceras rubeyi, and baculites either smooth or with weak flank ribs. Dominantly coarse ribbed forms of S. hippocrepis and S. aquisgranensis associated with Haresiceras placentiforme, Baculites haresi or B. aquilaensis, and Inoceramus patootensis. Dominantly coarse ribbed forms of 8. hippocrepis and S. aquisgranensis associated with Baculites aquilaensis and a late form of Haresiceras montanaense. Early form of Haresiceras montanaense associated with Scaphites leei and Baculites haresi. Late form of Haresiceras (Mancosiceras) mancosense CRETACEOUS CEPHALOPOD HARESICERAS associated with . leei, B. haresi, Desmoscaphites bassleri, Inoceramus patootensis, Marsupites sp., and Uintacrinus socialis. Early form of H. (M.) mancosense associated with 8. leei, B. thomi, D. erdmanni, I. patootensis, and Uintacrinus spcialis. Clioscaphites choteauensis Clioscaphites vermiformis and Inoceramus cordiformis In this sequence of fossils, Haresiceras is found im- mediately above the highest CHoscaphites and ap- parently ranges on up through the Scaphites hip- pocrepis Range Zone. It is not found in the younger rocks that are characterized by species of baculites. Two forms are assigned to Haresiceras (Mancosi- ceras) mancosense; one has the venter of the late juvenile whorls rounded as in the holotype, and the other has a flattened venter. The round-ventered form seems to be associated with both Desmoscaphites erd- manni and D. bassleri, whereas the flat-ventered form has been found only with D. bassleri. Haresiceras montanaense occurs as a stout form associated with Sceaphites lee? at one locality and as a more slender form associated with dominantly coarse ribbed specimens of 8. Aippocrepis in other localities. Inasmuch as Z. montanaense has not been found with Desmoscaphites bassleri, it is assigned to the lowest part of the 8. Aippocrepis Range Zone. Haresiceras placentiforme has been found with coarse forms of S. Aippocrepis but not with 8. leei. It seems to lie in the middle part of the S. Aippocrepis Range Zone. Haresiceras natronense is known only with fineribbed forms of S. Aippocrepis and is assigned to the upper- most part of the S. Aippocrepis Range Zone. Likewise, H. fisheri seems to lie high in this zone (Fisher and others, 1960, pl. 10). Aside from Desmoscaphites and Scaphites hippo- crepis, important fossils associated with Haresiceras are Imnoceramus patootensis, Scaphites leei, Baculites haresi, and B. aquilaensis. Inoceramus patootensis and Seaphites leei, first appear in the Desmoscaphites erd- manni Range Zone and persist on up into the Scaphites Mppoc‘repz's Range Zone; Z. patootensis is not known above the middle of the zone and 8. Zee? may be re- stricted to the lower part. Paculites haresi first ap- pears in the Desmoscaphites bassleri Range Zone and ranges on up into the middle of the Scaphites hippo- crepis Range Zone. - Baculites aquilaensis seems to be confined to the 8. Aippocrepis Zone. AGE OF HARESICERAS Haresiceras, as defined in this paper, ranges in age from late Santonian to early Campanian. All the species except ZZ. mancosense are assigned to the Campanian. P11 The oldest species, ZZ. mancosense, is associated with the free-swimming crinoids Uintacrinus and Marsupites which, in Europe, are guide fossils to the upper part of the Santonian Stage. Haresiceras fisheri, H. no- tronense, H. placentiforme, and the younger form of H. montanaense, are associated with Scaphites hippo- crepis which is a well-accepted index fossil in Europe for rocks of early Campanian age. The early form of Haresiceras montanaense from Porcupine dome in east- central Montana (fig. 1, locs. 6, 7) is younger than the upper zone of the Santonian Stage that has Marsupites and Uintacrinus and older than strata containing the first appearance of Ncaphites Ahippocrepis. This form of Haresiceras montanaense possibly lies in the Diplac- moceras bidorsatum Zone which is the oldest zone recog- nized in the Campanian Stage in Europe. The possible arrangement of the species of Haresiceras in regard to the commonly accepted European guide fossils of the late Santonian and early Campanian Stages is shown in table 2 as follows. TaBur 2.-Possible correlation of the zones of Haresiceras to the late Santonian and early Campanian faunal zones in Europe Stage European guide fossils Western Interior guide fossils Haresiceras matronense, H. fisheri, and fine-ribbed forms of Scaphites hippo- crepis and S. aquisgranensis. § p Scaphites hippocrepis, S. aqu- 3 E isgramensis, S. binodosus, | Haresiceras placentiforme and coarse- S E and Gonioteuthis quadrata. ribbed forms of Scaphites hippocrepis a E and S. aquisgranensis. ® O I? Haresiceras montanaense (late form) and 5 coarse-ribbed forms of Scaphites E hippocrepis and S. aquisgramensis. - Diplacmoceras - bidorsatum, | Haresiceras montanaense (early form) 5 p Havuericeras pseudogardeni, and Scaphites leei. E8 and Gonicteuthis granulata 44 ** (typical form). g Placenticeras syrtale, Marsu- | Haresiceras mancosense, Scaphigea leei, 53 pites spp., Uintacrinus Desmoscaphites SDP., Marsupites sp., &. S spp., and Gonioteuthis gran- and Uintacrinus socialis. g g wlata (early form). w In regard to the dominance of fine-ribbed forms of Scaphites hippocrepis and 8. aquisgranensis higher in the sequence of Western Interior fossils than coarse- ribbed forms, it is interesting to note that Grossouvre (1893, pl. 31, 32, 35, 37) figured both types from the Campanian of France but he did not indicate a strati- graphic separation. ORIGIN OF AND EVOLUTION WITHIN HARESICERAS Haresiceras is known only from the upper Santonian and lower Campanian rocks of the Western Interior region. Reeside (1927a, p. 17, 18) offered no explana- tion concerning the origin of his genus although he noted some resemblances to Placenticeras, Hoplites, Metaplacenticeras, Forbesiceras, and Sonneratia. He 112 assigned the genus to the subfamily Hoplitinae of the family Kosmoceratidae owing to certain similarities of Haresiceras to Hoplites such as the similar shape of the lateral ribs and whorl sections as well as some resem- blance in parts of the suture. Basse (1952, p. 659) and Wright (1957, p. L392), on the other hand, assigned Haregiceras to the family Placenticeratidae Hyatt be- cause of the compressed whorls, flat venter, weak sculpture, and "* * * suture with adventive and aux- iliary elements." The older species of Haresiceras have some characters in common with Desmoscaphites and Clioscaphites such as similar suture pattern and type of ribbing (fig. 5). The writer believes the origin of Haresiceras is to be found in the Santonian scaphites of the Western Interior. Maresiceras natronense Haresiceras placentiforme Lower Campanian Haresiceras montanaense (late form) Haresiceras montanaense (early form) Desmoscaphites bassleri Haresiceras mancosense (late form) Upper Santonian Desmoscaphites erdmanni | li hites chot. is li L Middle C e hp Haresiceras mancosense (early form) strus Santonian ; R P Clioscaphites vermiformis --> C. vermiformis var. toolensis FIGURE 5.-Lineages of Clioscaphites, Desmoscaphites, and Haresiceras and probable origin of Haresiceras from Clioscaphites. 'During latest Turonian time the Western Interior scaphites tended to become less unrolled in the adult stage and this trend continued through the Coniacian and Santonian (Cobban, 1951b, p. 11 and fig. 2). By the beginning of Santonian time the entire dorsum of the adult body chamber was in contact with the venter of the last septate whorl. There was a corresponding change in the size of the umbilicus which became greatly reduced in the middle and late Santonian. Near the close of the Turonian, the main stock of Western Interior scaphites split into two lines. One lineage was characterized by species that had at first high primary ribs on the adult body chamber and later a row of ventrolateral nodes. The other lineage con- sists of scaphites that never developed nodes. The lineage of noded scaphites departed further from the line of nodeless scaphites during middle Santonian time SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY by the ribbing on the internal whorls developing a pro- nounced forward arching on crossing the venter. Clioscaphites vermiformis (Meek and Hayden) rep- resents the noded line of scaphites during the early part of the middle Santonian. In this species the dorsum of the body chamber is entirely in contact with the venter of the last septate whorl, the umbilicus is very small, and the ribs cross the venter on the internal whorls with a forward arching (pl. 1, figs. 11-13). The adults have a considerable range in stoutness from the more slender form of the holotype to the very broad variety toolensis Cobban (for illustrations of these forms see Cobban, 1951b, pls. 18, 19). The variety foolensis has a very broadly rounded venter and well-defined ventrolateral shoulder. By the later part of middle Santonian time the broad- ventered form of C. vermiformis seems to have given rise to a nearly flat-ventered species, C. platygastrus Cobban (1951b. p. 36, pl. 20, figs. 12-16; also pl. 3, figs. 10-13 of this report), whereas the more round-ventered and slenderer form of the species developed into C. choteauensis Cobban (1951b, p. 38, pl. 20, figs. 8-11) by having the adult body chamber more densely ribbed and the internal whorls more compressed. (Compare figs. 9 and 12 on pl. 1.) Desmoscaphites erdmanni developed out of C. choteauensis by the adult body chamber becoming more densely ribbed, by the internal whorls being more com- pressed (compare figs. 2 and 9 on pl. 1), and by the loss of ribbing on the early juvenile whorls accom- panied by the sudden appearance of constrictions (pl. 1, figs. 2, 3). A parallel development of this is the probable descent of Haresiceras (Mancosiceras) manco- sense from Clioscaphites platygastrus. The early septate whorls of H. (M.) mancosense have constrictions similar to those on D. erdmanni (compare figs. 3, 4, 25, 26 on pl. 1) and there is a tendency toward loss of ribbing on these early whorls. The younger form of H. (M.) mancosense (pl. 2, figs. 41-48) reveals an earlier appearance of a flat- tened venter on the septate whorls but ventrolateral nodes are confined to the adult body chamber. The adults are more compressed than their probable C. platygastrus ancestor and the ribbing is weaker. The early form of H. montanaense developed out of the late form of H. (M.) mancosense by an acceleration in the appearance of a flattened venter early on the septate whorls, by the ventral flattening being more conspicuous, by the presence of ventrolateral nodes on the septate whorls as well as on the body chamber, and by a narrowing of the venter on the body chamber and further weakening of the sculpture there. Con- CRETACEOUS CEPHALOPOD HARESICERAS strictions tend to disappear; they are present only on the early whorls of some individuals. The late form of H. montanaense descended from the early form by further narrowing of the whorl sections and continuing the trend toward loss of ribbing and reduction in size of the ventrolateral nodes. Constric- tions may have disappeared. Haresiceras placentiforme (pl. 3, figs. 1-6) developed out of the late form of H. montanaense by further re- duction in the strength of the ribbing and in the size of the ventrolateral nodes. The ribs are nearly of equal eight and are confined to the ventrad half of the flank. The venter, which was slightly arched on older species, is perfectly flat on H. placentiforme. Haresiceras natronense (pl. 3, figs. 14-21) continues the trend toward compression of the whorls. The ven- ter is flat or even slightly concave. With the exception of the apertural end of the shell, ribbing is of uniform height and spacing and is confined to the outer part of the flank. Comparison of the sutures of CHoscaphites, Desmo- scaphites, and Haresiceras reveals a similarity in the overall pattern (fig. 6). In general the lobes and sad- dles trend toward lengthening and deeper folding in the younger species. The trifid lateral lobes of CHioscaphites developed out of the bifid lateral lobes of Scaphites by rotation of the umbilical side of the lobes toward the venter ( Cobban, 1951b, p. 11 and fig. 3). The suture of C. vermiformis has the lobes and saddles decreasing uniformly in size away from the first lateral saddle; the second lateral saddle tends to be wider than the first lateral lobe, and the third lateral saddle is broader than the second lat- eral lobe (fig. 6). In the lineage, C. vermiformis-D. bassteri, the second lateral lobe migrates toward the venter causing a corresponding reduction in size of the second lateral saddle; this reduction is such that in the suture of C. chotecuensis the lobe and saddle are of equal size, but in the younger Desmoscaphites, the saddle is smaller than the lobe (fig. 6). A parallel of this change is seen in the suture patterns of the lineage, C. vermiformis var. toolensis-Haresiceras natronense. The first lateral lobe and second lateral saddle are of equal size in C. vermiformis var. toolensis, but in C. platygastrus the saddle is a little smaller than the lobe and becomes increasingly smaller in the species of Haresiceras (fig. 6). The second lateral saddle is symmetrically bifid through most of this lineage (C. vermiformis var. toolensis-H. montanaense) , but in the younger species the branch nearest the venter becomes smaller and migrates downward imparting a distinctive asymmetry to the saddle. 113 Another interesting evolutionary change takes place in the sutures of Haresiceras. The third and fourth lateral lobes remain small, but the third and fourth lateral saddles widen to such an extent that in the younger species the third lateral saddle surpasses the second lateral saddle in width which is the reverse con- dition in CHoscaphites. In addition to the widening of the third and fourth lateral saddles, the lobes that bi- furcate these saddles lengthen and enlarge to such an extent that they almost match the third and fourth lateral lobes (pl. 3, figs. 4, 17). SYSTEMATIC DESCRIPTIONS Class Cephalopoda Family Scaphitidae Meek, 1876 Genus Haresiceras Reeside, 1927 Reeside's original description of this genus is as follows: The fundamental generic characters combined in this genus are compressed whorls with flat venter bordered by two rows of nodes, very narrow umbilicus, and subparallel flanks; obscure sigmoid ribs curving sharply forward from the umbilicus to the middle of the flank, then passing radially to the venter, and crossing it uninterrupted but with a forward bend; suture with long triangular first lateral lobe and numerous auxiliary lobes. The present writer adds to the generic description the following observations concerning the adolescent whorls and the suture pattern. The early whorls of the older species have rounded venters and weak constrictions, whereas those of the younger species have flattened venters and no constrictions. The suture is complex and has four or five trifid lateral lobes separated by bifid saddles; the first lateral saddle is typically scaphitid in its large size and form. Haresiceras placentiforme Reeside Plate 3, figures 1-6; text figure 7 1927. Haresiceras placentiforme Reeside, U.S. Geol. Survey Prof. Paper 151, p. 18, pl. 13, figs. 1-14; pl. 45, fig. 4. 1952. Haresiceras placentiforme Reeside. Basse, in Piveteau, Traité de Paléontologie, v. 2, p. 659, fig. 54-18. 1957. Haresiceras placentiforme Reeside. Wright, in Moore, Treatise on Invertebrate Paleontology, pt. L, Mollusca 4, p. L392, figs. 510, Sa-c. 1960. Haresiceras placentiforme Reeside. Paleontology, figs. 11.31-6a, 6b. Easton, Invertebrate The adult of this species is characterized by very weak flank ribbing and a moderately broad flat venter bordered by a finely nodose ventrolateral keel. The species has been described very thoroughly by 114 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Haresiceras natronense Haresiceras placentiforme | Haresiceras montanaense | Desmoscaphites bassleri | A & Haresiceras mancosense Desmoscaphites erdmannti | Clioscaphites platygastrus Clioscaphites choteauensis | Clioscaphites vermiformis e> Clioscaphites vermiformis var. toolensis Fisurs 6.-Drawings of sutures (simplified) illustrating changes in width and form of the second lateral saddle (solid black) and third lateral saddle (stippled) of species of Olioscaphites, Desmoscaphites, and Haresiceras (compare with fig. 5). CRETACEOUS CEPHALOPOD HARESICERAS Reeside who made the following statements regarding the growth forms: Whorls up to a diameter of 3.5 millimeters (2% whorls) stout, at first wider than high, then circular in cross section. From this stage to that at a diameter of 15 millimeters (4%, whorls) the whorl increases in relative height, the flanks flatten, and finally the venter begins to flatten. At the stage with diameter of 15 millimeters a pair of nodose keels appears bordering the flattened venter, and the cross section of the whorl takes on the quadrate aspect maintained in all the later stages. ~ _- 1 FiGurE 7.-Cross sections, X 3 and X 12, of Haresiceras placenti- forme Reeside (after Reeside). USNM 73317. Regarding the form of the adult, Reeside noted that the umbilicus was very small (one-thirtieth the diam- eter of the largest specimens), the umbilical shoulder was rounded, and the aperture was sinuous and followed the shape of the ribs. Reeside observed also that ribs first appeared on the flanks at a diameter of 11 or 12 mm and that ventral ribs appeared at a slightly larger diameter. The venter and adjoining part of the flank on the older half of the holotype is badly weathered and the ribbing is obscured. A very well preserved septate coil (pl. 3, figs. 1-4) of comparable size from the Pierre Shale of the Black Hills reveals the sculptural details not seen on the holotype. The half whorl ending at a diameter of about 18 mm has 20 moderately strong ventral ribs of even height and spacing. At that diameter the rib- bing changes abruptly by becoming denser, weaker, and of uneven height. The half whorl beginning at a diam- eter of 18 mm and ending at 28.5 mm has about 40 ventral ribs. On the entire whorl the ribs on the flank are strongest near the ventrolateral border and weaken 115 and disappear toward the umbilicus. This loss of ribbing toward the umbilicus was observed on the younger part of the holotype by Reeside who thought it might be due to the condition of preservation of the specimen. In addition to the change to irregular and denser ribbing at a diameter of about 18 mm on the Black Hills specimen, secondary ribs appear as well as a clearly defined nodose ventrolateral keel. The nodes are very small, clavate, and irregular in size, the largest and highest being on the strongest ribs. The suture is perfectly exposed on the specimen from the Black Hills and reveals an interesting pattern (pl. 3, fig. 4). The ventral lobe is broad and bifid. The first lateral saddle is as large as the ventral lobe and very asymmetrically bifurcated by a deep trifid lobe. The first lateral lobe is trifid and about as long as the ventral lobe but not as wide. The second lateral saddle is high, narrower than the first lateral lobe, and very asymmetrically bifurcated by a deep trifid lobe. The second lateral lobe is trifid, shorter than the first lateral lobe and half as wide. The third lateral saddle is broader and shallower than the second lateral lobe and deeply bifurcated by a large trifid lobe. The third lateral lobe is trifid, almost as wide as the second lateral lobe but only half as long. The fourth lateral saddle is half as large as the third lateral saddle and deeply bifurcated by a trifid lobe. The fourth lateral lobe is trifid and half as large as the third lateral lobe. Occurrence: The holotype came from the Elk Basin Sand- stone Member of the Telegraph Creek Formation in the Elk Basin oil field in Park County, Wyo. (fig. 1, loc. 14). Other specimens are known from this sandstone in the northern part of the Bighorn Basin in Wyoming (fig. 1, locs. 15, 18). The species has been found also in the upper part of the Cody Shale in the southeastern part of the Bighorn Basin (fig. 1, loc. 25), in the Gammon Ferruginous Member of the Pierre Shale around the northern half of the Black Hills (fig. 1, locs. 11-13, 20-22, 33), and in the upper part of the Smoky Hill Shale Member of the Niobrara Formation in southeastern Colorado (fig. 1, loc. 42). Types: Holotype USNM 73317; plesiotypes USNM 131483, 131484. Haresiceras natronense Reeside Plate 3, figures 14-21 1927. Haresiceras natronense Keeside, U.S. Geol. Survey Prof. Paper 151, p. 19, pl. 14, figs. 4-16. Very compressed whorls and conspicuous ribbing characterize this species. The venter flattens and is bordered by nodose keels at a very small diameter. Reeside observed the following changes in the growth forms of this species: Earliest whorls well rounded and relatively stout, increasing in relative height until at a diameter of 8 or 9 millimeters the whorls have distinctively flattened flanks, the venter becomes 116 flattened and the nodose keels appear. The cross section in the subsequent stages has a quadrate aspect. Reeside recorded the presence of faint lateral ribs on a whorl of only 2 mm diameter and that the succeeding whorl had well-marked ribs at a diameter of 6 mm. He noted that as growth continued these lateral ribs spread across the venter and were very distinct there at a diam- eter of 7 or 8 mm. - The holotype, a juvenile of 16.5 mm diameter, has a well-defined flat venter bordered by nodose keels at a diameter of 9 mm. The largest collections at hand came from the Gam- mon Ferruginous Member of the Pierre Shale on the east side of the Black Hills (fig. 1, locs. 34, 35). These lots contain about 25 specimens, chiefly crushed adults (pl. 3, figs. 17-21). The few uncrushed juveniles of less than 20 mm diameter reveal considerable variation in stoutness and diameter at which the venter flattens (10-14 mm). As in Haresiceras placentiforme the lateral ribs are strongest near the margin of the venter but weaken and disappear toward the umbilicus. These ribs cross the venter with uniform height and spacing up to a diameter of 20 or 21 mm where those crossing the venter become weaker, denser, and irregular in height and spacing. Where they cross the ventro- lateral keel the weaker ribs bear smaller nodes than the stronger ribs. Lateral rib counts for the complete whorls of two of the figured specimens are 50 at a diameter of 26.5 mm (pl. 3, fig. 14) and 44 at a diameter of 31.5 mm (pl. 3, figs. 18, 21). Reeside did not illustrate the suture. The suture figured here (pl. 3, fig. 17) is from near the end of the septate coil of a large adult from figure 1, locality 35. Except for having longer and more deeply digitate elements, the suture resembles that of H. placentiforme. Occurrence . The holotype is from the Cody Shale 200 ft below the Shannon Sandstone Member in the Salt Creek oil field, Na- trona County, Wyo. (fig. 1, loc. 27). The species is known else- where from the Cody Shale near Kaycee, Wyo. (fig. 1, loc. 26), from the upper part of the Cody Shale in the Wind River Basin in central Wyoming (fig. 1, loc. 30), from the Gammon Ferru- ginous Member of the Pierre Shale on the east side of the Black Hills in western South Dakota (fig. 1, locs. 34, 35), from the upper part of the Mancos Shale in northwestern Colorado (fig. 1, loc. 40), and questionably from near the top of the Smoky Hill Shale Member of the Niobrara Formation near Boulder, Colo. (fig. 1, loc. 41). Types: Holotype 131485-131487. USNM 73320 ; plesiotypes USNM Haresiceras fisheri Reeside Plate 3, figures 7-9 1927. Haresiceras fisheri Reeside, U.S. Geol. Survey Prof. Paper 151, p. 19, pl, 45, figs. 1-3. This form is known only from the holotype, a septate coil with about three-fifths of the body whorl. The specimen is very compressed, conspicuously ribbed, and further characterized by an unusually narrow venter. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY The venter is rounded up to a diameter of 20 mm but truncated at larger diameters. The umbilicus is very small and the umbilical shoulder rounded. The ventral half of the flattened flanks is crossed by ribs of which every third or fourth is more elevated than the others. At the ventrolateral margin each rib is raised into a small node. About 40 ribs cross the venter on the last half whorl. - Reeside did not figure the suture and noted that it was not well preserved. This form most closely resembles H. matronemnse by its compressed cross section, narrow venter, and con- spicuous ribbing. - Possibly it is no more than a variant. Its association with Scaphites Aippocrepis and its strat- igraphic position high in that Range Zone (Fisher and others, 1960, p. 29, pl. 10) seems comparable to that of H. natronense. Occurrence : The holotype and only specimen came from about 800 ft below the top of the Mancos Shale near Green River, Emery County, Utah (fig. 1, loc. 39). Type: Holotype USNM 73387. Haresiceras montanaense (Reeside) Plate 2, figures 1-40 1927. Acanthoceras? montangaense Reeside, U.S. Geol. Survey Prof. Paper 151, p. 20, pl. 22, figs. 1-4. Reeside based this species on a single poorly pre- served specimen, a partly crushed and distorted young adult. This specimen, about 22 mm in diameter, has flattened flanks, a very broad gently arched venter, and a sharply defined ventrolateral edge. The flank on the last half whorl has about 12 moderately high ribs that curve back from the umbilicus, then arch forward on the outer part of the flank and finally straighten to the ventrolateral border. The ribs then cross the venter with a forward arching. Each rib is raised into a small node at the ventrolateral margin, and the result- ing row of nodes resembles a false keel. The writer has at hand about 50 specimens, chiefly juveniles, that seem assignable to Reeside's species. These can be divided into an older stout form associated with Sceaphites leei and a younger and more slender form associated with coarse-ribbed Seaphites hippo- crepis. Reeside's holotype is typical of the older form. The older form is represented best by a collection of 35 uncrushed juveniles 8-17 mm in diameter that came from a limestone concretion in the Gammon Shale on Porcupine dome in east-central Montana (fig. 1, loc. 7). These specimens reveal much variation in the degree of stoutness and in the diameter at which ribbing and the ventrolateral shoulder first appear (pl. 2, figs. 13-24). In general the stouter the specimen the smaller the diameter at which ribbing and the ventrolateral shoulder appear. This suggests that the stouter adults should be smaller than the more slender adults. (For comparable examples, see Reeside and Cobban, 1960.) CRETACEOUS CEPHALOPOD HARESICERAS A distinct ventrolateral shoulder first appears at a diameter of from 6 to 11 mm and ribbing appears at slightly larger diameters (7-12 mm). The ribs appear first on the venter and adjoining part of the flank, and within the next half whorl, the ribs extend across the flank to the umbilicus. Nodes rise from the ventro- lateral edge within the next quarter of a whorl follow- ing the initial rise of ribbing. Constrictions are pres- ent at diameters less than 12 mm on internal molds of a few specimens. These constrictions follow the shape of the ribs, number five or less per whorl, and are present only on the venter and outer part of the flank. On some individuals the constrictions occur in pairs in which the constrictions of a pair are closely spaced but separated by a high rib. On other specimens the constrictions may be single and bounded by high ribs or they may be single without accompanying ribs. The younger form of Haresiceres montanaense is represented best by a few very well preserved specimens from limestone concretions in the Cody Shale at Elgin Creek in Johnson County, Wyo. (fig. 1, loc. 19). Three of these specimens are shown on plate 2, figures 5, 35, 39. These specimens as well as other examples differ from the older form of H. montanaense chiefly by being a little more compressed and having weaker ribbing. T'wo specimens of the late form of H. montanaense from Park County, Wyo., have adult body chambers. One is a small individual, 2 mm in diameter from figure 1, locality 17, that is crushed but otherwise com- plete (pl. 2, figs. 29, 30). Its body chamber includes three-fourths of the last whorl. The ribs on the venter and flanks of the chambered part are uniform in height and spacing, but on the body chamber they are dif- ferentiated into stronger primaries that extend to the umbilicus and weaker secondaries that trend from the ventrolateral margin 14-14 of the distance to the um- bilicus before fading away. Near the aperture many weak intercalaries appear on the venter and flank and each bears a very small node at the ventrolateral edge. The aperture is sinuous following the shape of the ribs. The other body chamber is from figure 1, locality 16, and represents a large individual of possibly 50 mm diameter (pl. 2, figs. 37, 38). This specimen shows numerous intercalated ribs near the aperture and a general weakening of the ribbing there. The suture of H. montanaense cannot be distinguished on the holotype. A specimen from the Cody Shale of the Wind River Basin in Wyoming (fig. 1, loc. 24) shows the suture very well (pl. 2, fig. 28). The suture is typical of Haresiceras and almost as complex as that of H. placentiforme and H. natronense. The only noticeable difference is in the second lateral saddle which is symmetrically bifid in contrast to the asym- IH metry of this saddle in H. placentiforme and H. natronense. Occurrence: The holotype is from 150 ft below the Elk Basin Sandstone Member of the Telegraph Creek Formation in Carbon County, Mont. (fig. 1, loc. 9; not from Elk Basin Sandstone Member as stated on explanation of pl. 22 in Prof. Paper 151). The only other localities for the older form of H. montanaense are on Porcupine dome in east-central Montana (fig. 1, locs. 6, 7). The younger form is more widespread and is known from the basal part of the Telegraph Creek Formation and just below it in the northern part of the Bighorn Basin in Wyoming (fig. 1, locs. 16, 17), from the upper part of the Cody Shale of the Wind River Basin in Wyoming (fig. 1, locs. 24, 28, 29), from the Cody Shale on the east side of the Bighorn Mountains of Wyoming (fig. 1, loc. 19), from the lower part of the Steele Shale near Rawlins, Wyo. (fig. 1, loc. 32), and from the upper part of the Mancos Shale in northeastern Utah (fig. 1, locs. 36, 37). _ Types: Holotype USNM 73364; plesiotypes USNM 131466- 131482. Subgenus Mancosiceras Cobban, n. subgen. Type species.-Haresiceras (Mancosiceras) manco- sense (Reeside). The distinguishing characters are the well-ribbed compressed whorls, the tendency of the septate whorls to be round ventered, and the confinement of the nodose ventrolateral edge to the body chamber. Haresiceras (Mancosiceras) mancosense (Reeside) Plate 1, figures 14-27; plate 2, figures 41-48 1927. Pusosia (Latidorsella) mancosensis Reeside, U.S. Geol. Survey Prof. Paper 151, p. 15, pl. 12, figs. 1-8. 1960. Desmophyllites mancosensis (Reeside). Fisher, Erd- mann, and Reeside, U.S. Geol. Survey Prof. Paper 332, p. 29. Reeside based this species on five juveniles from three localities. The holotype is a septate coil 24 mm in diameter. It is moderately stout and has flattened flanks, rounded venter, and a very small umbilicus. The complete whorl has six or seven weak constrictions that extend from the umbilicus across the flank and over the venter. Strong forwardly arched ribs cross the venter but weaken and disappear at about the middle of the flank. Ribs are not visible on the older part of the whorl but 21 are present on the younger half of the whorl. | The suture of the holotype (pl. 1, fig. 21) is typical of the genus in its trifid lateral lobes, narrow second lateral saddle, and broad third lateral saddle. The second lateral saddle is symmetrically bifid like that of H. montanaense. The writer assigns two forms to this species, one characterized by a rounded venter on most or all of the septate whorls and the other marked by a flattening of the venter early on the last septate whorl. The round- venteréd form, which includes the holotype, is inter- preted as the older. 118 The best collection at hand of the round-ventered form consists of four uncrushed specimens, all septate coils 25-38 mm in diameter, from a bed of limestone concretions near the base of the Gammon Shale near Mosby in east-central Montana (fig. 1, loc. 5). The presence of a septate individual (pl. 1, figs. 16-18) 38 mm in diameter suggests that the larger adults attained a size comparable to that of adult H. natron- ense (pl. 3, fig. 17). This septate specimen has the venter flattened at an earlier growth stage than that of the associated specimens. One fragment (pl. 1, figs. 14, 15) has closely spaced ventral ribs of even height, but on the flank they are differentiated into flexuous primary and secondary ribs, the primaries extending to the umbilicus. This fragment is probably from the younger end of the septate coil of an adult. The septate whorls of a specimen (pl. 1, figs. 25, 26) from the Sweetgrass arch in northwestern Montana (fig. 1, loc. 1) have weaker ribbing than that of any of the specimens from the Mosby locality. This individ- ual, 21 mm in diameter, has seven conspicuous constric- tions on the complete whorl and 27 ventral ribs on the last half whorl of which all are very weak except those on the oral side of the constrictions. Reeside (19272, p. 16) considered this specimen as a new species. The body chamber of the early form of H. (M.) mancosense is represented by a single fragment from the upper part of the Cody Shale in the Wind River Basin of Wyoming (fig. 1, loc. 23). This fragment (pl. 1, fig. 27) reveals a slightly arched venter, well- defined ventrolateral shoulder, and flattened flanks. The venter has ribs of even height and spacing that bend forward slightly. For every four ribs a sharp node rises from the ventrolateral shoulder. Sculpture on the flanks is obscured by weathering. The flat-ventered or younger form of the species is known with certainty only from the Telegraph Creek Formation along the Marias River near Shelby Mont. The largest collection consists of four septate coils 24-26 mm in diameter and part of a body chamber from a sandstone unit in the lower part of the Telegraph Creek Formation (fig. 1, loc. 2). The best specimen (pl. 2, figs. 41, 42), 26 mm in diameter, has the venter rounded on the earliest part visible (diam of about 14 mm) but distinctly flattened on the last half of the whorl where the ventrolateral shoulder is sharply rounded. For- wardly arched strong ribs cross the venter ; these num- ber 32 or 33 for the complete whorl. The flanks of most of the early half of the whorl are smooth but, beginning at a diameter of 19 mm, the ventral ribs pass into sinuous primaries that extend to the umbilicus and secondaries that weaken and disappear on the outer SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY third of the flank. The primaries bend back slightly on leaving the umbilicus then curve forward to a point about two-thirds of the distance to the edge of the venter where they gently turn back a little and then arch slightly forward to the ventral margin. - Only parts of the suture are visible, but these reveal a pattern about as complex as that of the holotype of H. (M <] mancosense. Fragments of three body chambers (pl. 2, figs. 43-48) from the Telegraph Creek Formation in the Shelby area (fig. 1, locs. 24) are interpreted as belonging to the flat-ventered form of this species. These have broad gently arched venters, flattened flanks, and a well- defined angular ventrolateral margin. The venter is crossed by numerous ribs that bend forward a little. Ribbing on the flank is likewise dense but is differen- tiated into primaries and secondaries. Each primary ends in a small pointed node on the ventrolateral shoulder. Two or three secondaries are present for each primary. The largest specimen (pl. 2, figs. 47, 48) is more coarsely ribbed than the others and probably is as large as H. natronense (pl. 3, fig. 17). Reeside (19272, p. 15) originally assigned his species to Puzosia (Latidorsella). Latidorselle Jacob (1907, p. 35) is an objective synonym of Desmoceras Zittel (1884, p. 465) which differs from Reeside's species by its stouter form, wider umbilicus, and suture that has more numerous lobes and saddles, all of which decrease regularly in size away from the venter. Later Reeside (in Fisher and others, 1960, p. 29) assigned his species to Desmophyllites Spath (1929, p. 270) of Santonian and Campanian age. - DesmopAyllites is a much larger ammonite that has a deeply digitate desmoceratid suture. Occurence: The holotype is from 160 ft below the top of the Mancos Shale in San Jaun County, N. Mex. (fig. 1, loc. 48). The paratypes came from the Telegraph Creek Formation in south- central Montana (fig. 1, locs. 8, 10). Other specimens came from the Telegraph Creek and the uppermost part of the Marias River Shale in northwestern Montana (fig. 1, locs. 1-4), from the Cody Shale in the Wind River Basin of west-central Wyom- ing (fig. 1, loc. 23), from the Baxter Shale near Rock Springs, Wyo. (fig. 1, loc. 31), and from the Mancos Shale of east-central Utah (fig. 1, loc. 88). Types: Holotype USNM 73314; paratypes USNM 73313, 73314; plesiotypes USNM 131455-131463. LITERATURE CITED Basse, Elaine, 1952, Classe des Céphalopodes, in Jean Piveteau, Traité de Paléontologie, pt. 2, p. 461-688, pls. 1-24. Cobban, W. A., 1950, Telegraph Creek Formation of Sweetgrass arch, north-central Montana: Am. Assoc. Petroleum Geol- ogists Bull., v. 34, no. 9, p. 1899, 1900. 1951a, Colorado shale of central and northwestern Mon- tana and equivalent rocks of Black Hills: Am. Assoc. Pe- troleum Geologists Bull., v. 35, no. 10, p. 2170-2198, 2 figs. CRETACEOUS CEPHALOPOD HARESICERAS Cobban, W. A., 1951b, Scaphitoid cephalopods of the Colorado group: U.S. Geol. Survey Prof. Paper 239, 42 p., 21 pls., 4 text figs. [1952]. 1953, An Upper Cretaceous section near Mosby, Montana, in Billings Geol. Soc. Guidebook 4th Ann. Field Conf., Little Rocky Mountains, Montana-Southwestern Saskat- chewan, 1953: p. 98-101. 1955, Cretaceous rocks of northwestern Montana, in Billings Geol. Soc. Guidebook 6th Ann. Field Conf., Sweet- grass arch-Disturbed belt, Montana, 1955: p. 107-119, 9 figs. 1962, Late Cretaceous Desmoscaphites Range Zone in the western interior region, in Short papers in geology hydrol- ogy, and topography: U.S. Geol. Survey Prof. Paper 450-D, p. D140-D144. Cobban, W. A., and Reeside, J. B. Jr., 1952, Correlation of the Cretaceous formations of the Western Interior of the United States: Geol. Soc. America Bull., v. 63, no. 10, p. 1011-1048. Cobban, W. A., Scott, G. R., and Gill, J. R., 1962, Recent dis- coveries of the Cretaceous ammonite Haresiceras and their stratigraphic significance, in Short papers in geology, hydrology, and topography : U.S. Geol. Survey Prof. Paper 450-B, p. B58-B60. Collier, A. J., 1929, The Kevin-Sunburst oil field and other possibilities of oil and gas in the Sweetgrass arch, Montana : U.S. Geol. Survey Bull. 812-B, p. 57-189, pls. 11-18 [1930]. Dobbin, C. E., and Erdmann, C. E., 1955, Structure contour map of the Montana Plains: U.S. Geol. Survey Oil and Gas Inv. Map OM-178-B. Dobbin, C. E., Kramer, W. B., Miller, J. C., and French, H. F., 1944, Geologic and structure map of the Elk Basin oil and gas field and vicinity, Park County, Wyoming, and Carbon County, Montana : U.S. Geol. Survey. Fisher, D. J., Erdmann, C. E., and Reeside, J. B., Jr., 1960, Cretaceous and Tertiary formations of the Book Cliffs, Carbon, Emery, and Grand Counties, Utah, and Garfield and Mesa Counties, Colorado: U.S. Geol. Survey Prof. Paper 332, 80 p., 12 pfs., 1 fig. Grossouvre, A. de, 1893, Récherches sur la craie supérieure; pt. 2, Paléontologie. Les Ammonites de la craie supérieure : Carte Géol. France Mém., 264 p., pls. 1-39. Hose, R. K., 1955, Geology of the Crazy Woman Creek area, Johnson County, Wyoming : U.S. Geol. Survey Bull. 1027-B, p. 33-118, pls. 6-13, figs. 13-27, [1956]. Jacob, Charles, 1907, Etude sur quelques Ammonites du Crétacé moyen: Soc. géol. France, Mém., Paléont., v. 15, no. 38, p. 1-64, 9 pls. [1908]. T19 Keefer, W. R., and Troyer, M. L., 1956, Stratigraphy of the Upper Cretaceous and lower Tertiary rocks of the Shotgun Butte area, Fremont County, Wyoming: U.S. Geol. Survey Oil and Gas Inv. Chart OC-56. Reeside, J. B., Jr., 1924, Upper Cretaceous and Tertiary for- mations of the western part of the San Juan Basin, Colo- rado and New Mexico: U.S. Geol. Survey Prof. Paper 134, p. 1-70, pls. 1-4, text figs. 1-5. 1927a, The cephalopods of the Eagle sandstone and re- lated formations in the Western Interior of the United States: U.S. Geol. Survey Prof. Paper 151, 87 p., 45 pls. 1927b, The scaphites, an Upper Cretaceous ammonite group: U.S. Geol. Survey Prof. Paper 150-B, p. 2140, pls. 9-11. 1944, Maps showing thickness and general character of the Cretaceous deposits in the western interior of the United States: U.S. Geol. Survey Oil and Gas Prelim. Map 10. Reeside, J. B., Jr., and Cobban, W. A., 1960, Studies of the Mowry shale (Cretaceous) and contemporary formations in the United States and Canada: U.S. Geol. Survey Prof. Paper 355, 126 p., 58 pls., 30 text figs. Richards, P. W., 1955, Geology of the Bighorn Canyon-Hardin area, Montana and Wyoming: U.S. Geol. Survey Bull. 1026, 93 p., 7 pls., 8 text figs [1956]. Seitz, Otto, 1956, Uber Ontogenie, Variabilitit und Biostrati- graphie einiger Inoceramen: Palaeont. Zeitschr., v. 30, p. 3-6. Spath, L. F., 1929, Corrections of cephalopod nomenclature: The Naturalist, no. 871, p. 269-271. Thom, W. T., Jr., Hall, G. M., Wegemann, C. H., and Moulton, G. F., 1935, Geology of Big Horn County and the Crow Indian Reservation, Montana, with special reference to the water, coal, oil, and gas resources: U.S. Geol. Survey Bull. 856, 200 p., 15 pls., 13 text figs. Wegemann, C. H., 1918, The Salt Creek oil field, Wyoming: U.S. Geol. Survey Bull. 670, 52 p., 7 pls. Wilson, J. B., 1951, Stratigraphy of the Sussex Sandstone, Pow- der River Basin, Wyoming: Wyoming Geol. Survey Rept. Inv. 3, p. 1-11, pls. 1-8. Wright, C. W., 1957, Hoplitaceae, in Arkell, W. J., Kummel, Bernard, and Wright, C. W., Mesozoic Ammonoidea: Treatise on invertebrate paleontology, R. C., Moore, ed., Part L, Mollusca 4, p. L80-L465. Yenne, K. A., and Pipiringos, G. N., 1954, Stratigraphic sections of Cody shale and younger Cretaceous and Paleocene rocks in the Wind River Basin, Fremont County, Wyoming: U.S. Geol. Survey Oil and Gas Inv. Chart OC-49. Zittel, K. A. von, 1884, Handbuch der Palaeontologie, v. 2, p. 1-893, figs. 1-1109. Page Acanthoceras montanaense......__.______ 11,4,5, 6,16 alcesense, Eutrephoceras 8 aquilaensis, Baculites..__________________ 6, 8, 9, 10, 11 costatus, Scaphites.________________________ 8 manus, Seaphites._________________________ 8 6,8, 9 aquisgranensis, Scaphites....____._______ 6, 8, 9, 10, 11 asper, 9 Baculites aquilaensis.._________________ 6, 8, 9, 10, 11 coco minerensis. ...... ALIA YL eL ne ens 6,7, 8, 9, 10 CI- oon 0000s oue 5,6, 11 ELE - 10 bassleri, Desmoscaphites -. - 1,4, 5, 8, 9, 10, 11 bidorsatum, Diplacmoceras.....______________. 1 binodosus, Scaphites...._______________________ 11 Cephalopoda. 18 choteauensis, Clioscaphites. 4,5, 11,12, 13,’p1. 1 CHOSCADRIfER. .. . ...... 1,11, 12,13 choteauensig.....______________ 4,5, 11, 12,13, pl. 1 platygastrug. . 1,12, 13, pl. 3 vermiformis ... - 4,5, 6, 8, 9, 10, 11, 12, 18, pl. 1 fopi¢néis.1221...20.00.0... . 1213 cordiformis, Inoceramus. .._... - 4,11 costatus, Scaphites aquilaensig.________________ 8 crassus, Scaphites hippocrepis...______________ 8, 9 LYLE. 2.00 nes nics andante e 18 Desmophyllites.....__________________. 18 ...................... 17 ............... 1,5, 11,12, 13 -- 1, 4, 5, 8, 9, 10, 11 CCEA L Le nese nee w 4,5, 6, 11,12, pl. 1 SDs noo on 6, 11 Diplacmoceras bidorsatum.........._____.____. 11 erdmanni, Desmoscaphites.... ___.. 4, 5, 6, 11, 12, pl. 1 Eutrephoceras alcesense_.......________________ 8 fisheri, Haresiceras....._.___________ 1,10, 11, 16, pl. 3 Forbesiceras 11 Glyptozoceras rubeyi..........________________ 8, 9, 10 Gonioteuthis gramulata........________________. 11 quadrata........... 11 granulata, Gonioteuthis........._________._____ 11 INDEX [Italic numbers indicate descriptions] Page haresi, Baculites.__.______________ -... 5,6, 9, 10, 11 Haresiceras.....___________ 1, 5, 6, 9, 11,12, 18 . 22112000 2s 1,10, 11, 16, pl. 3 TOMCOBEM&GL LLL 22220222 1,5,11 montanaense. .. . .. 1,8, 9, 10, 11,12, 18, 16,17, pl. 2 natronense..-~ 1, 6,7, 9,10, 11,18, 15, 16, 17,18, pl. 3 placentiforme. ...... 1, 6, 8, 9, 10, 11, 13, 16, 17, pl. 3 02000020 6 (Mancosiceras) mancosense_....___._______ 1, 5, 6, 8, 9, 10, 11, 12, 17, 18, pls. 1, 2 Hauericeras 11 hippocrepis, Scaphites.:~ 1, 4,5, 6, 7,8, 9,10, 11, 16, pl. 1 crassus, Scaphites.._______________________ 8,9 pusillus, Scaphites.. ___. 8 tenuis, Scaphites.....____ -- 6,8,9 Hopliteg. . 11,12 IMmOC@PAMUS®L 6 4,11 lundbreckengig. . .. .____._________________ 5, 9 5, 6, 8, 9, 10, 11 . . . . 2 22000000 000000000 oun 18 (Latidorsella), Puzosia_.._.__________________. 18 mancosensis, Puzosia....._____________ 1,4,5,17 leei, Scaphites...._.________.. 18018, BUEDHHEES. . ... . . . 2220000000000 00000000000. lundbreckensis, Inoceramus....._______________ 5,9 mancosense, Haresiceras......________________ 1,5, 11 Haresiceras (Mancosiceras).......___...._. 1, 5, 6, 8, 9, 10, 11, 12, 17, 18, pls. 1, 2 mancosensis, Desmophyllites .. 17 so ooeraberenene ers ua 9 (Latidorsela). ...... -- 1,4, 5,17 Mancosiceras......_..____...._. (Mancosiceras) mancosense, Haresiceras. ...... 1, 5, 6, 9, 10, 11, 12, 17, 18, pls. 1, 2 Marsupites. . 1,9, 11 Sere 2B vere a 08 8, 11 Metaplacenticeras_...__..... 11 minerensis, Baculites.......____._________.______ 9 montanaense, Acanthoceras.... -- 1,4,5,16 Haresiceras........ 1, 8, 9, 10, 11, 12, 13, 16, 17, pl. 2 manus, Scaphites aquilaensis...._______________ 8 matronense, Haresiceras....._.____.____________ 1, 6, 7, 9, 10, 11, 18, 15, 16, 17, 18, pl. 3 obtusus, Baculites........___...____._.._.__. 6,7, 8, 9,10 O Page parvum Haresiceras placentiforme....._.....__. 6 patootensis, Inoceramus.._.___________ 5, 6, 8, 9, 10, 11 Placenticeras 11 syrtale. .._... 11 placentiforme, Haresiceras 6891011131617pl 3 parvum, Haresiceras...._________________. 6 platygastrus, Clioscaphites.......______. 1,12, 13, pl. 3 pseudogardeni, Hauericeras ... M 1 pusillus, Scaphites hippocrepis......____.._.____ 8 Puzosia mancosensig........__._______________ 9 (Latidorsella). ... 18 1,4, 5,17 (Schlueteria) 5 quadrata, Gonioteuthis....._____________._____._. 11 rubeyi, Glyptozoceras........_________________ 8, 9, 10 . .. ... .c... ool 6,7, 13 OJUHOENEIEL ..... . . 2200000000 meen ne 000 6,8, 9 \ ou 2 conn ne nnn take be vee be bass 8 HONE. ...o acl awe ue cone ew 8 aquisgranensis. 6, 8, 9, 10, 11 bin0d0828.. . ..... 11 hippocrepis......... 1,4, 5, 6, 7, 8, 9, 10, 11, 16, pl. 1 crassus .. 8,9 pusillug._.. .. 8 205 0.02080 290.002 o ole aioli a inte a cm meal 6,8, 9 Teff si ce 5, 6, 8, 9, 10, 11, 16, pl. 1 Scaphites levis 8 Scaphitidae...._...__.... 18 (Schlueteria), Puzosia.. .. 5 socialis, Uintacrinus._._ ._. 5,11 BORMETATINLL 1.1 ..o. o ooo aes ab cens ov 11 syrtale, Placenticeras..__......_______________ 11 tenuis, Scaphites hippocrepis...._._____________ 6,8, 9 thOMH, ...... . . . . . 0210002000000 seee. 5,6, 11 toolensis, Clioscaphites vermiformis.........._.. 12,13 .. .c. 2 1 112200000000 enone ann 1,9, 11 #00@H® ... ... 2 200000000 5,11 SD.... .L /l doli Rc ecb 8 vermiformis, Clioncaphites.._..._______________ 4, 5, 6, 8, 9, 10, 11, 12, 13, pl. 1 toolensis, Clioscaphites.._...._____________ 12,13 121 PLATES 1-3 PLATE 1 [All figures natural size except as indicated on plate] 1-7. Desmoscaphites erdmannt Cobban (p. 1 12). From 10 ft below top of Marias River Shale at USGS Mesozoic loc. 21419, 8 miles west of Shelby, Toole County, Mont. 1, 2, 7. Side and rear views of an internal mold of a young specimen showing constrictions, forwardly arched ventral ribs, and last suture (X 3). USNM 106725a. 3, 4. Side and front views of a smaller specimen showing constrictions and lack of ribbing on the early whorls. USNM 106725d. 5, 6. - Front and side views of an incomplete specimen showing the coarse-ribbed outer septate whorl and beginning of the fine-ribbed body chamber. USNM 106725c. 8-10. Clioscaphites choteauensis Cobban (p. 1 12). Side, rear, and front views of a juvenile from upper part of Marias River Shale at USGS Mesozoic loc. 23889, in the E see. 31, T. 32 N., R. 3 W., Toole County, Mont. Note the forwardly arched ventral ribbing, lack of constrictions, and stouter shell than that of fig. 2. USNM 131454. 11-13. Clioscaphites vermiformis (Meek and Hayden) (p. 1 12). Side, rear, and front views of a septate coil from limestone concretions 234-252 ft below top of Marias River Shale at USGS Mesozoic loc. 21425, 11 miles southwest of Shelby, Toole County, Mont. - This individual has forwardly arched ventral ribbing similar to that of figs. 2 and 9 but differs readily by its stouter shell. USNM 106718e. 14-27. Haresiceras (Mancosiceras) mancosense (Reeside) (p. 117). 14, 15. Rear and side views of a fragment showing slightly flexuous primary and secondary ribbing near the end of the septate coil. From a limestone concretion collected at loc. 5 (fig. 1). USNM 131455. 16-18. - Side, front, and rear views of a very large septate coil from the same locality as fig. 14. USNM 131456. 19-21. Side and rear views and suture (X 4), of the holotype collected from 160 ft below top of Mancos Shale at loc. 43 (fig. 1), San Juan County, N. Mex. USNM 738314. After Reeside. 22-24. Side, rear, and front views of a septate coil from the same locality as fig. 14. This individual lacks constrictions, but it does show the compressed whorl section, strong forwardly arched ventral ribbing, and flexuous flank ribbing. USNM 131457. 25, 26. Side and rear views of a septate internal mold collected from loc. 1 (fig. 1). This specimen has well- defined constrictions but unusually weak ribs. USNM 131458. 27. View of part of the venter of an adult showing three of the ventrolateral nodes; collected from loc. 23 (fig. 1). USNM 131459. 28-30. Scaphites cf. S. hippocrepis (DeKay) (p. 18). Side, top, and rear views of an adult, an internal mold, from upper part of Elk Basin Sandstone Member of Telegraph Creek Formation at USGS Mesozoic loc. D3295, in the SE!4 see. 19, T. 58 N., R. 99 W., Park County, Wyo. This specimen, transitional to S. leet Reeside, has the coarse ribbing that characterizes the scaphites from the lower and middle parts of the S. hippocrepis Range Zone. USNM 131464. 31, 32. Scaphites leet Reeside (p. I 11). Rear and side views of the holotype from upper part of Mancos Shale at USGS Mesozoic loc. 7165, 1 mile south- west of Waldo, Santa Fe County, N. Mex. USNM 73354. After Reeside. 33-36. Scaphites hippocrepis (DeKay) (p. 1 8). Side, top, rear, and front views of an adult retaining much of the shell, from Cody Shale at USGS Mesozoic loc. 21206, 6 miles east of Hardin, Big Horn County, Mont. This specimen has the fine ribbing characteristic of the scaphites in the upper part of the S. hippocrepis Range Zone. - USNM 131465. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-1 PLATE 1 l DESMOSCAPHITES, CLIOSCAPHITES, HARESICERAS, AND SCAPHITES PLATE 2 [All figures natural size except as indicated on plate] FicurEs 1-40. Haresiceras montanaense (Reeside) (p. I 16). 1, 2. Side and rear views of a small juvenile representing the early form of the species; collected from loc. 7 (fig. 1). USNM 131472. 3. Rear view of a slightly larger and more slender individual from the same locality showing a constriction. USNM 131473. 4. Rear view of a large juvenile from the same locality showing constrictions bordered by strong ribs. USNM 131474. 5, 6. Side and rear views of a juvenile collected from loc. 19 (fig. 1). This specimen represents the younger and more slender form of the species. USNM 131468. 7-9. Side, rear, and front views of a young septate specimen, an internal mold collected from loc. 6 (fig. 1). This individual is very slender for the early form of the species. USNM 131466. 10-12. Side, rear, and front views of another internal mold collected from loc. 6 (fig. 1). This specimen is of average stoutness for the early form and shows a constriction. USNM 131467. 13-24. Side and rear views of six juvenile specimens collected from loc. 7 (fig. 1) showing variation in stoutness and in the appearance of a flattened venter and ribbing. USNM 131475-131480. 25-28. Side, rear, and front views and suture (X 4), of a septate representative of the younger or slender form of the species; collected from loc. 24 (fig. 1). USNM 131471. 29, 30. Side and rear views of a very small adult collected from loc. 17 (fig. 1) showing well-ribbed flanks and, near the aperture, very small ventrolateral nodes. USNM 131481. 31-34. Two side, rear, and front views of the holotype collected from loc. 9 (fig. 1). USNM 73364. After Reeside. 35, 36. Side and rear views of a septate specimen representing the younger form of the species, from the same locality as fig. 5. USNM 131469. 37, 38. Side and rear views of most of a large adult body chamber collected from loc. 16 (fig. 1). USNM 131482. 39, 40. Side and rear views of a small adult of the younger form of the species from the same locality as fig. 5. USNM 131470. 41-48. Haresiceras (Mancosiceras) mancosense (Reeside) (p. I 17). 41, 42. Side and rear views of a septate specimen representing the late form of the species; collected from loc. 2 (fig. 1). USNM 131460. 43, 44. Side and rear views of part of a body chamber from the same locality as fig. 41. USNM 131461. 45, 46. Rear and side views of part of a body chamber of the late form; collected from loc. 3 (fig. 1) and showing primary and secondary ribs and small ventrolateral nodes. USNM 131462. 47, 48. Side and rear views of part of a large coarse-ribbed body chamber of an adult of the late form of the species; collected from loc. 4 (fig. 1). USNM 131463. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-1 PLATE 2 1‘ 2. 3. ' ‘ ' 4 5 6 7 8 9 10 11 12 14I 15l 16' 17. 18 19. 20' 21. 22' 23‘ 4' 2 27 X4 28 30 46 HARESICERAS PLATE 3 [All figures natural size except as noted on plate] FraurEs - 1-6. Haresiceras placentiforme Reeside (p. 113). 1-4. Side, front, and rear views and suture (X 4), of the septate whorls of a specimen collected from loc. 13 (fig. 1). USNM 131483. 5, 6. - Side and rear views of part of a juvenile from the same locality. USNM 131484. 7-9. Haresiceras fisheri Reeside (p. 1 16). Side, rear, and front views of the holotype; collected from loc. 39 (fig. 1). USNM 73387. After Reeside. 10-13. Clioscaphites platygastrus Cobban (p. 1 12). Part of suture (X 3), and side, bottom, and top views of the holotype from near top of Marias River Shale 4 miles west of Sunburst, Toole County, Mont. USNM 106729. 14-21. Haresiceras natronense Reeside (p. I 15). From marlstone concretions in lower part of Gammon Ferruginous Member of Pierre Shale; collected at loc. 35 (fig. 1). 14-16. - Side, rear, and front views of a septate coil. USNM 131485. 17-19, 21. Suture (X 4), two side views of a partly crushed adult, and a front view of the last septate whorl with part of the crushed body chamber. USNM 131486. 20. View of part of an adult showing the shape of the aperture. USNM 131487. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-1 PLATE 3 X4 X3 X4 17 15 16 HARESICERAS AND CLIOSCAPHITES yo s : J - / -la e&C (Geology of Bullfrog Quadrangleand Ore Deposits Related to Bullfrog Hills Caldera, Nye County, Nevada and Inyo County, California GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-J Prepared in cooperation with the Nevada Bureau of Mines Geology of Bullfrog Quadrangleand Ore Deposits Related to Bullfrog Hills Caldera, Nye County, Nevada and Inyo County, California By HENRY R. CORNWALL and FRANK J. KLEINHAMPL SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY -PROFESSIONAL PAPER 4 5 4 - J Prepared in cooperation with the Nevada Bureau of Mines UNITED STATES GOVERNMENT PRINTING OEFLCE,. WASHINGTON .-: - -1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page s rit i o J1 introduction...." .l". c.. Nlt oa ill O7 {jln} Precambrian rocks a-..." n. ln. l Ealsosole rocks:. '-.. 0D (Olt u_ 0 Daylight .. ';r..:_ >:. _ Ngee and correlation. ___... Corkecrew Quartrite. -... _._} -_ /_ _ ___ Age:and correlation." _._" ___; Carrara Formation.... ..:... 4_i ~. _. l c Nopa .': 2 ° Pogonip Group: ..- ool t 2010 oll '.: Llc: ;( Ot _C ~} Fly Springs Dolomite......: ~...." i co __: Roberts Mountains Formation. ..._____________.__ Lone Mountain ; Other:Paloosoic rocks...:_..l }.... O..} _; Cenozoic rocks and __ Monolithologic :" " -_} _._ Titus Canyon Formation of Stock and Bode (1935). Bullfrog Hills caldera and associated rocks. _. ___ ___ Description of the volcanic rocks._____________ Ash flows.... _ig.c:. soo f I Air-fall tuffs!.__:.z ol. n lol tla in 602" _ a l—iCDanflo'aQCSU‘CflUICflCHPQWWNtot—twfl Rhyolite flows and intrusives_________________ 11 Basalt flows and intrusives___________________ 11 Latite flows and intrusives___________________ 11 Cenozoic rocks and volcanism-Continued Bullfrog Hills caldera and associated rocks-Con. Chemical composition of the rocks. ___ ________ Older ___ Colace t 3.4 Recent 30200004 tater nl. ca 00 lof O_O L el ao wtel aie Tectonic deformation.... =_. .a t", voce Relation to Walker Lane and Las Vegas Valley shear zone :.. _n osa ~ Basin-range faulting. ... .t} Volcanic deformation f _y. _;. Ore deposits associated with the caldera. ______________ . n.. _ scr cn Aloo Daisy mine. -...}. ll -t ax Artin t Geologic {1X}.3 Structure of the ore deposit. Nature of the ore: 2 Production... _c 40 luc t (e Origin of the deposit:. ; " .y Gold.. .y acl ono NCCo Originof the deposits. L c=" Bentonite:= .. 0.0.0.0 ___ 12 (l Misc hi al 1} "f_. c a Iln lj n l_ ay t Pummicite:-t..." ___ Llc o ''In My. {y ed ina nge ad car ice Reforences.cited ' -our "t_ fou?" ILLUSTRATIONS [Plates are in pocket] PratE 1. Geologic map and sections of the Bullfrog quadrangle, Nevada-California. 2. Columnar section of Paleozoic rocks on Bare Mountain. 3. Columnar section of Titus Canyon Formation of Stock and Bode (1935), 1 mile southeast of Daylight Pass, Funeral Mountains. Mine workings of the Daisy fluorspar mine. w p 1 o ons - Generalized geologic map of the Bullfrog Hills and Yucca Mountain calderas. . Columnar section of rocks in the Bullfrog Hills caldera near Beatty. Geologic map of levels 3, 5, 6, and 8, Daisy fluorspar mine. . Geologic map of levels 9 to 13, Daisy fluorspar mine. . Longitudinal and cross sections of the Daisy fluorspar mine. FicurE 1. View of Bonanza King and Nopah Formations in Carrara Canyon, Bare - 20; C, Devitrified densely welded lithoidal zone of same ash flow as in A. Groundmass of microcrystalline eutaxitic schlieren, elongated more or less parallel to the flow plane, but deflected around crystals and fragments. Dark fragment is glass. White crystals are sanidine and anorthoclase. Plain light, X 20. D, Partly welded tuff just below the vitrophyre zone of an ash flow. Pumice fragments (speckled gray) are flattened parallel to the flow plane. Groundmass consists of glass dust (black), small pumice fragments (gray), and angular glass shards (white and light gray). Crystals (white) are quartz, plagioclase, and sanidine. Plain light, X 20. J14 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY A B Ficurs 7.-Photomicrographs of perlitic and spherulitic rhyolite gray than the glass). Plain light, X 16. B, Spherulites from the bodies. A, Perlite from the margin of a rhyolite intrusion. Rock is margin of a rhyolite flow. Rock consists of spherulites of various mostly perlitic glass, but it contains several subrounded crystals of sizes and scattered crystals (white). Large crystal is oligoclase; quartz (white), plagioclase (white), and sanidine (slightly darker small crystal is quartz. Crossed nicols, X 20. A B FIicuUur® 8.-Photomicrographs of felsitic rocks. A, Rhyolite porphyry x 15. B, Latite porphyry flow. Phenocrysts of oligoclase (white), intrusive. Rectangular white patches are anorthoclase phenocrysts. augite (gray, in or adjacent to oligoclase), and altered biotite (black) Small white streaks are miarolitic cavities filled with quartz and tend to be clustered together. The groundmass is very fine grained, anorthoclase. Groundmass (dark gray) consists of a very fine inter- slightly trachytic, and consists of intergrown oligoclase, K-feldspar. growth of quartz and feldspar speckled with hematite. Plain light, and magnetite. Plain light, X 15. BULLFROG QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. FIGURE 9.-Rhyolitic vitrophyre breccia at base of flow in the upper part of the Bullfrog Hills volcanic sequence, Rainbow Mountain, Bull- frog quadrangle, Nevada. and basalts is 3 to 10 times Vinogradov's figure for the same rocks. Ba and Sr are nearly equal to Vino- gradov's figure in the rhyolites, but in the latite and basalts they are 2 to 7 times higher. F is about average in the rhyolites of the Beatty area, but it is 3 times higher than Vinogradov's estimates in the latite and basalt. OLDER GRAVELS Older gravels, probably Pleistocene in age and characterized by the variable sorting of the detritus, occur in the south and northeastern parts of the Bull- frog quadrangle. These gravels are old dissected fans, which have been eroded and partly covered by Recent alluvium. These dissected fans consist of rel- atively fine detritus, cobbles, and boulders. The up- per surfaces are strewn with boulders, mostly less than 3 feet across, derived from the various types of bedrock in the adjacent areas. In the south part of the quadrangle, the boulders on the fans are quartzite from the Corkscrew and Daylight Formations, dolo- mite and limestone from the Bonanza King and Car- rara Formations, and welded tuff and basalt from the Tertiary volcanic rocks. In the northeastern part of the quadrangle, the dissected fans are strewn with the same types of boulders, but rhyolite derived from welded tuffs and intrusives predominates. Two of the dissected fan remnants in the southern part of the quadrangle had been intruded by basalt (pl. 1) prior to dissection and the surfaces adjacent to these areas are strewn with basalt boulders. RECENT ALLUVIUM The Amargosa Desert and Sarcobatus Flat in the southeastern and northwestern parts of the quad- J15 rangle, respectively, are mostly underlain by Recent alluvium composed of gravel, sand, and silt. The alluvium has encroached on the Funeral and Grape- vine Mountains in the southwestern part of the quad- rangle, and on the Bullfrog Hills in the northern part. Large areas of the alluvium are covered by smooth desert pavement broken by the gullies of ephemeral streams. STRUCTURE The structural features of the rocks in the Bullfrog quadrangle, like those in the Bare Mountain quad- rangle, are due both to tectonic deformation and to volcanic activity. The Paleozoic rocks have been in- tensely folded and faulted by a major tectonic orogeny (Cornwall and Kleinhampl, 19602), probably in the Cretaceous and early Tertiary, that also produced major thrust faults and right-lateral strike-slip faults in the Las Vegas Valley shear zone (Longwell, 1960) southeast of Bare Mountain. The volcanic rocks in the northern parts of the two quadrangles have been deformed by the catastrophic subsidence (Cornwall, 1962) of the edifices from which these rocks were erupted to form the Bullfrog Hills caldera, probably in the Miocene, and the Yucca Mountain graben, probably in the Pliocene (pl. 4). During the Tertiary and Quaternary the whole region has been subjected to basin-range normal faulting. TECTONIC DEFORMATION In the southwestern part of the Bullfrog quadrangle a flat thrust plate of Corkscrew Quartzite and overly- ing carbonate rocks of the Carrara and Bonanza King Formations moved northeastward over the older Day- light Formation. Erosional remnants of the thrust plate, consisting mostly of Corkscrew Quartzite, are scattered over the area (pl. 1). This is essentially a bedding-plane fault and stratigraphic displacement has for the most part not been great; the sole of the fault lies near the base of the Corkscrew Quartzite, and in most places it overlies the upper part of the Day- light Formation. The Johnnie thrust in the northern Spring Mountains (Nolan, 1929, p. 466-471) shows sim- ilar relations. Movement along the fault has been sufficient to thoroughly brecciate the basal 20 to 30 feet of the Corkscrew Quartzite immediately above the fault. Percolating group water has subsequently bleached the normally reddish-brown rock. Underneath the thrust fault the incompetent Day- light Formation has been folded with axes trending northwest at right angles to the direction of movement of the thrust plate. The Daylight Formation has been rather thoroughly fractured and faulted, and the basal part of the formation is also faulted against a massive quartzite (shown as four patches of Paleozoic rocks, undifferentiated, on pl. 1) near the south boundary of J16 DIFFERENTIATION INDEX: 98 90 50 0 ' T T T T Tetra T T T T T fern £0 r sio, 1 IT.~- y- o 5- kafi‘\\x A .\\@i ya o Welded tuff (ash flow) B axe 60 |- @ Nonwelded tuff (ash flow) EIPA - a Air-fall tuff x X Lava flow X C Intrusive rocks 'x _.. Oxide trend for the 5000 analyses * of Washington's tables (after A R 40 |- Thornton and Tuttle, 1960) i | St 1 --- -t --- Bg} ATO; y | 18 |- x yess | Lae \> J 3 x 8 e mi ef | 4 |- x 1 0 a | 0 2 | A 8 8 y 969 col *e | 0 |- 3 F eS H - --- %+4—4 | | Mgo 10 |- x / 8 - >/ i. y //’< *J #2 // 2 wo /)g o} A_ -$-x --% $% 4 1 fos 2s I A- 1 I 1 l SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY DIFFERENTIATION INDEX 98 90 50 0 T T T T PoE Cs T T T T I 1 T3 CaO 12 ~ _o Welded tuff (ash flow) #7, © Nonwelded tuff (ash flow) / 10 |- A Air-fall tuff x x Lava flow 4 g __ _C Intrusive rocks / _- Oxide trend for the 5000 analyses # % of Washington's tables (after "4 | 6 Thornton and Tuttle, 1960) // | ws (a) /x// | A I 2T -- *A & <1 \c a- G._« | 0 g_s *_* mB | freer ir I chert y x 4 r E E Ly A i i ae hear -<, J x * ~)( B * \ 5 % a) K NaZO 3 ‘ #1 \i m tz os 5 ® al A c &. o --t----H-- --- - | o IC 8 6; ] W sessed o 3 3% < $ BAIS é \‘§\m x 4 i 4 K.0 C-, ¢ ° s x x tat A x~ 2 L Py { X | s ¥ % ge- sm pm- ote --- yl ol 81 119 | 2 x 1 5L x x a x 1.0 |- 7 0.5 l» a 4 | s t & £ x 2 & Jx P2 'A 0 4 1 1 1 (o dec oat 1 L I 1 1 Fut to FIGURE 10.-Variation diagrams of oxide versus differentiation index of volcanic rocks in the Beatty area, Nevada. the quadrangle. This fault, like the thrust fault be- neath the Corkscrew Quartzite, is generally rather flat and may also be a thrust fault. Thus the shaly Day- light Formation probably occurs as an incompetent plate between two massive quartzites. Just east of the Bullfrog quadrangle on Bare Moun- tain, the Paleozoic rocks have been intensely deformed by flat thrust faults and north-trending right-lateral strike-slip faults (Cornwall and Kleinhampl, 1960 a, b, 1961b). The oldest thrust plates moved southwest, and younger overlying plates moved south or south- east. The rocks on the east sides of the strike-slip faults have moved south relative to those on the west sides. BULLFROG QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. RELATION TO WALKER LANE AND LAS VEGAS VALLEY SHEAR ZONE The Las Vegas Valley shear zone, a major trans- current lineament with right-lateral displacement esti- mated at about 25 miles (Longwell, 1960, p. 197; B. C. Burchfiel * 1961, p. 134-135), has been traced north- west to the west end of the Spectre Range quadrangle (fig. 11). Bare Mountain is only 25 miles northwest of there, and it is most likely that the shear zone passes northwestward near Bare Mountain either on the east in Crater Flat or on the west across the Amargosa Desert. The general east-west strike of the beds on Bare Mountain (Cornwall and Kleinhampl, 1961b) may be due to drag along the shear zone, similar to the situation farther southeast in Las Vegas Valley (fig. 11), and may thus indicate proximity to the shear zone. Gianella and Callaghan (1934, p. 3, 18-19) sug- gested that the Las Vegas Valley shear zone may be part of a major lineament that extends 200 miles northwest to the area of Cedar Mountain, Nev., and Locke and others (1940, p. 522-523) named this linea- ment the Walker Lane for the valley at Goldfield, which was the route used by the explorer Walker. This valley, in which there are indications of a right- lateral shear zone at Goldfield according to Locke, extends south to the Bullfrog quadrangle along Sar- cobatus Flat and thence into Amargosa Desert. Recent mapping by B. C. Burchfiel * (1961, pls. 10, 14) indicates that the Las Vegas Valley shear zone strikes nearly due west at the west border of the Spectre Range quadrangle (fig. 11). If this is the case, the shear zone probably passes south of Bare Mountain and thence northwestward across the Amar- gosa Desert and the Bullfrog Hills in the Bullfrog quadrangle as shown in figure 11. Burchfiel (1961; p. 136-140) further suggests that a major branch of the shear zone may continue northwestward just south of Silver Peak, 60 miles northwest of the Bullfrog quadrangle, and thence into California north of the White Mountains, but geologic mapping in this area, described below, does not favor this interpretation. J. P. Albers and J. H. Stewart (oral communica- tion, 1962) have recently completed geologic mapping of Esmeralda County, Nev., and their data indicate that the shear zone may extend, as shown in figure 11, northwestward from the Bullfrog quadrangle to- ward Coaldale and thence northwestward up the Soda Spring Valley, where a right-lateral fault with a displacement of 4 miles has been postulated by Fer- guson and Muller (1949, pl. 1 and p. 14, 29). It is now ? Burchfiel, B. C., 1961, Structure and stratigraphy of the Spectre Range quadrangle, Nye County, Nevada : New Haven, Conn., Yale Uni- versity, Ph. D. thesis. J17 - considered more likely (Albers, oral communication, 1963) that the shear zone extends northward up Sar- cobatus Flat past Goldfield to connect with the Cedar Mountains fault zone near Tonopah, as suggested by Gianella and Callaghan (1934) and Locke and others (1940). The right-lateral transcurrent fault along the east side of the White Mountains in the valley west of Sil- ver Peak, considered by Burchfiel * (1961, p. 136-140) to be a possible extension of the Las Vegas Valley shear zone, has been recently studied by E. H. McKee (oral communication, 1962). According to McKee this fault can be traced southeastward into Death Val- ley and down the east side of Death Valley where it is known as the Furnace Creek fault (Jennings, 1958). It thus appears that there are two major right-lateral fault zones in this region (fig. 11). One, the Las Vegas Valley shear zone, extends northwestward past Beatty up Sarcobatus Flat, and possibly into Soda Spring Valley, or to Tonopah and thence northwest- ward to the Cedar Mountains. The other, the Furnace Creek fault, extends northwestward along Death Val- ley and thence along the east side of the White Moun- tains. BASIN-RANGE FAULTING Basin-range normal faults have probably been de- veloping in the Bullfrog quadrangle from Tertiary to Recent time. One Recent fault along the east-central border of the quadrangle (pl. 1) and extending into the Bare Mountain quadrangle has displaced Recent alluvial fans by as much as 40 feet, with the west or valley side down. Older normal faults, trending more or less north- south, have moderately disrupted the Paleozoic and Tertiary rocks in the southwestern part of the quad- rangle. One such fault underlies Boundary Canyon and another is in the next canyon to 'the west that runs south from Willow Spring. A northwest-striking fault has dropped a small graben of Titus Canyon Formation of Stock and Bode (1935) into the older Daylight Formation at the south border of the map, southeast of Boundary Canyon. All of these faults have downward displacement on the west side. Other normal faults of the basin-range type, due to regional subsidence, may occur in the volcanic rocks of the Bullfrog Hills caldera. The faults there are normal, and due to subsidence, but most of the de- formation is probably related to the local collapse of the Bullfrog Hills caldera. VOLCANIC DEFORMATION The Bullfrog Hills caldera has been described above (p. J8-J15), and only a brief review of the principal J18 SHORTER CONTRIBUTIONS GENERAL GEOLOGY 38° EXPLANATION Fault Major strike-slip fault Arrows indicate direction of relative displacement; dashed where inferred Thrust fault Sawteeth on side of upper plate \ Direction of movement of thrust plates Anticline Showing trace of axial plane ___B__— Overturned anticline L . member t Winnemucca \ « NEVADA B sf ** Bullfrog rangle \ f Quadrangle Showing trace of axial plane 20 MILES Bare Mountain Spectre Range 36° #4 ~ ~ {D ya $3 eath Valley Jet [qx KC 118° FIGURE 11.-Map of the major tectonic features of southwestern Nevada. Longwell (1960, p. 194, fig. 2), and in the Spectre Range quadrangle from B. C. Burchfiel (unpublished data). 116° Generalized tectonic features in the Las Vegas Valley from Other data from Gianella and Callaghan (1934, p. 3-5, figs. 1 and 2), Locke and others (1940, pl. 1), Ferguson and Muller (1949), Jennings (1958), J. P. Albers (oral communication, 1962), and E. H. McKee (oral communication, 1962). structural features will be given here. The caldera measures approximately 10 by 13 miles and is elong- ated in a northeasterly direction. The rocks in the caldera, mainly ash flows and air-fall tuffs, have the form of an intricately faulted dome, developed sub- sequent to the initial collapse, with the ash flows and tuffs dipping outward toward the rim and normal faults commonly dipping inward (pl. 4, section A-4"'). The main fault on the rim of the caldera is exposed at the Montgomery-Shoshone mine on the southeast rim (pls. 1, 4), where rocks in the caldera on the northwest side have been displaced downward about 3,500 feet with respect to those on the southeast. Ad- ditional subsidence of about 500 feet has occurred along several other faults parallel to this fault in a zone about 1 mile wide east of the Montgomery-Sho- shone mine (pls. 1, 4). Extending northeastward from the southeast rim of the caldera into the Bare Mountain quadrangle (Corn- wall, 1962) is a series of normal faults that have BULLFROG -QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. dropped the volcanic rocks downward successively to the northwest (pl. 4). This subsidence is also prob- ably due to withdrawal of magma from an underlying chamber.. These fault blocks are bounded on the south by a north-dipping fault of variable strike and dip along which the volcanic rocks have apparently slid down toward the north across underlying Paleozoic rocks. This fault was earlier considered by the pres- ent writers (1961b) to be a thrust fault, before the general pattern of subsidence related to the caldera was recognized. Ransome (Ransome and others, 1910, p. 101-102) favored the interpretation of this fault as a thrust, but he considered that normal movement was also a possibility. The rocks in the caldera were still further deformed when magma re-entered the underlying magma cham- ber at a late stage and pushed the basement of Pre- cambrian and Paleozoic rocks up into the volcanic sequence (p. 33; pl. 1, section B-2'). The youngest extrusive rocks of the Bullfrog Hills volcanic sequence are latite and quartz basalt flows, mainly in the eastern part of the caldera. These gently dipping flows in part unconformably overlie the older steeply dipping volcanic rocks (pl. 1, see- tion B-B') but they, too, are deformed, though to a lesser degree, in the same general pattern as the older rocks. It thus appears that the major part of the deformation, owing to the subsidence of the cal- dera, occurred before the latest volcanic event, namely, the extrusion of the latite flows. ORE DEPOSITS ASSOCIATED WITH THE CALDERA The four most prominent known ore deposits in the Bullfrog and Bare Mountain quadrangles, as well as the majority of the smaller deposits, are located along marginal faults of the Bullfrog Hills caldera, or near the related area of subsidence that extends outward from the southeast rim of the caldera (pls. 1, 4). Three of the deposits, the Montgomery-Soshone, May- flower, and Pioneer (one-half mile north of the May- flower) gold-silver mines, are on the east rim of the caldera. The fourth, the Daisy fluorspar mine, occurs in Paleozoic rocks adjacent to the southern margin of the subsidence zone that extends tangentially out- ward from the caldera toward the northeast. The greatest concentration of mineral prospects, mostly gold-silver, also occur along the east rim of the Bullfrog Hills caldera near the Montgomery- Soshone mine. In addition, several small gold de- posits, including the initial discovery of the district, the original Bullfrog mine, occur within the caldera along the north margin of the area of pre-Tertiary J19 basement rocks that have been pushed up into the tuffs and ash flows. Mineral exploration has been carried on actively in the Bare Mountain and Bullfrog quadrangles since 1904 when gold was discovered at the Original Bull- frog mine (Ransome and others, 1910, p. 12) at the south end of Bullfrog Mountain. The total production of gold-silver ore is valued at nearly $2 million. Most of the ore has come from the Bullfrog district in the Bullfrog Hills west of Beatty and most of the mining was prior to 1910 (Kral, 1951, p. 29). Fluorspar is the only other mineral commodity that has been produced in significant amounts in the two quadrangles under consideration. Since the discovery of fluorite in 1918, production of somewhat more than 100,000 tons has come mostly from the Daisy mine at the north end of Bare Mountain. In addition to these minerals, a small production of bentonite, mercury, and pumicite has been recorded. FLUORSPAR Several fluorspar deposits have been explored in the Paleozoic carbonate rocks of Bare Mountain. These deposits have been briefly described by the present authors elsewhere (Cornwall and Kleinhampl, 1961b) ; only those at the north end of Bare Mountain near, and possibly related to, the caldera subsidence struc- ture mentioned above will be discussed here. Part of these deposits have been described by Thurston (1949). By far the largest deposit occurs in the No- pah Formation, a dolomite of Late Cambrian age, at the north end of Bare Mountain in Fluorspar Canyon (pl. 4). This deposit, at the Daisy mine, is described in detail below. A small prospect, the Enif, occurs a quarter mile west of the Daisy in the same formation. A shaft was first sunk in the Enif deposit in 1906 in a search for gold; the small amount of fluorite found was not of interest at that time. In 1918 the Conti- nental Fluorspar Company found fluorite on the Daisy claim; 1,300 tons of fluorspar were mined between then and 1922. Another fluorite deposit occurs in limestone of the Carrara Formation (Lower and Mid- dle Cambrian) three-quarters of a mile south of the Daisy mine. All the fluorite deposits have similar characteristics and are undoubtedly related in origin. They occur in highly deformed and fractured dolomite or limestone near major faults. The fluorite ranges in color from white to yellow, purple, or nearly black, but most of it is purple. It is commonly intergrown with yellow or brown clay from the faults with which the deposits are associated. Really large bodies of nearly pure massive fluorite are known only in the Daisy deposit. J20 DAISY MINE The Daisy fluorspar mine is by far the largest of the known fluorspar deposits in the Bare Mountain area. -It is located at the north end of Bare Mountain 5 miles east of Beatty in Fluorspar Canyon, in the NW!4, see. 23, T. 12 S., R. 47 E. As mentioned above, the Daisy mine was one of several fluorspar prospects that were explored during the period 1919-22 by the Continental Fluorspar Company, headed by J. Irving Crowell. In 1927 the claims were acquired by J. Irving Crowell, Jr., and the Daisy mine has been ac- tively operated since that time. The deposit has been developed to a depth of over 500 feet and for a horizon- tal length of 900 feet in a maze of workings (pl. 6) that includes 14 levels and sublevels. GEOLOGIC SETTING The Daisy fluorspar deposit occurs in dolomite of the Nopah Formation of Upper Cambrian age in an area of great structural complexity. The Paleozoic rocks in the area have been intensely deformed by repeated thrust faults, locally to the point of imbrication, and by steeply dipping right-lateral strike-slip faults. Rhyolitic pyroclastic rocks of probable Miocene age are faulted against the deformed Paleozoic rocks less than a quarter of a mile north of the Daisy mine. The Tertiary rocks are also deformed, but the pat- tern of deformation is quite different from that in the Paleozoic rocks. As has been discussed earlier (p. J15-J17), the prin- cipal deformation of the Paleozoic rocks occurred dur- ing a major period of thrusting and right-lateral strike-slip faulting along the Las Vegas Valley shear zone, probably in the Cretaceous. The thrust faults dip gently to moderately north and northeast at the north end of Bare Mountain and the major right- lateral strike-slip faults strike nearly north-south. The Miocene pyroclastic rocks are cut by a series of northeast-trending normal faults which have, for the most part, dropped the rocks successively toward the northwest. This subsidence structure, described above, is bounded on the south by an undulating nor- mal fault, variable both in strike and in dip, that sepa- rates pyroclastic rocks from the Paleozoic rocks to the south in which the fluorite deposits occur. This fault was earlier mapped and described as a thrust (reverse) fault by the present writers (Cornwall and Kleinhampl, 1961b) before they recognized evidence of subsidence in the Tertiary volcanic rocks. STRUCTURE OF THE ORE DEPOSIT The shape and distribution of ore shoots in the flu- orite deposit appear to be controlled in large part by SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY two principal sets of faults. One set strikes roughly northeast and dips vertically to steeply east. The ore shoots extend along and are bounded laterally by faults of this set. In detail the individual faults un- dulate quite markedly, both in plan and in section, and the fluorite bodies bounded by such faults ac- cordingly range in thickness from less than 1 foot to a maximum of 80 feet. Examples of these patterns are seen both in the plan maps (pls. 7, 8) and in the sec- tions (pl. 9.) Level 3 on plate 7 and the upper four levels on plate 9 are modifications of mapping done by Thurston (1949). The shoot with the maximum horizontal thickness of 80 feet occurs on and adjacent to level 6. The other set of faults that control the distribution of ore strikes more or less northwest and dips gently to moderately northeast. These faults, like the first set, undulate markedly in strike and dip. There are only a few of these faults, but their control on the dis- tribution of ore appears to be quite fundamental. The three most important of these faults are best seen in the sections (pl. 9), particularly in section A-4'. These faults do not bound the ore shoots quite as abruptly as is indicated on the somewhat generalized sections. For example, the fault that limits the base of an ore shoot in the upper four levels and the top of a larger shoot in levels 5 through 8 (pl. 9, section A-4") has some ore below and adjacent to it on level 3 and some above it on level 8. The second of these faults bounds the bottom of the larger shoot on the interme- diate levels and also limits the base of another shoot at the southwest end of levels 3 and 5. On levels 5 and 8 a little ore occurs below it. A pipelike shoot extends downward from this fault to level 13 along the south winze (pl. 9, section A-4'). It was by following this shoot, in places not much larger than the winze, that the large ore shoot on level 13 was discovered. The third important low-angle fault of this set bounds the top of the shoot on level 13. These low-angle, northeast-dipping faults definitely cut off the northeast-striking steep faults in places, but elsewhere they appear to bend and branch into the steep faults. It was not possible to determine the di- rection of displacement along any of the major faults. The available evidence indicates that most of the faulting occurred before the fluorite mineralization and that the zones of fractured rock along the steep, north- east-trending faults served as channels for the ore solutions. The ore shoots are almost everywhere bounded by gouge zones of faults, and it appears that these impermeable zones restricted the ore solutions to definite channels where the fractured dolomite was almost completely replaced by the fluorite-bearing BULLFROG QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. solutions. As has been indicated by the breccia pattern on the level maps (pls. 7, 8), quite a bit of the ore con- tains scattered angular fragments, and these fragments are mostly dolomite as much as a foot in diameter but mostly less than 2 inches. Locally the wall rock is limestone or shale and these may also occur as frag- ments in the ore in such areas. Small fragments of clayey gouge are also sparingly present, and the fluo- rite itself is locally fragmented. The lower part of the deposit below level 8 contains less fragmental ore than the upper levels. The local presence of, fluorite frag- ments indicates some fault movement during the min- eralization process. The matrix of all the brecciated ore is mostly fluorite. NATURE OF THE ORE The ore consists mostly of fine-grained purple flu- orite with seams, lenses, and layers of yellow clayey gouge. The ore is partly banded parallel to the faults that bound the shoots. The banding is due to the al- ternation of light-purple fluorite, dark-purple fluorite, and scattered seams and layers of yellow gouge, and also to the alternation of dense and vuggy layers. Most of the fluorite appears aphanitic, but part of it is visibly crystalline. The aphanitic fluorite actually consists of tiny crystals less than 0.1 mm in diameter. In places the fluorite has a comb structure due to the growth of elongated crystals outward from the walls of cavities. In the lower levels the fluorite is partly to largely white or yellow with a fine granular texture. Locally it tends to be loosely consolidated and may flow like granulated sugar when struck with a pick. Calcite fissures as much as 3 feet wide are rather common in this ore, particularly where the ore pinches out along the strike. These calcite veins are vuggy, even cav- ernous, and the vugs are lined with yellow or white fluorite, clear calcite, quartz crystals, and locally fine crystals of cinnabar. X-ray study of the yellow clayey gouge that occurs as seams or layers in the fluorite shows that it is mont- morillonite. The shale member of the Nopah Forma- tion that locally is adjacent to ore consists, on the other hand, of illite and very small amounts of mont- morillonite and chlorite. The purple and white vari- eties of fluorite were examined with the X-ray spectrograph and found to be nearly pure except for small amounts of iron in the purple fluorite and a trace of iron in the white fluorite. The iron may be due to small amounts of limonite in the fluorite sample. The radioactivity of the Daisy fluorspar deposit has been investigated by Chesterman and Main (in Lover- ing, 1954, p. 91-92). Six channel samples of the J21 purple fluorite ranged from 0.007 to 0.015 percent equivalent uranium, and a sample of mill concentrate ran 0.002 percent. These values, while high enough to merit consideration, are probably not recoverable commercially. For comparison, the fluorspar de- posits of the Thomas Range, Utah, which are consid- ered to be high in uranium for this type of deposit, range from 0.003 to 0.33 percent uranium (Staatz and Osterwald, 1956). The highest values are apparently due to secondary enrichment of uranium near the surface. The present writers, using a scintillation detector, mapped the distribution of radioactivity throughout the Daisy mine. The fluorite ore has a radioactivity of one to two orders of magnitude greater than the barren dolomite wallrock. The highest values were found in purple ore that contains appreciable clay gouge or. occurs adjacent to shale, indicating that the radioactive material is concentrated in the clay. PRODUCTION The total production from the Daisy mine, given in table 3, amounts to 118,000 short tons through 1961. Since 1945, production has been at a rate of about 5,000 tons per year. The grade of the ore has ranged between 70 and 80 percent CaF, and the average is probably close to 75 percent. The SiO; content has averaged less than 2 percent. The remaining mate- rial in the ore consists of calcite, dolomite, and clay (fault gouge). TaBu® 3.-Fluorspar production of the Daisy mine Year Short tons 1919 - .no ae ben en eee iain A ua oes 700 1920-2 e LEE 20-2 alo ean ee noch cio pee an ange ace 632 1921...... :c 00 _L ftom - cs - 1922-1... ...r... uve. toin. sunon ilt Paley 300 1925..0 .... "_._. lc il ifti dI Sii fee - 19241. ._ Lect a ore { o c o toad -= 1925... 1c..ll_ LL nou c a atea -- 1926. Jon n calle. -- | roe sere e tal s c e 1 (t € =-- 1928. 0000900 Lofi aet e ey og one 495 1929. vier, culte us ap 757 1950. - - _il.enl ll cea neni o en p a at soc aaa t 992 : 0000000 i105 tur celica t L oen 478 _.. 00 cor lfs cot a 175 . {A. t AS Omit 75 1994: 0:0 0pm non rl on Nue 200 1955. ice canta alc tare 250 1996. lion: axon [acoso talk 225 1997. 00000000 erat 350 1988: cs .o. event ac i ial tos aL T75b 1990... Llc en. fis ln lee tin Ail m eties 1, 200 1940... [ecu 000 cnl. LL _i tio melo cogs 3, 700 1941: 0 Cette cine e tie a an 5, 000 1942.90.00 LE io oor i Leer Mike f 3, 600 J22 masts 3.-Fluorspar production of the Daisy mine-Continued Year Short tons 6,321 6, 548 6, 408 7, 066 4, 726 5, 069 4, 807 1950: I1. EEC -w - Amana bols oa ae mie 1961}: cron ce oci st lc - 7, 672 Totals 22 0 ay: stare a evan 117, 648 The largest tonnage of ore occurs in the shoot that has its greatest width and length on levels 6 and 8 and extends downward at the northeast end of the mine to below level 12, but the most promising area for finding new ore is at the southwest end of the mine in the lower levels where a large recently discovered ore shoot is being developed at the present time. Mr. Crowell, the owner and operator of the Daisy mine, has done a remarkable job of following the ir- regular, lenticular ore shoots downward, and of find- ing new shoots. His exploration technique of staying in ore as much as possible has been very successful. In 1945 an exploration was carried out by the Bureau of Mines (Geehan, 1946) in the Daisy mine area. Twelve diamond-drill holes were drilled but no ore was found. The mine workings were mapped geolog- ically by W. R. Thurston (1949) of the U.S. Geolog- ical Survey as a part of this exploration program. ORIGIN OF THE DEPOSIT The Daisy fluorite depost is believed to be a hydro- thermal deposit from ascending solutions that moved along permeable zones in the highly deformed and fractured Paleozoic rocks. The ore channels and sites of deposition were determined by the spatial ar- rangement of two sets of faults and fissures, one steep and northeastward trending, the other flat and north- westward trending. Impermeable gouge along the more important faults apparently confined the ore solu- tions to certain zones where the CaF, from the solu- tions almost completely replaced the dolomite and minor limestone. - Fluorite was also deposited in cavi- ties that resulted either from brecciation during the deformation or from solution of the carbonate rocks by the migrating hydrothermal solutions. Calcite and small amounts of quartz and cinnabar were also de- posited in cavities. The ore-bearing solutions were probably related to the Tertiary volcanism that erupted large volumes of rhyolite ash flows, tuffs, and flows immediately north of the Daisy mine. The volcanic rocks, as men- SHORTER CONTRIBUTIONS TO GENERAL cEOLOGY tioned above, are in an area of subsidence that prob- ably was underlain by a magma chamber from which the ore solutions may have come. It was noted above that locally fragments of fluorite occur in a fluorite matrix and this indicates deforma- tion during the ore-forming period, but the deforma- tion must have been very minor as the amount of such breccia is small. The principal deformation in the mine area is clearly related to the thrusting and strike-slip faulting elsewhere in the Paleozoic rocks on Bare Mountain and must be pre-Tertiary because the Tertiary rocks were not involved. GoLD The early prospectors roamed the Bullfrog Hills and Bare Mountain looking for gold, and it was found in 1904 at the Original Bullfrog mine, 7 miles west of Beatty (Ransome and others, 1910, p. 12; Lincoln, 1923, p. 162; Kral, 1951, p. 28). A rush of prospectors followed and by 1905 a number of claims were being explored. Most of the gold showings were found in the pyroclastic rocks of the Bullfrog Hills, but several prospects were explored in the Paleozoic rocks on Bare Mountain. Recorded gold and silver production through 1948 amounted to $1,886,000 (Kral, 1951, p. 29). Most of the production came before 1910 and from the Mont- gomery-Shoshone mine, which yielded 128,980 tons of ore valued at $1,344,000. The total production from Bare Mountain is not known but small. The gold deposits in the Bullfrog Hills are in fis- sures and veins related to normal faults. These de- posits have been described in detail by Ransome (Ransome and others, 1910, p. 90-125) and will only be briefly described here. Most of the gold-bearing fissures, including the Montgomery-Soshone, are steep and occur at or near the rim of the Bullfrog Hills cal- dera, and this relationship is probably more than co- incidence. Several other deposits, including the Original Bullfrog mine, occur along the north contact of the central domal uplift of basement rocks into the Tertiary pyroclastics This contact is a low-angle, north-dipping fault. The mineralogy of the gold fissure deposits is simple and consists of quartz, calcite, and finely disseminated gold-silver in scattered grains of pyrite. Near the surface the pyrite has been altered to limonite. The Original Bullfrog mine also contains a little chalcocite that has been oxidized to malachite and chrysocolla. Cerargyrite has been detected but is apparently not prominent even in rich ore. - The production record in- dicates that for the district as a whole the ratio of sil- ver to gold in the ore is 8 to 1 (Lincoln, 1923, p. 162). BULLFROG QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. The mined ore averaged about $10 per ton. (Kral, 1951, p. 29). The gold-silver mineralization of most of the fissures is meager, even though hydrothermal alteration of the rhyolite may be pronounced; but in the Montgomery-Soshone mine a sizable body of fractured rhyolite on 'the footwall (southeast) side of the Montgomery-Soshone fault averaged $10 per ton in gold-silver. This ore body occurred near the surface in a fractured zone near the fault where numerous, nearly vertical, north-striking fissures intersect the northeast-trending fault (Ransome and others, 1910, p. 97). The Montgomery-Soshone fault is a northwest- dipping, steep normal fault with an apparent down- ward displacement of 3,500 feet on the north side. Most of the other gold-silver prospects in the Bull- frog Hills are similar to but leaner than the Montgomery-Soshone deposit and occur along steep normal faults near the rim of the caldera. Two of the most promising deposits, other than the Montgomery-Soshone, are the Mayflower and Pioneer mines on the northeast rim of the caldera. The May- flower deposit occurs along a fissure or fault that strikes N. 50° W. and dips 60° to 65° SW. (Ransome and others, 1910, p. 124). The Pioneer deposit occurs half a mile north of the Mayflower mine (just north of the north border of the Bullfrog quadrangle, which is shown on plate 1) and is said to be "almost identical to the adjoining Mayflower" (Kral, 1951, p. 39). One of the gold prospects on Bare Mountain is lo- cated 2 miles northeast of the Daisy fluorspar mine (pl. 4), near the subsidence feature associated with the Bullfrog Hills caldera described earlier, and may be related to it. This mine, called the Harvey (formerly known as the Telluride), was first prospected for gold in 1905 and later mined for mercury. It will be de- scribed under quicksilver. ORIGIN OF THE DEPOSITS It has been pointed out that most of the gold deposits in the Bullfrog Hills district occur either along steep normal faults near the rim of the Bullfrog Hills cal- dera, or near the domal uplift of basement rocks into the Tertiary pyroclastic rocks within the caldera. It is probable that the ore-bearing solutions were derived from the magma chamber that presumably existed beneath the caldera. The mineralization must have occurred late in the period of volcanism after the development of the structures to which the deposits are related. The probable age thus is late Miocene or Pliocene. BENTONITE A small bentonite deposit at the Vanderbilt mine has been operated for over 10 years by the Silicates J28 Corporation; it is located 114 miles south of Beatty (pl. 4). Two bodies of bentonite occur 300 feet apart on the footwall side of a fault that dips 50° W. Most of the production has come from the larger deposit, which is shown in figure 12. The bentonite was formed by the alteration of densely welded and nonwelded tuff of cooling units Nos. 4 and 5 respectively of the ash-flow sequence in the Bullfrog Hills caldera. The bentonite occurs in a zone of in- tense fracturing and faulting and apparently resulted from the activity of hydrothermal solutions that mi- grated through this permeable zone. The deposit oc- curs at the south edge of the subsidence zone that extends eastward from the Bullfrog Hills caldera. The high-grade bentonite ore is soft and white and has scattered waxy pink or tan spots which probably represent replaced pumice fragments. The original unaltered rock had rather abundant phenocrysts of quartz, sanidine, oligoclase, and biotite, and these are still present in the bentonite ore but the feldspar and biotite are moderately to intensely altered. In part the contacts between bentontinte ore and unal- tered welded or nonwelded tuff are sharp, but else- where a zone of moderately altered rock forms a transition. X-ray analysis shows that the bentonitic clay, both the white rock and also the pink fragments, is nearly pure montmorillonite. QUICKSILVER Cinnabar (HgS) was discovered in 1908 at the north end of Meiklejohn Peak (NW14 sec. 18, T. 12 S., R. 48 E., unsurveyed) in the Bare Mountain quadrangle. Quicksilver production from this property, the Harvey mine, was recorded as 72 flasks up to 1943 according to Bailey and Phoenix (1944, p. 142). The deposit was mined again for about a year in 1956, but the amount of production is unknown and probably small. The mercury occurs as cinnabar sparsely disseminated in a lens of chalcedony and opal along a steeply dip- ping fissure in dolomite of the Fluorspar Canyon Formation of Devonian age. Another small mercury deposit known as the Tip Top mine, is located 600 feet north of the Harvey mine in the Lone Mountain Dolomite of Silurian age. Pro- duction here is reported as possibly about 100 flasks of quicksilver (Bailey and Phoenix, 1944, p. 144). The cinnabar occurs along a south west-trending, nearly vertical fault and is in 1- to 2-inch veins and also disseminated in the gouge. PUMICITE A moderate amount of pumicite was quarried around 1950 from pumiceous tuff located 3 miles northeast of Beatty (SE1 see. 28, T. 11 S., R. 47 E.) J24 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 10 N EXPLANATION Welded tuff d shud LCA_E3 Nonwelded tuff 0 ~ 10.20 30 40 CEET 33 a Ore 50 \45 A 45 Contact, showing dip JN P 2 Ae Fault, showing dip & Dashed where approximately PK % located 30 Strike and dip of beds N Head of winze K Foot of raise FIGURE 12.-Geologic plan of the Vanderbilt bentonite mine, Nye County, Nev. near Nevada Highway 95. The pumicite was used to make lightweight aggregate building blocks according to Kral (1951, p. 68). PERLITE Several large bodies of perlite have been prospected but no production is reported. One occurs in Beatty Wash (SW14 see. 25, T. 11 S., R. 47 E.) ; another is lo- cated in the NE1G of see. 10, T. 12 S., R. 47 E. All of these perlite bodies are glassy facies of rhyolite flows or intrusives. REFERENCES CITED Bailey, E. H., and Phoenix. D. A., 1944, Quicksilver depos- its in Nevada: Nevada Univ. Bull, v. 38, no. 5, Geol. and Mining ser. no. 41, 206 p. Ball, S. H., 1907, A geologic reconnaissance in southwestern Nevada and eastern California: U.S. Geol. Survey Bull. 308, 218 p. : Barnes, Harley, and Palmer, A. R., 1961, Revision of strati- graphic nomenclature of Cambrian rocks, Nevada Test Site and vicinity, Nevada: Art. 187 in U.S. Geol. Survey Prof. Paper 424-C, p. ©100-C103. Chesterman, C. W., and Main, F. H., 1954, Daisy fluorspar mine, in Lovering, T. G., Radioactive deposits of Ne- vada : U.S. Geol. Survey Bull. 1009-C, p. 91-94. Cornwall, H. R., 1962, Calderas and associated volcanic rocks near Beatty, Nye County, Nevada, in Petrologic studies: Geol. Soc. America, Buddington, Volume, p. 357-371. Cornwall, H. R., and Kleinhampl, F. J., 19602, Structural features of the Beatty area, Nevada [abs.] : Geol. Soc. America Bull., v. 71, no. 12, pt. 2, p. 1845-1846. 1960b, Preliminary geologic map of the Bare. Moun- tain quadrangle, Nye County, Nevada: U.S. Geol. Sur- vey Mineral Inv. Field Studies Map MF-239, scale 1 : 48,000. 1961a, Preliminary geologic map and sections of the Bullfrog quadrangle, Nevada-California : U.S. Geol. Sur- vey Mineral Inv. Field Studies Map MF-177, scale 1 : 48,000. 1961b, Geology of the Bare Mountain quadrangle, Ne- vada: U.S. Geol. Survey Geol. Quad. Map GQ-157, scale 1 : 62,500. Ferguson, H. G., and Muller, §. W., 1949, Structural geology of the Hawthorne and Tonopah quadrangles, Nevada : U.S. Geol. Survey Prof. Paper 216, 55 p. Geehan, R. W., 1946, Exploration of the Crowell fluorspar mine, Nye County, Nevada: U.S. Bur. Mines Rept. Inv. 3954, 9 p. Gianella, V. P., and Callaghan, Eugene, 1934, The earth- quake of December 20, 1932, at Cedar Mountain, Ne- vada, and its bearing on the genesis of Basin-Range structure : Jour. Geology, v. 42, no. 1, p. 1-22. BULLFROG QUADRANGLE AND BULLFROG CALDERA, NEV.-CALIF. 128 Grose, L. T., 1959, Structure and petrology of the northeast part of the Soda Mountains, San Bernardino County, California: Geol. Soc. America Bull., v. 70, no. 12, pt. 1, p. 1509-1548. Hazzard, J. C., 1937, Paleozoic section in the Nopah and | Resting Springs Mountains, Inyo County, California: California Jour. Mines and Geology, v. 33, no. 4, p. 273- 339. 1954, Rocks and structure of the northern Providence Mountains, San Bernardino County, California, [Pt.] 4 in Chap. 4 of Jahns, R. H., ed., Geology of southern California : California Div. Mines Bull. 170, p. 27-35. Jennings, C. W., 1958, Geologic map of California, Olaf P. Jenkins edition, Death Valley sheet: California Div. Mines, scale 1 :250,000. Johnson, M. S., and Hibbard, D. E., 1957, Geology of the Atomic Energy Commission Nevada proving grounds area, Nevada: U.S. Geol. Survey Bull. 1021-K, p. 333- 884. Kral, V. E., 1951, Mineral resources of Nye County, Nevada: Nevada Univ. Bull., v. 45, no. 3, Geol. and Mining ser. no. 50, 223 p. Kupfer, D. H., 1960, Thrust faulting and chaos structure, Silurian Hills, San Bernardino County, California: Geol. Soc. America Bull., v. 71, no. 2, p. 181-214. Lincoln, F. C., 1923, Mining districts and mineral resources of Nevada: Reno, Nevada Newsletter Publishing Co., 296 p. Locke, Augustus, Billingsley, P. R., and Mayo, E. B., 1940, Sierra Nevada tectonic patterns: Geol. Soc. America Bull., v. 51, no. 4, p. 518-540. Longwell, C. R., i951, Megabreccia developed downslope from large faults: Am. Jour. Sci., v. 249, no. 5, p. 343-355. 1960, Possible explanation of diverse structural pat- terns in southern Nevada: Am. Jour. Sci., v. 258-A (Bradley Volume), p. 192-203. Mackin, J. H., 1960, Structural significance of Tertiary vol- canic rocks in southwestern Utah: Am. Jour. Sci., v. 258, p. 81-131. Merriam, C. W., 1940, Devonian stratigraphy and paleontology of the Roberts Mountains region, Nevada: Geol. Soc. America Spec. Paper 25, 114 p. Merriam, C. W., and Anderson, C. A., 1942, Reconnaissance survey of the Roberts Mountains, Nevada: Geol. Soc. America Bull., v. 53, no. 12, p. 1675-1728. Noble, L. F., 1941, Structural features of the Virgin Springs area, Death Valley, California: Geol. Soc. America Bull., v. 52, no. 7, p. 941-999. Noble, L. F., and Wright, L. A., 1954, Geology of the central and southern Death Valley region, California, [Pt.] 10 in Chap. 2 of Jahns, R. H., ed., Geology of southern California: California Div. Mines Bull. 170, p. 143-160. Nolan, T. B., 1929, Notes on the stratigraphy and structure of the northwest portion of Spring Mountain, Nevada: Am. Jour. Sci., 5th ser., v. 17, p. 461-472. Nolan, T. B., Merriam, C. W., and Williams, J. S., 1956, The stratigraphic section in the vicinity of Eureka, Ne- vada : U.S. Geol. Survey Prof. Paper 276, 77 p. Ransome, F. L., Emmons, W. H., and Garry, G. H., 1910, Geology and ore deposits of the Bullfrog district, Ne- vada: U.S. Geol. Survey Bull. 407, 130 p. Ross, C. S., and Smith, R. L., 1961, Ash-flow tuffs-their origin, geologic relations, and identification: U.S. Geol. Survey Prof. Paper 366, 81 p. Ross, R. J., Jr., and Cornwall, H. R., 1961, Bioherms in the upper part of the Pogonip in southern Nevada: Art. 97 in U.S. Geol. Survey Prof. Paper 424-B, p. B231-B233. Smith, R. L., 1960a, Ash flows: Geol. Soc. America Bull., v. 71, p. 795-842. 1960b, Zones and zonal variations in welded ash flows : U.S. Geol. Survey Prof. Paper 854-F, p. 149-159. Staatz, M. H., and Osterwald, F. W., 1956, Uranium in the fluorspar deposits of the Thomas Range, Utah, in United Nations, Geology of uranium and thorium: Internat. Conf. Peaceful Uses Atomic Energy, Geneva, Aug. 1955, Proc., v. 6, p. 275-278; revised in Page, L. R., and others, Contributions to the geology of uranium and thorium by the United States Geological Survey and Atomic Energy Commission for the United Nations In- ternational Conference on Peaceful Uses of Atomic En- ergy, Geneva, Switzerland, 1955: U.S. Geol. Survey Prof. Paper 300, p. 131-136. Steven, T. A., and Ratté, J. C., 1960, Relation of mineraliza- tion to caldera subsidence in the Creede district, San Juan Mountains, Colorado: Art. 8 in U.S. Geol. Survey Prof. Paper 400-B, p. B14-B17. s Stock, Chester, and Bode, F. D., 1935, Occurrence of lower Oligocene mammal-bearing beds near Death Valley, California: Natl. Acad. Sci. Proc., v. 21, no. 10, p. 571- 579. Thornton, C. P., and Tuttle, O. F., 1956, Applications of the differentiation index to petrologic problems [abs.] : Geol. Soc. America Bull., v. 67, no. 12, pt. 2, p. 1738-1739. 1960, Differentiation index, Pt. 1 of Chemistry of ig- neous rocks : Am. Jour. Sci., v. 258, p. 664-684. Thurston, W. R., 1949, The Daisy flourspar deposit near Beatty, Nye County, Nevada: U.S. Geol. Survey Stra- tegic Mineral Inv. Prelim. Rept. 3-209, 10 p. Vinogradov, A. P., 1956, Zakonomernosti raspredeleniya khimicheskikh elementoy i zemnoi kore [The regularity of distribution of chemical elements in the earth's crust] : Geokhimiya, no. 1, p. 1-52. Wilcox, R. E., 1958, Petrography and chemistry of the Oak Spring Formation, in Diment, W. H., and others, Prop- erties of Oak Spring Formation in Area 12 at the Ne- vada Test Site : U.S. Geol. Survey TEI-672; also open- file report, May 12, 1959, p. 2-1 to 2-16. Williams, Howel, 1941, Calderas and their origin: California Univ., Dept. Geol. Sci. Bull., v. 25, no. 6, p. 239-346. Williams, P. L., 1960, A stained slice method for rapid de- termination of phenocryst composition of volcanic rocks : Am. Jour. Sci., v. 258, p. 148-152. Wright, L. A., 1955, Rainbow Mountain breccias, Amargosa Valley, California [abs.]: Geol. Soc. America Bull., v. 66, no. 12, pt. 2, p. 1670. U. S, GOVERNMENT PRINTING OFFICE : 1964 O - 724-437 ¥ UNITED STATES DEPARTMENT OF THE INTERIOR & (@) & GEOLOGICAL SURVEY 117°00' §5° 37°00" R. 46 E (KAWICH 1 250 000) 50° T. 11 S. ps gt: G - WBY ¥ 55r L T. Y2i5. 116°45" | » Beatty / g 7©@’\ B Bh 3308 % QQ mee. \ + (GRAPEVINE PEAK) | f T.. 11 S.. (BARE MTN.) s 7a4 4 w* BM 3568,¢1 / fpr 4 4 / T. 14°85; ~©36°45" sae . Om sts . , &. % 117°00 (Ess ] * & (CHLORIDE CLIFF) .. Base map by Topographic Divisien -- SCALE 1:48 000 : Q U.S..Geological Survey . ;> +308» V rer 'we & Fas who Ya 0 1 l -E- 2 3 MILES 1 As 0 1 2 3 KILOMETERS RHB BHF pom CONTOUR INTERVAL 40 FEET DATUM IS MEAN SEA LEVEL "hors. * ae A' *e ~ } 6000' 6000" iy 5000' 5000 g se mod mb Qal __ Ttc 4000' - 4000" 3000" © R 3000' _ 3000" l;- 9980, 2000' 2000 *s - 1000" 1000' 1000" SEA LEVEL SEa LeveL INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-1964-G63077 Geology by H. R. Cornwall and F. J. Kleinhampl, 1956-1960, U.S. Geological Survey 37°00 Qal Alluvium Fan and stream gravels flanking mountains and hills and grading out- ward into sands and silts in valley bottoms Qog Pleistocene and Recent Older gravels Boulders, cobbles, and finer material of varied lithology in older partly dissected fans Rhyolite and rhyodacite Tr, dikes, irregular stocks, and flows of gray to reddish-brown rhyolite and rhyodacite, partly porphyritic with phenocrysts of feldspar, quartz, and biotite Trg, parts of the bodies that are glassy Basalt and basanite Tb, dark-gray to black fine-grained porphyritic basalt flows and dikes Tha, basanite, occurs locally as a facies of basalt and has analcite in the groundmass. Both types contain phenocrysts of olivine, plagioclase, and locally augite Latite Brownish-gray to reddish-brown fine-grained porphyritic latite flows and intrusions, contain phenocrysts of oligoclase or andesine, biotite, and a little augite or pigeonite ANGULAR UNCONFORMITY Miocene and Pliocene Welded tuff Tw, stony, rhyolitic, welded tuff; gray to reddish-brown, partly eutazitic or spherulitic; commonly contains partly broken crystals of sanidine, oligoclase, quartz, and biotite, and fragments of stony and glassy rhyolite, and rarely basalt Twg, glass zones occur at the base of welded tuff units, and locally in the 55° interior or upper parts Tuff White, gray, and yellowish-brown tuff; loosely consolidated to well lithified; mostly massive, but locally stratified; contains broken crystals of samidine, plagioclase, quartz, and biotite, and small frag- ments of pumice, stony rhyolite, rhyolitic glass, and basalt in a pumiceous matrix Sedimentary rocks in tuff Interbedded tuffaceous sandstone, siltstone, shale, conglomerate, and tuff; colors are gray, greenish, yellowish, and brownish gray, reddish brown, and black; locally contain lenses as much as 40 feet thick of brownish- and dark-grar aphanitic cherty limestone [t: s UNCONFORMITY Titus Canyon Formation 0 and Bode (1935) Red, brown, and gray conglomerate willffienspicuous pebbles and cobbles of black chert and white to light-h»-»wn quartzite; contains interbeds, most abundant in the lower an upper parts, of red, yellow, green, and gray muddy limestone, s'@wstone, sandstone, and tuff Oligocene Monolitholo#te breccia Momnolithologicbreccia of Lower and Middle Cambrian limestone and dolomite; forred for the most part, if not entirely, by landslide during the Mesozoic ad Tertiary f ANGULAR UNCONFORMITY Rocks, undifferentiated - Moderate sized areas of quartzite near south margin of quadrangle and isolated areas elsewhere of limestone, dolomite, quartzite; and a little shale 50° Limit of caldera Contact Dashed where approximately located _1_——U moim D Normal or reverse fault, showing dip Dashed where approximately located; dotted where concealed. U, upthrown side; D, downthrown side 70 __AJ_A__h-_~_A_ ..... Thrust fault, showing dip Dashed where approximately located, dotted where concealed. T.43 8. Sawteeth on upper plate Anticl{ne Showing trace of axial plane and direction of plunge of axis; dashed where approximately located Synciine Showing trace of axial plane; dasled where approximately located T. 148. 36°45 116°45 6000 120° 5000" 42} ©°4 | 4000" 3000 2000" 1000" -g $ * B B 1 -* %. 6000 6000 Pei r we Tws 5000" f 4000 4000' 3000 3000 2000" 2 \ Sy Nib 2000" 1000' 1000' LEVEL SEA LEVEL T .m ~> ~ -~ GEOLOGIC MAP AND SECTIONS OF THE BULLFROG QUADRANGLE, VADA-CALIFORNIA SEA LEVEL 50 PROFESSIONAL PAPER 454-J PLATE 1 EXPLANATION >- A C Lone Mountain Dolomite <2]: Indistinctly stratified, massive, homogeneous fine- to medium-grained x partly recrystallized saccharoidal dolomite. Weathers to a pitted L light-gray surface. Fragments of poorly preserved crinoid stems - abundant locally 74 < < 2 C e) 3 - . (O] Roberts Mountains Formation Light- to dark-gray dolomite, calcareous dolomite, and limestone. Most of formation is faintly to distinctly stratified, laminated to thin bedded, and platy to slabby. Sandy and cherty dolomite at base. Platy lime- stone in middle part and dolomite in upper part. Uppermost dolomite partly recrystallized and transitional into overlying formation. Fossils abundant in middle of formation & .S 8 - t$ S o N8 A » 6 Ely Springs Dolomite & Cherty dark-gray very thin bedded aphanitic to fine-grained dolomite; & chert, as anastomosing and finely-intercalated lenses, constitutes 10 per- S cent of entire formation but locally is much more abundant « 2 g € -S Eureka Quartzite > 5 Vitreous quartzite with thin sandstone beds at the base and top. Quartzite O eS is chiefly white and grayish orange with some brown staining fine Q g grained with well-rounded and well-sorted grains, and distinctly to g g indistinctly thin to thick bedded with local faint low-angle cross- stratification an \- C] "s S § § :$ "3 o o § 8 Pogonip Group £ é Medium-gray limestone and olive-gray to olive-brown shaly limestone. p Fossils are locally abundant © y an] . < S E a e € E 8 Nopah Formation & Fine- to coarse-grained light- to dark-gray dolomite and medium- to dark- g; gray limestone. - Dolomite predominates in alternate thin and thick ho light- and dark-gray bands but is partly sandy in the lower part & S *s 35 § O g Carrara Formation §S) Greenish-gray to brownish-gray micaceous shale with interstratified 3 dark-gray very fine grained limestone and minor siltstone in lower o half and white to orange and brown fine-grained limestone and marble § in upper half. Ellipsoidal algal structures common in some limestones 5 in lower half of formation, and shale of same part locally contains 3 trilobite remains 9 z x C > m Corkscrew Quartzite 6 Light-gray, orange, and brown indistinctly stratified fine- to medium- grained quartzite. The quartzite is conglomeratic locally, laminated to thin bedded, partly cross stratified, and slabby to massive & .S < asd § D + A 5 Daylight Formation 3 Interstratified zones as much as several hundred feet thick of sandstone, S siltstone, shale and minor carbonate rock, and conglomerate. These rocks are commonly metamorphosed to phyllite, schist, quartzite, and marble. One bed in the upper part of the formation, shown on the map, ml is oolitic and contains archaeocyathids;adjacent shale contains olenellid < - trilobites <> OE €ds, light olive-, greenish-, or brownish-gray micaceous shale and inter- 6 C calated sandstone NY €dq, light-gray quartzite O u €do, yellowish-brown oolitic limestone V- LU T> ANGULAR UNCONFORMITY #4 < O re O m N & 3 & ps 's Gneiss, schist, and pegmatite #7 L pE€m, quartz-feldspar-mica gneiss and schist, light and dark gray (6) El respectively Lu fn p€g, gneissic granite pegmatite, white g xf? Strike and dip of beds -+- Strike of vertical beds 30 _p_ Strike and dip of overturned beds 45 sos Strike and dip of foliation + Strike of vertical foliation a Shaft l Adit X Prospect pit § APPROXIMATE MEAN DECLINATION, 1963 118° 116° 114° —|' 42° I I I I F- 40° I I o Ely I I I I 38 ~- -- 38° X, | 118° ~ % I X T AREA OF THIS REPORT \ % \\ 36°, |-36° + 116". 114° 0 50 100 MILES INDEX MAP GEOLOGICAL SURVEY EXPLANATION Sit He Ro fe. te ~ pio he sige in- ~#~ Tuff Conglomerate Sandstone Siltstone, and tuffaceous siltstone -he =r --- Limy shale and limy mudstone Limestone Silty or shaly limestone FEET r- 600 |[-400 [- 200 UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-J PEATE 3 DESCRIPTION whim 466 aige spe Unit 4: Sandy and silty tuffs interstratified with tuffaceous sandstone, siltstone, conglomerate, and shale. The basal member is a conspicuous lithified tuff with conspicuous white feldspar and quartz crystals and black biotite. The rock also contains shards and has abundant cavities elongate parallel to the bedding plane. As indicated in the columnar section, tuffs are most abundant in the upper half of this unit, but the upper 100 feet is mostly sandstone and siltstone Unit 3: Tuffaceous siltstone and sandstone at base grading up into limy siltstone and silty limestone. The beds weather yellowish to pinkish gray. The limestone is locally algal. The algal zone was used as a correlation horizon by Stock and Bode (1935, p. 574-577) Unit 2: Reddish brown arkosic conglomerate, similar to below, with conspicuous highly polished pebbles and cobbles of black chert; gray, white, and pink quartzite, clasts of brown rhyolite, gray limestone, and gray dolomite are locally conspicuous. There are scattered interbeds of limestone and tuffaceous siltstone. A 25-foot tuffaceous sandstone bed near the middle is strikingly green colored and contains scattered small octahedra of magnetite Unit 1: Pale reddish brown and yellow interbedded arkosic conglomerate, gritty sandstone, limy mudstone, and muddy limestone COLUMNAR SECTION OF THE TITUS CANYON FORMATION OF STOCK AND BODE (1935), 1 MILE SOUTHEAST OF DAYLIGHT PASS, BULLFROG QUADRANGLE, NEVADA 724-437. O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-J GEOLOGICAL SURVEY PLATE 4 117"00" y bo R.A44 E. R: 45 C. R. 46 E. MAYFLOWER R:d47 E. R. 48.5. R. 49 E. iad o aas rte" poste, ip ~ 37100 EXPLANATION < }Z C L I.— Alluvium g 0 Flows and intrusive rocks Ir Rhyolite Felsitic and glassy rhyolite flows and intrusive rocks TAE. Tits. Tw TERTIARY Welded tuff “($00 \ - ap f / \ y \ BSA ao (gh S * $ r es ave lly, & Tt Tuff Rhyolitic pumiceous tuff loosely consolidated to well lithified Older rocks Undifferentiated, mostly Paleozoic sedimentary rocks BULLFROG QUADRANGLE BARE MOUNTAIN QUADRANGLE PRE-TERTIARY Contact l65 Fault, showing dip Concealed fault SSSSSS few... Thrust fault Saw teeth on upper plate 50 woluss Strike and dip of beds % , **s. ORIGINAL ~. BULLFROG % - # , *, f y , T 128, : t f B . * 3 Phace e a. wy u" A 5 \ f ~.,. N Tirmit cf saldera Spgs 3 . ( Ruled area indicates volcanic rocks t> 7 > . that are younger than those of $100. the Bullfrog Hills caldera X Prospect pit a Shaft F Adit 5 Number indicates number of cooling units, where known, in welded tuffs of the Bullfrog Hills caldera IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII -1964 -G6é3077 SCALE 1:48 000 Geology by H. R. Cornwell and F. J. Kleinhampl, 1 [) 1 24 3 MILES 1956-1960, U.S. Geological Survey C pp -p --- 1 5 0 1 2 3 KILOMETERS HHHHH rs --- Tt Tb! Gal Tt Tbl T / \\ K) Qal T 1a ._ TW Gal Tw SEA LEVEL SEA LEVEL 6000' 4000" 2000' GENERALIZED GEOLOGIC MAP OF THE BULLFROG HILLS AND YUCCA MOUNTAIN CALDERAS, NYE COUNTY, NEVADA UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-J GEOLOGICAL SURVEY PLATE 5 FEET EXPLANATION 10,000 Tk %o) > te T> km Latite flow ooo apt fite to o om Lui not d o a unes? 3 “0° Cooling unit,_ a_ a_ * 9 0,0 a i ; o 9° 0° a a" p° Lithoidal zone of welded ash flow a o A an°o°v°°°qqu mo a 6 a g 0 g 9 0 F r- po o 084 ana -0" Vitrophyre zone of welded ash flow s 4 Nonwelded to partly welded ash flow Tuffaceous sedimentary rocks Air-fall tuff COLUMNAR SECTION OF ROCKS IN THE BULLFROG HILLS CALDERA NEAR BEATTY, NEVADA 724-437 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY y . 4500 N wew suarrg COMPOSITE PEAN OF LEVELS 1-5 mai lad u g P m w t w w s s s g 2 3 S z § A COMPOSITE:.PLAN-OF LEVELS 6-13 MINE WORKINGS OF THE DAISY FLUORSPAR MINE, NYE COUNTY, NEVADA 80 0 80 160 240 FEET i L ] 18 (J) 110 2|O 3|O 4|O 510 60 70 METERS i 1 1 PROFESSIONAL PAPER 454-J PLATE 6 EXPLANATION First level fn das eds. hr Sixth level Seventh level Seven and three fourths level Eighth level Ninth level Tenth level Eleventh level Twelfth level North winze Thirteenth level South winze ¥ Top of shaft or major winze X] Shaft or major winze going above and below levels Lx] Bottom of shaft or major winze Inclined workings M Head of raise or winze I Foot of raise or winze 724-437 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY LW W 9 8 s ® 5000 N a 453 4900 N € DAISY SHAFT 20-4 4800 N p 4700 NJ THIRD LEVEL FIFTH CEVEL PROFESSIONAL PAPER 454-J I o O| O| D 5000 N 4900 N & a 4800 N SIXTH. LEVEL ( 3 \ w [m m (27 y’ o o o = § ¥ © % Is s hel n 80 5100 N \ 47 og 5000 N , |70" worth winze 85 i DAISY SHAFT 4700 N 80 30 40 < Shaft or major winze going above and below levels re Bottom of shaft or major winze Inclined workings A Head of raise or winze K Foot of raise or winze 724-437 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ty ted e o 8 S 3 O «- O D w 1 5100 N 20 x o 30 # é; $ *( 85 7 sx? 80 /* SS 5000 N 50 85 z* 80 \\C) 70 Jff7O 90 90 3. 4900 N | > C- NINTH LEVEL L Lut C t o o o lel o 0 O O o ra Ist o w w u iy 5100 N \ b> A 5000 N naff \\C> sof" £ 90 70 A. 4900 N p> & TENTH LEVEL LJ LJ L W 8 8 8 8 G «- Is 0 w 1 1 © 5100 N p hel § \\ 90 P 5000 N 8 \\Jv 90 5 CSF eo, 50 64 4900 N 'a ELEVENTH LEVEL GEOLOGIC MAP OF LEVELS 9 TO 13, DAISY FLUORSPAR MINE, NYE COUNTY, NEVADA 5000 E 5100 N 5000 N p o TWELFTH LEVEL 4700 E 4800 E 5000. N 4900 E 5000 E 5100 E *y % PROFESSIONAL PAPER 454-J PLATE 8 EXPLANATION Fluorspar ore 90 Saree ce nce Contact, showing dip 60 ace doce Fault, showing dip Dashed where approximately located Fault zone or shear zone Trench or cut ><] Shaft or major winze going above and below levels G Bottom of shaft or major winze Inclined workings A Head of raise or winze 5200 E 4900 N X Foot of raise or winze 4800 N 4700 N 4600 N 4500 N COMPOSITE GEOLOGIC PLAN OF LEVELS NINE, TEN, ELEVEN, AND THIRTEEN 0 80 160 1 10 2|O 30 40 510 60 70 METERS 1 1 1 1 1 724-437 O - 64 (In pocket) PROFESSIONAL PAPER 454-J UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY PLATE 9 A Al 4400" T [- 4400' AIR /,_f——//’—‘ \ $ [=" " \ LI) Q N: & FIRST LEVEL \ « Z 4300' 4 A a 0 - 4300" o E 6 o EXPLANATION s ECONB TEVET g U1 | LL. | | o THIRD LEVEL 1—4; | m \‘ Fluorspar ore I|! \ Q\ 4200 - P "d - 4200" 1 ,\ 7a f DAISY SHAFT (PROJECTED) 5, -See 1 Fault i Dashed where approximately located } f fall 1 I jd Ron 1 I Shear zone I } 10d 4100" 4 e SIXTH LEVEL m SIXTH LEVEL |- 4100" % + 1 seventnH Lever [V ? I # TU, EiGhHTH LEvEL\_} 4000" 4 Eo \ - 4000" “é “M“ NINTH LEVEL PA o . + 17mm”, TENTH LEVEL O LJ U LL. 3900' O ELEVENTH LEVEL 3900 LU F4 j TWELFTH LEVEL THIRTEENTH LEVEL 3800' 3800 B B' € 2 p p' 4400" -’ Ajay. r 4400'- r 4400" 4 : r 4400' SHAFT / [Lit l | FIRST LEVEL 4300' 7 Fi 43004 F 4300" 4 F 4300' Z =d | 74 q nemimides, O |H rirp LeveL 4200 - - 4200 - - 4200 - aly |- 4200" D rourtH Lever SX FOURTH LEVEL L } SAL 1 N LL. O X4 Ll LL. FIFTH LEVEL z 0 \\ a LLl U z SIXTH LEVEL - 410011 PEM sixtu cever | 4100' 7 SIXTH LEveL - 4100" -l SEVENTH LEVEL §¢ SEVEN AND THREE FOURTH LEVEL \\\,‘~i:1' A N Leven EIGHTH LEVEL j} EIGHTH LEVEL wg 1 I | 4000' 1 | 1} F 40007 J F 4000" 4 [ - 4000" tr} NINTH LEVEL # ninth Lever | [PB NINTH LEVEL @ Tres “n i H1 ‘\/South winze (projected) TENTH LeveL TENTS LEVEL '.l I \ 1 {j ELEVENTH LEVEL & /_\,\ \ *% PSs i P= 3900 4 - 3900! 4 eceventH LEVEL\\D/k F. 3900' 4 ELEVENTH LEVEL F 3900' North winze TWELFTH LEVEL \ THIRTEENTH LEVEL 3800" 3800' 3800' 3800' LONGITUDINAL AND CROSS SECTIONS OF THE DAISY FLUORSPAR MINE, NYE COUNTY, NEVADA 724-437 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-J GEOLOGICAL SURVEY TABLE 2 Chemical and spectrographic analyses, norms, and modes of volcanic rocks in the Beatty area, Nevada [Analyses Nos. 1, 2, 8, 9, 15, and liby Paula M. Montalto; Nos. 4, 5, 6, 10, 11, 12, 24, and 25 by Dorothy F. Power; Nos. %, 13, 14, 16, 20, and 21 by Ruth Kittrell; Nos. 3, 18, 19, and 22 by George Steiger; No. 23 by Margaret Balazs; and No. 26 by Paul Elmore] ithoi ithoi ithoids Basal tuff | Basallass| Lithoidal | Basalglass | Basalglass | Felsitic Basalglass | Felitic Glass zone | Rhyolite Rhyolite |Rhyodacite Quartz Lithoidal Welded 1355312? $3132? $ $535? 5 ofa svelded zone welded zonegof zonge zone of Tuff zone zore of of flow or stock ._ glass dike Latite flow basalt Basalt flow Analcime Tuff welded Tuff tuff tuft tuff tuff tuff weldec tuft tuff welded tuff | of flow flow of flow flow intrusive intrusive flow basanite tuff 1 2 8 4 5 6 7 8 9 10 11 B 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Chemical aralyses (weight percent) 72. 57 74.71 77.26 70.29 78. 21 75.02 72.99 71.46 75. 94 69. 46 74. 68 76. 18 73. 89 75. 96 74.05 63. 95 60. 58 63. 34 59.72 47.70 50. 50 43. 62 72.95 74.10 69. 82 75.6 13.16 13.18 11. 54 11.38 12.16 12. 56 12. 43 12. 29 12. 40 11.10 12.20 1.32 12.10 12. 67 11.85 15.39 17. 80 15. 46 14. 63 16. 86 17. 36 12.73 10. 60 11. 59 12. 09 12.2 2.06 1.14 . 85 . 96 . 74 .99 +18 . 65 97 . 59 41 . 50 . 39 . 99 .44 1.21 3.35 4.14 3. 40 5.86 2. 98 4. 89 . 81 3. 36 1.33 . 58 . 26 13 13 . 00 . 23 .00 .28 . 45 17 .00 16 13 .20 . 07 27 2. 24 1.08 . 39 2.37 4.10 6. 64 4.10 .05 . 03 15 11 . 27 , 22 . 20 . 49 12 13 . 81 .82 19 . b1 «24 20 .09 11 . 21 . 98 1.08 . 66 2. 69 6. 62 5.12 9. 37 . 05 .08 .93 .36 . 58 . 44 . 58 1.78 . 5(0 .18 . 38 1.20 . 50 2.10 . 38 . 94 . 48 . 31 . 74 3.11. 4.10 2. 01 6. 55 9.71 8.76 11. 62 . 97 14 2. 58 . 54 8. 07 3. 66 2. 96 1,19 3. 60 4. 34 3. 65 3. 63 8. 41 75 8. 42 3. 65 3. 29 4. 24 3.19 3. 16 4.27 3. 89 3. 28 2. 98 3.14 2, 96 1. 46 4.00 1. 55 §.2 - 6. 48 4. 91 4. 65 3.77 4.77 4.74 4. 94 3. 60 5. 62 8. 91 4.86 4.81 4.72 4.85 4. 50 4. 68 4. 59 5. 31 3. 33 1.67 1.65 1.30 4.77 5. 54 2. 44 4. 4 . 57 . 69 . 96 4. 98 2.95 .36 3. 01 5. 31 . 28 6.15 3.13 BU 3. 90 11 3.59 . 97 . 53 1.16 1.38 79 41 3. 94 3.76 .22 5.07 20 ..36 1.03 4.41 1.07 118 . 64 . 58 . 09 5.03 14 .21 .39 +18 . 58 15 . 60 1.89 e 45 20 1.91 3. 91 . 35 3. 52 } 2.9 30 .13 18 15 14 15 15 "47 A7 .09 . 09 .09 .10 15 12 . 50 1.18 1. 53 . 95 1.79 1.47 1.46 11 122 .18 .10 07 .00 tr. .01 . O1 .02 .03 . 04 . 04 .01 01 .02 . O1 . 01 . 00 15 . 38 .22 . 40 19 1.06 . 82 .00 . 02 .03 . 00 .09 . 05 .03 12 . 09 10 10 . 06 .06 . 06 . O7 «07 . 07 . 07 . 05 12 . 09 s 16 .18 & v4 . 05 15 . 05 . 06 22 . 08 00 .02 . O1 . 43 .01 . 04 .01 .03 01 41 . 03 . 09 19 2. 51 . 05 27 . 07 . 63 . O1 .02 .00 . 06 . 05 208 HL tubers s at ae ob Bucs Leavens ae le ae con 11 .03 £00 o eens ene 9012002. . 08 .02 . 04 .07 15 10 2097 [LAr TLL RL EIR fevers (ei- bebe need el sea aude te seca e 99.95 99. 73 99. 83 99. 91 99. 79 99. 67 99. 690 99. 74 99. 78 99. 82 99. 74 99. 78 99. 85 99. 63 99. 47 99. 50 99. 82 99. 74 100. .02 .01 .91 108 JE.... LL.. coule denn aa == deed 03 . 01 . 02 . 03 . 06 . 04 204 "o otes ested d. o,. a Hei aco) rat av acl oa ai 99. 93 99. 72 99. 82 99. 88 99. 79 99.67 99. 60 99.71 99. 77 99. 80 99. 71 99. 72 99. 81 99. 59 2.62 2.62 2.37 2. 62 2.23 2. 38 2.62 2.36 2. 63 2. 43 2. 66 2. 69 2. 91 2.99 2. 52 2.36 2. 31 4. 48 "|:. el eu 2. 33 2. 50 2. 34 2. 59 2. 56 2. 81 2.71 Differentiation in 93.3 93. 6 286. 3 95. 6 278.5 92. 9 94.6 91. 3 96.8 91. 4 80.5 78. 4 35.2 37.5 Quantitative spectrographic analyses [Analyst, Paul R. Barnett] 0. 001 0. 001 0.001 0. 003 0. 003 0. 0057 0.0024 0. 004 0 0. 003 $0: [Pest ok . 0042 . 0058 . 0049 . 032 . 032 . 0044 . 0005 . 0014 . 0007 . 0057 . 005 16 a . 0005 . 0004 . 0003 . 0004 . 0005 . 0002 . 0006 . 0006 . 0004 . 0002 . 0004 0 . 0001 <. 0001 0 0 <. 0001 .0028 |. . 0008 . 0005 0 0 . 0001 . 0001 . 014 a . 00004 00009 . 00008 . 0002 . 0001 . 00009 . 00004 . 00017 . 00004 . 00009 . 0001 0071 |- . 0020 0022 . 0021 . 001 . 001 . 0012 . 0017 . 0017 . 0018 . 0021 . 001 0018 _ |. 004 003 . 003 . 004 . 004 0 0 0 . 003 . 003 . 020 ' ________________________ . 004 We Aura ree ados a sie vel a as [a's s nik o a a's o a (2 o wien on ae pare [aks s s on bo u ta . 003 . 004 levee . 002 6 0 . 0003 . 0002 . 0001 . 0005 0003 . 0004 0 . 0002 0 & . 0028 . 0032 0030 . 002 .002 0024 0033 0033 . 0032 0032 002 0 a 0 0 0 0 0 0 0 0 . 0054 |. . 0044 . 0044 . 0053 . 003 . 003 . 0026 . 0033 0035 . 0041 . 0044 . 003 0 < 0 0 0 . 0003 . 0003 . 0004 . 0004 0004 . 0004 . 0005 . 0003 0026 |. . 0040 . 0015 . 0014 . 01 . O1 . 0074 0002 0007 . 0004 . 0012 . 004 092 & 0 0 0 .. 001 . 001 0 0 0 . 0004 . 021 z . 0066 . 0060 . 0060 . 003 . 003 . 0040 . 0051 . 0055 . 0052 . 0055 .002 0053 |. 00050 . 00050 . 00051 . 0003 0003 . 00046 00054 00055 . 00051 . 00046 . 0003 . 00049 |- Meal oa n a avers . 024 023 .024 . 010 . 010 . 0086 0085 0077 . 0084 . 020 . 008 $040. 1222 veni Looked for but not a detected......._... O] (§). . olgoe ens ad (O (4) («) (8) (3) O (© (©) O) (©) ($) (8) (§) anf Haan ee o. Ae anwar n a Pree d (as wee neh 22 To 1 oul I+ 2 axe QBATER.LZ... :.: Orthoclase. Albite. . ..- Anorthite Acmite...- Nepheliné. Corundum. Wollastonite. Enstatite.. Ferrosilite : Forsterite. Fayalite . Magnetite. IInienite. Hematite Quartz... Plagioclase. Sanidine .. Magnetite. . Pyroxene. Olivine. Biotite. Amphibole. a XKenoliths......... -... see Approximate plagi- oclase composition... Anio Ange Ange ................... Anas a eugene ooc Ange Anss Anas Ano Anss Anrs-s0 Anas-ss Anso-ss Anzo ETU A oul ed erve ce ana nn nen s enews { Differentiation index of Thornton and Tuttle (1960). ? Calculated after subtraction of H20~. £ Ag, As, Au, Bi, Cd, Co, Cr, Ge, In, Ni, Pt, Sb, Sn, Ta, Th, Tl, U, V, W, Zn, and 5 Ag, As, Au, Bi, Cd, Ge, In, Pt, Sb, Sn, Ta, Th, Tl, U, W, Zn, and where zero 20 1: w - co or 3 Ag, As, Au, Bi, Cd, Ge, In, Ni, Pt, Sb, Sn, Ta, Th, T, U, W, Zn, and where ro is written. Lithoidal welded tuff (sample BC 100), first (lowest) cooling unit of the welded tuff in the Bullfrog Hills caldera. . Lithoidal welded tuff (sample BC 149), second cooling unit of the welded tuff in the Bullfrog Hills caldera. . Lithoidal welded tuff (sample B 374, Ransome and others, 1910), fourth cooling unit of the welded tuff in the Bullfrog Hills caldera. . Basal nonwelded tuff (zeolitized to clinoptilolite) of welded tuff (sample MC 2748), probably the third cooling unit (analyses 4, 5, 6) of the welded tuff in the Yucca Mountain sequence. . Basal vitrophyre zone of welded tuff (sample MC 274b), probably the third cooling unit (analyses 4, 5, 6) of the welded tuff in the Yucca Mountain sequen:e. . Lithoidal welded tuff, devitrification zone (sample MC 274c), probably the thrd cooling unit (analyses 4, 5, 6) of the welded tuff in the Yucca Mountain sequene. where zero is written. is 7. Basal vitrophyre zone of welded tuff (sample MC 299), late cooling unit of the 13 Yucca Mountain sequence. 8. Basal vitrophyre zone of rhyolitic flow (sample BC 72b), same flow as analysis 14. No. 9, upper part of Bullfrog Hills caldera sequence. 15. 9. Felsitic zone of rhyolitic flow (sample BC 72¢), same flow as analysis No. 8, upper part of Bullfrog Hills caldera sequence. 16. 10. Zeolitized (clinoptilolite) tuff (sample MC 170a), probably lower part of Bullfrog Hills caldera sequence. 17. 11. Basal vitrophyre zone of rhyolitic flow (sample MC 170b), same flow as analysis No. 12, probably lower part of Bullfrog Hills caldera sequence. 18. 12. Felsitic zone of rhyolitic flow (sample MC 170c), same flow as analysis No. 11, probably lower part of Bullfrog Hills caldera sequence. 19. written. . Vitrophyre zone of rhyolitic flow or intrusive (sample MC 295), probably lower part of Bullfrog Hills caldera sequence. Rhyolite stock (sample MC 175), Yueca Mountain sequence. Vitrophyric zone of rhyolite intrusion (sample MC 336), Yucca Mountain sequence. Porphyry dike (sample MC 275) probably late Tertiary, intrudes Paleozoic sedimentary rocks. Porphyritic latite flow (sample BC 148), upper part of Bullfrog Hills caldera sequence. Porphyritic latite flow (sample B 172, Ransome and others, 1910), upper part of Bullfrog Hills caldera sequence. Porphyritic quartz basalt flow (sample B 314, Ransome and others, 1910), upper part of Bullfrog Hills caldera sequence. f 6. Welded tuff (sample DDH 3-251), 5 Anorthoclase and sanidine. Anortheclase. 20. Basalt flow (sample MC 211), probably lower part of Bullfrog Hills caldera sequence. . Recent basalt flow (sample MC 297). . Analcime basanite (sample B 107, Ransome and others, 1910), probably alteration facies of a basalt flow in the Bullfrog Hills caldera sequence. 3. Zeolitized (clinoptilolite) tuff (sample TU-1), unit No. 3 of the Oak Spring Formation, Nevada Test Site, Nye County, Nev. . Lithoidal welded tuff (sample DDH 3-1029), unit No. 6 of the Oak Spring Forma- tion, Nevada Test Site, Nye County, Nev. . Zeolitized (clinoptilolite) tuff (sample DDH 3-889), unit No. 7 of the Oak Spring Formation, Nevada Test Site, Nye County, Nev. unit No. 8 of the Oak Spring Formation, Nevada Test Site, Nye County, Nev. 724-437 O - 64 (In pocket) UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 454-J GEOLOGICAL SURVEY PLATE 2 S$ TEM FEET FORMATION EXPLANATION Dolomite Meiklejohn Formation Aimestons CARBONIFEROUS MISSISSIPPIAN Conglomerate Sandstone, top regularly and horizontally strati- fied; bottom cross- stratified Fluorspar Canyon Formation Quartzite and quartzitic sandstone DEVONIAN Siltstone, underlain by schistose siltstone Lone Mountain Dolomite Brecciated zone SILURIAN Scolithus zone, vertical tubular forms Roberts Mountains Formation Ely Springs Dolomite $ par yi Eureka Quartzite muh an, dri Pa Pl (x V000 fizzfié/fl Phyllite ORDOVICIAN Pogonip Group Chert, nodular and lentic- ular top; bedded bottom Limestone, sandy and dolomite Nopah Formation Siltstone, sandy, under- lain by sandy schistose siltstone Bonanza King Formation Carrara Formation CAMBRIAN Girvamella Corkscrew Quartzite Oolite Daylight Formation Stirling(?) Quartzite 0 COLUMNAR SECTION OF PALEOZOIC ROCKS ON BARE MOUNTAIN NYE COUNTY, NEVADA 724-437 O - 64 (In pocket) 91/2; 7 5 Z7 * Upper Paleozoic Floral Zones and Floral Provinces of the United States ([is L GEOLOGICAL SURVEY, PROFESSIONAL PAPER 454-K '\ your vity survey Froress101al Faper 404-=BR van wa me nr cnm aur imum anu aaa iand § Q % to g NW scievce ue Upper Paleozoic Floral Zones and Floral Provinces of the United States By CHARLES B. READ end SERGIUS H. MAMAY With a GLOSSARY OF STRATIGRAPHIC TERMS By GRACE C. KEROHER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K An analysis of the succession of floras in the Mississippian, Pennsylvanian, and Permian Systems UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington D.C. 20402 CONTENTS Page Page R =_ oeil ai arn. K1 - Upper Paleozoic floral zones-Continued N 1 Pennsylvanian floral zones-Continued Meknowledaments 1. c_ (|___. 2 Zone 11. Zone of Lescuropteris $pp.-.:......2z2 K11 Horas 2 Zone 12. Zone of Danaeites 12 Upper Paleozole floral ___ 4 Zones 11 and 12 (locally combined). Zone of Mississipplan floral zones......_.__.__.______).___ 4 Odontopteris spp. [_. 12 Zone 1. Zone of Adiantites 4 Permian floral /___. L_ Lull 12 Zone 2. Zone of Triphyllopteris 5 Zone 13. Zone of Callipteris 12 Zone 83. Zone of Fryopsis spp. and Sphenop- Zone 14. Zone of the older Gigantopteris flora in féridium _o. 5 parts of Texas, Oklahoma, and New Mexico, Pennsylvanian [-_ : 6 equivalent zone of Glenopteris spp. in Kansas, Zone 4. Zone of N europteris pocahontas and and equivalent zone of the Supai@ flora in Mariopteris eremopteroides_____ ___ ___ __ ___ __ 6 New Mexico and 13 Zone 5. Zone of Mariopteris pottsvillea and of The Supata Hora... l}} 13 common occurrence of Aneimites spp.______. 7. The @ienopteris flora:............___.:.} 14 Zone 6. Zone of Neuropteris tennesseeana and The Gigantopteris fHlora....._._...____..._ 14 Mariopteris pygmaea, and to some extent of Zone 15. Zone of the younger Gigantopteris flora 15 Ovopteris communis, Alloropteris ingequilat- Upper Paleozoic floral _ _. _[. 16 eralis, and Alethopteris 7 Mississippian floral 16 Zone 7. Zone of common occurrence of Megal- Pennsylvanian floral 16 Opiéeris spp.. -..: _ ill-. 7 Permian floral provinees.__......_._....__i.lll_} 16 Zone 8. Zone of N europteris tenuifolia _ ___ ___ _ O References. .c. 18 Zone 9. Zone of Neuropteris rarinervis_ ___ ___ 9 _ Glossary of stratigraphic terms, by Grace C. Keroher___ 19 Zone 10. Zone of Neuropteris Rexuosa and References to glossary.... ___.... .__l__ _ [._ 29 appearance of abundant Pecopteris spp. __ 10 00 tell m aO 33 Prats Ou Q ho +- ed 19. ILLUSTRATIONS [Plates follow index] . Zone of Adiantites spp.; zone of Triphyllopteris spp. . Zone of Triphyllopteris spp.; zone of Fryopsis spp. . Zone of Fryopsis spp. . Zone of Neuropteris pocahontas and Mariopteris eremopteroides; zone of Mariopteris pottsvillea and Ancimites spp. . Zone of Mariopteris pottsvillea and Aneimites spp.; zone of Neuropteris tennesseeana, Mariopteris pygmaea, Ovopteris communis, Alloiopteris inaequilateralis, and Alethopteris decurrens. . Zone of Neuropteris tennesseeana, Mariopteris pygmaea, Ovopteris communis, Alloiopteris inaequilateralis, and Alethopteris decurrens. . Zone of Neuropteris tennesseeana, Mariopteris pygmaea, Ovopteris communis, Alloiopteris inaequilateralis, and Alethop- teris decurrens; zone of M egalopteris spp.; zone of Neuropteris tenuifolia. . Zone of Neuropteris rarinervis. . Zone of Neuropteris flexuosa and Pecopteris spp. 10. 11. 12. 13. 14-18. Zone of Neuropteris flexuosa and Pecopteris spp. Zone of Lescuropteris spp.; zone of Danaeites spp. Zone of Danacites spp.; zone of Odontopteris spp. Zone of Callipteris spp. Zone of older Gigantopteris flora: 14. Supaia flora. 15. Supaia flora. 16. Glenopteris flora. 17. Gigantopteris flora. 18. Gigantopteris flora. Zone of younger Gigantopteris flora. HI CONTENTS TABLES Tarues 1-5. Floral zones: in p $o po C socal ak Lower ~ Middle PennSyI¥ANRIAM. c.. cess ns ss Upper cass ances ue co es Lura c ans ane enses bols an ahi a a on pe ae u aln h Be aln e tn eles au hn m mile ben an ain antee mn eela o Page K5 10 13 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES OF THE UNITED STATES By B. Reap and SErervs H. Manmay ABSTRACT : Fifteen more or less well-defined floral zones occur in Missis- sipian, Pennsylvanian, and Permian rocks of the United States. The Mississippian contains three zones in eastern North America, where its continental facies is best formed. In ascend- ing order they are the zones of Adiantites spp., Triphyllopteris spp., and Fryopsis spp. This sequence is probably incomplete, because the American Mississippian is dominantly marine. By contrast, the Pennsylvanian contains uninterrupted floral sequences that provide bases for subdivisions and correlation of strata over broad areas. In ascending order, Pennsylvanian floral zones are characterized by : Newropteris pocahontas and Mariopteris eremopteroides, Mariopteris pottsvillee and Anei- mites spp., Mariopteris pygmaea and Neuropteris tennesseeana, Megalopteris spp., Neuropteris tenuifolia, Neuropteris rariner- vis, Newropteris flexuosa and Pecopteris spp., Lescuropteris spp., and Danaeites spp. The Permian of the Southwestern United States contains three floral zones, the lowermost characterized by Callipteris Spp. This underlies a zone containing three contemporaneous but geographically restricted floras whose provinciality may be due to paleophysiographic or paleoedaphic features of that region These are the Supai@ flora of Arizona and New Mexico, the Glenopteris flora of Kansas and the Gigantopteris flora of Texas, Oklahoma, and New Mexico. The third and youngest zone, containing a modified Gigantopteris flora, is known only in a restricted area in northwest Texas. INTRODUCTION Much information has been accumulated during the past 75 years in regard to the distribution in both time and space of upper Paleozoic floras in the conterminous United States," and it now seems appropriate to sum- marize briefly the acquired knowledge. This report is to be regarded as an account of progress based on data that are admittedly incomplete and will likely continue to 'be so for some decades. Serious attempts to use Palezoic plants in the solution of stratigraphic problems in the United States were first *This abstract was first published in Congreso Geologico Interna- cional, 20th, Mexico 1956, Resumenes de los Trabajos Presentados, p. 123-124. 2 Inasmuch as there are no Paleozoic rocks in Hawaii and the Paleo- zoic floras of Alaska are too scantily understood for inclusion in this report, the term '"conterminous'" should be understood as applicable throughout this report. made by Lesquereux during the period 1852-93. This pioneer paleobotanist wrote and published a large se- ries of articles on Paleozoic paleobotany. His greatest work, generally referred to as the "Coal Flora," care- fully lists locality data for all species described and also includes lists of plants from various parts of the upper Paleozoic sequences in the eastern United States (Lesquereux, 1880, 1884). Contemporaneous with the work of Lesquereux were the investigations of Fontaine and White ( 1880) on the Permian floras of the Appalachians. Their work, which was similar in pattern to that of Lesquereux, described the floras of the Dunkard Group with special emphasis on the large and varied flora of the Cassville Shale Member of the Washington Formation. David White (1862-1935) joined the U.S. Geological Survey in 1886 and began his long and brilliant paleo- botanical career, which was terminated by his death in 1935. His published works are many, and most of them are attempts to use fossil plants in problems that in- volve the dating and correlation of the containing strata. His reports form a substantial framework for the application of paleobotany to stratigraphic prob- lems in the upper Paleozoic systems. Excluding investigators of the present generation, the list of others who made contributions to Paleozoic paleobotany is small. A. C. Noé contributed to our knowledge of the flora of the famous Mazon Creek lo- cality in the Pennsylvanian of northern Illinois. Ward and Berry casually described a few species of Paleozoic plants from time to time, as have some others. The present generation of Paleozoic paleobotanists in the United States includes students of morphology and anatomy of fossil plants and a few stratigraphic paleo- botanists working with megafossils. A large number of palynologists are investigating the abundant spores and pollens that occur in the upper Paleozoic systems and the applications of these to stratigraphic paleobotany. Their publications are not referred to in this report, as they deal entirely with microfossils rather than megafossils. K1 K2 Upper Paleozoic floras, as used in this report, are de- fined as those occurring in the Mississippian, Pennsyl- vanian, and Permian Systems. The Dovonian floras, although related, are not discussed in detail, because they present special problems involving the origin and development of subaerial assemblages that can best be discussed elsewhere. Any discussion of the sequence of upper Paleozoic land plants, however, should also take into account in a general way the kinds of plants that existed immediately before the beginning of upper Paleozoic time. An understanding of these forerun- ners is necessary, in fact, to visualize the setting for the floral evolution that took place later. A prefatory dis- cussion of these antecedent floras is therefore included here. The fossil record indicates that the plants that lived during upper Paleozoic times were different from their modern descendants. Undoubtedly there were repre- sentatives of the lower groups of plants, such as the algae, fungi, mosses, and liverworts. The remains of most of these, with the exception of the algae, are rarely incorporated into the fossil record. The remains ordi- narily found are of various groups of higher plants that are characterized by the presence of woody tissue in stems and leaves and hence are more apt to be preserved as fossils. f ~The floras of the upper Paleozoic systems have often been referred to as being dominated by ferns. Al- though many of these plants were similar to ferns in many respects, this belief is incorrect. The dominant types, both in species and in genera, and probably in masses of vegetation, were fernlike gymnosperms that are commonly referred to as seedferns; however, some true ferns lived. Many of the ferns appear to have been rather small, but others were large and resembled modern treeferns. Also common in the fossil record were ancestors of the modern clubmosses, scouring- . rushes, and conifers. The remainer of the upper Paleozoic floral assem- blages consisted of two important groups, the spheno- phylls and psilophytes, for which modern counterparts are lacking. ACKNOWLEDGMENTS The writers wish to acknowledge the technical counsel and aid received during the preparation of this report. First they express their gratitude to the late John B. Reeside, Jr., who some 20 years ago urged the senior author to prepare one or more summaries of the type here presented. Early drafts discussing parts of the upper Paleozoic floral sequence were prepared ; but dur- ing and after the war years,technical activities were di- verted into other fields. In 1956, while on a visit to New Mexico, Dr. Reeside again urged that a report SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY summarizing the status of knowledge of upper Paleo- zoic floral sequences be prepared. The writers are indebted to Thomas A. Hendricks and Richard A. Scott of the U.S. Geological Survey and to Robert M. Kosanke of the Illinois Geological Survey for critically reading drafts of the manuseript and offering many valuable suggestions. They also thank Hannah A. Kath, Sidney R. Ash, and Arthur D. Watt of the U.S. Geological Survey. Miss Kath and Mr. Ash, in Albuquerque, N. Mex., took special care in the final preparation of the manuscript and the illustrations. - In Washington, D.C., Mr. Watt worked with the authors in the selection of specimens for use in illustrating the report. THE ANTECEDENT FLORAS Striking similarities and surprising differences exist betwen the known Devonian floras and those of the succeeding Mississippian. It is evident that most of the major groups of plants characteristic of the upper Paleozoic systems existed during Devonian time. There are representatives of the Sphenopsida-types ancestral to the common sphenophylls and calamites that characterize upper Paleozoic floras. The Lycop- sida are represented by several types that apparently were the precursors of the Lepidodendrons and Sigil- larias, which are common in the Mississippian and Pennsylvanian Systems. Among the Pteropsida in the Devonian are representatives of the ferns, the seed- ferns, and the primitive conifers. In addition, a surprisingly large number of unusual types of plants apparently became extinct near the end of the Devonian. These plants have been assigned to several major groups. They appear to represent evo- lutionary trends or lineages that for one reason or an- other could not compete with the plants that domi- nated the landscapes in later times. Although the beginnings of plant life were certainly in Precambrian time, as evinced by the fairly common occurrence of the problematical calcareous algae called stromatolites, a reasonably clear and continuous record of land plants does not begin until Devonian time. It is well known that there are plantlike remains in the Silurian that could have been terrestrial. Halle (1920) described Psilophyton-like material from the Silurian of Gotland. Somewhat similar material has been de- scribed from the Silurian of England (Seward, 1983). The upper Silurian of Australia has yielded both stemlike organs that bear small crowded scalelike leaves and branched leafless specimens (Lang and Cookston, 1927). These compare with TAursophyton Nathorst and Hostimella Barrande, both fairly well known in Devonian rocks (Seward, 1933). Although fragmen- UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES tary, these records reasonably establish the fact that pre- Devonian land floras existed. The earlier Devonian floras are dominated by plants belonging to groups that became extinct in later De- vonian time. - Among the more abundant are the Psilo- phytales. Representatives of this major group of plants are known in the Devonian of Canada (Dawson, 1859), the eastern and central United States (Arnold, 1935; Read, 1939), the Rocky Mountains (Dorf, 1983), and the Basin and Range province (Teichert and Schopf, 1958). These were small simple land plants, some of which were mosslike in general aspect. This general resemblance has, in fact, led to some specula- tion that the Psilophytales represent a link between the true mosses and the vascular plants (Bower, 1985). Contemporaneous with the earlier Psilophytales are the rare remains of highly specialized types such as Cladozylon scoparium Kriusel and Weyland. Such material appears to be in the fern lineage but is known only from petrifications. The Sphenopsida or articulated types related to the late Paleozoic Calamites Schlotheim and Sphenophy!- lum Koenig are known in the Early Devonian at several localities. Some of the best preserved of these are Hyenia Nathorst and Calamophyton Kriusel and Wey- land from the Devonian of Germany and Norway. One of the more advanced groups of plants in the Early Devonian was that of the coniferlike gymno- sperms. In the United States the best known of these is the genus Callizylon Zalessky, first thoroughly in- vestigated by Arnold (1930). The specimens known from the Early Devonian are only a few inches in diameter, but by Late Devonian time representatives of the genus Callizylon were sufficiently large that the main trunks were several feet in diameter (Arnold, 1930) ; the trees may well have been similar to modern conifers in height and general appearance. Beck (1960) reported organic connection between Archaeopteris cf. A. macilenta Lesquereux and pyri- tized fragments of wood showing the characteristic structure of Callizylon in a specimen from the Kats- berg Redbeds of Chadwick (1933) of Late Devonian age near Sidney, N.Y. This connection suggests that Callizylon may have had fernlike foliage and possibly occupied a position intermediate between the Paleozoic gymnosperms and fern or fernlike ancestors (Beck, 1960). Additional material is necessary in order to confirm this possibility. One of the more enigmatic groups of Early Devonian plants is represented by the genus Nematophyton Daw- son. Material referred to this genus is widespread in the Devonian of eastern Canada and the United States. Originally regarded as the remains of a conifer in a K3 rather primitive stage of development, such remains are now believed to be algal, although unlike any of the modern forms of this group. Possibly the group represented by Nematophyton was an unsuccessful evolutionary lineage among the aquatic algae. As might be expected, the Upper Devonian floras are not only more diverse but also have more similarities to the Mississippian floras that follow than do the Lower Devonian floras One of the most character- istic Upper Devonian plants is the fernlike Archaeop- teris. The remains of this fossil are in the form of highly dissected fronds, some of which are large. Fer- tile bodies borne on the fronds are ascribed by some investigators to sporangia, but they may be seeds. Both possibilities have been considered by Arnold (1935; 1947). Another fernlike plant that is well known at one locality in the United States is Fosper- matopteris textilis Goldring from the Catskill Forma- tion at Gilboa, N.Y. (Goldring, 1924). This material is known mainly from molds and casts of large plants probably similar in habit to the modern treeferns. Strata of Late Devonian age have also yielded the remains of small zygopterid ferns, the forerunners of types that are well known in upper Paleozoic strata (Dawson, 1881; Read, 1939). The Lepidodendrales are represented in Upper De- vonian rocks, possibly by Protolepidodendron Krejci and by several other types that are unquestioned. Most of these early forms were smaller than the Lepidoden- drons and Sigillarias of the Mississippian and Pennsyl- vanian Systems. The Sphenopsida, or jointed stemmed plants, are rep- resented in Late Devonian strata by several genera, the best known of which is probably Protocalamites Goebel. Except for anatomical details, such plants are similar to the Calamites of upper Paleozoic times. Other rep- resentatives of this group are Nathorst and Prosseriq Read. The earlier mentioned CGaZlizylon continued into strata of Late Devonian age where it is abundant. It is the best-known representative of several coniferlike gymnosperms that occur in Upper Devonian strata in North America. The Late Devonian seedferns are best known from the remains of structurally preserved stems and petioles from localities in the eastern and central parts of the United States; they include such genera as Calamopitys Unger, Diichnia Read, Stenomyelon Kidston, and Kal- ymma Unger (Scott and Jeffrey, 1914; Read, 1936, 1937). As previously mentioned, the Psilophytales were one of the more common groups in earlier Devonian time. Similar plants are known from strata of Late Devonian K4 age, but they appear to have become nearly, if not quite, extinct prior to Misissippian times. Another group of vascular plants that also became extinct near the close of Devonian time is best known from the genus Cladoxylon Unger (Bertrand, 1985). Appearing in Early Devonian time and probably representing an offshoot from the ferns, this highly specialized group is another example of plants that were unable to fit into the plant associations characteristic of the upper Paleo- zoic systems. The genus Nematophyton, previously mentioned, is abundant in rocks of Late Devonian age. It, too, appears to have become extinct near the end of Devonian time and like some of the land plants, it was probably unable to find a niche in the changing asso- ciations of aquatic plants. From the foregoing discussion it is apparent that all the major groups of plants that occur in the rocks of late Paleozoic ages existed during the Devonian. Some of these were obviously primitive, but most were surprisingly specialized in many of their characteris- ties. A comparison of these Devonian floras with those of the Mississippian and Pennsylvanian Systems reveals major differences, however; and both the extinction of older types and the development of new ones proceeded seemingly at a rapid rate. UPPER PALEOZOIC FLORAL ZONES Investigations of tipper Paleozoic floras have been largely studies of the plants that occur in coal meas- ures-nonmarine strata sufficiently rich in plant debris for coal beds to be common. Throughout the Missis- sippian, Pennsylvania, and Permian strata in parts of North America, however, several floras have been re- ported that do not appear to have grown or accumulated in coal swamps. Several facies problems therefore, exist in interpreting the sequences of floras with respect to time. At present, 15 more or less well-defined floral zones are recognized in the Mississipian, Pennsylvanian, and Permian Systems in parts of the United States. Three of these are in the Mississippian ; nine are in the Penn- sylvanian; and three are in the pre-Guadalupe Per- mian. These floral zones are named either for com- mon or for characteristic genera or species. Acquaint- ance only with the so-called index fossils, however, is not sufficient to identify the zones with assurance. Defi- nite zone identification requires careful study of assem- blages that have been carefully and thoroughly col- lected. Although the Mississippian and Pennsylvanian floral zones are reasonably consistent in their botanical make- up throughout, the floristic situation in the North Amer- ican Permian is more complex. The floras of lower- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY most, or Wolfcamp, Permian maintain much similarity wherever found, but the succeeding floras display strik- ing provincialities that invite speculation as to the causes in terms of evolving paleogeography, paleoeda- phology, and other ecologic factors. MISSISSIPPIAN FLORAL ZONES ZONE 1. ZONE OF ADIANTITES SPP. (Table 1; pl. 1, figs. 1, 2) The oldest Mississippian floral zone that can be con- sistently recognized in the United States is referred to here as the zone of Adiantites spp. (Read, 1955). It characterizes the basal strata of the Pocono and Price Formations in parts of the Appalachian trough, and fragmentary material tentatively assigned to the same zone has been reported at various localities elsewhere on the continent. - Collectively, this flora is rather small and includes species of Adiantites Goeppert, emend., Rhodea Presl, Rhacopteris Schimper, Alcicornopteris Kidston, Lagenospermum Nathorst, Calathiops Géep- pert, Girtya Read, and Lepidodendropsis Lutz (Read, 1955). Similar floras characterized by Adiantites and RAha- copteris are also known in the lower part of Lower Carboniferous sequences of nonmarine facies in South America (Read, 1938, 1941a, 1942), Australia (David and Sussmilch, 1936), and Europe (Jongmans, 1989). Jongmans (1954) pointed out the worldwide uniformity of basal Mississippian floras; he referred to them as the "Lepidodendropsis floras," and regarded them as the chief element of distinction between Upper De- vonian and Lower Mississippian strata. Jongman's (1954) reference to the Pocono floras as the "Lepidodendropsis floras" is, of course, correct. The genus Lepidodendropsis occurs in both the zone of Adiantites spp. and the overlying zone of Triphyllop-- teris spp. Lepidodendropsis, however, is not common in the zone of Adiantites spp. but is one of the more abundant types of plants in the zone of TripAyllopteris spp. Although distinct from the floras of the Upper Devonian in the United States, the zone of Adiantites spp. contains elements that show some affinities with the antecedent floras. Forms similar to, if not conge- neric with, the genus RZAhacopteris are known to occur in the Upper Devonian (Smith and White, 1905). The genus Adiantites also resembles in many general as- pects some of the late Devonian fern or fernlike types in pinnule architecture. The genus has not, to the writers' knowledge, been reported in the Upper De- vonian. - Although RAhodea is also unreported from the Upper Devonian, there are many examples of imper- fectly preserved, finely divided pinnules in the Devo- UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES K5 Taur 1.-Mississippian floral zones Floral Name zone ern anthracite field Appalachian region except for South- Southern anthracite field Midcontinent region 3 | Fryopsis spp. and Spheno- pteridium spp. Mauch Chunk Formation. _. Chester Series. Similar flora occurs in Stanley Shale. Mauch Chunk Formation. ._ _ No floras known...... No floras known._..........._. Meramec Series. No floras known. 2 | Triphyllopteris spp-______. Upper part of Pocono and | Upper part of Pocono Forma- Osage Series. No floras Price Formations. tion. known. 1 | Adiantites spp............ Price Formations. Lower part of Pocono and Kinderhook Series. Only spores and fossil wood known. Lower part of Pocono Forma- tion. nian strata that can be compared with the dominantly Mississippian genus RAhodeac. Lepidodendropsis is known only from incrustations and impressions. It can be reasonably interpreted as a forerunner of the later Lepidodendrons and as a dis- tinct structural advance over the Devonian lycopods. Alcicornopteris is a rather poorly understood genus of plants that is known only from the Mississippian and correlative lower Carboniferous strata of other continents. In its flabellate appearance it, too, is remi- niscent of some of the Devonian plants. The most striking contrasts with Upper Devonian floras are shown in the fertile organs of genera such as Lageno- spermum, Calathiops, and Girtya. All these genera are advanced and specialized in their morphology and sug- gest rapid evolution of the seedferns in the Lower Mis- sissippian after their appearance and early development in the Devonian. ZONE 2, ZONE OF TRIPHYLLOPTERIS SPP. (Table 1; pl. 1, fig. 3; pl. 2, figs. 1-8) The upper part of the Pocono and equivalent forma- tions in the Appalachian trough are characterized by a flora that shares certain elements with the older Adian- tites flora but which is dominated by several species of Tryphyllopteris Schimper. In addition, the Triphy!- lopteris flora is characterized by some early forms of Eryopsis Wolfe (=Cardiopteris Schimper ; see Wolfe, 1962) and by species of RAodea, Lagenospermum, and Lepidodendropsis (Read, 1955). The flora of the zone of Triphyllopteris spp. is very distinct from the zone of Adiantites spp. Several spe- cies of Triphyllopteris and of Lepidodendropsis char- acterize the zone. Lepidodendropsis is sparingly known in the Adiantites assemblage and appears in abundance for the first time in the zone of T'riphyllop- teris spp. As the name of the zone indicates, most col- lections from the interval are dominated by T'ripAy/llop- teris, and this genus is known only from the upper part of the Pocono and its correlatives in the United States. Present also are species of Rhodea that are in general similar to those in the zone of Adiantites spp. Lageno- spermum is also present in both zones. Plant material from the medial part of the Mississip- pian above the zone of T'riphyllopteris spp. has not been found in sufficient abundance to permit characterization of floral sequences. Because facies of the middle Mis- sissippian strata are dominantly marine, it is unlikely that material will be found in the United States that will increase knowledge of the middle Mississippian floras. In consequence, the strata cannot be expected to yield plant material other than scattered specimens that have been rafted or otherwise transported considerable distances. ZONE 3. ZONE OF FRYOPSIS SPP. AND SPHENOPTERIDIUM SPP. (Table 1; pl. 2, fig. 4; pl. 3, fig. 1) The uppermost Mississippian strata in the Appala- chian trough, represented by the Mauch Chunk Forma- tion and correlative strata, are characterized by a small flora with abundant F'ryopsis and specimens of Sphen- opteridium Schimper and Ameimites-like Adiantites (Read, 1955). Although Fryopsis makes its appear- ance in the zone of Tryphyllopteris spp., it is rare in the collections. The genus, in general, is probably most characteristic of Late Mississippian strata. The fragmentary and little-known floras from the Bluestone Formation of West Virginia and adjacent parts of Virginia and the Parkwood Formation of Ala- bama are also tentatively assigned to zone 3. These formations contain many examples of a small alethop- teroid species of Newropteris (Brongniart) Sternberg that is similar to Newropteris pocahontas. Observations by one of the authors (Read, unpublished data), both in the field and in the laboratory, suggest, however, that the form is new. Associated with Newropteris is fragmentary material of SpAenopteris (Brongniart) Sternberg. Neither Fryopsis nor SpAhenopteridium are known to occur in these formations at the present time. K6 In consequence, a fourth floral zone may be recognized eventually in the uppermost Mississippian. As pre- viously stated, however, so little is known about this flora that it is included in zone 8. Fryopsis, in association with one or more species of Lepidodendron Sternberg, is found at some localities in the Chester Series in parts of southern Illinois and western Kentucky. Strata containing these meager floras are almost certainly correlative with the strata that contain the floras here called the zone of Fryopsis spp. and ApAhenopteridium spp. in the Appalachian trough. White (1937) described a fragmentary flora from the Wedington sandstone in northern Arkansas. The types critical for dating include representatives of Adiantites, Fryopsis, Neuropteris, Rhodea, Sphenop- teris, Lepidodendron, and Archaeocalamites Stur. This flora is probably characteristic of a late subzone in zone 3. White (1936) described a flora from the Stanley Shale and Jackfork Sandstone in west-central and southeastern Oklahoma, and expressed the opinion that these rocks are Lower Pennsylvanian in age. White listed the genera Adiantites, Alloiopteris, Archaeocal- amites, Calamites Schlotheim, Lepidodendron, Nevrop- teris, Rhodea, Sigillaria Brongniart, Sphenophylium Koenig, and Wardia White as the more critical forms. Recent reexamination of White's collections (Mamay im SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Miser and Hendricks, 1960) indicates that the genera have closer affinities with the flora of the Wedington Sandstone Member of the Fayetteville Shale than White had suspected. Other geologic data (Miser and Hend- ricks, 1960) also support the conclusions that the upper or plant-bearing part of the Stanley Shale, as well as the overlying Jackfork Sandstone, is Mississippian in age. It is suggested that this flora is most likely the equivalent of the Wedington flora but may find its counterpart in the floras of the Bluestone and Park- wood Formations in the Appalachian trough, which are possibly slightly younger than those contained in the Wedington Sandstone Member of the Fayetteville Shale. PENNSYLVANIAN FLORAL ZONES ZONE 4. ZONE OF NEUROPTERIS POCAHONTAS AND MARIOPTERIS EREMOPTEROIDES (Table 2; pl. 4, figs. 1, 2) The oldest Pennsylvanian strata of continental facies known to contain abundant fossil plants in North Amer- ica comprise the Pocahontas Formation * and correla- tive beds in the Appalachian trough. The older Penn- sylvanian rocks in the anthracite fields of Pennsylvania and in the deeper parts of the trough to the south (table 2) are characterized by an abundance of N europteris pocahontas White and Mariopteris eremopteroides White (White, 19002 ; Read, 1947). TaBum 2.-Lower Pennsylvanian floral zones Floral zone Name ern anthracite field Appalachian region except for South- Southern anthracite field Midcontinent region 6 | Neuropteris Tennesseeana and Mariopteris pygmaea. Upper part New River For- mation and upper part Lee Formation. Schuylkill Member, Pottsville Formation. Bloyd Shale, Morrow Series. 5 | Mariopteris pottsvillea and Aneimites spp. Lower part New River Formation. Lykens Valley No. 4 coal bed and adjacent strata of Tum- bling Run Member, Potts- ville Formation. Locally, basal strata of Penn- sylvanian System in mid- continent region. 4 | Neuropteris pocahontas and Mariopteris _ eremopter- Pocahontas Formation. Lykens Valley No. 5 and No. 6 coal beds and ajdacent No floras known. oides. strata of Tumbling Run Member, Pottsville For- mation. Although the zone is best characterized by these two species, it also contains several species of Sphenopteris of the diminutive and round-lobed types. Prevalent in most collections are species of Fremopteris and vari- ous species of Lepidodendron and Calamites. Most localities that contain floras assigned to this zone are relatively poor in species. Thus, Lykens No. 5 coal in the southern anthracite field has yielded Mariopteris eremopteroides, Sphenopteris asplenioides Sternberg, 8. patentissima (Ettinghausen) Schimper, N exuropteris pocahontas, Calamites roemeri Geppert, Asterophyt- lites parvulus, Lepidophyllium quinnimontanum White, L. lanceolatum Lindley and Hutton, and Sigillaric kalmiana White (White, 1900a). Because this small flora was obtained from several localities in the west- ern part of the coal field, it is a composite flora. 8 Pocahontas Formation is here redefined and stratigraphically ex- panded upward to include strata up to the top of the Flattop Mountain Sandstone, which is here reduced in rank to member status in the Pocahontas. As redefined, the Pocahontas overlies the Mauch Chunk Formation or the Bluestone Formation and underlies the New River Formation (redefined). UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES One of the writers (Read) spent some time collect- ing and studying floras from the lower part of the Pocahontas Formation in southern West Virginia and adjacent parts of Virginia. The flora in this lower part is also small, and almost every collection contains specimens of Newropteris pocahontas and Mariopteris eremopteroides. Strata of nonmarine facies equivalent to the oldest Pennsylvanian of the Appalachian trough have not been definitely recognized elsewhere in the United States. Floras assigned to zone 4 thus appear to be restricted to the eastern part of the country. ZONE 5. ZONE OF MARIOPTERIS POTTSYILLEA AND OF COMMON OCCURRENCE OF ANEIMITES SPP. (Table 2; pl. 4, figs. 3, 4; pl. 5, fig. 1) Floras of the zone of Mariopteris pottsvillee and Anmeimites spp. occur in much of the Appalachian trough and are found locally at the very base of the system in the midcontinent region (White, 19002; Read, 1947). These floras are typically represented in the Lykens Valley No. 4 coal and adjacent strata and are also char- acteristic of the Quinnimont Shale Member in the lower part of the New River Formation * of southern West Virginia. They are presumed to occur farther south in the deeper parts of the Appalachian basin in Ten- nessee, Alabama, and Georgia. The species Mariop- teris pottsvillee White and one or more species of Aneimites (Dawson) Ettinghausen are present in al- most all collections. Associated with these species are early alethopteroid forms of Newropteris, such as Newr- opteris smithsii Lesquereux. Aphenophyllum tenue White is a fairly common in this zone. Several species of Sphenopteris, early species of Alethopteris Stern- berg, and representatives of Lepidodendron Sternberg and Calamites Schlotheim are present. Although most characteristic of zone 5, it must be recognized that Mariopteris pottsvillee makes a first appearance somewhat lower than Lykens Valley No. 4 coal and its correlatives and is commonly found in the strata tran- sitional between zone 4 and zone 5. Such florules are known not only in the Appalachian region but also in the Eastern Interior coal field. The Hindostan Whet- stone of Cox (1876) in Orange County, southern Indi- ana, appears to represent the transition between these two zones. There, Mariopteris pottsvillea is associated with Newropteris pocahontas. It is perhaps note- worthy that Mariopteris eremoptercides and Ancimites *The New River Formation is here redefined to include the Quinni- mont Shale Member (near the base), the Raleigh Sandstone Member, and the Sewell Member whose Nuttall Sandstone Bed is at the top. The formation overlies the Pocahontas Formation (redefined) and underlies the Kanawha Formation. K7 spp. are unknown at this locality, just as they are absent in transitional sequences in the Appalachians. As is true of the flora of zone 4, the interval may be represented elsewhere in North America, but the facies are unfavorable for the preservation of fossil plants. ZONE 6. ZONE OF NEUROPTERIS TENNESSEEANA AND MARIOPTERIS PYGMAEA, AND TO SOME EXTENT OF ovOPTERIS COMMUNIS, ALLOIOPTERIS INAEQUI- LATERALIS, AND ALETHOPTERIS DECURRENS (Table 2; pl. 5, figs. 2-5; pl. 6, figs. 1-3; pl. 7, fig. 1) The zone of Newropteris tennesseeana (Lesquereux mss.) White and Mariopteris pygmaea White is wide- spread in the Appalachian area and is recognized at several places in the Ancestral Rocky Mountain prov- ince (White, 19002 ; Read, 1947). In the Appalachian area, the flora of zone 6 occurs in the roof of Lykens Valley No. 2 and No. 3 coals in the Southern Anthracite region and in the Sewell Mem- ber of the New River Formation of West Virginia. Equivalents also occur in Tennessee and Alabama. In western Pennsylvania and adjacent parts of Ohio, the roof of the Sharon coal contains this flora. In the Eastern Interior coal field, the Caseyville For- mation of the McCormick Group " occupies zone 6. In northern Arkansas in the Ozark region, the Bloyd Shale of the Morrow Series is partly in this floral zone. Knowledge of the appearance of this floral zone in the Rocky Mountain area is derived from far fewer localities than in the eastern part of the United States. In central Colorado a section of the Weber ( ?) Forma- tion in the Leadville mining district yielded a florule referable to this zone (Read, 1934). Present are speci- mens of Newropteris of the alethopteroid type, as well as Sphenopteris cheathami Lesquereux and 7 'richopitys whitei Read, a somewhat problematical coniferous type. It has been suggested that these plants indicate less swampy, possibly mesophytic conditions. Similar floras, which have not yet been described, are found in the lower part of the Sandia Formation in parts of New Mexico. This zone is probably represented by marine strata in the Cordilleran province. ZONE 7, ZONE OF COMMON OCCURRENCE OF MEGALOPTERIS SPP. (Table 3; pl. 7, figs. 2, 3) The zone of Megalopteris spp. can be recognized in the Appalachian region at or near the base of the Kanawha Formation and its equivalents and in the midcontinent in the lower part of sequences that are 5 As used in Illinois, the McCormick Group consists of the Caseyville Formation overlain by the Abbott Formation. The name Tradewater Group has been abandoned in Illinois by the Illinois Geological Survey (Kosanke and others, 1960). It included strata now belonging to the Abbott Formation. K8 believed to be equivalent to the Atoka Series (Read, 1947). In New Brunswick it is represented in the Little River group (Stopes, 1914). In Illinois it is prominently represented in the Tarter Member of the Abbott Formation of the McCormick Group and occurs in equivalent units in eastern Iowa. In Texas the zone can be recognized in the base of the Lampasas Series of Cheney (1940). This zone has not been identified in the Ancestral Rocky Mountain and Cordilleran prov- inces but is probably represented by marine strata. Although species of Megalopteris Schenk are espe- cially characteristic of zone 7, they are by no means present in all collections from this zone. The zone is also characterized by Newriopteris lanceolata Newberry and by large cardiocarpons of the Cardiocarpon phil- lipsi Read type. Species that occur in this zone in Illinois are as follows: Pecopteris serrulata Hartt Alethopteris Sternberg n. sp. Neuropteris missouriensis Lesquereux? tenuifolia (Schlotheim) Brongniart? Eremopteris sp. Sphenopteris palmatiloba White communis Lesquereux Megalopteris dawson Hartt hartii Andrews southwellii Lesquereux abbreviata Lesquereux fasciculata Lesquereux marginata Lesquereux Psygmophyllum Schimper sp. Cordaites principalis (Germar) Cordaianthus Grand 'Eury sp. Cardiocarpon Brongniart spp. Trigonocarpon Brongniart spp. Sigillaria rugosa Brongniart Lepidodendron crenatum Sternberg volkmannianum Sternberg Annularia cuspidata Lesquereux The various species of Megalopteris seem to be most abundant where Pennsylvanian strata of early Atoka age occur immediately above pre-Pennsylvanian karst surfaces. This occurrence suggests the possibility that Megalopteris spp. found habitats most favorable for SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY growth in and adjacent to sinkholes and in calcareous soil. One of the best-known floras of this zone is from the "Fern Ledges" of Little River Group (Lancaster For- mation: see Bell, in Moore and others, 1944) near St. John, New Brunswick (Stopes, 1914). The known species that characterize the flora at this locality are given by Stopes (1914) as follows: Calamites suckowi Brongniart Annularia sphenophyloides (Zenker) Stopes stellata (Schlotheim) Wood latifolia (Dawson) Kidston Stigmaria ficoides Brongniart Adiantites obtusus (Dawson) Stopes Rhacopteris busseana Stur Sphenopteris marginata Dawson Oligocarpia splendens (Dawson) Stopes Sphenopteris valida (Dawson) Stopes Pecopteris plumosa (Artis) Stopes Diplothmema subfurcatum (Dawson) Stopes Alethopteris lonchitica (Schlotheim) Stopes Megalopteris dawsoni (Hartt) Stopes Neuropteris heterophylla Brongniart gigantea Sternberg Sporangites acuminata Dawson Pterispermostrobus bifurcatus Stopes Dicranophyllum glabrum (Dawson) Stopes Whittleseya dawsoniana D. White concinna Matthew Cordaites robbii Dawson principalis (Germar) Stopes Dadozylon ouangondianum Dawson Cordaianthus devonicus (Dawson) Stopes Cardiocarpon obliquum Dawson baileyi Dawson cornutum Dawson crampiui Hartt Sphenophyllum? cuneifolium (Sternberg) Zeiller Lepidodendron sp. (foliage) Lepidodendron sp. (in "Bergeria" condition) Sigillaria sp. Neuropteris selwyni Dawson eriana (Dawson) Stopes Poacordaites sp. Sternbergia sp. An especially interesting situation exists in the Morien Series, which is apparently slightly younger Tapur 3.-Middle Pennsylvanian floral zones Floral zone Name ern anthracite field Appalachian region except for South- Southern anthracite field Midcontinent region 9 | Neuropteris rarinervis Lower part Allegheny For- Upper part Sharp Mountain | Lower part of Des Moines mation. Member, Pottsville For- Series. mation. 8 | Neuropteris tenuifolia Major part Kanawha For- Not known. Major part of Atoka Series. mation. 7 | Megalopteris spp. Base of Kanawha Forma- | Not known. Base of Atoka Series. tion. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES than the Little River Group in the Sydney coal field of Nova Scotia. The lower part of this coal-bearing se- quence of rocks is characterized by a flora that is marked by the only known occurrences of the genus Lonchopteris Brongniart (Bell, 1938) in North Amer- ica. Although widely found in Europe, Lonchopteris has not been reported elsewhere on the North American continent. The Lonchopteris flora of the lower part of the Morien Series may eventually be found some- where in the middle of the Kanawha Formation and equivalent coal-bearing strata in the central part of the United States; in this event a floral zone intermediate between zones 7 and 8 of this report may be established. Because of its possible significance, the known species in this flora are listed from Bell (1988) as follows: Sphenopteris missouriensis ? (Lesquereux) White Hymenotheca dathei Potonié Hymenotheca? sp. Hymenophyllites bronni Gutbier Zeilleria avoldensis (Stur) Kidston Dipplotmema furcatum (Brongniart) Stur Neuropteris tenuifolia (Schlotheim) Sternberg aculeata Bell scheuchzeri forma angustifolia Linopteris milensteri (Eichwald) Potonié Alethopteris lonchitica {Schlotheim) Brongniart serli (Brongniart) Goeppert Lonchopteris eschweileriana Andrae Eupecopteris (Dactylotheca) dentata (Brongniart) Zeiller Asterotheca miltoni (Artis) Zeiller Calamites suckowi Brongniart waldenburgensis Kidston Annularia radiate Brongniart sphenophylloides (Zenker) Gutbier Asterophyllites equisetiformis ( Schlotheim) Brongniart Calamostachys germanica Weiss Sphenophyllum cuneifolium (Sternberg) Zeiller Cordaites principalis (Germar) Geinitz Samaropsis cornuta (Dawson) Grand 'Eury ZONE 8. ZONE OF NEUROPTERIS TENUIFOLIA (Table 3; pl. 7, fig. 4) The zone of Newropteris tenuifolia is widespread in the Appalachian area where it appears to include the Mercer Shale, the major part of the Kanawha Forma- tion, and other equivalents farther south (Read, 1947). It is present in the Morien Series in Nova Scotia (Bell, 1938). In the midcontinent region it includes most of the Atoka Series. In the Ancestral Rocky Moun- tains this zone is recognized in the upper part of the Sandia Formation in New Mexico and in the Kerber Formation in Colorado. Elsewhere the zone is un- known, but it is almost certainly represented by marine rocks. This zone is characterized by the first appearance of Neuwropteris Brongniart of the N. ovata Hoffman. type. Both Neuropteris rarinervis Bunbury and N. #eruose K9 Brongniart also make their appearances in this zone, although they are scarce and are most characteristic of higher zones. Pecopteris vestite Lesquereux may occur sparingly in this zone. A flora from the Eagle coal bed of the Kanawha For- mation is characteristic of the zone (White, 19002) and is listed from White (1900b) as follows: Eremopteris sp. sp. ef. E. lincolniana White Pseudopecopteris trifoliolata (Artis) Lesquereux Mariopteris muricata (Schlotheim) Zeiller nervosa (Brongniart) Zeiller acuta (Brongniart) Zeiller inflata (Newberry) White Aphenopteris spinosa GGeppert furcata Brongniart linkit Goeppert cf. 8. dubuissonis Brongniart tracyana Lesquereux schatzlarensis Stur cf. 8. microcarpa Lesquereux Pecopteris sp. cf. P. integra Andrk Alethopteris decurrrens Artis serlii (Brongniart) Neuropteris sp. cf. N. zeilleri Potoni¢ tenuifolia Calamites ramosus Artis Asterophyllites minutus Andrews rigidus Sternberg Annularia ramosa Weiss acicularis (Dawson) Renault Calamostachys ramosus Weiss Sphenophyllum furcatum Lesquereux cuneifolium (Sternberg) Zeiller Lepidodendron sp. cf. L. dichotomum Sternberg obovatum Sternberg Bothrodendron sp. Lepidostrobus variabilis Lindley and Hutton Lepidophyllum campbellianum Lesquereux Rhabdocarpos sulcatus Goeppert and Bein ZONE 9. ZONE OF NEUROPTERIS RARINERVIS (Table 3; pl. 8, figs. 1-3) Zone 9 marks the appearance of the cyatheoid pecop- terids, although they occur sporadically and rarely in abundance. Newropteris ovate occurs abundantly in this zone, but it is not especially characteristic, inas- much as it also occurs in higher strata. A flora characterized by N euwropteris rarinervis in association with Pecopteris vestita, M. ariopteris occiden- talis White, and Linopteris rubella (Lesquereux) White occurs in the lower part of the Allegheny Formation in the Appalachian region and in the lower part of the Des Moines Series in the midcontinent region (Read, 1947). A typical assemblage from the Hartshorne Sandstone of Oklahoma and Arkansas is given by Read (in Hen- dricks and Read, 1934) as follows: K10 Sphenopteris miata cf. 8. stipulata Gupta cristata (Brongniart) Presl Pseudopecopteris obtusiloba (Sternberg) Lesquereux neuropteroides Bouley (not Kutorga) macilenta (Lindley and Hutton) Lesquereux Mariopteris occidentalis muricata nervosa Neuroptersis scheuchzeri Hoffmann rarinervis Bunbury harrist White ovata missouriensis Lesquereux grifithii Lesquereux capitata Lesquereux Limopteris gilkersonensis White Pecopteris vestita cf. P. candolliana Brongniart oreopteridia (Schlotheim) Brongniart clintoni cf. P. arborescens Brongniart dentata Brongniart Callipteridium sullivantii (Lesquereux) Weiss Alethopteris serlii (Brongniart) Goeppert Taeniopteris? missouriensis White Odontopteris wortheni Lesquereux Annularia stellata sphenophylloides (Zenker) Gutbier Calamites suckowi Calamodendron approzimatum Cotta Asterophyllites equisetiformis (Schlotheim) Brongniart Sphenophyllum emarginatum Brongniart cuneifolium suspectum White lescurianum White Lepidophyllium truncatum Lesquereux Lepidocystis vesicularis Lesquereux Rhabdocarpus multistriatus (Sternberg) Lesquereux In the Ancestral Rocky Mountain region, the zone of Newropteris rarinervis occurs in the lower part of the Madera Formation in New Mexico and in the lower part of the Hermosa Formation in Colorado but is un- known elsewhere in that area. This occurrence is prob- ably due to the dominantly marine character of rocks of Middle Pennsylvanian age throughout this province. In Canada the zone is identified in the Morien Series in Nova Scotia (Bell, 1988). SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY ZONE 10. ZONE OF NEUROPTERIS FLEXUOSA AND APPEARANCE OF ABUNDANT PECOPTERIS SPP. (Table 4; pl. 9, figs. 1-3 ; pl. 10, fig. 1) The zone of Newropteris rarinervis (zone 9) is suc- ceeded by an interval characterized by abundant Neu- ropteris flexuosa and by abundant representatives of the cyatheoid species of Pecopteris (Brongniart) Sternberg. Although Newropteris flexuosa rarely occurs in strata younger than zone 10, the cyatheoid pecopterids occur abundantly in much younger strata and, in fact, are present in the youngest Permian strata that carry fossil plants in the United States. (See zones 14 and 15.) Zone 10, therefore, is best referred to as the zone of appearance of abundant species of Pecopteris and can be determined on the basis of this genus only by noting the floral succession in older strata in any sequence of rocks under investigation. Zone 10 occurs in the upper part of the Allegheny Formation and the lower part of the overlying Cone- maugh Formation in the Appalachians. It is also characteristic of the upper part of the Des Moines Series and its equivalents in the midcontinent region. In the Rocky Mountains a few collections indicate its presence in the medial parts of the Madera and Her- mosa Formations of New Mexico and Colorado. In the Rocky Mountain area conifers of types usually consid- ered to be characteristic of the Permian occur locally in strata that on other floristic bases are assigned to this zone. Thus, in the McCoy Formation of Roth (1930) in north-central Colorado there occurs a florule charac- terized by Odontopteris mecoyensis Arnold, Samarop- sis hesperius Arnold, Walchia stricta Florin, Wailchia sp., and Walchiostrobus sp. (Arnold, 1941 ; Read, 1947). Similar floras have been noted by one of the authors (Read) at several stations in northern and central New Mexico. TABLE 4.-Upper Pennsylvanian floral zones Floral Name zone ern anthracite field Appalachian region except for South- Southern anthracite field Midcontinent region 12 | Danaeites spp. Upper part Monongahela Not known. Missouri and Virgil Series. Formation. 11 | Lescuropteris spp. Lower part Monongahela Not known. In midcontinent region, Formation and _ upper zones 11 and 12 are not part Conemaugh Forma- separable and are together tion. designated the - zone of Odontopteris spp. 10 | Newropteris flexuosa and Lower part Conemaugh Post-Pottsville rocks undiffer- | Upper part of Des Moines Pecopteris spp. Formation - and _ upper entiated. Series. part Allegheny Forma- tion. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES The presence of coniferous material in the Rocky Mountains in zone 10 suggests that the plant associa- tions represented in collections are from sediments of more nearly piedmont than coal-swamp facies. Inde- pendent geologic data provide supporting evidence for this suggestion, inasmuch as this was a time of wide- spread orogeny during which the Ancestral Rocky Mountains were in the process of being formed. In consequence, it is believed that swamp habitats were restricted and piedmont and upland habitats were expanded (Read, 1947; Read and Wood, 1947). A typical flora from zone 10 is the flora of the Buck Mountain or Twin coal bed in the southern anthracite region of Pennsylvania which is listed from White (1900a) as follows: Mariopteris sphenoptercides (Lesquereux) Zeiller muricata var. nervosa (Brongniart) Kidston of. sillimanni (Brongniart) White Pseudopecopteris squamosa (Lesquereux) White obtusiloba (Brongniart) Lesquereux Aphenopteris pseudomurrayana Lesquereux? nummularia Gutbier Aphenopteris n. sp.? mizta Schimper suspecta White Oliogocarpia cf. Brongniarti Stur Pecopteris dentata Brongniart arguta Sternberg unita Brongniart villosa Brongniart? oreopteridia pennaeformis Brongniart Alethopteris aquilina (Schlotheim) Goeppert seri Callipteridium grandini (Brongniart) Lesquereux Neuropteris flewuosa ovata plicata Sternberg capitata vermicularis Lesquereux fimbriata Lesquereux scheuchzeri Calamites cistii Brongniart Cyclocladia sp. Asterophyllites equisetiformis Annularia stellata Aphenophyllum emarginatum cuneifolium fasciculatum (Lesquereux) White Lepidodendron brittsii Lesquereux? modulatum Lesquereux? vestitum Lesquereux? sp. indet. Lepidostrobus ef. L. variabilis Lindley and Hutton cf. L. geinitzii Schimper Lepidophyllum cultriforme Lesquereux oblongifolium Lesquereux cf. L. mansfieldi Lesquereux affine Lesquereux ? Lepidocystis vesicularis (Rigillariostrobus ?) quadrangularis Lesquereux K11 Rigillaria cf. 8. brardii Brongniart tessellata (Steinhauer) Brongniart Trigonocarpum olivaeforme Lindley and Hutton ? Rhabdocarpos sp. multistriatus mamillatus Lesquereux Cordaicarpon cinctum Lesquereux Carpolithes transsectus Lesquereux cf. C. ellipticus Sternberg ZONE 11, ZONE OF LESCUROPTERIS SPP. (Table 4; pl. 11, figs. 1, 2) The zone of Lescuropteris spp. has been clearly recog- nized only in the Appalachian region, where it is char- acteristic of the upper part of the Conemaugh and the lower part of the Monongahela Formations. Unfortu- nately, the collections of fossil plants from the Conemaugh Formation in the possession of the U.S. Geological Survey and the U.S. National Museum are relatively poor compared with those from both under- lying and overlying stratigraphic units, because the rocks containing the plants are of types that are poorly suited for plant preservation. The Lescuropteris flora is best known from shales a short distance below the Pittsburgh coal bed and from overlying strata in the lower part of the Monongahela Formation. A typical flora from this interval is listed below ; knowledge of the flora in this zone is limited virtually to these species. The flora is based on collections made by White (1913) in the vicinity of Wheeling, W. VA:, from the roof of the Pittsburgh coal bed and is as fol- lows: Mariopteris? spinulosa (Lesquereux) White, AZe- thopteris aquilina, Pecopteris unita, P. villosa 1, Pecop- teris sp. cf. P. jenneyi White, Neuropteris grangeri Brongniart, N. scheuchzeri, Lescuropteris moore? (Les- quereux) Schimper, and Aphilebic fAliciformis (Gut- bier) Schimper. In the midcontinent region this zone has been re- ported only from the Elmdale Shale of former usage near Onaga, Kans. As identified by White (1903) the flora is as follows: Pecopteris newberriana Fontaine and White, P. Ahemitelioides Brongniart, P. oreopteri- diat, Pecopteris cf. P. polymorpha Brongniart, Odon- topteris brardii Brongniart, 0. moori (Lesquereux) White (=Lescuropteris moorii Lesquereux), Newrop- teris plicata Sternberg, N. quriculata Brongniart ?, N. scheuchzeri, Daubrecia sp., AsterophyUites equisetifor- mis, Annularia stellata, Radicites capillaceous (Lindley and Hutton) Potonié. White preferred to consider Lescuropteris moori a species of Odontopteris. Clearly the genus Lescurop- teris is an odontopterid type. The generic distinction, however, seems to be valid. The species of Lescurop- tersis possibly remain unreported in many collections, and their stratigraphic significance is therefore not K12 recognized because of their identification by some in- vestigators as Odontopteris spp. Strata in about the same position in the Rocky Moun- tains are characterized by primitive conifers, such as Walchia piniformis and typical odontopterids. Such an assemblage is characteristic of the upper member of the Madera Formation in parts of central New Mexico. ZONE 12. ZONE OF DANAEITES SPP. (Table 4; pl. 11, fig. 3; pl. 12, fig. 1) Danaeites is especially characteristic of the upper- most Pennsylvanian strata in the Appalachian trough, and, although not present everywhere, it is sufficiently common to be regarded as most useful in the identifica- tion of these strata. The presence of this zone was first pointed out in 1944 (Read in Moore and others, 1944) on the basis of examination of available collections in the possession of the U.S. Geological Survey and the U.S. National Mu- seum. In 1954 examination of Upper Pennsylvanian and Lower Permian strata in the Georges Creek coal basin, Allegany County, Md., resulted in additional col- lections which further confirm the presence of the zone of Danaeites Gbéeppert and its position in the sequence of rocks (Berryhill and de Witt, 1955). The flora found in the roof shales of the Koontz coal bed, which is probably the equivalent of the Uniontown coal bed, is characterized by abundant Danaeites emersoni Les- quereux. Several species of cyatheoid pecopterids are also present, as are some of the later variations of Newropteris scheuchzeri. The Uniontown coal and the apparently correlative Koontz coal are about 100 feet below the Cassville Shale Member of the Washington Formation. The member is regarded by some as the base of the Permian System ; others question that the member is the base of the Permian System. ZONES 11 AND 12 (LOCALLY COMBINED). ODOoNTOPTERIS SPP. ZONE OF (PL. 12, figs. 2-5) As previously indicated, the zones of Lescuropteris spp. and Danaeites spp. are readily recognizable in the Appalachian region but are clearly formed only locally in the midcontinent and Ancestral Rocky Mountain regions. - Consequently, it seems desirable to group the two zones together and classify them as the zone of Odontopteris spp. in the latter areas (Read, 1947). The general equivalence of the Lescuropteris and Danaeites zones with the Odontopteris zone is attested by the abundance of Odontopteris in the two zones in the Appalachian region. This floral zone is usually characterized by the ab- sence of Lepidodendron, by numerous species of cyathe- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY oid pecopterids, by the larger varieties of Newropteris ovata, and by the presence, at least in some areas, of Neuropteris lindahli. N. lindahli is relatively abun- dant in the southwest and is of considerable use as an index fossil in some areas. It seems to be restricted to strata that on the bases of other evidence are prob- ably of Virgil age. In the Ancestral Rocky Mountain area, associations of plants that are characterized by mixtures of ferns and fernlike types with conifers are common. Similar associations are also known to occur at a few localities in the Virgil of Kansas. PERMIAN FLORAL ZONES ZONE 13. ZONE OF CALLIPTERIS SPP. (Table 5; pl. 13, figs. 1-5) Permian time represents a significant chapter in the geological history of vascular plants, inasmuch as it was a period of marked floristic transition. The long- stabilized luxuriant cosmopolitan coal-forming plant assemblages of the Pennsylvanian were gradually sub- jected to more variable and, in some areas, more rigor- ous ecological conditions. More demanding physio- logical requirements were imposed on plant populations and new forms appeared. The subtlety of the changes is suggested by the fact that many remnants of the cos- mopolitan Pennsylvanian floras persisted as conspicu- ous elements into the Permian. Indeed, the differences between the uppermost Pennsylvanian floras and those of Early Permian age are commonly so slight that only the presence of theindex genus Callipteris Brongniart may serve to distinguish a lowermost Permian flora. The Callipteris flora is characteristic of the lowest Permian strata over a large area. The upper part of the Dunkard Group in parts of Pennsylvania and West Virginia contains such a flora (Fontaine and White, 1880). In parts of Kansas, Oklahoma, and west Texas the Wolfcamp Series contains a well developed Cal- lipteris flora (Read, 1941b). Finally, the flora is well developed at several localities in New Mexico in the lower part of the Abo Formation, in strata that are adjudged for other reasons to be Lower Permian (Read, 1941b; Mamay and Read, 1954). Although Callipteris is the. one reliable index fossil in these assemblages, it is not necessarily dominant either with respect to number of species or to individ- uals in a given collection. The North American Cal- lipteris floras are in general dominated by several species of Pecopteris and are further characterized by strong representations of Sphenopteris, Sphenophyt- lum Koenig, Odontopteris Brongniatt, Newropteris, Annularia Sternberg, and other typically Pennsyl- vanian genera. Taemiopteris Brongniart appears in UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES K13 TABLE 5.-Permian floral zones Floral Name Kansas zone Oklahoma North Texas Arizona and New Mexico 15 | Younger Gigantop- Lueders Limestone teris flora. and Clear Fork Group. 14 | Zone of older Gigan- Sumner Group (Glen- Garber Sandstone Belle Plains, Clyde Upper part Abo topteris flora; G@len- opteris flora). (older @igantopteris Formations (older PPormation; Hermit opteris flora; Supaia flora). Gigantopteris flora). Shale (Supata flora. flora). 13 | Callipteris spp. Wolfcamp equivalents; Wolfcamp equivalents; Wolf camp equivalents; | Lower part of Abo highest occurrences highest occurrences highest occurrences Formation. in Chase Group. in Stratford in Moran Formation. Formation. moderate numbers and the Walchic complex is domi- nant locally. On the other hand, the cordaiteans and arborescent lycopods, which were among the principal "coal-makers" during the Pennsylvanian, are only sparingly represented in the zone of Callipteris. ZONE 14. ZONE OF THE OLDER GIGANTOPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEXICO, HQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA (Table 5; pls. 14-18) As Permian time advanced, floral assemblages gradu- ally assumed more individuality and lost much of the cosmopolitan aspect of their Pennsylvanian forerun- ners. - The lowermost Permian Callipteris floras, which apparently occupied a circumpolar distribution in the northern hemisphere, became modified by the appear- ance of strikingly new, geographically restricted dominant forms. Relatively limited areas of the south- western and midcontinental United States became capable of producing a variety of distinct assemblages. There, strata that probably represent approximately synchronous deposits of early Leonard age contain the remains of at least three distinct floras. Although they approach each other closely, horizon- tal ranges of these floras are not known to overlap. Thus, a flora referable to as the older Gigantopteris flora ® succeeds the Gallipteris flora in the Garber Sandstone of early Leonard age in parts of north and west Texas and in Oklahoma (White, 1912; Mamay and Read, 1954) and New Mexico. The Wellington Formation of the Sumner Group in southern and cen- tral Kansas, which is the equivalent of the Gigantop- teris-bearing strata in Oklahoma, contains a distinct ® Detailed descriptions of the American gigantopterids and associ- ated plant assemblages are being studied by Mamay. In this connec- tion, a revision of the Gigantopteridaceae by Asama (1959) suggests the necessity for revision of nomenclatural treatment of the American gigantopterids ; however, for the purpose of the present paper, the old generic designation will be adhered to, pending formal revision by Mamay. flora, which is referred to as the Glenopteris flora (Sellards, 1908). Similarly, in the Ancestral Rocky Mountain province the upper parts of the Abo Forma- tion and the Hermit Shale contain the Supaia flora (White, 1929) and are also known to be early Leonard in age (Read in King, 1942). The floras of zone 14 collectively are the most di- versified Permian assemblages known in the world. They share four common genera (Taemiopteris, Cal- lipteris, Walchia, and Sphenophyllum), but, on the other hand, each flora is characterized by at least one distinctive genus; the distinguishing genera-Supaic White, @Glemopteris Sellards, and Gigantopteris Schenk-are nowhere known to have coexisted. The fact that the Gigantopteris, Supaia, and G@lenopteris floras share several common elements is not surprising, in view of their probable derivation from a common ancestral complex-the Wolfcamp Callipteris flora. The dissimilar morphologic aspects of their dominant genera and their failure to intermingle, however, are of considerable interest, inasmuch as they imply evolution under dissimilar environmental conditions and provide a basis for speculation on the ecological factors respon- sible for such floristic differentiation and segregation. THE SUPAIA FLORA (PI. 14, figs. 1-3 ; pl. 15, figs. 1-2) The Supaia flora, known only from a few localities on the western flank of the Ancestral Rocky Mountains, is the least diversified flora of zone 14. Although about 20 plant genera have been attributed to the flora, several of these are doubtful because of generally poor preservation, and a more realistic appraisal of the flora would likely yield no more than half as many generic designations. The flora is a conifer-pteridophyll as- sociation ; it lacks lycopods and the true ferns that occur abundantly in other Permian floras; the arthrophytes are represented by only one species, Sphenophyllum gilmorei White. The conifers, predominantly of the K14 W alchia type, contribute nothing unusual to the aspect of a flora of this age. - The pteridophylls include Z'aeni- opteris, Callipteris, and several callipteroid species, of which the majority are referable to Supaic, the domi- nant genus. Supaia is distinguished by the dichotomous forking of its frond, its simple pinnation and large lin- ear pinnae, and the unequal development of pinnae, of which the longest are on the outside of the frond. Physical features of the enclosing sediments indi- cate that the Supaia flora lived under drier conditions than those of the coal floras, which would, in part, ex- plain the generally impoverished aspect of the assem- blage. THE GLENOPTERIS FLORA (PI. 16, figs. 1-4) The Glenopteris flora is apparently restricted strati- graphically to rocks of the Sumner Group and has been found only at a few localities in central Kansas. This flora shows more diversification that the Supaia flora, both in total numbers of genera and in supergeneric groups represented. Associated with @lenopteris are several pecopterid ferns, cordaiteans, sparse lycopods, calamarians, neuropterids, odentopterids, and a few other elements not found in association with Supaic. Glenopteris is represented by five species (Sellards, 1908, p. 467). This genus, presumably a pteridosperm, is the most abundant element in the flora. It is charac- terized by simple pinnation, large pinnae with decur- rent or auriculate bases, an extremely stout and striated rachis, and an originally thick fleshy texture. The tex- tural feature is implied by the fact that the fronds are invariably preserved as a thick carbonaceous residue, which often obscures the laminar venation. THE GIGANTOPTERIS FLORA (PL. 17, figs. 1-4; pl. 18, figs. 1-4) The Gigantopteris flora 'is the most diversified as- semblage characteristic of zone 14. It is known from several occurrences in the Garber Sandstone of north- central Oklahoma and from several others in the Belle Plains and Clyde Formations of north-central Texas; there is also one known occurrence in the upper part of the Abo Formation near Orogrande, N. Mex., but the material consists of only one small fragment of Gigan- topteris and a few small unidentifiable fragments of other plant types. The Oklahoma material is generally sparse at any given locality and is commonly very poorly preserved; consequently, the Oklahoma flora is not well understood. In Baylor County, Tex., how- ever, the red beds of the Belle Plains Formation locally contain lenses and channel deposits of fine-grained gray shales and mudstones, which at various localities have produced an extremely rich and well-preserved flora. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY The same flora is found in the Clyde Formation but is generally not as abundantly or as excellently preserved as in the Belle Plains occurrences. The Gigantopteris flora of zone 14, particularly the assemblages found in the Belle Plains sediments, is re- markable in its diversity and luxuriance. The abun- dance and variety of plant remains at certain localities suggest that locally this flora rivaled the Pennsylvanian coal-swamp floras in specific differentiation and popula- tion density but grew under conditions not amenable to coal formation. Several species of Pecopteris form a strong link with the pre-Permian stock ancestral to this flora; locally, the pecopterids assume such dominance as to constitute more than half the total of plant mate- rial. Callipteris is a prominent constituent of the flora ; here it reaches the greatest degree of specific differen- tiation known in the American Permian, including rep- resentatiives of the fabellifera-strigosa ty pes, as well as the more common conferta-lyratifolia ty pes. Odontop- teris is moderately abundant and is represented in part by extremely large-pinnuled species that suggest a rela- tionship between this flora and the Permian Angara flora of Siberia, which has been described in a long series of papers by Zalessky (1918). The pteridophyl- lous element in the flora is completed by a great abun- dance of Gigantopteris americana White, relatively abundant Taemiopteris and Aphlebia Presl, and rare specimens of V europteris. In zone 14 the primitive conifers are generally con- spicuous and locally dominant, particularly at a lower- most Clyde locality near Fulda in Baylor County, Tex. There they are abundantly represented by species of Walchia, Florin, - Gomphostrobus Marion, and several types of winged seeds of Samarop- sis GGoeppert. Cordiatean conifers are almost totally absent from this zone. Only a few lepidodendralean and sigillarian frag- ments have been found in zone 14, and their scarcity foreshadows the extinction of the arborescent lycopods. The arthrophytes are fairly conspicuous and include several species of Annularia and ASphenophyllum, as well as Lobatanmnularia Kawasaki, which provides an interesting link with the Permian floras of E'smst Asia. The noeggerathialean genus Discinites K. Feistmantel is also present in this flora; this discovery marks the first known Permian occurrence of Discinites (Mamay, 1954). Other interesting elements in this flora are sexieral types of unidentified and undescribed fructifications, some of which resemble the megasporophylIs of Recent cyeads. Unfortunately, the specimens are among those collected by White in 1910, and efforts to rediscover White's original locality have been unsuccessful; prob- UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES ably the outcrop was very small and has been com- pletely destroyed by erosion. The characteristic genus of this flora is, of course, Gigantopteris, which appears abundantly in lower Leonard rocks and has no obvious precursors in the underlying Callipteris flora. It is the most easily recog- nized of Permian plant genera and is distinguished by the following features : The frond is very large, as much as 20 cm in width and an unknown maximum length;; the lamina is undissected but usually dichotomously forked and has entire or slightly undulate margins; the ultimate veins assume the general pattern of a "herring- bone weave," variably forking and anastomosing, and join a "sutural vein" to create a series of irregularly shaped meshes, to some extent reminiscent of the reticu- late venation of dicotyledonous angiosperms. The venation is so characteristic that, unlike many of its contemporary genera, only a small fragment of a Gigan- topteris frond is necessary for positive identification, even on the specific level. Although Gigantopteris is not always dominant at zone-14 localities in the Gigantopteris province, it is almost invariably present, at least as a minor element where plant remains are found in significant amounts. Peculiarly enough, although this is the richest flora known in the American Permian, its characteristic genus, @igantopteris, is known only from one species, Gigantopteris americana. This occurrence of Gigan- topteris contrasts with the occurrence of the character- istic genera of the two contemporary floras in zone 14. These contemporary floras are poorer in total species than the Gigantopteris flora, but instead of just one species each, the distinguishing genera Supaic and Glenopteris are each represented 'by several species. One other important element first appears in the Gigantopteris flora of zone 14. 'This is a genus of pin- nate fronds, whose large entire-margined parallel- veined pinnae are strongly reminiscent of cycadean fo- liage but which were identified by Darrah (1938) as Tingic Halle; the genus is otherwise known only from eastern Asia. Because a large suite of specimens has now been collected and neither anisophylly nor the digi- tate pinna apices characteristic of Tingic are evident, there is reason to believe that Darrah's identification of his limited material as Tingiz was erroneous. This plant seems thus far to be restricted to the Belle Plains Formation and occurs in abundance at only one locality. ZONE 15. ZONE OF THE YOUNGER GIGANTOPTERIS FLORA (Table 5; pl. 19, figs. 1-7) In a restricted area of north Texas a few scattered localities in the Lueders Limestone and the Clear Fork K15 Group have yielded sparse plant collections. These assemblages are generally less well preserved and bio- logically less diversified than the older Gigantopteris flora of zone 14. Sufficient differences, however, are apparent in their composition to warrant recognition of another floral zone, zone 15. Aside from a relatively impoverished aspect-which, of course, may actually be a function of the generally poorer conditions for preservation of plants that pre- vail higher in the Permian section-the flora of zone 15 differs from the older Gigantopteris flora by the ab- sence of Gigantopteris americana and by its apparent replacement by at least two new, yet undescribed, spe- cies of Gigantopteris, whose evolutionary relationship to G@igantopteris americana is at present difficult to assess. However, features of their ultimate venation clearly indicate that they are distinct from the older species and, at the same time, can 'be used to make easy identifications of the species from small fragments. A small florule from about the middle of the Lueders Limestone is one of the best known assemblages in zone 15 and is characterized by @igantopteris new species A. This species is distinct from @. americana in hav- ing four orders of venation, whereas G. americana has only three. Associated with this species is a sparse con- ifer-Callipteris assemblage. Gigantopteris new species A apparently persists as far as the bottom of the Vale Formation of the Clear Fork Group. Gigantopteris new species B first appears at about the same horizon as that of the earliest known appear- ance of @. new species A. This species, like G. ameri- cana, has only three orders of venation but is distin- guished by the simplicity of its venation; whereas the tertiary veins of G. americana frequently dichotomize and anastomose, those of @igantopteris new species B rarely dichotomize and never anastomose. Gigantopteris new species B has been found at several localities, and its associated flora is best known from two outcrops in the lower part of the Vale in Taylor County, Tex., where it is associated with a fairly di- verse assemblage of callipterids, sphenopsids, pecop- terids, odontopterids, neuropterids, abundant Taemiop- teris, and several conifers. Several of the callipterids and odontopterids are extremely large pinnuled types that occur elsewhere only in the Permian Angara flora of Siberia; however, in certain features the two species of Gigantopteris (Gigantopteris new species A occurs sparingly in the Taylor County flora) are remarkably similar to gigantopterid species that occur together in the flora of the Shihhotse Series in Shansi province, China (Halle, 1927). A small collection of plants, including fragments of Gigantopteris new species B, was made by Mamay from K16 the uppermost part of the Vale Formation in Knox County, Tex. This is the youngest Paleozoic mega- fossil flora presently known in North America." The plants are poorly preserved and, with the exception of Gigantopteris new species B, reliable specific or even generic identification are not possible; however, the flora was clearly dominated by coniferous elements. This assemblage also contains some unidentifiable leaf fragments, which show, in general, odontopterid vena- tion but which are of a laminar size not approached by any other Paleozoic nongigantopterid pteridophylls ex- cept some of the Siberian Angara plants. This flora contains fragmentary fronds related to, if not identifi- able with, Pterophyllum Brongniart. This is the only known occurrence in the American Permian of this type of foliage, which lends the flora a Mesozoic aspect. UPPER PALEOZOIC FLORAL PROVINCES Mississippian and Pennsylvanian floral provinces contrast sharply with Permian floral provinces in the United States. The following notes, although obvi- ously incomplete, substantially summarize our knowl- edge regarding the geographic distribution of the suc- cessive Paleozoic floras. MISSISSIPPIAN FLORAL PROVINCES As previously indicated, three floral zones have been recognized in the Mississippian strata in parts of the United States and Canada. These are the zones of Adiantites spp., Triphyllopteris spp., and Fryopsis spp. The paleogeography of North America during Missis- sippian time was such that the areas of continental sedi- mentation were largely restricted to the eastern part of the United States and to eastern Canada. In conse- quence, our knowledge of the distribution of floras is similarly restricted. Floras that can be assigned to the zone of Adiantites spp. with confidence are found primarily in basal Mis- sissippian strata only in the eastern part of the United States and the martime provinces of Canada (Dawson, 1858, 1873). However, this flora, when carefully ana- lyzed, seems to be similar to lower Carboniferous floras elsewhere in the world that are dominated by species of Adiantites. In consequence, the Adiantites flora is strongly suspected to be cosmopolitan, occurring not only over much if not all of North America but also in parts of Europe. The flora perhaps occurs even in the Southern Hemisphere, as suggested by floras described Scattered fragments of unidentifiable wood are known to occur higher in the American Permian, and Wilson (1959) has reported a small assemblage of gymnospermlike pollen from the Flowerpot Shale (El Reno Group) of Oklahoma. Affinities of these fossils are not suf- ficiently well understood, nowever, to warrant recognition of another floral zone. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY from South America (Read, 1938) and Australia (David and Sussmilch, 1936). The succeeding TripAhyllopteris flora is also known chiefly from the Appalachian trough and the adjacent Maritime Provinces. Again one may assume on the basis of rather meager evidence that the T'riphylopteris flora was widespread in suitable environmental realms during Osage time. The Fryopsis-dominated floras occur in beds of latest Mississippian age both in the Appalachian belt and in the midcontinent of the United States. These floras also were probably cosmopolitan over the continent. PENNSYLVANIAN FLORAL PROVINCES The study of Pennsylvanian plants has been largely a study of floras of the coal measures; that is, associa- tions of plants in strata that are largely continental in origin and that probably accumulated in extensive flood plains and in deltas under mild and humid cli- matic conditions. - As previously indicated, nine Penn- sylvanian floral zones are recognized in the eastern and midcontinent regions of North America. These zones provide a practical basis for general correlation of the fossil-containing rocks in these areas. When one compares the floras of the Pennsylvanian coal measures with the floras from the Rocky Mountain and Pacific Coast regions, certain differences may be noted (Read, 1947). The plant associations in the older parts of the Pennsylvanian requences in the west- ern areas are similar to those of the coal measures, but the relative rarity of Lycopodiales suggests drier habi- tats than those indicated by the approximately contem- poraneous floras in the eastern coal basins. The younger Pennsylvanian floras in the western United States, however, are striking departures from the plant associations of the same general ages in the eastern part of the country, as inferred from index forms and in- dependent stratigraphic data. The plants in the west- ern area occur in suites of sediments that were deposited during a period of widespread orogeny in parts of the Rocky Mountain region. Many geological data indi- cate that the lowlands were restricted and the upland habitats or areas were expanded during this period of mountain building. The floral modifications include the presence of abundant conifers and appear to be in the direction of mesophytic associations. The term "Cordilleran flora" has been used for the modifications that occur in the Rocky Mountains (Read, 1947). PERMIAN FLORAL PROVINCES Although Permian plant fossils in the United States are much more sporadic in occurrence than those of the Pennsylvanian, it is evident that the geographic dis- tribution and botanical makeup of the post- Wolfcamp UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES assemblages constitute a more complex problem than those of the Mississippian and Pennsylvanian floral provinces. This floral differentiation and segregation did not develop until early Leonard time, for American floras of the Wolfcamp and correlative units are charac- teristically similar to the CaZlipteris floras of the Euro- pean Lower Permian. The American COallipteris flora is known to occur in the Appalachian basin and at var- ious points in the midcontinent and southwestern re- gions; its botanical similarity at all places indicates a broad, virtually uninterrupted geographic distribu- tion. Overlying the Wolfcamp, the Leonard Series con- tains a floral complex that is of much interest from the standpoints of characteristic genera and provincial geo- graphic distribution which climaxes a long Paleozoic history of cosmopolitan floral successions. Thus, the Glenopteris flora characterizes the Wellington Forma- tion of the Sumner Group in central and Southern Kan- sas, whereas farther south in central and northern Okla- homa the G@/enopteris flora is unknown. Instead, the older G@igantopteris flora occurs there in the Wellington Formation and the Garber Sandstone, which are re- garded as equivalents of the strata containing the Gen- opteris flora to the north. Still farther south, the older Gigantopteris flora again appears in the Belle Plains Formation, which independent evidence indicates to be equivalent to the Wellington rocks of northern Okla- homa. - The westernmost known occurrence of this flora is in southeastern New Mexico at approximately the southern tip of the Ancestral Rocky Mountains where fragments of the flora have been found in the upper part of the Abo Formation. To the west of the Ancestral Rockies in central and northern New Mexico, strata that are probably basal Leonard and therefore the lateral equivalents of the Summer Group, the Garber Sandstone, the Wellington Formation and the Belle Plains Formation contain plant fossils that are indistinguishable from certain ele- ments of the Supaia flora and that were originally de- scribed by White (1929) from the Hermit Shale in the Grand Canyon of Arizona. The Grand Canyon occur- rence marks the westernmost limit of the known range of the Supaia flora; to the east, the lower part of the Supai Formation in areas along the Mogollon rim in Arizona has also yielded traces of the Supaia flora. Even though these three floras have geographic ranges that closely approach each other, they are not known to have overlapped. Some explanation of the provinciality of these contemporary assemblages is de- sirable, and although this attempt will be largely specu- lative, we feel that the correct answers possibly are to be found in the paleophysiography and paleoedaphol- K17 ogy of the region involved. It is almost certain that environmental differentiation was largely responsible for the floristic differentiation, because the presence in the floras of several common elements suggests deri- vation of the specialized floras from a common ancestry. The Ancestral Rocky Mountain system appears to have been the chief physical factor affecting floral dis- tribution during Leonard time. They separated the Supaia flora on the west from the Gigantopteris flora to the east. The fact that the concentration of known occurrences of the Supaia flora is greatest at points nearest the mountain system may indicate that east- ward dispersal of the flora was blocked by the moun- tain barrier, even though the western flank of the moun- tains was well populated by members of the Supaia flora. Conditions under which the Supaic flora existed may be inferred from certain features of the flora itself and features of the enclosing sediments. The sediments contain mud cracks and molds of salt crystals, which suggest a relatively rigorous climate; and rapid depo- sition of sediments is indicated by plant stems and leaves that are preserved in nearly erect positions that cut across bedding planes (White, 1929). The flora itself lacks true ferns, arborescent lycopods, calamite- ans, and other elements that normally grew under swampy or nearly swampy conditions. The evidence thus suggests that the Swpaiz flora represents the remnants of a lush flora that became impoverished by an unfavorable environment and was barred from east- ward dissemination by the Ancestral Rocky Mountains. The older Gigantopteris flora, on the other hand, pre- sents a more "normal" aspect, as it includes a variety of ferns, scattered lycopods, calamarians, and other mesophytic elements. Its province is limited to the east of the Ancestral Rocky Mountains, and it occurs in greatest abundance in the deltaic and fluviatile facies that characterize the north and south flanks of the Wichita and Amarillo uplifts; the plant fossils are frequently found closely associated with terrestrial tetrapod bones. This flora appears to have been a vig- orous association that grew under much milder eco- logic conditions than did the Supaia flora. It persisted within the same provincial limits until at least late Vale time, by which time specific differentiation of Gigantopteris had been accomplished and the introduc- tion of new types had lent the younger Gigantopteris flora a more Mesozoic aspect. As mentioned previ- ously, traces of the Gigantopteris flora have been found in southern New Mexico at approximately the southern tip of the Ancestral Rocky Mountain uplift but not to the northwest in the Supaic province. If our conjec- K18 tures regarding the climatic conditions under which the two floras grew are correct, the Gigantopteris flora, although vigorous in its own province, was possibly not capable of surviving in the presumably more ad- verse climate of the province to the west. Thus, a combination of climatic contrasts and physical bar- riers was seemingly responsible for the failure of the two floras to intermingle. The narrow geographic limits of the Kansas @/en- opteris province seem to be a manifestation of edaphic conditions, for the floral remains there occur in, and in association with, highly saline sediments. This occurrence suggests a physiological aridity that was incompatible with the ecological tolerances of the Gigantopteris flora and that prevented this flora from migrating the short distance to the north necessary to permit it to intermingle with the @lemopteris flora. The fossil remains of the G@lenopteris flora support such a supposition, for the leaf compressions, in particular those of Glenopteris, are invariably preserved as thick carbonaceous crusts, which suggest that in life the leaves were thick and fleshy, as in typically halophytic plants. 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Rept., v. 1, p. 1-354, v. 2, p. 355-694, pls. 86, 87 ; atlas published in 1879, pls. 1-85. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES Lesquereux, Leo, 1884, Description of the coal flora of the Car- boniferous formation in Pennsylvania : Pennsylvania Geol. Survey, 2d Ann. Rept., v. 8, p. 695-977, pls. 89-111. Mamay, S. H., 1954, A Permian Discinites cone: Washington Acad. Sci. Jour., v. 44, no. 1, p. T-11. Mamay, S. H., and Read, C. B., 1954, Differentiation of Permian floras in the southwestern United States: Internat. Bot. Cong., 8th, Paris, Comptes rendus and Rept. and Commun., see. 5, p. 157-158. Miser, H. D., and Hendricks, T. A., 1960, Age of Johns Valley shale, Jackfork sandstone and Stanley shale: Am. Assoc. Petroleum Geologists Bull., v. 44, no. 11, p. 1829-1832. Moore, R. C., chm., and others, 1944, Correlation of Pennsyl- vanian formations of North America: Geol. Soc. America Bull., v. 55, p. 657-706, 1 chart. Read, C. B., 1934, A flora of Pottsville age from the Mosquito Range, Colorado: U.S. Geol. Survey Prof. Paper 185-D, p. 79-96, 1 fig., 3 pls. 1936, The flora of the New Albany shale, Part I, Diichnia kentuckiensis, a new representative of the Calamopityeae : U.S. Geol. Survey Prof. Paper 185-H, p. 149-155, pls. 30-33, figs. 9-10. 1937, The flora of the New Albany shale, Part II, The Calamopityeae and their relationships: U.S. Geol. Survey Prof. Paper 186-E, p. 81-104, pls. 16-26. 1938, The age of the Carboniferous strata of the Paracas Peninsula, Peru: Washington Acad. Sci. 'Jour., v. 28, no. 9, p. 396-403. 1939, Some Psilophytales from the Hamilton group in western New York: Torrey Bot. Club. Bull., v. 65, no. 9, p. 599-606, 5 figs. 1941a, Plantas fosseis do neo-paleozoico do Paran e Santa Catarina: Brazil, da Div. Geologia e Mineralogia, Mon. 12, 102 p., 8 pls. 1941b, Sequence and relationships of late Paleozoic floras of the southwestern United States [abs.] : Oil and Gas Jour., v. 39, no. 47, p. 65. 1942, The Upper Paleozoic floras of South America [abs.] : Am. Sci. Cong., 8th, 1942, Proc., v. 4, Geol. Sei., p. 79. 1947, Pennsylvanian floral zones and floral provinces: Jour. Geology, v. 55, no. 3, p. 271-279. 1955, Floras of the Pocono formation and Price sand- stone in parts of Pennsylvania, Maryland, West Virginia, and Virginia: U.S. Geol. Survey Prof. Paper 263, 32 p., 20 pls. Read, C. B., and Wood, G. H., 1947, Distribution and correlation of Pennsylvanian rocks in late Paleozoic sedimentary basins of northern New Mexico: Jour. Geology, v. 55, no. 3, p. 220-236. Roth, Robert, 1930, Regional extent of Marmaton and Cherokee midcontinent Pennsylvanian formations: Am. Assoc. Petro- leum Geologists Bull., v. 14, no. 10, p. 1249-1278. Scott, D. H., and Jeffrey, E. C., 1914, On fossil plants, showing structure, from the base of the Waverly shale of Kentucky : Royal Soc. London Philos. Trans., ser. B, v. 205, p. 815-373, pls. 27-39. Sellards, E. H. 1908, Fossil plants of the Upper Paleozoic of Kansas : Kansas Geol. Survey [rept.], v. 9, p. 484-467, pls. 61-69. Seward, A. C., 1933, Plant life through the ages : London, Cam- bridge Univ. Press, 603 p., 139 figs. ; reprinted, 1959. Smith, G. O., and White, David, 1905, The geology of the Perry Basin in southeastern Maine : U.S. Geol. Survey Prof. Paper 35, p. 1-92, pls. 1-6. - K1Q Stopes, M. C., 1914, The "Fern Ledges" Carboniferous flora of St. John, New Brunswick: Canada Geol. Survey Mem. 41, 167 p., 25 pls. Teichert, Curt, and Schopf, J. M., 1958, A Middle or Lower Devonian Psilophyte flora from central Arizona and its paleogeographic significance: Jour. Geology, v. 66, no. 2, p. 208-217, 2 figs. White, David, 1900a, The stratigraphic succession of the fossil floras of the Pottsville formation in the southern anthracite coal field, Pennsylvania : U.S. Geol. Survey 20th Ann. Rept., pt. 2, p. 751-980, pls. 180-193. 1900b, Relative ages of the Kanawha and Allegheny Series as indicated by the fossil plants : Geol. Soc. America Bull., v. 11, p. 145-178. 1903, Summary of the fossil plants recorded from the Upper Carboniferous and Permian formations of Kansas, in Adams, G. I., Girty, G. H., and White, David, Stratig- raphy and paleontology of the Upper Carboniferous rocks of the Kansas section: U.S. Geol. Survey Bull. 211, p. 85-117. 1912, The characters of the fossil plant Gigantopteris Schenk and its occurrence in North America : U.S. Nat. Mus. Proc., v. 41, p. 493-516, pls. 48-49. 1913, The fossil flora of West Virginia: West Virginia Geol. Survey, v. 5 (A), pt. 2, p. 390-453, 488-491. 1929, Flora of the Hermit shale, Grand Canyon, Arizona : Carnegie Inst. Washington Pub. 405, 221 p., 51 pls. 1936, Fossil flora of the Weddington sandstone member of the Fayetteville shale : U.S. Geol. Survey Prof. Paper 186-B, p. 13-41, pls. 4-9. 1937, Fossil plants from the Stanley shale and Jackfork sandstone in southeastern Oklahoma and western Arkan- sas: U.S. Geol. Survey Prof. Paper 186-C, p. 48-67, plis. 10-14. Wilson, L. R., 1959, Plant microfossils from the Flowerpot shale (Permian) of Oklahoma [abs.] : Internat. Bot. Cong., 9th, Montreal, Proc., v. 2, p. 482. Wolfe, J. A., 1962, New name for Cardiopteris Schimper : Taxon, v. 11, n. 4, p. 141. Zalessky, M. D., 1918, Flora paléozoique de la Série d'Angara : Mém. du Com. Géol., St. Pétersbourg, N.S. 174, Atlas, 63 pls., T6 p. GLOSSARY OF STRATIGRAPHIC TERMS By Grack C. KrronErR Names printed in boldface type have been adopted for use by the U.S. Geological Survey. Names pre- ceded by a dagger ($) have been abandoned for use by the Survey. Names in roman type without a dagger are those that the Survey has had no occasion to con- sider for use. Reports are indicated in glossary by reference number. Parentheses enclose numbers of cited publications. Abbott Formation (in McCormick Group) Middle Pennsylvanian :; Illinois Consists of strata that were included in lower part of se- quence formerly called Tradewater Group. Character- ized by dominance of sandstone, sandy shale, and silt- stone; some coal beds. Maximum thickness, 300 to 350 ft in southern Illinois; thins westward and northward. K20 Overlies Caseyville Formation; underlies Spoon Forma- tion. Type locality: Along Illinois Central Railroad, sec. 5-7, T. 11 S., R. 5 E., Pope County. Named for Abbott Station. Reference : 75. Abo Formation, Sandstone or Redbeds Lower Permian (Wolfcamp and Leonard Series) : Central New Mexico. Red shale, mudstone, sandstone, arkose, and conglomerate. Thickness, 910 feet at type locality ; as much as 1,400 ft in Sacramento Mountains. Intertongues with Hueco Lime- stone. Underlies Yeso Formation. Rests on beds rang- ing in age from early Wolfcamp in area of type locality to Precambrian in Zuni Mountains. Overliee Bursum Formation at type locality; overlies Laborcita Forma- tion (103) in Sacramento Mountains. Type locality : In Abo Canyon, Valencia and Torrance Coun- ties: Base of formation lies about 1 mile northwest of village of Scholle, and top, 2 miles west-northwest of village of Abo. References : 11, 77, 96, 103. Allegheny Formation Middle Pennsylvania: Western Maryland, eastern Ohio, Pennsylvania, Virginia, and West Virginia. Cyclic sequence of sandstone, shale, limestone, and coal. Overlies Pottsville Formation or Group; underlies Cone- maugh Formation. Classified as group by Pennsylvania Geological Survey and as series by Ohio and West Vir- ginia Geological Surveys. Named for exposures in valley of Allegheny River, Pa. References : 57, 93, 99, 115, 117. Atoka Series or Formation Middle Pennsylvanian: Arkansas, Iowa, Kansas, Missouri, Nebraska, and Oklahoma. Atoka Series is time-rock term defined to include beds from top of Morrow Series to base of Des Moines Series. Com- prises zones of Profusulinella and Fusulinella. As orig- inally defined included the Marble Falls Limestone, Smith- wick Shale, and overlying Fusulinella (restricted) -bear- ing beds of central and north Texas and Derry Series (134) in New Mexico and Texas. Term Atoka Forma- tion is used in Oklahoma and Arkansas. Formation, in type area, consists of about 7,000 ft of alternating sand- stone and shale beds that underlie Hartshorne Sandstone and overlie Wapanucka Limestone. In Oklahoma six sandstone members have been named ; an overlying shale unit is associated with each member. Overlies Bloyd, Hale, or Fayetteville Formations, or Johns Valley Shale. Named for Atoka, Atoka County, Okla. References : 18, 63, 67, 91, 123, 126, 132, 134. Belle Plains Formation (in Wichita Group) Lower Permian (Leonard Series): Central and central northern Texas. Chiefly gray limestone beds, 1 to 5 ft thick, separated by shale or marl in beds of comparable thickness. Thick- ness near Colorado River 400 ft. Underlies Clyde For- mation : overlies Admiral Formation. Named for town of Belle Plains, Callahan County. References : 92, 107. Bethany Falls Limestone Member (of Swope Limestone) Pennsylvanian (Missouri Series) : Southwestern Towa, east- ern Kansas, northwestern Missouri, and southeastern Nebraska. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Light-gray dense thin-bedded limestone overlain by gray massive algal limestone or white oolitic limestone. Thick- ness, as much as 30 ft. Uppermost member of Swope; overlies Hushpuckney Shale Member (94) ; underlies Galesburg Shale. Named for exposures at falls of Big Creek, near Bethany, Harrison County, Mo. References : 22, 90, 94. Bloyd Shale or Formation Lower Pennsylvanian (Morrow Series) : Northwestern Ar- kansas and eastern Oklahoma. First defined and named as a division in the Morrow Group. A sequence of alternating limestones and shales and ter- restrial sediments including coals. Thickness, as much as 350 ft. In Arkansas subdivided into three named members and an upper unnamed shale; only lowermost member typically developed in Oklahoma. Overlies Hale Formation ; underlies Atoka Formation. Named for Bloyd Mountain, 9 miles southwest of Fayette ville, Washington County, Ark. y References : 63, 67, 110. Bluefield Shale or Formation Upper Mississippian : Eastern Kentucky, southwestern Vir- ginia, and southern West Virginia. Principally calcareous shale with some limestone, siltstone, sandstone, and coal beds. Thickness, about 1,250 ft at type locality. Overlies Greenbrier Limestone; underlies Hinton Formation. Reger (114) classified the Bluefield as a group and subdivided it into 31 named units. Named for exposures at Bluefield, Mercer County, w. Va. References : 30, 41, 114, 148. Bluestone Formation (in Pennington Group) Upper Mississippian: Eastern Kentucky, southwestern Vir- ginia, and southern West Virginia. Interbedded shale, mudstone, siltstone, sandstone, lime- stone, and impure coal beds. Overlies Princeton Sand- stone; underlies Pocahontas Formation and, in some areas, Lee Formation. Reger (114) referred to unit as group and subdivided it into several formations. Cooper (41) referred to unit as formation and redefined Reger's subdivisions as members. Well exposed along Bluestone River, Mercer County, W. Va. References : 30, 41, 114, 148. Boggy Shale or Formation (in Krebs Group) Pennsylvanian (Des Moines Series) : Western Arkansas and central-southern and eastern Oklahoma. Predominantly dark shale with conspicuous sandstone zones. Thickness ranges from thin edge to maximum of more than 4,000 ft in Cavanal Mountain, Le Flore County, Okla., where top is eroded. Underliee Thurman Sandstone ; overlies Savanna Formation; on east flank of Arbuckle Mountains rests on beds as old as Ordovician. Named for exposures along North Boggy Creek, Pittsburg and Atoka Counties, Okla. References : 100, 101, 130. Buck Mountain Coal Pennsylvanian: Eastern Pennsylvania. Occurs in post-Pottsville strata which overlie Sharp Moun- tain Member of Pottsville Formation at type section and reference section of Pottsville. Reference: 151. Caseyville Formation or Sandstone (in McCormick Group) Lower Pennsylvanian: Southeastern Illinois and western Kentucky. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES Lowermost formation of Pennsylvanian in area. Charac- terized by dominance of sandstone and prominent de- velopment of sandy shale and siltstone. Thickness, com- monly 350 ft. Underlies Abbott Formation. In Illinois subdivided into several members. Type section: Outcrops on Illinois shore of Ohio River be- tween mouth of Saline River and Gentry Landing, below Battery Rock, T. 11 S., R. 10 E., Shawneetown quad- rangle, Hardin County. Named for Caseyville, Union County, Ky. References : 75, 104. Cassville Shale Member (of Washington Formation) Pennsylvanian: Southwestern Pennsylvania and northern West Virginia. Dark gray shale, 5 to 15 ft thick. Commonly separates Waynesburg Sandstone Member of the Washington For- mation from Waynesburg coal at top of underlying Monongahela Formation. Named from exposures in vicinity of Cassville, Monongalia County, W. Va. References : 16, 144. Catskill Formation or Redbeds (in Susquehanna Group) Middle and Upper Devonian and Lower Mississippian: Maryland, New York, and Pennsylvania. Predominantly red-bed sequence with gray conglomerate, sandstone, siltstone, and shale, interbedded. Upper part continental; lower part continental and marine. Maxi- mum thickness, about 9,000 ft. Type Catskill is Middle and Upper Devonian. As facies is followed southwest ward from New York into Pennsylvania and Maryland, the red beds become younger, so that Catskill of cen- tral and most of eastern Pennsylvania is all Late De- vonian. In areas where a "Pocono-Catskill transition group" is recognized, a part of the Catskill may be early Mississippian. In eastern Pennsylvania the Cats- kill underlies Pocono Formation and overlies Trimmers Rock Sandstone; in central Pennsylvania, it underlies Oswayo Formation and overlies Chemung. The Penn- sylvania Geological Survey and the U.S. Geological Survey classify the Catskill as a formation in the Sus- quehanna Group. From the time the term Catskill was introduced by Mather (83) in 1840, there has been, and continues to be, a discussion as to the precise definition of the Catskill in its type area. Hence, the Virginia and West Virginia Geological Surveys and the U.S. Geo- logical Survey currently apply term Hampshire Forma- tion to Devonian red beds south of Maryland. Terms Catskill and Hampshire are used interchangeably in Maryland Survey reports. Named for exposures in Catskill Mountains, Greene County, N.Y. References : 5, 6, 27, 34, 38, 42, 57, 88. Chase Group Permian: Eastern Kansas, southeastern Nebraska, and central-northern Oklahoma. Limestones and shales; chert or flint-bearing limestones. Thickness, about 335 ft. Comprises seven formations. Underlies Wellington Formation of Sumner Group ; over- lies Council Grove Group. Named for Chase County, Kans. References : 51, 94, 109. Cherokee Group or Shale Pennsylvanian (Des Moines Series) : Iowa, Kansas, Mis- souri, and Nebraska. 6890-427 O-64--2 K21 Lower major rock unit of Des Moines Series north of Kansas-Oklahoma line. Composed largely of shale, sandstone, carbonaceous shales, thin coals, and thin lime- stones. As defined in Iowa, Nebraska, Missouri, and Kansas includes about 400 ft of section between post- Mississippian unconformity and Marmaton Group. In Kansas, subdivided into Krebs and Cabaniss Formations; includes same interval as is contained by Krebs and Cabaniss Groups in Oklahoma. In Missouri, comprises all strata in Krebs and Cabaniss Subgroups and is sub- divided into several formations. Named for prominent exposures in Cherokee County, Kans. References : 60, 65, 69, 91. Chester Series Upper Mississippian: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Oklahoma, and Tennessee. Uppermost of four time-rock divisions of Mississippian in type area. Preceded by Meramec Series. Composed of alternating limestones, sandstones, and shales. In stand- ard reference section includes New Design, Homberg, and Elvira Groups (139) which comprise 16 formations. Named for Chester, Randolph County, Ill. References : 139, 152. Clear Fork Group Lower Permian (Leonard Series) : northern Texas. Comprises (ascending) Arroyo, Vale, and Choza Forma- tions. Overlies Wichita Group; underlies Pease River Group. Probably named for Clear Fork of Brazos River, Jones and Shackelford Counties, Tex. References : 49, 51. Clyde Formation (in Wichita Group) Lower Permian (Leonard Series): Central and central- northern Texas. < Regular beds of moderately hard, medium- to fine-grained gray limestone alternating with shale and marl beds. Thickness, 500 ft near Colorado River. Overlies Belle Plains Formation; underlies Lueders Limestone. Named for town of Clyde, 8 miles west of Baird, Callahan County. References : 92, 107. Conemaugh Formation Upper Pennsylvanian: Western Maryland, eastern Ohio, Pennsylvania, and northern West Virginia. Cyclic sequences of red and gray shales and siltstones alternating with thin limestones and coals. Overlies Allegheny Formation ; underlies Monongahela Formation. Classified as series by Ohio and West Virginia Geol. Surveys. Named for exposures along Conemaugh River, Pa. References : 57, 93, 99, 105, 115. Des Moines Series Middle Pennsylvanian: Arkansas, Iowa, Kansas, Missouri, Nebraska, and Oklahoma. Major time-stratigraphic division of the Pennsylvanian in midcontinent. Spans interval between Atoka Series, below, and Missouri Series, above. Designated paleon- tologically as zone of Fusulina. Upper boundary defined by a disconformity that is inconspicuous in most places but that, on basis of paleontological changes, is judged to be division of first-rank intrasystemic magnitude. Named for Des Moines River, Iowa. References : 72, 90, 98. Central and central K22 Dunkard Group Pennsylvanian and Permian: Western Maryland, eastern Ohio, southwestern Pennsylvania, and northern West Virginia. Cyclic sequences of sandstone, limestone, coal, and red shale. Overlies Monongahela Formation; base at top of Waynesburg coal. Comprises Washington Formation, below, and Greene Formation, above. Named for occurrence on Dunkard Creek, Greene County, Pa. References: 16, 144. Eagle coal Pennsylvanian : Southern West Virginia. According to I. C. White (143) this name was applied to the lowest workable bed in the Lower Coal Measures (No. XIII) on the Kanawha River. Correlates with Clarion coal of Pennsylvania. Occurs in Kanawha For- mation (or Group) as now defined. Extensively developed at Eagle mines, near Cannelton, Fayette County. References : 115, 148. {Elmdale Shale or Formation Pennsylvanian: Eastern Kansas, southeastern Nebraska, and central-northern and central Oklahoma. Elmdale Shale, as originally defined and as used for sev- eral years, included beds of shale and limestone above Americus Limestone (13) and below Neva Limestone. When Permian boundary was lowered to include Ameri- cus Limestone Member of Foraker Limestone, term Elm- dale was discarded and formation names applied to the various shales and limestones. Named for exposures east of Elmdale, Chase County, Kans. References : 13, 89. El Reno Group Permian: Oklahoma. Name applied to strata above Hennessey Shale and below Whitehorse Group. Includes Flowerpot Shale in lower part. Permian correlation chart (51) uses term Pease River Group in preference to El Reno Group in Texas. Named for El Reno, Canadian County. References : 12, 51, 122. Fayetteville Shale Upper Mississippian (Chester Series) : Northern Arkansas, southern Missouri, and northeastern, central, and eastern Oklahoma. Chiefly brown to black shales. Contains Wedington Sand- stone Member in upper part. In Arkansas underlies Pit- kin Limestone and overlies Batesville Sandstone or Boone Limestone. In Oklahoma overlies Hindsville Limestone or, where Hindsville is absent, rests on "Boone" chert knobs; where Pitkin Limestone is missing, the Fayette- ville underlies Hale Formation. Named for Fayetteville, in valley of West Fork of White River, Washington County, Ark. References : 20, 53, 67, 124. Flattop Mountain Sandstone Member (of Pocahontas Forma- tion) Lower Pennsylvanian : Southern West Virginia. Bluish-gray to brown massive to current-bedded medium- grained micaceous sandstone, 20 to 50 ft. thick. Occurs at top of formation above unit termed Rift Shale by West Virginia Geological Survey; underlies fireclay and shale below Pocahontas No. 8 coal at base of New River For- mation. West Virginia Geological Survey treats the Flat- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY top Mountain Sandstone as a formation in Pocahontas Group. Named for Flattop Mountain, 2 miles northwest of Poca- hontas, Va. References : 115, 146. Flowerpot Shale (in El Reno, Nippewalla, or Pease River Group) Permian : Central-southern Kansas, western Oklahoma, and Texas. Predominantly red, brown, and maroon shales interstratified with green and light-gray shale, thin impure gypsum beds, and thin dolomites. In Oklahoma and Texas, con- tains named gypsum members. Average thickness in Kansas, 180 ft.; 165 ft. in Carter area, Oklahoma ; 274 ft. at type locality of Pease River Group, Texas. Underlies Blaine Formation; underlying units vary according to locality. Named for Flowerpot Mound, Barber County, Kans. References : 45, 69, 94, 121, 122. Garber Sandstone Permian: Northwestern, central-northern, and south-cen- tral Oklahoma. Thick series of red sandstones and intervening red shales. Underlies Hennessey Shale; overlies Wellington Forma- tion. Named for exposures at Garber, Garfield County. References : 7, 51. Greenbrier Limestone or Formation Upper Mississippian : Eastern Kentucky, western Maryland, southern Pennsylvania, Virginia, and northern West Virginia. A sequence of dense crystalline highly fossiliferous locally cherty limestone; commonly grades from gray to brown- ish gray to black; beds normally thick bedded but rela- tively thin bedded near top of formation ; mottled red and green beds of limestone, calcareous mudstone, and small amounts of gray shale present; crossbedded oolitic and clastic limestones abundant ; dolomitic zone near base in many sections. Thickness, 250 to 848 ft. Hillsdale Mem- ber and Taggard Red Member differentiated in many areas. Overlies Maccrady Shale or Pocono Formation ; underlies Bluefield Formation or Mauch Chunk Forma- tion. In some areas of western Maryland, includes Loyal- hanna Member at base. In some areas of Pennsylvania considered a member in Mauch Chunk Formation. West Virginia Geological Survey reports use term Greenbrier Series to include several formations; term Greenbrier Series is used on Mississippian correlation chart (139). Named for exposures On Greenbrier River, Pocahontas County, W. Va. References : 5, 57, 114, 119, 139, 148. Guadalupe Series Lower and Upper Permian : Southeastern New Mexico and western Texas. Time-stratigraphic division of the Permian. The series, as defined by Adams and others (2), is 4,100 ft thick at type locality and consists of 2,300 ft. at northern margin of Delaware basin, referred to as type section by Dunbar and others (51). Lower and middle parts characterized by advanced species of Parafusulina ; upper part by genus Polydiexodina. Overlies Leonard Series ; underlies Ochoa Series. The U.S. Geological Survey recognizes a twofold division of the Permian. In Permian outcrops of north- western Trans-Pecos (Delaware Mountains, 'Guadalupe UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES Mountains, and Sierra Diablo Mountains) approximate faunal boundary is taken as that between Cherry Canyon and Bell Canyon Formations; this boundary falls between Word and Capitan Formations 'as recognized in Glass Mountain area. Type locality : South end of Guadalupe Mountains, Tex. References : 2, 89, 51, 55. i Hartshorne Sandstone (in Krebs Group) Pennsylvanian (Des Moines Series) : Western Arkansas and eastern Oklahoma. Basal formation in Krebs Group. Includes beds between top of Atoka Formation and base of McAlester Forma- tion. Thickness, about 200 ft in area of type locality. Named for exposures near Hartshorne, Pittsburg County, Okla. References : 93, 100, 116, 130. Hermit Shale (in Aubrey Group) Permian: Northern Arizona, southeastern Nevada, and southern Utah. Brick-red sandstones and shales. Thickness, 300 to 900 ft. Overlies Supai Formation ; unconformably underlies Co- conino Sandstone. In Grand Wash and Hurricane Cliffs areas overlies Queantoweap Sandstone (82). Type locality : Hermit basin, Arizona. References : 51, 82, 98. Hermosa Formation Middle Pennsylvanian ; Northeastern Arizona, southwestern Colorado, northwestern New Mexico, and southeastern Utah. Commonly described as comprising: lower member consist- ing of limestones and dolomites interbedded with dark- gray silty shales; Paradox Member consisting mostly of evaporites; upper carbonate member which consistently recognized only where it overlies Paradox Member. Thickness, about 2,000 ft in type area where it overlies Molas Formation and underlies Cutler Formation. Wen- gerd and Matheny (140) raised the Hermosa to group rank and subdivided it into (ascending) Pinkerton Trail, Paradox, and Honaker Trail Formations. Type section: Sees. 26 and 35, T. 37 N., R. 9 W., La Plata County, Colo. Named for Hermosa Creek which flows into Animas River north of Durango. This is composite section measured across strata that dip gently southward into San Juan basin. References : 10, 46, 140. Hindostan Whetstone or Beds Pennsylvanian : Southwestern Indiana. Series of thin fine-grained laminated beds in lower part of Mansfield Formation. Thickness, about 20 ft. Named for village which was formerly county seat of Mar- tin County. Village abandoned since 1870. References : 43, 98, 125. Jackfork Sandstone Mississippian: Southwestern Arkansas and southeastern and central-southern Oklahoma. Where typically developed consists of 5,600 to 5,800 ft of alternating sandstones and dark-gray shales and minor amounts of 'black siliceous shales that include some thin chert beds. Overlies Stanley Shale; underlies Johns Valley Shale. Oklahoma Geological Survey classifies the Jackfork as a group and subdivides it into five forma- tions. K23 Named for Jackfork Mountain in frontal Quachitas, Pitts- burg, and Pushmataha Counties, Okla. References : 37, 86, 131. Kanawha Formation (in Pottsville Group) Middle Pennsylvanian: Kentucky, Virginia, and West Virginia. Shales, sandstones, and coals. Thickness, 2,100 ft in West Virginia. Overlies New River Formation ; underlies Alle- gheny Formation. Classified as group by West Virginia Geological Survey. Well exposed in hills north of Kanawha Falls, W. Va. References : 32, 115. Katsberg Red Beds Upper Devonian : Eastern New York. Name applied to upper or Enfield part of Catskill Forma- tion. Overlies Onteora Red Beds, underlies Slide Moun- tain Conglomerate. Thickness, about 3,000 ft where complete. Type section: Slopes of highest peak, Slide Mountain (in Catskill Mountains). Katsberg is Dutch name for the mountains miscalled "Catskills" by the English. Reference: 33. Kerber Formation Pennsylvanian : Southern Colorado. In type area consists of about 200 ft of white to gray coarse-grained sandstone and carbonaceous shale, which overlie Leadville Limestone and extend up to base of low- est red micaceous sediments or sandy facies of Maroon Formation. In some areas underlies Minturn Formation or Hermosa Formation. On basis of stratigraphic posi- tion may be Morrow or Atoka. Named for exposures along Kerber Creek, Bonanza district, Saguache County. References : 19, 21, 24, 81. Kinderhook Series Lower Mississippian: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Oklahoma, and Tennessee. Lowermost time-rock division of the Mississippian in type area. Succeeded by Osage Series. Varies lithologically from place to place. In standard reference section in- cludes Fabius and Easley Groups (139), which comprise seven formations. Named for exposures at Kinderhook, Pike County, Ill. References : 85, 139. Koontz coal Pennsylvanian: Western Maryland. Coal bed in Monongahela Formation. tive of Uniontown coal. Reference : 17. Lampasas Series Pennsylvanian : Texas. Time-stratigraphic term proposed for beds younger than Morrow and older than type Strawn of Brazos River valley section, Texas. Later redefined to include all beds up to top of Dennis Bridge Limestone (36). By this definition the series included equivalents of Atoka Formation of Oklahoma, Derry Series (134) of New Mex- ico, and about haif of Cherokee Group of Oklahoma, Kansas, and Iowa. Spivey and Roberts (126) considered Lampasas unsatisfactory as series name and proposed that term Atoka Formation be raised to series rank and defined to include all beds from top of Morrow Series to base of Des Moines Series. Considered correla- K24 Type section: Around Llano uplift of central Texas and in area to north. Well exposed in western Lampasas and eastern San Saba Counties near village of Bend. References : 35, 36, 93, 126, 134. Lancaster Formation (in Little River Group or Series) Pennsylvanian: New Brunswick, Canada. Thick deposits of clastic sediments that locally carry plant remains - Includes "Fern Ledge Beds." St. John region, New Brunswick. References: 3, 4. Lee Formation or Group Lower Pennsylvanian: Eastern Kentucky, eastern Tennes- see, and southwestern Virginia. Sandstones, (conglomerates, shales, and coals. Overlies Pennington Formation or Group and in some areas Blue- stone Formation. Overlying units: Briceville Forma- tion, Tennessee; Norton Formation, Virginia; Hance Formation, Cumberland Gap, Tenn., area; Breathitt For- mation, eastern Kentucky. The U.S. Geological Survey classifies the Lee as a group in east-central Tennessee. The Tennessee Geological Survey has discontinued term Lee Group and uses terms Gizzard, Crab Orchard Moun- tains, and Crooked Fork Groups. Named for Lee County, Va. References : 28, 93, 150. Leonard Series Lower Permian : New Mexico and Texas. Time-stratigraphic division of the Permian. At type sec- tion is about 2,000 ft thick and consists chiefly of lime- stone and siliceous shales. Common fusulinids are prim- itive types of Parafusulina; Perrinites is representative of the ammonoids. Disconformably overlies Wolfcamp Series; underlies Word Formation of Guadalupe Series. Type section: On south face of Glass Mountains, western Texas. References : 2, 51, 136. Little River Group or Series Pennsylvanian: New Brunswick, Canada. Sandstones, shales, grits, and conglomerates. Lancaster Formation and "Fern Ledge Beds." Crops out along Little River and shore of Courtney Bay, St. John district. References : 3, 84, 128. Lookout Sandstone (in Pottsville Group) - Lower Pennsylvanian: Northeastern Alabama, northwest- ern Georgia, and southern Tennessee. Includes two conglomeratic sandstones. Thickness, 50 to 600 ft. In Lookout Mountains, Ga., underlies Whitwell Shale ; overlies Pennington Shale. Named for exposures on Lookout Mountain, northeastern Alabama and northwestern Georgia. Réferences : 62, 70. Lueders Limestone (in Wichita Group) Lower Permian (Leonard Series): Northern and central Texas. Consists mainly of limestone beds, 1 ft or less to about 3 ft thick, separated by shale beds 1 or 2 in. thick ; locally, shale is as much as 5 ft. Thickness, about 225 ft. Limestone characterized by fine algal pellets. Overlies Clyde Formation ; underlies Arroyo Formation. Has been referred to as group and subdivided into several forma- tions. Includes SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Named for town on Clear Fork of Brazos River, eastern Jones County. References : 35, 92, 153. Lykens Valley coals Pennsylvanian : Eastern Pennsylvania. A series of seven coals (numbered in descending order) in Pottsville Formation in the anthracite field. Sometimes referred to as Lykens coals. References : 93, 151. McCormick Group Lower and Middle Pennsylvanian: Western and southern Illinois. Comprises Caseyville and Abbott Formations. Includes strata formerly included in Caseyville Group and lower part of Tradewater Group. Maximum thickness, 850 ft. Lowest group in Pennsylvanian of Illinois. Under- lies Kewanee Group. Named for village of McCormick in northwestern Pope County, which is located in area where strata of the two formations are prominently exposed. Reference: 75. McCoy Formation Pennsylvanian : Northwestern Colorado. Redefined by Donner (48) to include over 3,500 ft of coarse arkosic sandstones and grits and interbedded shales and limestones. Contains Walchia-bearing beds. Uncom- formably overlies Mississippian Leadville Limestone; underlies Permian(?) State Bridge Siltstone (48). Named for exposures at McCoy, Eagle County. References : 48, 120. Madera Limestone or Formation (in Magdalena Group) Pennsylvanian: Southern Colorado and central and north- ern New Mexico. In New Mexico commonly consists of a lower gray limestone member and an upper arkosic limestone member. Thick- ness, as much as 3,000 ft. Locally subdivided into named formations. Overlies Sandia Formation ; underlies Abo, Sangre de Cristo, or Bursum Formations. In La Veta Pass area, Colorado, overlies Deer Creek Formation (19) and underlies Pass Creek Sandstone (19) ; grades later- ally into Minturn Formation. Named for village of La Madera on eastern slope of Sandia Mountains, N. Mex. References : 8, 19, 71, 73, 149. Massillon coal Pennsylvanian : Northeastern Ohio. Name applied in early reports to Sharon No. 1 coal in the Massillon coal field, which was mapped in parts of Sum- mit, Medina, Wayne, and Stark Counties; also referred to as "Coal No. 1," "Brier Hill," and "Jackson" coal. References : 97, 102. Mauch Chunk Shale or Formation Upper Mississippian: Western Maryland, Pennsylvania, and northern West Virginia. Commonly red shales with brown to greenish-gray flaggy sandstones. - Thickness may be as much as 3,500 ft locally. Underlies Pottsville Formation at type section and refer- ence section of Pottsville. In West Virginia, underlies Pocahontas Formation ' (or Group). Underlying units vary according to area: Pocono Formation or Group, Greenbrier Limestone, or Loyalhanna Limestone. Geo- logic map of Pennsylvania (57) shows the Mauch Chunk includes Greenbrier and Loyalhanna Limestones and over- lies Pocono Group. West Virginia Geol. Survey classifies UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES the Mauch Chunk as a series comprising Bluefield, Hinton, Princeton, and Bluestone Groups. Mississippian correla- tion chart (139) uses term Mauch Chunk in virtually this same sense. Type locality not stated but commonly assumed to be at Jim Thorpe, formerly Mauch Chunk, Carbon County, Pa. References : 57, 79, 139, 151. Meramec Series Upper Mississippian: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Oklahoma, and Tennessee. Third (ascending) of four time-rock divisions of the Mis- sissippian in type area. Spans interval between Osage Series, below, and Chester Series, above. In standard reference section, includes (ascending) Warsaw, Salem, and Ste. Genevieve Limestones. Named for Meramec Highlands and Meramec River, west of St. Louis, Mo. References : 137, 139. Mercer Shale Member (of Pottsville Formation) Pennsylvanian: Maryland, eastern Ohio, western Pennsyl- vania, and northwestern Virginia. Shale, fire clay, and coal. Thickness about 40 ft. Under- lie Homewood Sandstone Member; overlies Conno- quenessing Sandstone Member. Also referred to as Mercer Shale in Pottsville Series (93). Type locality : Mercer, Mercer County, Pa. References : 25, 80, 93. Merrimac coal Mississippian: Virginia and West Virginia. Minable coal in upper part of Price Formation in Vir- ginia. In Greenbrier County, W. Va., coal in upper part of Pocono Series is correlated with Merrimac coal of Montgomery County, Va. References : 23, 108. Missouri Series Upper Pennsylvanian : Arkansas, Iowa, Kansas, Missouri, Nebraska, and Oklahoma. Major time-stratigraphic division of the Pennsylvanian in the midcontinent. Separated by regional disconformities from overlying Virgil Series and underlying Des Moines Series. Composes lower part of zone of Triticites. Named for exposures in northwestern Missouri and along Missouri River, Iowa. References : 72, 90, 93, 94. Monongahela Formation Upper Pennsylvanian: Western Maryland, eastern Ohio, western Pennsylvania, Virginia, and West Virginia. Cyclic sequences of sandstone, shale, limestone, and coal; limestone prominent in northern outcrop areas; shale and sandstone increase in prominence southward. In- cludes beds from base of Pittsburgh coal to top of Waynes- burg coal. Overlies Conemaugh Formation ; underlies Dunkard Group. Also referred to as Monongahela Series. Named for exposures along Monongahela River, Pa. References : 57, 98, 117. Moran Formation (in Wichita Group) Lower Permian (Wolfcamp Series) : Central and central northern Texas. Consists of alternating limestone and shale but includes some sandstone. Comprises two limestone members and two shale members. Thickness, about 100 ft near Colo- rado River. Overlies Pueblo Formation ; underlies Put- nam Formation. K25 Named for Moran, Shackelford County. References : 92, 106. Morien Series or Group Pennsylvanian: Nova Scotia, Canada. Laterally changing alternation of sandstones and shales. Subdivided into three zones on basis of fossil plant and animal remains. Thickness, 2,900 to 6,500 ft. Includes many coal-bearing beds. Occurs in southern part of Sydney coal field. References : 15, 61. Morrow Series Lower Pennsylvanian: Arkansas, Iowa, Kansas, Missouri, Nebraska, and Oklahoma. Time-rock term applied to major subdivision of Lower Pennsylvanian in midcontinent. Underlies Atoka Series. In terms of fusuline zonation, deposits belong to zone of Millerella. Probably throughout most of northern mid- continent area, lower boundary of Morrow Series coin- cides with a major unconformity that separates Pennsyl- vanian from older systems. Named for Morrow, Washington County, Ark. References : 1, 91. New River Formation (in Pottsville Group) Lower Pennsylvanian: Southwestern Virginia and southern West Virginia. Sandstones, shales, and coals. Thickness 1,030 ft in West Virginia. Includes Pocahontas coals 8 and 9. Comprises (ascending) Quinnimont Shale, Raleigh Sandstone, Sewell, and Nuttall Sandstone Members. Overlies Poca- hontas Formation; underlies Kanawha Formation. Classified as group by West Virginia Geological Survey. Well exposed along New River, Raleigh and Fayette Coun- ties, W. Va. References : 54, 115, 142. Nuttall coal seam Pennsylvanian : Southern West Virginia. Name applied by I. C. White (143) to first workable coal bed at top of Pottsville or No. XII Conglomerate (about 400 ft below top of Nuttall Sandstone Member of New River Formation). First commercial mining was made by John Nuttall, who established the mining town of Nuttallburg, Fayette County, soon after the C & O Railroad was con- structed. The coal had previously been mined for local use near top of Sewell Mountain ; hence the name Sewell became attached to the coal, and it is now commonly known by that name. References : 148, 145. Nuttall Sandstone Member (of New River Formation) Lower Pennsylvanian : Southwestern Virginia and southern West Virginia. Massive sandstone, conglomeratic in many localities. Thickness, 180 to 220 feet. Commonly forms two ledges, each as much as 100 ft thick. Overlies Sewell Member ; underlies Kanawha Formation. West Virginia Geological Survey does not use term Sewell and refers to the units as Lower Nuttall and Upper-Nuttall Sandstones in New River Group. Forms cliffs from Gauley Bridge to Nuttallburg, Fayette County, W. Va. References : 31, 115. Osage Series Lower Mississippian: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Oklahoma, and Tennessee. K26 Second of four time-rock divisions of the Mississippian in type area. Spans interval between Kinderhook Series, below, and Meramec Series, above. In standard reference section includes (ascending) Fern Glen, Burlington, and Keokuk Limestones. Named for Osage River in Missouri. References : 139, 147. Parkwood Formation Upper Mississippian : Northern Alabama. Predominantly gray or greenish-gray sandy shale and sand- stone. Thickness, 0 to 2,000 ft. Underlies Pottsville Formation ; overlies Floyd Shale. Named for exposures at Parkwood, J efferson County. References : 26, 93. Pittsburgh coal Pennsylvanian: Maryland, Ohio, Pennsylvania, and West Virginia. Coal at base of Monongahela Formation (Series). Reference : 93. Pocahontas coal beds Pennsylvanian: Virginia and West Virginia. Pocahontas coals consist of nine coal beds numbered in ascending order. Coals 1 through 7 are present in Pocahontas Formation (Group) and coals 8 and 9 are in New River Formation (Group) in West Virginia. These coals also occur in lower part of Lee Formation in Virginia. References: 23, 93. Pocahontas Formation (in Pottsville Group) Lower Pennsylvanian: Southwestern Virginia and south- ern West Virginia. Sandstones, shales, and coals. Thickness, 720 ft in West Virginia. Includes Flattop Mountain Sandstone Member at top. Underliese New River Formation ; overlies Mauch Chunk Shale or Bluestone Formation. Includes Poca- hontas coals 1-7. This definition corresponds to I. C. White's (146) Pocahontas Group and to Pocahontas Group as used by West Virginia Geological Survey. Named for Pocahontas, Tazewell County, Va. References : 30, 115, 146. Pocono Formation, Sandstone, or Group Mississippian: Western Maryland, eastern Ohio, Pennsyl- vania, Virginia, and West Virginia. Predominantly gray hard massive crossbedded conglomer- ate and sandstone. - Thickness as much as 1,600 ft. Over- lies Upper Devonian: Chemung, Catskill, or Hampshire Formations or Mount Pleasant Sandstone (139). Under- lies Mauch Chunk, Maccrady, Greenbrier, or Loyalhanna Formations. In Virginia, names Pocono and Price are practically synonymous; name Pocono is applied as far south as western Alleghany County, and name Price, throughout region from southern Alleghany and western Botetourt Counties to Tennessee. West Virginia Geo- logical Survey classifies the Pocono as a series compris- ing several formations. Mississippian correlation chart uses term Pocono Series in virtually the same sense. No type locality designated by Lesley (79). Later workers have assumed type area to be in the Pocono Mountains of northeastern Pennsylvania. References : 27, 79, 112, 139. Pottsville Formation or Group Lower and Middle Pennsylvanian: Alabama, Georgia, In- diana, Kentucky, Maryland, Mississippi, New York, Pennsylvania, Tennessee, Virginia, and West Virginia. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Formation, at type section and reference section, consists of about 1,200 ft of strata composed predominantly of cobble and pebble conglomerate, conglomeratic sandstone, sandstone, and lesser amounts of siltstone, shale, and coal; comprises (ascending) Tumbling Run, Schuylkill, and Sharp Mountain Members. At type section and reference section overlies Mauch Chunk Formation and underlies later Pennsylvanian Buck Mountain or Twin coal bed. Elsewhere underlies Allegheny Formation. In some areas overlies Bluestone Formation; in Ala- bama overlies Parkwood Formation. Pennsylvania Geo- logical Survey classifies the Pottsville as a group. Indiana, Ohio, and West Virginia Geological Surveys classify the Pottsville as a series. Type section: South of city of Pottsville, along Pennsyl- vania Railroad cut on east side of water gap through Sharp Mountain, Schuylkill County, Pa. Reference sec- tion: About 150 ft east of type section is along east side of roadcut for U.S. Highway 122. References : 57, 58, 79, 93, 115, 129, 151. Price Sandstone, Siltstone, or Formation Mississippian: Southwestern Virginia. Lithology varies; in some areas, predominantly siltstone and some interbedded shale; elsewhere, coarse grained and referred to as sandstone. Thickness, as much as 1,700 ft. Underlies Maccrady Shale; overlies Big Stone Gap Shale. Names Price and Pocono are practically synonymous; name Price is applied throughout region from southern Alleghany and western Botetourt Coun- ties to Tennessee; name Pocono applied in northern Virginia. Named for Price Mountain, Montgomery County. References: 27, 29, 139. Quinnimont Shale Member (of New River Formation) Lower Pennsylvanian: Southwestern Virginia and south- ern West Virginia. Shale containing thin beds of sandstone and a few coal seams. - Thickness, as much as 300 ft. Underlies Raleigh Sandstone Member; overlies unnamed interval of coal, shale, and clay in lower part of formation. Named for exposures at Quinnimont, Fayette County, W. Va. References : 30, 115. Raleigh Sandstone Member (of New River Formation) Lower Pennsylvanian: Southwestern Virginia and south- ern West Virginia. Commonly consists of two sandstone ledges separated by several feet of shale, coal, and fire clay. Sometimes referred to as Lower Raleigh and Upper Raleigh Sand- stones (146). Thickness, as much as 150 ft. Overlies Quinnimont Shale Member; underlies Sewell Member. Named for occurrence in Raleigh County, W. Va. References: 32, 115, 146. Sandia Formation (in Magdalena Group) Lower Pennsylvanian: Central-northern New Mexico. Series of sandstones, shales, and conglomerates. Thick- ness, 0 to over 2,000 ft. Basal formation in group. Underlies Madera Formation. Underlying units: Kelly Limestone, Lake Valley Limestone, Arroyo Penasco Formation, Tererro Formation, or Precambrian rocks. First described in Sandia, Manzano, and San Andres Moun- tains. References : 9, 64, 113. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES Schuylkill Member (of Pottsville Formation) Lower Pennsylvanian: Eastern Pennsylvania. Several beds of fine to coarse pebble conglomerate and quartzose sandstone intercalated with thinner beds of shale and coal. About 300 ft thick at type section. In- cludes coal beds that may be correlative with Lykens Valley No. 1, 2, and 3 coals. Middle member of Potts- ville is present at reference section of Pottsville; overlies Tumbling Run Member; underlies Sharp Mountain Member. Pennsylvania Geological Survey classifies the Schuylkill as a formation in Pottsville Group. Type section: East side U.S. Highway 122 about half a mile south of Pottsville. Mapped in Pine Grove, Potts- ville, Mahoney, Catawissa, and Lykens quadrangles. References : 57, 151. Sewell Member (of New River Formation) Lower Pennsylvanian : Southwestern Virginia and southern West Virginia. Overlies Raleigh Sandstone Member; underlies Nuttall Sandstone Member. West Virginia Geological Survey does not use term Sewell but applies names to the several sandstone and shale units that make up the interval. Named for Sewell, Fayette County, W. Va. Reference: 82. Sharon coal Pennsylvanian: Maryland, Ohio, Pennsylvania, and West Virginia. Coal in lower part of Pottsville and New River Formations. Lies above Sharon Shale. Reference: 98. Sharon Shale Member (of Pottsville Formation) Lower Pennsylvanian: Western Maryland, New York, eastern Ohio, western Pennsylvania, and northern West Virginia. Overlies Sharon Conglomerate Member; underlies Con- noquenessing Sandstone Member; overlies Olean Con- glomerate Member in New York. Ohio Geological Survey refers to the unit as Sharon Shale in Pottsville Series. Named for Sharon, Mercer County, Pa. References : 76, 93, 118. Sharp Mountain Member (of Pottsville Formation). Lower and Middle Pennsylvanian: Eastern Pennsylvania. Chiefly cobble and coarse pebble conglomerate and fine to coarse sandstone, siltstone, shale, and coal. About 280 ft thick at type section. Uppermost member of Pottsville is present at reference section of Pottsville; overlies Schuylkill Member ; contact with post-Pottsville rocks is at base of carbonaceous shale beneath Buck Mountain coal bed. At type section basal beds are about 70 ft above Lykens Valley No. 1 coal; in many areas in southern anthracite field, basal beds are about 30 ft above the coal. Pennsylvania Geological Survey classifies the Sharp Mountain as a formation in Pottsville Group. Type section : East side U.S. Highway 122 about half a mile south of Pottsville Mapped in Pine Grove, Pottsville, Mahoney, Catawissa, and Lykens quadrangles. References : 57, 151. Shihhotsi Series Permian: Northern China. Light-colored fresh-water and delta deposits without marine intercalations and almost without coal seams. Thickness, about 450 m. Divided into upper and lower parts on basis of lithology. K27 Occurs in central Shansi Province. Reference: 59. Stanley Shale Mississippian: Western Arkansas and central-southern and southeastern Oklahoma. Predominantly shale ; sandstone common ; siltstone in subor- dinate amounts. Maximum thickness, 11,000 ft in central Ouachitas. Underlies Jackfork Sandstone; overlies Ar- kansas Novaculite or Woodford Chert. Oklahoma Geo- logical Survey classifies the Stanley as a group and sub- divides it into three formations. Mississippian; evidence indicates Meramec. Unit has been assigned to Ordovician. Mississippian, and Pennsylvanian by various workers. Named for outcrops in valley of Kiamichi River near Stan: ley, Pushmataha County, Okla. References : 37, 86, 131. Stratford Formation (in Pontotoc Group) Permian : Central-southern Oklahoma. Consists of series of limestones at base (Hart Limestone Member) and undetermined thickness of dark shales above. About 400 ft of formation exposed in Stonewall quadrangle. Also classified as a facies of Konawa For- mation (183). Named for exposures at and around Stratford, Garvin County. References : 87, 95, 133. Sumner Group Permian: Eastern Kansas. About 1,000 ft of strata at outcrop. Predominantly gray shale but includes beds of red and green shale, deposits of dolomite, limestone, gypsum, and anhydrite. Thickness, about 1,000 ft. Comprises Wellington Formation, Nin- nescah Shale, and Stone Corral Formation. Overlies Chase Group; underlies Nippewalla Group. Named for Sumner County. References : 45, 69, 94. Supai Formation (in Aubrey Group) Pennsylvanian and Permian: Northern Arizona, western New Mexico, and southern Utah. Red beds of sandstones, shales, siltstones. Average thick- ness, about 1,400 ft. In Grand Canyon sections the Supai overlies Mississippian Redwall Limestone and underlies Hermit Shale. In central Arizona, where it is subdivided into several members, it underlies Coconino Sandstone and overlies Naco Limestone. Over Grand Canyon dome, entire Supai is probably Permian. Southeastward the Supai facies descends in the section and has yielded Penn- sylvanian fusulinids. Formation transgresses time lines and probably varies in age from Des Moines through Leonard. Named for exposures at Supai village in Havasu (Cataract) Canyon, northern Arizona. Havasu Canyon drains north- ward into the Grand Canyon and joins it about 85 miles north of Black Mesa. Supai is contraction of word Havasupai. References : 47, 51, 66, 68, 78, 82. Swope Limestone (in Kansas City Group) Pennsylvanian (Missouri Series): Southwestern Iowa, eastern Kansas, northwestern Missouri, and southeastern Nebraska. Comprises (ascending) Middle Creek Limestone (94), Hush- puckney Shale (94), and Bethany Falls Limestone Mem- bers. Thickness, about 27 ft in Iowa, 21 ft in Nebraska, K28 28 to 30 ft in Missouri, 20 to 30 ft in Bourbon County, Kans. Overlies Ladore Shale ; underlies Galesburg Shale. Named for Swope Park, Kansas City, Mo. References : 40, 50, 94. Tarter Member (of Abbott Formation) Lower Pennsylvanian : Western Illinois. Light-gray or bluish-gray argillaceous sandstone; locally discolored by carbonaceous matter. Thickness, a few inches to 3 ft. Present locally below Tarter Coal Mem- ber (75) of Abbott Formation. Illinois Geological Survey has discontinued name Tarter Sandstone in order to retain name Tarter for a coal member. % Type section: SE% sec. 2, T. 5 N., R. 1 E., Fulton County. Named for Tarter Bridge over Spoon River. References : 75, 111, 138. Tradewater Formation Middle Pennsylvanian: Western Kentucky. Chiefly shale and a few sandstone beds. Thickness, 175 to TOO ft in Webster County, Ky. Name Tradewater has been used as a group term in Illinois for strata overlying Caseyville Group and underlying Carbondale Group. Re cently the Illinois Geological Survey abandoned term Tradewater. Strata formerly included in unit are now included in the Abbott Formation of McCormick Group and Spoon Formation of Kewanee Group. Named for exposures along Tradewater River, east of Bat- tery Rock, Ky. References : 56, 75. Tumbling Run Member (of Pottsville Formation) Lower Pennsylvanian : Eastern Pennsylvania. Predominantly conglomerate and sandstone ; lesser amounts of conglomeratic sandstone, siltsone, shale, and coal. About 535 ft thick at type section. Basal member of Pottsville is present at reference section of Pottsville; underlies Schuylkill Member ; conformably overlies Mauch Chunk Formation. Pennsylvania Geological Survey classi- fies the Tumbling Run as a formation in Pottsville Group. Type section : East side U.S. Highway 122 about half a mile south of Pottsville Mapped in Pine Grove, Pottsville, Mahoney, Catawissa, and Lykens quadrangles. References : 57, 151. Twin coal Pennsylvanian: Eastern Pennsylvania. An equivalent of the Buck Mountain coal. References: 141, 151. Uniontown coal Pennsylvanian: Ohio, Pennsylvania, and West Virginia. Coal in Monongahela Formation above Pittsburgh coal and below Waynesburg coal. Considered correlative of Koontz coal. References: 17, 93. Vale Formation (in Clear Fork Group) Permian (Leonard Series) : Central and central northern Texas. Middle formation in Clear Fork Group. Formation ; overlies Arroyo Formation. Named for old post office at Ballinger-Maverick road on east side of Valley Creek, Runnels County. References: 14, 51. Virgil Series Upper Pennsylvanian: Arkansas, Iowa, Missouri Nebraska, and Oklahoma. Time-stratigraphic term for youngest Pennsylvanian rocks of midcontinent region. Separated by disconformities Underlies Choza SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY from Missouri Series, below, and Permian strata above. Considered as composing upper part of zone of Triticites. Brownville zone in northern midcontinent area is recog- nized as defining the Pennsylvanian-Permian boundary. Named for town in eastern part of Greenwood County, Kans. References : 88, 90, 94. Washington Formation (in Dunkard Group) Pennsylvanian and Permian: Western Maryland, eastern Ohio, southwestern Pennsylvania, and northern West Virginia. Lower formation in Dunkard Group. Includes Cassville Shale Member at base. Underlies Greene Formation ; overlies Waynesburg coal bed at top of Monongahela Formation. Named for exposures in highlands of Washington County, Pa. References: 51, 127. Waynesburg coal Pennsylvanian: Maryland, Ohio, Pennsylvania, Virginia, and West Virginia. Coal at top of Monongahela Formation (Series). Gen- erally accepted as marking top of Pennsylvanian in Ap- palachian region. In many areas overlain by Cassville Shale Member of Washington Formation. References: 17, 93. Weber Quartzite, Formation, Sandstone, or Shale Pennsylvanian: Western Colorado and northeastern Utah. At type section consists chiefly of gray to white but buff- weathering quartzites and sandstones. Some gray and light-gray limestones containing chert nodules. Thick- ness, about 3,000 ft. Overlies Morgan Formation ; under- lies Park City Formation. Type section: Upper Weber Canyon east of Morgan, Mor- gan County, Utah. References : 52, 74. Wedington Sandstone Member (of Fayetteville Shale) Upper Mississippian (Chester Series) : Northern Arkansas and northeastern Oklahoma. Fine-grained hard buff to brown sandstone at type locality, becoming flaggy to the east and west. Lies near middle of formation. Thickness, commonly 50 ft; 150 ft at type locality. Named for Wedington Mountain, Washington County, Ark. References : 1, 53, 139. Wellington Formation (in Sumner Group) Permian: Central and southern Kansas and northern Oklahoma. Chiefly gray silty shale containing several more or less lenticular beds of gypsum and fine-grained limestone ; con- tains salt in middle part in subsurface. Total thickness, about 700 ft. Basal formation of Sumner Group in Kan- sas; underlies Ninnescah Shale; overlies Nolans Lime- stone of Chase Group. In Oklahoma underlies Garber Sandstone ; overlies Asher Sandstone in west-central part of the State and Herington Limestone of Chase Group in north-central part; in southwestern part of the State the Garber and Wellington are undifferentiated. Named for exposures at Wellington, Sumner County, Kans. References : 44, 51, M4. Wolfcamp Series Lower Permian : New Mexico and Texas. A time-stratigraphic division of the Permian. At type lo- cality consists of about 600 ft of limestones, limestone con- 10. 11. 12. 13. 14. 15. UPPER PALEOZOIC FLORAL ZONES AND FLORAL PROVINCES glomerate, and shales. Varied fauna of fusulines, of which zone fossil is Pseudoschwagerina. In West Texas rests with angular unconformity on rocks ranging in age from Precambrian to Late Pennsylvanian and is uncon- formably overlain by Leonard Series. Type locality : Along face of Glass Mountains, central Texas. Name derived from old site of Wolf Camp. Wolf Camp Hills, a range of hills 2 miles long having summits of 4,952 and 5,060 ft, are at base of south face of Glass Mountains, 12 to 14 miles northeast of Marathon, Brewster County. References : 2, 48, 185. REFERENCES TO GLOSSARY . Adams, G. I., Purdue, A. H., and Burchard, E. F., 1904, Zinc and lead deposits of northern Arkansas : U.S. Geol. Sur- vey Prof. Paper 24, p. 1-89. . Adams, J. E., and others, 1939, Standard Permian section of North America: Am. Assoc. Petroleum Geologists Bull., v. 23, no. 11, p. 1673-1681. . Alcock, F. J., no date, Geology of St. John region, New Brunswick : Canada Geol. Survey Mem. 216, 65 p. [1938]. . Ami, H. M., 1900, Synopsis of the geology of Canada : Royal Soc. Canada Proc. and Trans., 2d ser., v. 6, sec. 4, p. 187-225. . Amsden, T. W., 1954, Geology of Garrett County in Geology and water resources of Garrett County, Maryland: Maryland Dept. Geology, Mines and Water Resources Bull. 13, p. 1-116. . Arndt, H. H., and others, 1959, Structure and stratigraphy in central Pennsylvania and the anthracite region in Geol. Soc. America Guidebook for field trips, Pittsburgh Mtg., Field Trip 1 : p. 1-59. . Aurin, F. L., Officer, H. G., and Gould, C. N., 1926, The sub- division of the Enid formation: Am. Assoc. Petroleum Geologists Bull., v. 10, no. 8, p. 786-799. . Baltz, E. H., and Bachman, G. O., 1956, Notes on the geology of the southeastern Sangre de Cristo Mountains, New Mexico in New Mexico Geol. Soc. Guidebook 7th Field Conf.: p. 96-108. . Baltz, E. H., and Read, C. B., 1960, Rocks of Mississippian and probable Devonian age in Sangre de Cristo Moun- tains, New Mexico: Am. Assoc. Petroleum Geologists Bull., v. 44, no. 11, p. 1749-1774. Bass, N. W., 1944, Correlation of basal Permian and older rocks in southwestern Colorado, northwestern New Mexico, northeastern Arizona, and southeastern Utah : U.S. Geol. Survey Oil and Gas Inv. Prelim. Chart 7 [accompanied by mimeographed text]. Bates, R. L., and others, 1947, Geology of the Gran Quivera quadrangle, New Mexico: New Mexico Bur. Mines Min- eral Resources Bull. 26, p. 1-52. Becker, C. M., 1929, Correlation of Permian outcrops on eastern side of the West Texas Basin: Am. Assoc. Petroleum Geologists Bull., v. 13, no. 8, p. 945-956. Beede, J. W., 1902, Coal measures fauna studies: Kansas Univ. Sci. Bull., v. 1, no. 7, p. 163-181. Beede, J. W., and Waite, V. V., 1918, The geology of Run- nels County : Texas Univ. Bull. 1816, 64 p. Bell, W. A., no date, Fossil flora of Sydney coal field, Nova Scotia: Canada Geol. Survey Mem. 215, 335 p. [1938]. 16. 17. 18. 19. 20. 21. 23. 25. 26. 27. 30. 31. 32. 33. 37. K29 Berryhill, H. L., 1960, in Dunbar, C. O., and others, Correla- tion of the Permian formations 'of North America: Geol. Soc. America Bull., v. 71, no. 12, pt. 1, p. 1763- 1806, Chart 7. Berryhill, H. L., Jr., and de Witt, Wallace, Jr., 1955, Revised correlation of Koontz coal and Pennsylvanian-Permian boundary in Georges Creek Basin, Allegany County, Maryland : Am. Assoc. Petroleum Geologists Bull., v. 39, no. 10, p. 2087-2090. Blythe, J. G., 1959, Atoka formation on north side of the McAlester Basin: Oklahoma Geol. Survey Cire. 47, 74 p. Bolyard, D. W., 1959, Pennsylvanian and Permian stra- tigraphy in Sangre de Cristo Mountains between La Veta Pass and Westcliffe, Colorado: Am. Assoc. Petro- leum Geologists Bull., v. 43, no. 8, p. 1896-1939. Branson, E. B., 1944, The geology of Missouri : Missouri Univ. Studies, v. 19, no. 3, 535 p. Brill, K. G., 1952, Stratigraphy in the Permo-Pennsylvanian zeugogeosyncline of Colorado and northern New Mexico : Geol. Soc. America Bull., v. 63, no. 8, p. 809-880. . Broadhead, G. C., 1866, Coal measures in Missouri: St. Louis Acad. Sci. Trans., v. 2, p. 311-333. Brown, Andrew, and others, 1952, Coal resources of Vir- ginia : U.S. Geol. Survey Cire. 171, 57 p. . Burbank, W. S., 1932, Geology and ore deposits of the Bonanza mining district, Colorado: U.S. Geol. Survey Prof. Paper 169, 166 p. Butts, Charles, 1905, Description of Ebensburg quadrangle: U.S. Geol. Survey Geol. Atlas, Folio 133. 1910, in Burchard, E. F., and Butts, Charles, Iron ores, fuels, and fluxes of the Birmingham district, Alabama : U.S. Geol. Survey Bull. 400, p. 11-25. 1940, Geology of the Appalachian Valley in Virginia : Virginia Geol. Survey Bull. 52, pt. 1, 568 p. . Campbell, M. R., 1893, Geology of the Big Stone Gap coal field of Virginia and Kentucky : U.S. Geol. Survey Bull. 111, 106 p. 1894, Paleozoic overlaps in Montgomery and Pulaski Counties, Virginia: Geol. Soc. America Bull., v. 5, p. 171-190. --- 1896, Description of the Pocahontas sheet [Virginia- West Virginia] : U.S. Geol. Survey Geol. Atlas, Folio 26. 1902, Description of the Raleigh quadrangle [West Virginia] : U.S. Geol. Survey Geol. Atlas, Folio 77. Campbell, M. R., and Mendenhall, W. C., 1896, Geologic see- tion along the New and Kanawha Rivers in West Vir- ginia: U.S. Geol. Survey 17th Ann. Rept., pt. 2, p. 473- 511. Chadwick, G. H., 1933, Catskill as a geologic name: Am. Jour. Sci., 5th ser., v. 26, p. 479-484. - 1986, History and value of name "Catskill" in geology : New York State Mus. Bull. 307, 116 p. . Cheney, M. G., 1940, Geology of north-central Texas: Am. Assoc. Petroleum Geologists Bull., v. 24, no. 1, p. 65-118. . Cheney, M. G., and others, 1945, Classification of Mississip- pian and Pennsylvanian rocks of North America: Am. Assoc. Petroleum Geologists Bull., v. 29, no. 2, p. 125 169. Cline, L. M., 1960, Late Paleozoic rocks of the Ouachita Mountains, Oklahoma : Oklahoma Geol. Survey Bull. 85, 113 p. K30 38. 39. 40. 41. 42. 43. 46. 47. 48. 49. 52. 56. 57. Cloos, Ernest, 1951, Stratigraphy of sedimentary rocks of Washington County in The physical features of Wash- ington County: Maryland Dept. Geology, Mines and Water Resources [Rept.], p. 17-94. Cohee, G. V., 1960, Series subdivisions of Permian System : Am. Assoc. Petroleum Geologists Bull., v. 44, no. 9, p. 1578-1579. Condra, G. E., 1949, The nomenclature, type localities, and correlation of the Pennsylvanian subdivisions in eastern Nebraska and adjacent states: Nebraska Geol. Survey Bull. 16, 67 p. Cooper, B. N., 1944, Geology and mineral resources of the Burkes Garden quadrangle, Virginia: Virginia Geol. Survey Bull. 60, 299 p. Cooper, G. A., and others, 1942, Correlation of the Devonian sedimentary formations of North America: Geol. Soc. America Bull., v. 53, no. 12, pt. 1, p. 1729-1794, Chart 4. Cox, E. T., 1871, Western coal measures and Indiana coal: Indiana Geol. Survey 2d Ann. Rept., p. 164-187. . Cragin, F. W., 1885, Notes on the geology of southern Kan- sas: Washburn Coll. Lab. Nat. History Bull., v. 1, no. 3, p. 85-91. 1896, The Permian system in Kansas: Colorado Coll. Studies, v. 6, p. 49-52. Cross, C. W., and Spencer, A. C., 1899, Description of the La Plata quadrangle, [Colorado]: U.S. Geol. Survey Geol. Atlas, Folio 60. Darton, N. H., 1910, A reconnaissance of parts of north- western New Mexico and northern Arizona: U.S. Geol. Survey Bull. 435, 88 p. Donner, H. F., 1949, Geology of McCoy area, Eagle and Routt Counties, Colorado: Geol. Soc. America Bull., v. 60, no. 8, p. 1215-1247. Dumble, E. T., 1890, Report of the State Geologist for 1889: Texas Geol. Survey 1st Ann. Rept., p. xvii-xe. . Dunbar, C. O., and Condra, G. E., 1932, Brachiopoda of the Pennsylvania system in Nebraska: Survey Bull. 5, 2d ser., 377 p. Nebraska Geol. . Dunbar, C. O., and others, 1960, Correlation of the Permian formations of North America: Geol. Soc. America Bull., v. 71, no. 12, pt. 1, p. 1763-1806, Chart 7. Eardley, A. J., 1944, Geology of the north-central Wasatch Mountains, Utah: Geol. Soc. America Bull., v. 55, no. 7, p. 819-895. 58. Easton, W. H., 1942, Pitkin limestone of northern Arkansas : Arkansas Geol. Survey Bull. 8, 115 p. . Fontaine, W. M., 1874, The "Great Conglomerate" on New River, West Virginia: Am. Jour. Sci., 3d ser., v. 7, p. 459-465. . Girty, G. H., 1902, The Upper Permian in western Texas: Am. Jour. Sci., 4th ser., v. 14, p. 363-368. Glenn, L. C., 1912, The geology of Webster County: Ken- tucky Geol. Survey Rept. Prog. 1910-11, p. 25-35. Gray, Carlyle, and others, 1959, Geologic map of Pennsyl- vania (1:250,000): Pennsylvania Geol. Survey, 4th ser. . Gray, H. H., Jenkins, R. D., and Weidman, R. M., 1960, Geology of the Huron area, south-central Indiana: In- diana Geol. Survey Bull. 20, pl. 1. . Halle, T. G., 1927, Paleozoic plants from central Shansi: Paleontologia Sinica, ser. A, v. 11, fase. 1, p. 1-316. 60. 61. 62. 65. 66. 67. 68. 69. 70. T1. T2. 73. 74. 75. 76. TT. 78. 79. 80. 81. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Haworth, E., and Kirk, M. Z., 1894, A geologic section along the Neosho River from the Mississippian formation of the Indian Territory to White River, Kansas, and along the Cottonwood River from Wycoff to Peabody: Kansas Univ. Quart., v. 2, p. 104-115. Hayes, A. O., and Bell, W. A., 1923, Southern part of Sydney coal field, Nova Scotia: Canada Geol. Survey Mem. 133, 108 p. Hayes, C. W., 1892, Report on the geology of northeastern Alabama and adjacent portions of Georgia and Ten- nessee: Alabama Geol. Survey Bull. 4, 85 p. . Henbest, L. G., 1958, Morrow group and lower Atoka for- mation of Arkansas: Am. Assoc. Petroleum Geologists Bull., v. 37, no. 8, p. 1935-1953. . Herrick, C. L., 1900, Geology of white sands of New Mexico : Jour. Geology, v. 8, p. 112-126. Howe, W. B., 1956, Stratigraphy of pre-Marmaton Des- moinesian (Cherokee) rocks in southeastern Kansas : Kansas Geol. Survey Bull. 123, 132 p. Huddle, J. W., and Dobrovolny, Ernest, 1945, Late Paleozoic stratigraphy of central and northeastern Arizona: U.S. Geol. Survey Oil and Gas Inv. Prelim. Chart 10. Huffman, G. G., and others, 1958, Geology of the flanks of the Ozark uplift, northeastern Oklahoma : Oklahoma Geol. Survey Bull. 77, 281 p. Jackson, R. L., 1951, Stratigraphic relationships of the Supai formation of central Arizona: Plateau, v. 24, no. 2, p. 84-91. Jewett, J. M., 1959, Graphic column and classification of rocks in Kansas: Kansas Geol. Survey. Johnson, V. H., 1946, Coal deposits on Sand and Lookout Mountains, Dade and Walker Counties, Georgia: U.S. Geol. Survey Prelim. Map. Kelley, V. C., and Wood, G. H., 1946, Geology of the Lucero uplift, Valencia, Socorro, and Bernalillo Counties, New Mexico: U.S, Geol. Survey Oil and Gas Inv. Prelim. Map 47. Keyes, C. R., 1893, Geological formations of Iowa : Towa Geol. Survey Ann. Rept. 1892, v. 1, 161 p. 1903, Ores and Metals, v. 12, p. 48. King, Charles, 1876, Paleozoic subdivisions on the fortieth parallel: Am. Jour. Sci., 34 ser., v. 11, p. 475-482. Kosanke, R. M., and others, 1960, Classification of Pennsyl- vanian strata of Illinois: Illinois Geol. Survey Rept. Inv. 214, 84 p. Lamborn, R. E., Austin, C. R., and Schaaf, Downs, 1938, Shales and surface clays of Ohio: Ohio Geol. Survey, 4th ser., Bull. 39, 281 p. Lee, W. T., 1909, Stratigraphy of the Manzano group of the Rio Grande Valley, New Mexico: U.S. Geol. Survey Bull. 389, p. 5-40. Lehner, R. E., 1958, Geology of the Clarkdale quadrangle, Arizona: U.S. Geol. Survey Bull. 1021-N, p. 511-590. Lesley, J. P., 1876, The Boyd's Hill gas well at Pittsburg in Platt, Franklin, Special report of the coke manufac- ture of the Youghiogheny River valley in Fayette and Westmoreland Counties: Pennsylvania 2d Geol. Survey Rept. L, App. E, p. 217-237. 1879, in White, I. C., The geology of Lawrence County: Pennsylvania 2d Geol. Survey Rept. Q:, p. ix-xxxvi. Litsey, L. R., 1958, Stratigraphy and structure of the north- ern Sangre de Cristo Mountains, Colorado: Geol. Soc. America Bull., v. 69, no. 9, p. 1143-1178. 82. 83. 84. 85. 86. 87. 88. 89. 91. 92. 93. 94. 95. 97. 98. 99. UPPER PALEOZOIC FLORAL ZONES McNair, A. H., 1951, Paleozoic stratigraphy of part of north- western Arizona: Am. Assoc. Petroleum Geologists Bull., v. 35, no. 3, p. 508-541. Mather, W. W., 1840, Fourth annual report on the geological survey of the first geological district of State of New York: New York Geol. Survey Rept. 4, p. 209-258. Matthew, G. F., 1863, Observations on the geology of St. John County, New Brunswick: Canadian Naturalist, v. 8, p. 241-259. Meek, F. B., and Worthen, A. H., 1861, Remarks on the age of the Goniatite limestone at Rockford, Indiana, and its relation to the "black slate" of the Western States, and to some of the succeeding rocks above the latter: Am. Jour. Sci., 2d, v. 82, p. 167-177. Miser, H. D., and Hendricks, T. A., 1960, Age of Johns Valley shale, Jackfork sandstone, and Stanley shale: Am. Assoc. Petroleum Geologists Bull., v. 44, no. 11, p. 1829- 1832. Miser, H. D., and others, 1954, Geologic map of Oklahoma (1: 500,000) : U.S. Geol. Survey. Moore, R. C., 1931, Correlation chart of post-Devonian rocks in part of the Midcontinent reigon in Kansas Geol. Soc. Guidebook 5th Ann. Field Conf. 1936, Stratigraphic classification of the Pennsyl- vanian rocks of Kansas: Kansas Geol. Survey Bull. 22, 256 p. 1948, Classification of Pennsylvanian rocks in Towa, Kansas, Missouri, Nebraska, and northern Oklahoma : Am. Assoc. Petroleum Geologists Bull., v. 32, no. 11, p. 2011-2040. 1949, Divisions of the Pennsylvanian system in Kan- sas: Kansas Geol. Survey Bull. 83, 203 p. 1949, Rocks of Permian(?) age, Colorado River val- ley, north-central Texas: U.S. Geol. Survey Oil and Gas Inv. Prelim. Map 80. Moore, R. C. and others, 1944, Correlation of the Pennsyl- vanian formations of North America: Geol. Soc. America Bull., v. 55, no. 6, p. 657-701, chart 6. 1951, The Kansas rock column: Kansas Geol. Sur- vey Bull. 89, 132 p. Morgan, G. D., 1924, Geology of the Stonewall quadrangle : [Oklahoma] Bur. Geology Bull. 2, 248 p. . Needham, C. E., and Bates, R. L., 1943, Permian type sec- tions in central New Mexico: Geol. Soc. America Bull. v. 54, no. 11, p. 1653-1668. Newberry, J. S., 1874, The Carboniferous System: Ohio Geol. Survey Rept., v. 2, pt. 1, p. 81-180. Noble, L. F., 1922, A section of Paleozoic formations of the Grand Canyon at the Bass trail: U.S. Geol. Survey Prof. Paper 131-B, p. 23-73. Norling, D. L., 1958, Geology and mineral resources of Mor- gan County: Ohio Geol. Survey Bull. 56, 131 p. 100. Oakes, M. C., 1953, Krebs and Cabaniss groups of Pennsyl- vanian age in Oklahoma: Am. Assoc. Petroleum Ge- ologists Bull., v. 37, no. 6, p. 1523-1526. 101. Oakes, M. C., and Knechtel, M. M., 1948, Geology and min- eral resources of Haskell County, Oklahoma : Oklahoma Geol. Survey Bull. 67, 134 p. 102. Orton, Edward, 1884, Massillon coal field : Ohio Geol. Sur- vey Rept., v. 5, p. 778-815, map. 103. Otte, Carel, Jr., 1959, Late Pennsylvanian and early Per- mian stratigraphy of the northern Sacramento Moun- tains, Otero County, New Mexico: New Mexico Bur. Mines Mineral Resources Bull. 50, 108 p. 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. 117. 118. 119. 120. 121. 122. 123. 124. 125. AND FLORAL PROVINCES K31 Owen, D. D., 1856, Report of Geological Survey 1854-1855: Kentucky Geol. Survey Rept., v. 1, 248 p. Platt, Franklin, 1875, Report of progress in the Clearfield and Jefferson district of the bituminous coal fields of western Pennsylvania: Pennsylvania 2d Geol. Survey Rept. H, 296 p. Plummer, F. B., 1919, Preliminary paper on the stratigraphy of the Pennsylvanian formations of north-central Texas (with discussion): Am. Assoc. Petroleum Geologists Bull., v. 3, p. 132-150. Plummer, F. B., and Moore, R. C., 1922, Stratigraphy of the Pennsylvanian formations of north-central Texas: Texas Univ. Bull. 2132, 237 p. Price, P. H., and Heck, E. T., 1939, West Virginia Geol. Survey [Rept.], Greenbrier County, 846 p. Prosser, C. S., 1895, The classification of the upper Paleozoic rocks of central Kansas : Jour. Geology, v. 3, p. 682-800. Purdue, A. H., 1907, Description of the Winslow quadrangle [Arkansas-Indian Territory] : U.S. Geol. Survey Geol. Atlas, Folio 154. Read, C. B., 1947, Pennsylvanian floral zones and floral provinces : Jour. Geology, v. 55, no. 3, pt. 2, p. 271-279. 1955, Floras of the Pocono formation and Price sandstone in parts of Pennsylvania, Maryland, West Virginia, and Virginia: U.S. Geol. Survey Prof. Paper 263, 82 p. Read, C. B., and Andrews, D. A., 1944, The Upper Pecos River and Rio Galisteo region, New Mexico: U.S. Geol. Survey Oil and Gas Inv. Prelim. Map 8. . Reger, D. B., 1926, West Virginia Geol. Survey Rept. Mer- cer, Monroe, and Sumner Counties, 963 p. 1931, Peuusylvanian cycles in West Virginia : Illi- nois Geol. Survey Bull. 60, p. 217-239. . Reinmund, J. A., and Danilehik, Walter, 1957, Preliminary geologic map of the Waldron quadrangle and adjacent areas, Scott County, Arkansas: U.S. Geol. Survey Oil and Gas Inv. Map OM-192. Rogers, H. D., 1840, Pennsylvania Geological Survey 4th Annual Report : 215 p. 1858, Stratigraphic arrangement of the coal meas- ures of western Pennsylvania: Geology of Pennsyl- vania, v. 2, pt. 1, p. 474-493. Rogers, W. B., 1879, Macfarlene's Geological Railway Guide: p. 179. Roth, Robert, 1930, Regional extent of Marmaton and Cherokee midcontinent Pennsylvanian formations : Am. Assoc. Petroleum Geologists Bull., v. 14, no. 10, p. 1249- 1278. \ 1945, Permian Pease River group of Texas: Geol. Soc. America Bull., v. 56, no. 10, p. 893-907. Scott, G. L., Jr., and Ham, W. E., 1957, Geology and gypsum resources of the Carter area, Oklahoma: Oklahoma Geol. Survey Cire. 42, 64 p. Shelbourne, O. B., Jr., 1960, Geology of the Boktukola syn- cline, southeastern Oklahoma : Oklahoma Geol. Survey Bull. 88, 84 p. Simonds, F. W., 1891, The geology of Washington County : Arkansas Geol. Survey Ann. Rept. 1888, v. 4, 148 p. Spencer, F. D., 1953, Coal resources of Indiana : U.S. Geol. Survey Circ. 266, 42 p. K32 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. 140. Spivey, R. C., and Roberts, T. G., 1946, Lower Pennsyl- sylvanian terminology in central Texas: Am. Assoc. Petroleum Geologists Bull., v. 30, no. 2, p. 181-186. Stevenson, J. J., 1876, The report of progress in the Greene and Washington district of the bituminous coal field of western Pennsylvania : Pennsylvania 24 Geol. Sur- vey Rept. K, 397 p. Stopes, M. C., 1914, The "Fern Ledges" Carboniferous flora of St. John, New Brunswick: Canada Geol. Survey Mem. 41, 167 p. Sturgeon, M. T., and others, 1958, Geology and mineral re- sources of Athens County, Ohio: Ohio Geol. Survey Bull. 57, 600 p. Taff, J. A., 1899, Geology of the McAlester-Lehigh coal field, Indian Territory : U.S. Geol. Survey 19th Ann. Rept., pt. 3, p. 423-456. 1902, Description of the Atoka quadrangle, [Indian Territory] : U.S. Geol. Survey Geol. Atlas, Folio 79. Taff, J. A. and Adams, G. L., 1900, Geology of the eastern Choctaw coal field, Indian Territory: U.S. Geol. Sur- vey 21st Ann. Rept., pt. 2, p. 257-311. Tanner, W. F., 1956, Geology of Seminole County, Okla- homa: Oklahoma Geol. Survey Bull. 74, 175 p. Thompson, M. L., 1942, Pennsylvanian system in New Mexico: New Mexico Bur. Mines Mineral Resources Bull. 17, 92 p. Udden, J. A., 1917, Notes on the geology of Glass Moun- tains: Texas Univ. Bull. 1753 p. 3-59. Udden, J. A., Baker, C. L., and Bose, Emil, 1916, Review of the geology of Texas: Texas Univ. Bur. Econ. Geology and Technology Bull. 44 [1644], 164 p. Ulrich, E. O., 1904, in Buckley, E. R., and Buehler, H. A., The quarrying industry of Missouri: Missouri Bur. Geology and Mines, 2d ser. v. 2, 371 p. Wanless, H. R., 1957, Geology and mineral resources of the Beardstown, Glasford, Havana, and Vermont quad- rangles : Illinois Geol. Survey Bull. 82, 233 p. Weller, J. M., and others, 1948 Correlation of the Mis- sissippian formations of North America: Geol. Soc. America Bull., v. 59, no. 2, p. 91-196, Chart 5. Wengerd, S. A., and Matheny, M. L., 1958, Pennsylvanian system of Four Corners region : Am. Assoc. Petroleum Geologists Bull., v. 42, no. 9, p. 2048-2106. SHORTER CONTRIBUTIONS TO 141. 142. 143. 144. 145. 146. 147. 148. 149. 151. 152. GENERAL GEOLOGY White, David, 1900, The stratigraphic succession of the fossil floras of the Pottsville formation in the southern anthracite coal field, Pennsylvania: U.S. Geol. Sur- vey 20th Ann. Rept., pt. 2, p. 751-930. 1943, Lower Pennsylvanian species of Mariopteris, Eremopteris, Diplothmena, and Aneimites from the Appalachian region: U.S. Geol. Survey Prof. Paper 197-C, 140 p. White, I. C., 1885, Resume of the work of the U.S. Geo- logical Survey in the Great Kanawha Valley during summer 1884: The Virginias, v. 6, no. 1, p. 7-16. 1891, Stratigraphy of the bituminous coal field of Pennsylvania, Ohio, and West Virginia: U.S. Geol. Survey Bull. 65, 212 p. 1903, Report on coals: West Virginia Geol. Survey [Rept.], v. 2, 725 p. 1908, Supplementary coal report: West Virginia Geol. Survey, v. 2-A, 720 p. Williams, H. S., 1891, Correlation papers Devonian and Carboniferous: U.S. Geol. Survey Bull. 80, 279 p. Wilpolt, R. H., and Marden, D. W., 1959, Geology and oil and gas possibilities of Upper Mississippian rocks of southwestern Virginia, southern West Virginia, and eastern Kentucky: U.S. Geol. Survey Bull. 1072-K, p. 587-656. Wilpolt, R. H., and others, 1946, Geologic map and strati- graphic sections of the Paleozoic rocks of Joyita Hills, Los Pinos Mountains, and northern Chupadera Mesa, Valencia, Torrance, and Socorro Counties, New Mexico: U.S. Geol. Survey Oil and Gas Inv. Prelim. Map 61. . Wilson, C. W., Jr., Jewell, J. W., and Luther E. T. 1956, Pennsylvanian geology of the Cumberland Plateau: Tennessee Div. Geology [Folio]. Wood, G. H., Jr., and others, 1956, Subdivision of Potts- ville formation in southern anthracite field, Pennsyl- vania: Am. Assoc. Petroleum Geologists Bull., v. 40, no. 11, p. 2669-2688. Worthen, A. H., 1860 Remarks on discovery of a terrestrial flora in the mountain limestone of Illinois [abs.]: Am. Assoc. Adv. Sci. Proc., v. 13, p. 312-318. . Wrather, W. E., 1917, Notes on the Permian: South- western Assoc. Petroleum Geologists Bull., v. 1, p. 93-106. A Page Abbott Formation_......._..._________________ K7, 8 Abo Formation. 12,13, 14, 17 6 » 01 2.2 00.002 000 000000 enum eons re 20 n. 8 spectabilis... ___. - pl1 Adiantites spp., zone of.. ________________ - 4,16 Alabama.... 7 Alcicornopteris. 4,5 Alethopteris aquilina...__.___________ 11 decurrens. 7, 9, pl. 5 lonchitica . . 8, 9 Son co enne nie one ece n - 9,10, 11 Alethopteris decurrens, zone of_________ vea 7 Allegheny Formation......._.._______________ 9, 10 6 inaequilateralis.....____________ Alloiopteris inaequilateralis, zone of Ancestral Rocky Mountains... 7,8, 9, 10, 11, 12, 13, 17 .c. 00 0 0000000000 0000000000000, 5 . c 22.2020 0000000000000 eee nee nevus. pl. 4 temnvifolius. c pl. 4 Aneimites spp., zone of.... F 7 Angara flora... rf 14 -.. 12,14 acicularis..__________ - 9 cuspidata. latifolia..._____... radiata_._..._..... ___ sphenophylloides, stellata_______._ filiciformis... . Appalachian basin.. Appalachian trough.. Arborescent lycopods. Archaeocalamites_....._. Archaeopteris macilenta....___________________ 13, 14 Asterophyllites equisetiformis.._______________ 9, 10, 11 MHRUEUSL 20 0000000000000 000 9 6 2222000000000, 0 000 uuu seen lll, 9 Asterotheca 9 Atok@ 8, 9 B Belle Plains Formation_....____._________._ 14,15, 17 Bibliography......__. -. 18, 20 Bluestone Formation. 5 Bloyd Shale.... 7 Bothrodendron sp... .. - 9 Brachyphylum temue. . ............_........_. pl. 14 Brongniartites Sp.. pl. 19 Buck 11 C Cala ians, - e 14 Cala 3,7 CBH. cn c nnn none nnn 11 ramosus.. ._.... e+ 9 TOEMETH 6 SUOKOW .co cn nene nnn n nnn once 8,9, 10 Idenburgensis. 9 Cal dendron approzimat 10 INDEX [Italic page numbers indicate major references] Page Calamophyton.. .. K3 C@l@MOPitY8.. .. cc 2222222 3 Calamostachys germanica.............__.. 9 ramosus..._....... 9 C@IQIRODS. ... ccc 220000 nne 4,5 Callipteridium grandini... es 11 SUHHDOREH... 11.220 00000000000 nn cnn nn 10 Callipterids. .. 15 Callipteris_.......... 13, 15, pl. 17 Q@UZDGMEI8L... cc 0200 non nn noon pl. 19 CORT : ter e2ceris tubes er ane as an 14, pl. 13 Rabellifera.. ..... - 14, pl. 17 . . . . .. 2000 14, pl. 13 STIYOSN . . ooo cns seee ee 600 cum 14 crampii..... obliquum .. . phillipsi. Cardiopteris...... Carpolithes ellipticus. . 1 ETAMS8ECHLSL ... cll 1 Caseyville Formation..._.........______._____ Cassville Shale Member of the Washington 1,12 Catskill Formation..............__.._________ 3 Chester Series. .... 6 CHUOZYIOM.... .... .ll ll 4 8COPATHUM L L .l lolol 3 Clear Fork Group.. as 15 Clyde Formation.........___________________. 14 Coal measures, defined.. ....._.._..___________ 4 Colorado............. 9, 10 Compsopteris 8p.._....._________._________ pls. 18, 19 Conemaugh Formation........_.______________ 10, 11 Cordaianthus devonicus... 8 Cordaicarpon cimetum......._.________________ 11 13, 14 Cordaites principalis....._____________________ 8, 9 2222200000000 nono nono 8 Cordilleran flora................______________ 16 Cordilleran province..............____________ 7,8 Cyatheoid pecopterids._...._._________ -- 9,10, 12 Cyclocladia 11 D Dadozylon ouangondianum........._._________ 8 Danacites _.. -_ 12, pls. 11, 12 Danaeites spp., zone of... Daubrecia sp...... Des Moines Series. Dicranophylum glabrum.. ... Diichni Diplothmema subfurcatum.. Dipplotmema furcatum .... 14 Dunkard 1,12 E Eagle coal 9 Eastern Interior coal field..._.._.___________ 7 Page El Reno K16 Elmdale Shale.... 11 Eospermatopteris textilis_..___________ 3 6 lincolniana 9 soren eeu naa 8 Ernestiodendron.._..______________. 14 Eupecopteris (Dactylotheca) dentata._.__________ 9 F Fayetteville Shale....._______________________ 6 Fern Ledges of Little River Group.._________ 8 Floral zones, general discussion._......__._____ 4 Flowerpot Shal6...__._._.___._..____._________ 16 PTYODBN8. . .. . . 2.222 0020000000000 0000000 ene, 5,6 2222222222 pl. 3 Fryopsis spp., z0ne Of.._______________________ 6,16 G Garber Sandstone. ..... ern ine 13, 14, 17 Georges Creek coal basin. Gigantopteris....________ americana. sp. A.... Beoiy sone oren rer enas Gigantopteris, zone of the younger flora.... . __ Gigantopteris flora. 14 Gigantopteris flora, zone of.. & 18 . - ae 202000 ee oen ones ne ep uis neni none 4,5 Glenopteris. 13 pl. 16 .l pl. 16 Glenopteris spp., zone of. . ____________________ 18 ..... 14 . 12222222222 nnn noon pl. 13 H Hartshorne Sandstone.............___________ 9 Hermit 13,17 .................. 10 ........................ 7 .............................. 2 e 3 Hymenophyllites bronmi.._..__________________ 9 Hymenotheca dathei._........._______._______. 9 I TIIMOIS. . . 8 Indiana.... «> 7 IOW. sos 8 J Jackfork Sandstone.............____________.. 6 K EQ.... 3 Kanawha Formation..............._______.__. 7, 9 Katsberg Redbeds... 3 Kerber FOFMation............._______________ 9 Koontz coal bed......_______________________ 12 L Lagenospermum. «--- 45 Lampasas Series......._______________________ 8 Leonard Series. ..._..._______________________ 17 K33 K34 Page Lepidocystis (Sigillariostrobus) quadrangularis.. K11 10, 11 6,7 brittgli. .... 11 crenatum . .. 8 dichotomum.. 9 TROGMIGLUM. . 11 ODODMUIHL . . . .. f 9 vestitum . . ....- - 11 volkmannianum. 8 Lepidodendropsis.... 4,5 scobtniformis................ ... p12 Lepidophyllum affine...........~ a= 11 campbellianum... s 9 11 lanceolatum.. 6 MARSAAH. .. 11 oblongifolium . . . . ....- 11 quinnimontanum . 6 HUREQLUM cee >>> 10 Lepidostrobus géimitzii. . .._._............~~--- 11 variabilis........~~- Lescuropteris moorii... ... Lescuropteris spp., zone of.____.~- Limopteris milensteri..___._______________««---- 9 JiRETSOMER8i8.. . .... 10 rubella........~ Little River Group.. Lobatannularia .. e Lonchopteris eschweileriana.............- 9 Lueders Limestone.....--- 15 Lycopods.................. 14 Lykens Valley No. 2 Coal..............------- 7 No. 3 coal..................- 7 No. 4 coal................... 7 NO. 5 6 M McCormick GrOUp..................---«----- 7,8 McCoy FOrMatio®......_.............««~~--- 10 Madera Formation .. pottsvillea. .. pygmaga.. #ilHMARRME . . 11 SDhEMODLETOide8. ... 11 spinul 11 Mariopteris pottsvillea, 1000 Of.............--- 7 Mariopteris pygmaea, zone of. 7 Mauch Chunk Formation.......~~- 5 Mazon Cre@k.........._...........- 1 Megalopteris 8 a A 8 fasciculata. ... 8 ROHL . 8 8 thuellii _... 8, pl. 7 Megalopteris SDP., 208 Of..........___....«««~ 7 Mercer Shale of the Kanawha Formation....~ 9 Mississippian floral provinces, distribution.. . 16 Mississippian floral zones.. 4 Monongahela Formation. 11 Morien Serie8. .. 8, 9, 10 MOrrOW 7 N Nematophyton. . 3, 4 14 INDEX Page K14 AOWEUNLL.L. .- cucu non ees 9 . J .s -o coon er 11 CODIHQG. .._. 10, 11 ATNIQBHA:. . . -.- enone nne ues es 8 11 9, 11, pl. 9 iJAMICG... ._ sees 8 QTOMGETL .. . . 11 10 10 8 IROEOIGIL. ».... c anus nes 8 HLTH... . .\. sun onne onn sake 12, pl. 12 MMSSOUTIERSI8. . . . ___ 8, 10 ORN: -L -.- ris 9, 10, 11, 12, pl. 9 PHO... .. « POC@hOMIA8....................« ... . -. s 9, 10, pl. 8 scheuchzeri.. ..- - 10, 11, 12 QRQUSHJOHG . .._ 9 S@HYRE. .... c 8 7 tennesseeama...........-- -. plL6 tenuifolia . . ...- - 8,9, pl. 7 11 ..... 9 Neuropteris flexuosa, zone of 10 Neuropteris rarinervis, 2008 Of.____......_---- 9 Neuropteris tennesseeana, zone 7 Neuropteris tenuifolia, z0NG Of.............---- 9 New BrUunswitk....._.___.....___.__.........- 8 New Mexico.....~- 7,9, 10 New River Formation, redefined ...... secs 7 Nova Scotia.........-~- oul 9, 10 0 12,14, 15 OGOMEOPLETi8........ ccc 12, pl. 17 brardii. ... as 11 RASCRETL L.... ._ c ...l c WOMROMLL .. .cc. Odontopteris spp., zone of......~ A 18 es R 7 Oliogocarpia 11 .._ cesses eee 8 Ovopteris communis....... -.. pl. 6 Ovopteris communis, z0ne Of..................- 7 P Parkwood Formation......................--- 5 14 PeCODLETI8. .. 12 ............. pl. 9 OTJUQ. ... c 11 p formis. - 11 pl - $ 8 polymorpPha............~««. 11 10 K7 Pennsylvanian floral provinces, distribution.. 16 Permian floral provinces, distribution. ...... 16 Permian floral zones......................_... 12 Pittsburgh coalbed................._........- 11 8p. «..... 8 Pocahontas Formation, redefined... 6 Pocono Formation..........--- 5 PYOSSETHL . .... cos 3 3 Protolepidodendron... a 3 Pseudobornia........~- ae 3 Pseudopecopteris il 10 REUTODLETOIES.... es 10 OUAUODG........ .. 10, 11 squamosa ...... 11 trifoliolat pee 9 Psygomophyllum... 8 Pteridophylls.....- 14 Pterispermostrobus bifurcatus............ ~- az 8 16 Q Quinnimount Shale Member of New River Formation........................ 7 R Radicites 11 Rhabdocarpos mamillatUs.............~....~--- 11 multistriatus 10,11 F HEHE cel ceils ewe C 9 Rh teris - 4 b 8 THONG. cenno lecaicncss pl. 1 Rhodea. . ..- 4,5, 6 vespertina..... pl. 2 Rocky Mountain area................--..---- 7 8 Samaropsis......~-.~.-- 14 COPRUG .. .._ 9 RESDETHUS . . . seee} ->> 10 Sandia Formation.......~- 7, 9 Sewell Member of the New River Formation. 4 SR&AFON 7 Shihhotse Series..................«..~~-- 15 Sigillaria brardti. .. 11 RAUMGRQ... 6 rugosa . - 8 tessellata.... 11 Southern Anthracite region.....~ 7 Sphenophyllum.... cuncifolium... emarginatum...... .c cl sess ke 9 gilmorei............ ._ 13, pl. 15 lescurianum. ange 10 SUSDECHLIM .... ccc cece ess 10 7 Sphenopteridium brooksi..... - 2 Sphenopteridium spp., zone of....~ aese 5 Sphenopteris. ... 5,12 QSDIERIOiGES..... . 6 7 communis... ...- 8 10 9 9 9 8 9 11 10 9 jas m 3 nummularia. . palmatiloba. ... schatzlarensis. . . __ spinosa. ..____ suspecta. ..... tracyama...._......_______ valida... .. Sporangites acuminata. . Stanley Shale. Stenomyelon.....__.______ Sternbergia sp......_________________ Stigmaria ficoides.....______________ Stratigraphic terms, glossary of..... See also particular stratigraphic unit. Stromatolites.........________________ Sumner Group.........____________ La m o» co 1 fai m w o 1 ha w co co to > co co w INDEX Page Supai Formation.....................________ K17 Sydney coal 9 T 1222 lea lence ene 12,13, 14, 15 missouriensis. ___ 10 MEW . pl. 16 Tarter Member of the Abbott Formation .____ 8 TPOHINORSGG . . ... ... oll oon nene oen enone enna nee. 7 oer. eno beeen be eure. . 8 Thursophyton.....__. Tradewater 7 Trichopitys whiter. ..___________L.L_L__________ 7 8 OlVAefOPME..L LL. 11 Triphylopteris lescuriana. ..__________________ pl. 1 PATHRTIHSL L0. ..... ... 0020. coco ugs pl. 2 Triphyllopteris spp., zone of.___.______________ 6,16 Twin gol bed. co 11 K35 Page U Uniontown coal bed...._...._________________ K12 v Vale Formation. 16 w L.. clos 20 eee ee oe cen s -_ 13, 14 pintformiss .... - 12, pl. 13 stricta. . ._.___ 10 Walchiostrobus sp... 10 Wardia..__...__... 6 Washington Formation........_._________. 12 Weber Formation..._.______. 7 Wedington Sandstone..._._____._____________ 6 Wedington Sandstone Member....____._____. 6 Wellington Formation....___ «-w 49/17 West Virginia...______________ heve 7 Whittleseya concinna....._____ tp 8 L222 8 Wolfcamp Series. 12 Z Zeilleria avoldensis. .__________________________ 9 PLATES 1-19 The numbering of illustrations and positioning of the successively younger floral zones in plates 1-19 presents to the reader a series of illustrations of fossils as they might occur in an idealized stratigraphic section if the plates were removed from the report and at- tached one above the other with plate 1 at the base. PLATE 1 [All figures natural size] ZONE 1. ZONE OF ADIANTITES SPP. FicurE 1. Adiantites spectabilis Read Part of a rachis showing several pinnules. - Note that the pinnules are broadly ovate or obcuneate ovate and are com- monly incised into several divisions. The nervation is palmate from a single basal nerve. The rachis appears to have been lax and angularly sinuose; this evidence suggests that the fronds may have had a climbing or clambering habit. Locality: Shale in the lower part of the Pocono Formation at east end of railroad tunnel near Caledona, Clearfield County, Pa. USNM 40688. 2. Rhacopteris latifolia (Arnold) Read Specimen showing the possibly bipinnate nature of the frond. Note the crowded and overlapping pinnules which are subopposite, obovate, and apparently sessile on the rachis. The distal margins of the pinnules are either dentate or crenate. The venation apparently originates from a plexus of strands at the base and commonly dichotomizes as the veinlets pass to the margins. Locality: Shale in lower part of Pocono on Horseshoe Curve just above Kit- tanning Point on main line of Pennsylvania Railroad near Altoona, Blair County, Pa. USNM 40666. ZONE 2. ZONE OF TRIPHYLLOPTERIS SPP. Ficur® 3. Triphyllopteris lescuriana (Meek) Lesquereux Specimen of a pinna showing the rigid aspect and the slightly overlapping pinnules of the ultimate pinnae. The pinnules are obcuneate or oblanceolate, slightly decurrent, and rigid in general aspect. Locality: 1% miles north of Vicker, Montgomery County, Va., on road to Price Forks in an outcrop of upper part of Price Sandstone above Merrimac coal. USNM 19929. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 1 ZONE 2,Z0NE OF TRIPHYLLOPTERIS SPP. ZONE 1, ZONE OF ADIANTITES SPP. PLATE 2 [All figures natural size} ZONE 2. ZONE OF TRIPHYLLOPTERIS SPP. Frcur® 1. Triphyllopteris rarinervis Read Specimen showing the general aspect of a part of the frond that is probably bipinnate. The lateral pinnae alternate and are set at nearly right angles to the rachis, although they become slightly more acute apically. The pinnae slightly overlap and are rigid in general aspect. The bases are slightly decurrent. The pinnules are obcuneate or oblanceolate and asymmetrical; some are bidenticulate or tridenticulate at the apices. The nervation is coarse. Locality: 1% miles north of Vicker, Montgomery County, Va., on road to Price Forks, in an outcrop of upper part of Price Sandstone above Merrimac coal. - USNM 40641. 2. Lepidodendropsis scobiniformis (Meek) Read A specimen showing the elongate bolsters, arranged in a very close spiral so that they appear to be in nearly horizontal as well as vertical rows. - The lower parts of the bolsters are almost devoid of any markings. - The indistinct leaf scars are situated in the upper part of the bolsters and are somewhat quadrangular with the angles rounded. The vascular strands, which are centrally located, are not known in detail. There is no evidence of a parichnos scar in specimens of this species that have been examined. - Locality: Coaly and shaly beds in upper part of Pocono For- mation along Pennsylvania Railroad right-of-way south of Pottsville, Schuylkill County, Pa. USNM 40671. 3. Rhodea vespertina Read A specimen showing the delicate nature of the frond with the rigid and rather flexuose pinna axes. The ultimate pinnae are alternate to subopposite, distinct, and set at angles of approximately 45°. - The pinnules are finely divided, each lobe having only one nerve. The apices are rounded. Locality: 1% miles north of Vicker, Montgomery County, Va., on road to Price Forks, in an outcrop of upper part of Price Sandstone above Merrimac coal. - USNM 40639. ZONE 3. ZONE OF FRYOPSIS SPP. 4. Sphenopteridium brooksi Read A specimen that indistinctly shows the major part of a dichotomous frond in which the branches both above and below the dichotomy are disposed in a pinnate or bipinnate fashion. The pinnules are ovate-cuneate and are modified by lobation. Locality: Mauch Chunk Formation, on Beech Fork about half a mile southeast of Left Fork of Beech Fork at the level of the abandoned Alexander Lumber Co. railroad grade, Upshur County, W. Va. USNM 40655. PROFESSIONAL PAPER 454-K PLATE 2 GEOLOGICAL SURVE{ ZONE OF FRYOPSIS SPP. a ZONE 3 ZONE 2, ZONE OF TRIPHYLLOPTERIS SPP. PLATE 3 [Figure natural size} ZONE 3. ZONE OF FRYOPSIS SPP. FIGURE 1. Fryopsis abbensis (Read) Wolfe Shale slab showing many pinnules. The pinnules are round-cordate and symmetrical; the apices are gently rounded or slightly elongate and more sharply rounded. The venation radiates from the point of attachment to the rachis, and no midrib is apparent. - Locality: Lower part of Bluefield Shale, overlying Greenbrier Limestone in Abbs Valley, Tazewell County, Va. USNM 40680. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 3 ZONE 3. ZONE OF FRYOPSIS SPP. PLATE 4 [All figures natural size) ZONE 4. ZONE OF NEUROPTERIS POCAHONTAS AND MARIOPTERIS EREMOPTEROIDES Ficur® 1. Mariopteris eremopteroides White A specimen showing the slightly flexuose pinna axis of the crowded ultimate pinnae and pinnules. The pinnules are alternate to subopposite, oval-triangular, narrowly ovate to ovate or rhomboidal. The pinnules show a.tendency to lobation. - The nervation is coarse, distant, and usually clear. Locality: Brookside Colliery, Southern Anthracite coal field, Pennsylvania, from the lower Lykens coal group of the Pottsville Formation. USNM 40958. 2. Neuropteris pocahontas White A specimen showing the general characteristics of the species. Note the abundance of relatively small crowded pinnules and the long terminals, as well as the many pinnatifid pinnules. - The nervation, which is coarse and distinct, is alethopteroid in its general characteristics, as the nerves are crowded, regularly spaced, and very uniform. Locality: Below the Angle mine, West Virginia, at fork of stream from Pocahontas coal group near no. 1 or no. 2 coal. USNM 41213. ZONE 5. ZONE OF MARIOPTERIS POTTSVILLEA AND OF COMMON OCCURRENCE OF ANEIMITES SPP. 3. Aneimites tenuifolius (Goeppert) White A part of a sterile segment of the frond showing the slender pinnae and the distant uncrowded pinnules. - The pinnules are subpetiolate and obovate to obovate-cuneate, and some are asymmetrical. - The nerves originate from a bundle in the subpetiolate base and fork two or three times in passing to the distal margin in a manner similar to that of Adiantites. Locality: Shale beneath thick sandstone about 300 feet below Nuttall coal seam, Quinnimont Shale Member of New River Formation, Nuttalburg, W. Va. USNM 40113d. 4. Aneimites fertilis White A specimen showing the small relatively crowded pinnules disposed on several pinnae. Note the slender pinnae axes. The pinnules are narrowly cuneate to spatulate; most are bilobate or multilobate. The nervation is, in general, similar to that of the Aneimites tenuifolius. Locality: Below the second sandstone beneath the Raleigh Sandstone Member of the New River Formation (360 feet below Raleigh Sandstone Member), lower railroad cut, Nuttall, W. Va. USNM 401242. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 4 ZONE 5,Z0NE OF MARIOPTERIS POTTSVILLEA. um dat ZONE 4, ZONE OF NEUROPTERIS POCAHONTAS AND MARIOPTERIS EREMOPTEROIDES. 689-427 O-64--3 PLATE 5 [Figures natural size unless otherwise indicated] ZONE 5. ZONE OF MARIOPTERIS POTTSVILLEA AND OF COMMON OCCURRENCE OF ANEIMITES SPP. FrcurE 1. Mariopteris pottsvillea White A specimen showing a part of a polypinnate frond, characterized by distinct and relatively uncrowded pinnae and - pinnules. The pinnules are obliquely set on the pinnae axes, are ovate to ovate-pyriform, are asymmetrical, and have broad bases. Locality: Lookout Sandstone, Cole City, Dade County, Ga. USNM 13658. ZONE 6. ZONE OF NEUROPTERIS TENNESSEEANA AND MARIOPTERIS PYGMAEA, AND TO SOME EXTENT OF OovoPTERIS COMMUNIS, ALLOIOPTERIS INAEQUILATERALIS, AND ALETHOPTERIS DECURRENS 2, 3. Mariopteris pygmaea White A specimen of this diminutive species showing the small crowded pinnae and pinnules. - The pinnules are generally ovate, the laminae appearing to be very thick. The nervation is coarse and generally not very distinct. Locality: Massillon coal near Massillon, Ohio. USNM 41760. Figure 3 X 2. 4. Alethopteris decurrens (Artis) Sternberg A specimen showing parts of three pinnae. - The fronds of this species, as well as most other species of Alethopteris, are large and tripinnate to quadripinnate. The pinnae and the pinnules are crowded and may overlap. The pinnules are elongated and narrowly obtuse, seated at nearly right angles on the pinnae, and decurrent in the area of attachment. The nerves are coarse, distinct, and rather open for a member of this genus. Locality: Shale below massive sandstone, a quarter of a mile south of abandoned quarry in the north end of cut of Illinois Central Railroad, about 7% miles north of Cobden, Carbondale quadrangle, Illinois. USNM 41761. 5. Alloiopteris inaequilateralis (Lesquereux), White mss. A part of a pinna showing the delicate and plumose nature of segments of the frond. The pinnules are commonly alternate, decurrent, close, and some are overlapping; they are broadly deltoid when small and are rhomboidal when larger. They are more or less deeply dissected into two or three lobes, which are all short and bluntly denticulate. - The nervation is distinct and of the sphenopteroid type. - Locality: Lemon's coal bank, Morrow group, Washington County, Ark. USNM 14223. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 5 ZONE 5, ZONE OF MARIOPTERIS POTTSVILLEA PLATE 6 [All figures natural size] ZONE 6. ZONE OF NEUROPTERIS TENNESSEEANA AND MARIOPTERIS PYGMAFA, AND TO SOME EXTENT OF OVoPTERIS COMMUNIS, ALLOIOPTERIS INAEQUILATERALIS, AND ALETHOPTERIS DECURRENS Figur® 1. Ovopteris communis (Lesquereux) Potonié A portion of a large frond showing the crowded, overlapping pinnae. The pinnules vary considerably in size, are alternate and oblique on the rachis, and are ovate to oval when small and elongate and sublobate when large. - They are lax in general aspect and have typical sphenopteroid venation. - Locality: Morrow Formation, Washington County, Ark. USNM 41218. 2. Neuropteris tennesseeana Lesquereux The specimen designated in Lesquereux's manuscript as the type of the species. - This form belongs to the Neuropteris heterophylla group and contrasts sharply with the alethopteroid species of Newropteris, which are common in zones 4 and 5. The pinnules are crowded, and some overlap. They vary in form from ovate to oval to narrowly ovate- oblong and are very asymmetrical. - The terminals are relatively large and lanceolate-triangular. - The venation is less crowded than in most of the alethopteroid species of Newropteris. - Locality: Tracy, Tenn. USNM 11790. 3. Mariopteris pygmaea White A specimen showing additional characteristics of this diminutive species, which has been discussed in more detail in the description of plate 5, figs. 2 and 3. Locality: New Lincoln Colliery, 3 miles west of Tremont, Pa., Lykens no. 2(?) coal. USNM 40086. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 6 ZONE 6, ZONE OF NEUROPTERIS TENNESSEEANA AND MARIOPTERIS PYGMAEA. PLATE 7 [Figures natural size unless otherwise indicated] ZONE 6. ZONE OF NEUROPTERIS TENNESSEEANA AND MARIOPTERIS PYGM AEA, AND TO SOME EXTENT OF OvVOPTERIS COMMUNIS, ALLOIOPTERIS INAEQUILATERALIS AND ALETHOPTERIS DECURRENS FicurE 1. Mariopteris pygmaea White An enlarged photograph, X 2, of the specimen shown on plate 6, figure 3, showing more distinctly the form of the pinnules. Locality: New Lincoln Colliery, 3 miles west of Tremont, Pa., Lykens no. 2(?) coal. USNM 40086. ZONE 7. ZONE OF COMMON OCCURRENCE OF MEGALOPTERIS SPP. 2. Cardiocarpon akron Read The type specimen of this species is shown. The large strikingly winged species of Cardirocarpon, such as Cardiocarpon akroni and Cardiocarpon phillipsi, are very common in zone 7. At localities where plants occur in abundance, this group of cardiocarpons also appears to be characteristic of the zone. - Locality: Uppermost part of the Sharon Shale Member of Pottsville Formation, near Akron, Ohio. USNM 25382. 3. Megalopteris southwellii Lesquereux The American species of Megalopteris are characteristic of zone 7, especially in areas where the pre-Pennsylvanian strata are calcareous. - The large generally lanceolate pinnules with the distinct midribs and the regular close vena- tion which is nearly at right angles to the midveins and the margins are similar to those of Taeniopteris. - The details of the frond architecture are incompletely known, but at least in Megalopteris southwellit, the frond was possibly palmate. Locality: A few feet above the base of the Pennsylvanian System at Port Byron, IIl. USNM 41171. ZONE 8. ZONE OF NEUROPTERIS TENUIFOLI A 4. Neuropteris tenuifolia (Schlotheim) Sternberg The general characteristics of two pinnae of this well-known species are shown. Note the relatively large pinnules, which are crowded and set at acute angles on the pinnae axes. The terminals are lanceolate to rhomboi- dal in outline and are rather large. The venation is more open than in the Early Pennsylvanian alethopteroid species of Newropteris. Locality: Sandy Ridge, Center County, Pa., probably from the Mercer Shale Member, Pottsville Formation. USNM 21219. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 7 ZONE 6, ZONE TENNES MARIOPTR OF NEUROPTERIS SEEANA AND TRIS PYGMAEA ZONE 7, ZONE OF COMMON OCCURRENCE OF MEGALOPTERIS SPP. PLATE 8 [All figures natural size] ZONE 9. ZONE OF NEUROPTERIS RARINERVIS Frcur® 1. Pecopteris vestite Lesquereux Parts of several pinnae of Pecopteris vestita are shown. The pinnae on the left and upper right show the closely spaced simple pinnule phase of the species; the two in the upper center and lower right show the pinnatifid phase. The pinnules are covered by a moderately dense coating of villi or hairlike processes, which obscure the pecopteroid venation. - This species, which is one of the earliest representatives of the genus Pecopteris, seems to be fairly im- portant in a general way in separating the younger Pennsylvanian from the older Pennsylvanian strata, although it has only a moderate range in time. Locality: Lower part of the Cherokee shale, Owen's mine, Henry County, Mo. USN M 5745. 2. Mariopteris occidentalis White The rigid aspect of a pinna is shown. The pinnules are simple in outline as compared with the older Pennsylvanian species of Mariopteris; except for the inferior basal pinnule on each pinna, they rarely show location. In life, the pinnules may have been thick, inasmuch as the venation is generally obscure. - In the right center part of the photo- graph are two fragmentary specimens of Sphenophyllum emarginatum (Brongniart) Koenig, and immediately adjacent is a well preserved specimen of Lepidophyllum lanceolatum Lindley and Hutton. - Locality: Lower part of the Boggy Formation, on the south flank of Burning Springs dome in tributary to Gaines Creek on the McAlester-Blocker road, about 750 yards northeast of the Gaines Creek bridge, McAlester quadrangle, Oklahoma. USNM 41220. 3. Neuropteris rarinervis Bunbury A compound pinna of the species is shown. Although similar in many respects to Neuropteris tenuifolia and Neuropteris flexuosa, this species is distinct and is readily recognized by the relatively widely spaced veins, examples of which may be seen in the upper part of the photograph. Locality: Cherokee shale, Penitentiary shaft, Lansing, Kans. USNM 10873. GEOLOGICAL SURVE PROFESSIONAL PAPER 454-K PLATE 8 1 ZONE 9, ZONE OF NEUROPTERIS RARINERVIS PLATE 9 [All figures natural size] IZONE 10. ZONE OF NEUROPTERIS FLEXUOSA AND APPEARANCE OF ABUNDANT PECOPTERIS SPP. Figur® 1. Pecopteris arborescens (Schlotheim) Brongniart A part of a pinnatifid pinna showing the distant ultimate pinnae and the crowded pinnules, which are small, narrow, and characterized by a venation in which the laterals from the midvein fork only once or twice as they approach the margins. - This species is one of a group that is sometimes referred to as the cyatheaoid species of Pecopteris because of the similarity of the pinnules to those of the modern fern genus Cyathea. - Although the species is found sporadically in zone 9, it and other related species of Pecopteris become abundant in zone 10 and the succeeding zones. These forms, in fact, range as high as the middle Permian. Locality: Rocks of middle Allegheny age near Olymphant, Pa. USNM 12637. 2. Neuropteris ovata Hoffmann A specimen showing parts of two pinnae and several isolated pinnules. This species is characterized by crowded auriculate pinnules that are modified rhombs in outline. - The crowded venation is also characteristic. The species in one or the other of its variations is present in strata as low as zone 8 and extends at least as high as zone 12. However, it first becomes a common element in zone 9 and abundant in zone 10 and the succeeding zones. The early variations of this species are usually small. - In the later zones, however, the pinnules become very large. Locality: Cherokee shale, Coon Creek mine, Henry County, Mo. USN M 8901. 3. Neuropteris flexuosa Sternberg Specimen of a pinna showing the moderately crowded to overlapping pinnules. The pinnule form in this species is slightly to distinctly falcate. In comparison with Neuwropteris tenuifolia and Neuropteris rarinervis, the venation is also crowded. - As typically formed in the United States, the average of pinnules in N. fleawosa is larger than in the two previously mentioned forms, but the terminal is relatively smaller. - Locality: Mazon Creek, Will County, Ill. USNM 40311. PROFESSIONAL PAPER 454-K PLATE 9 GEOLOGICAL SURVEY Nees zi ad Qfi ZONE 10, ZONE OF NEUROPTERIS FLEXUOSA AND APPEARANCE OF ABUNDANT PECOPTERIS SPP. PLATE 10 [Figure natural size} ZONE 10. ZONE OF NEUROPTERIS FLEXUOSA AND APPEARANCE OF ABUNDANT PECOPTERIS SPP. Fraur® 1. Pecopteris miltont Brongniart A Jarge slab of shale showing a part of the frond representing a group of the genus Pecopteris that is characteristic of the Upper Pennsylvanian and that is abundant in zone 10. As contrasted with Pecopteris arborescens, the pin- nules are distinctly larger; the tips are acutely rather than bluntly rounded; and the pecopteroid venation is more crowded. - Although the relationship is not demonstrated conclusively, this species may be related to Pecopteris vestita rather than to the cyatheaoid species of Pecoteris. - Locality: Middle or upper part of the Allegheny Formation, Shamokin, Pa. USNM 12847. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 10 ZONE 10, ZONE OF NEUROPTERIS FLEXUOSA AND APPEARANCE OF ABUNDANT PECOPTERIS SPP. PLATE 11 [All figures natural size] ZONE 11. ZONE OF LESCUROPTERIS SPP. Ficurms 1, 2. Lescuropteris moorii Lesquereux Two specimens illustrating the characteristics of the genus and species. The fronds are at least bipinnate, as indicated in figure 2. The pinnae are closely spaced and often either touch or overlap. - Rachial pinnules are present between pinnae. The pinnules are odontopteroid in their general appearance, are broadly attached and are distinctly falcate or sickle shaped. The venation is odontopteroid. At the present time this genus is known to be represented in North America by two species, Lescuropteris moorit and Lescuropteris adiantites, according to the literature, although it is possible that the forms may be conspecific. The genus has been reported from strata of probable Conemaugh age in the Southern Anthracite coal field and from several localities in the Conemaugh and lowest part of the Monongahela Formation in western Pennsylvania and adjacent parts of the Allegheny Plateau. It is also found in the Elmdale shale of former usage in Kansas. Locality: Elmdale Shale near Onaga, Kans. USNM 41762 and USNM 41763. ZONE 12. ZONE OF DANAEITES SPP. 3. Danaeites emersoni Lesquereux The type specimen is shown. - The frond is at least bipinnate and in the type specimen consists of a well-defined lower segment that is fertile; the area above is sterile. - The pinnae are closely spaced and many overlap. The fertile pinnules are large and Alethopteris- or Calli pteridium-like in form; they are characterized by elongate soruslike bodies that are superimposed on the pinnules from midvein to margin and mask the venation. Avail- able information does not clearly show, however, whether the genus is a true fern or a seedfern. The distal sterile segment of the frond is characterized by smaller or more reduced pinnules that are alethopteroid in form and venation. The genus is known in the United States from many localities in western Pennsylvania and adjacent States where it occurs in the Monongahela Formation. - Present information indicates that it ranges as low as the shale beds a short distance above the Pittsburgh coal and as high as the youngest coal in the Monongahela in the Georges Creek coal basin, Maryland, where it occurs about 100 feet below the provisional base of the Dunkard Group. Locality: From shale a short distance above a coal, probably correlative with the Pittsburgh bed, in the vicinity of St. Clairsville, Ohio. USNM 12710. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 11 ZONE 12 , ZONE OF DANAEITES SPP. ZONE 11, ZONE OF LESCUROPTERIS SPP. FicurE 1. PLATE 12 [All figures natural size] ZONE 12. ZONE OF DANAEITES SPP. Danaeites emersoni Lesquereux A specimen similar to that photographed for plate 11, figure 3, showing parts of fertile pinnae on the right and sterile pinnae on the left. Locality: Strip pit 0.9 mile south of Lonaconing, Md., within 100 feet above the upper limit of the Monongahela Formation. USNM 41764. ZONES 11 AND 12 (LOCALLY COMBINED). ZONE OF ODONTOPTERIS SPP. . Odontopteris reichiana Gutbier A small pinna showing the rounded triangular form of the pinnules, which are acutely set and broadly attached to the pinna axis. The venation is open and neuropteroid. Species of Odontopteris are abundant in zones 11 and 12 in the Appalachian region but are rarely found in older strata. - In the western midcontinent region and the Rocky Mountain region, zones 11 and 12 can not be well differentiated at the present time, owing to the sporadic occur- rence of genera and species that characterize these zones in areas further east. However, the composite zone can be recognized by the abundance of several species of Odontopteris. - Locality: Strata, probably equivalents of the Cone- maugh Formation, in the eastern middle anthracite field near Hazelton, Pa. USNM 11267. . Odontopteris pachyderma Fontaine and White A pinna with crowded pinnules is shown. The pinnules are slightly falcate and some are rhomb shaped. The bases are broadly attached, but the pinnules are set less acutely on the pinna axis of this species than on that of Odon- topteris reichiana. Locality: Dents Run, W. Va. Shale above Waynesburg coal, Cassville, Monongalia County, W. Va. USNM 20622. . Mariopteris cordata-ovata (Lesquereux) White Parts of several pinnae set on an axis of a higher order are shown. - The pinnae are distant, and the angles at the points of attachment are variable. - The pinnules are set on the pinnae axes at open angles; they are unlobed except for the inferior basal pinnule on each pinna, which is generally either bilobate or trilobate. - The margins are entire, and the venation, except for the coarse midvein, is obscure. The species, which is similar to Martopteris occidentalis White appears initially in zone 10 but extends into zone 11 in the Appalachian region and into zones 11 and 12 combined in the midcontinent region. - It is one of the youngest species of the genus. - Locality: Strata, probably equivalents of the Conemaugh Formation, in the eastern middle anthracite field near Hazelton, Pa. USNM 41765. . Neuropteris lindahli White A specimen littered with abundant pinna fragments and isolated pinnules is shown. - On the basis of form of the sterile material, this species appears to be a late member of the alethopteroid group of Neuropteris. The pinnules are small, narrowly triangular, and falcate in form. They have cordate bases; the lateral nerves are coarse, close, and curve to form right angles at the pinna margins. - This species is common in strata of Late Pennsylvanian age in the western midcontinent region and is known from several localities in the southern part of the Rocky Mountains. Locality: the Bethany Falls Limestone Member of the Swope Limestone, near Kansas City, Mo. USNM 11622. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 12 ZONE 12, ZONE OF DANAEITES SPP. FicurE 1. PLATE 13 [All figures natural size] ZONE 13. ZONE OF CALLIPTERIS SPP. ?Dichophyllum sp. A specimen showing part of a pinna with several finely divided decurrent pinnules. This plant is poorly understood, but is probably related to Callipteris. - Locality: Lower part of the Abo Formation, the Spanish Queen mine, about 6 miles southwest of Jemez Springs, N. Mex., on the southeast side of the canyon. USNM 41221. Walchia piniformis (Schlotheim) Sternberg A specimen showing a part of a branch on which are borne many smaller branches. The branches are sheathed with the small, falcate, needlelike leaves that are characteristic of the form. Although the genus and species make their first appearances in the Upper Pennsylvanian of the western part of the United States, the genus is most characteristic of the Lower and middle Permian. - Locality: Lower part of the Abo Formation, the Spanish Queen mine, about 6 miles southwest of Jemez Springs, N. Mex., on the southeast side of the canyon. - USNM 41222. . Gomphostrobus bifdus Geinitz Part of a twig bearing the characteristic needlelike leaves, which fork just below the tips. - Locality: Lower part of the Abo Formation, the Spanish Queen mine, about 6 miles southwest of Jemez Springs, N. Mex., on the southeast side of the canyon. USNM 412238. Callipteris lyratifolia Zeiller Part of a pinna bearing several highly divided pinnules is shown. This genus and species make their first appearance in the Lower Permian but are found in higher strata. Locality: 1 mile south of Coyote Post Office, Rio Arriba County, N. Mex. USNM 41225. . Callipteris conferta (Sternberg) Brongniart Several pinnae with many attached pinnules are shown. - The pinnules are decurrent and broadly attached; the vena- tion is distinct. - Rachial pinnules are present between pinnae. The venation develops from several bundles at the base of the pinnules; the bundles fork several times as they pass toward the margins. Like Callipteris lyratifolia Zeiller, Callipteris conferta makes its first appearance in the United States in the Lower Permian but ranges upward into younger Permian strata. - Locality: Lower part of the Abo Formation, about 6 miles southwest of Jemez Springs, N. Mex., on the southeast side of the canyon. USNM 412283. PROFESSIONAL PAPER 454-K PLATE 13 GEOLOGICAL SURVEY ZONE OF CALLIPTERIS SPP. U ZONE 13 PLATE 14 [All figures natural size] ZONE 14. ZONE OF THE OLDER GIGANTOPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEXICO, EQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA-THE SUPAIA FLORA Frcur® 1. Supata sturdevantit White A specimen showing the forked or dichotomous rachis characteristic of the genus. - Pinnules are large, are set obliquely to the rachis, overlap, and are alethopteroid in form. - Very little is known of the venation, but it also appears to be alethopteroid. The genus Supaia with its several species is known only in Arizona and parts of central and western New Mexico, where it occurs in the Hermit Shale and the upper part of the Abo Formation. The genus and its associates appear to be characteristic of strata that are lower or possible middle Leonard in age. Locality: Lower part of Hermit Shale, Bright Angel trail below El Tovar, Grand Canyon National Park, Ariz. USNM 38040. 2. Supata compacta White A specimen, probably the apical portion of one of the major divisions of the frond, is shown. Note the strongly alethopteroid form of the first two well-preserved pinnules on the left side of the specimen. - The venation, although not clearly shown in the illustration, is characterized by a strong midrib, which extends almost to the apex of the pinnule. - The terminal of the pinna, although imperfectly preserved, appears to have been rather large. Locality: Hermit Shale, Hermit Basin, 7.5 miles west of Grand Canyon Station, Grand Canyon National Park, Ariz. USNM 38034. 3. Brachyphyllum tenue White Several branching twigs are shown. - Although not visible in the photograph, the small branches are sheathed with scalelike leaves similar in gross aspect to some of the modern scale-leaved conifers such as Juniperus Linne. Locality: Lower part of Hermit Shale in Hermit Basin, 7.5 miles west of Grand Canyon Station, Grand Canyon National Park, Ariz. USNM 38061. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 14 ZONE 14, THE SUPAIA FLORA. PLATE 15 [All figures natural size] ZONE 14. ZONE OF THE OLDER G1gaanNToPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEXICO, EQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA-THE sUPAIA FLORA FicurE 1. Supaia merriami White An illustration of the type specimen showing the large closely spaced alethopteroid pinnules. Note the distinct mid- vein and the auriculate bases of the pinnules. This is the largest representative of the genus Supaia known at the present time. - Locality: Lower part of Hermit Shale in Hermit Basin, 7.5 miles west of Grand Canyon Station, Grand Canyon National Park, Ariz. USNM 38033. 2. Sphenophyllum gilmore? White An illustration of a complete whorl of leaves is shown. Note the narrow, elongate form of the leaves; this form contrasts with most of the Late Pennsylvanian and Early Permian representatives of the genus, which are smaller and generally broadly triangular in form. Below the prominent whorl is another only partly exposed. Locality: Near "Red Top," Hermit Basin, at the site of a U.S. National Museum vertebrate-footprint collecting locality, Grand Canyon National Park, Ariz. USNM 38025. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 15 ZONE 14, THE SUPAIA FLORA. PLATE 16 [All figures natural size] ZONE 14. ZONE OF THE OLDER GIG@ANTOPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEXICO, EQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA-THE GLENOPTERIS FLORA FicurRE 1. Taeniopteris newberryana Fontaine and White Part of one of the straplike fronds which shows the broad midrib and the closely spaced lateral veins. - The laterals depart from the midvein at acute angles but rapidly curve so that they are nearly at right angles both to the mid- rib and the margin in most of their course. - Taeniopteris newberryana is a representative of a genus that appears in zone 13 but which reaches its peak of abundance in the United States in zone 14. It is one of the few genera common to the three provincial floras of zone 14. Locality: Wellington Formation, approximately 3 miles south of Banner City, Kans. USNM 8087. 2. Glenopteris simplex Sellards Part of a small pinnate frond is shown. - The principal characteristics of this species are its small size and relatively narrow pinnules as compared with the other species such as Glenopteris splendens Sellards, illustrated in figures 3 and 4 of this plate. The genus Glenopteris resembles in many respects the genus Supaia; however, the frond architecture is different. All specimens known and assigned to Glenopteris are simply pinnate, without any divisions of the rachis. In Supaia, the rachis is divided into two equal forks as shown in figure 1, plate 14. Glenopteris is known only from central Kansas, where it cocurs in strata that contain abundant evaporites. Locality: Wellington Formation, near Banner City, Kans. USNM 41766. 3, 4. Glenopteris splendens Sellards The largest known species of Glenopteris is shown. Figure 3 illustrates the aspect of the lower and medial parts of a frond, and figure 4 shows the apical region. Note the relatively broad pinnules, as compared to G@lenopteris simplex Sellards, and the decurrent bases. The apex of the frond is triangular in form and slightly lobate in the lower part. - The texture in life was probably very thick, possibly coriaceous. Locality: Wellington Forma- tion, 3 miles south of Banner City, Kans. (fig. 3); 3% miles southeast of Elmo, Kans. (fig. 4). Figure 3, USNM 8074; figure 4, USNM 41767. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 16 ZONE 14, THE GLENOPTERIS FLORA. 689-427 O -64A--4 PLATE 17 [Figures natural size unless otherwise indicated] ZONE 14. ZONE OF THE OLDER G@GIGANTOPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEXICO, EQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA-THE GIGANTOPTERIS FLORA Figur®E 1. Gigantopteris americana White The base of a frond is shown. Note the equal forking of the frond, a characteristic of this species. Associated with the principal specimen are parts of pinnae of species of Pecopteris, some of which are fertile. Locality: Belle Plains Formation, Emily Irish grant, Baylor County, Tex. USN M 41768. s 2. Callipteris sp., cf. C. flabellifera (Weiss) Zeiller Part of a frond with several pinnae is shown. Note the highly divided nature of the pinnules. - Locality: Belle Plains Formation, Emily Irish grant, Baylor County, Tex. USNM 41769. 3, 4. Odontopteris cf. 0. fischeri Brongniart Two specimens showing fragments of a large species of Odontopteris, which is with some reservations assigned to O. fischeri Brongniart. Note the large lax pinnules. Locality: Belle Plains Formation, Castle Hollow, near Fulda, Baylor County, Tex. Figure 3, X 14, USNM 41770; figure 4, X 4, USNM 41846. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K PLATE 17 ZONE 14, THE GIGANTOPTERIS FLORA. PLATE 18 [All figures natural size] ZONE 14. ZONE OF THE OLDER G@IGANTOPTERIS FLORA IN PARTS OF TEXAS, OKLAHOMA, AND NEW MEX- ICO, EQUIVALENT ZONE OF GLENOPTERIS SPP. IN KANSAS, AND EQUIVALENT ZONE OF THE SUPAIA FLORA IN NEW MEXICO AND ARIZONA-THE GIGANTOPTERIS FLORA Fraur® 1. Gigantopteris americana White The apex of one lobe of a frond is shown. Note the characteristic anastomosing venation of the subdivisions of the simple frond. These subdivisions, although suggesting pinnules, are not lobed or otherwise divided. Locality: Lower part of the Clyde Formation, near Fulda, Tex. USNM 41771. 2. ?Compsopteris sp. Part of a pinna is shown, on which are borne large decurrent alethopteroidlike pinnules. Locality: Belle Plains For- mation, Godwins Creek, Baylor County, Tex. USNM 41772. 3. ?Tingia sp. Part of a frond bearing crowded pinnae characterized by parallel venation is shown. The specimen was originally assigned to the genus Tingia, but because of some details of the fronds, it appears that the generic assignment must be questioned. Locality: Belle Plains Formation, Emily Irish grant, Baylor County, Tex. USNM 41773. 4. Lobatannularia sp. Two whorls of leaves of this equisetaceous genus previously known only from eastern Asia are shown. Note the bilateral symmetry of the leaf whorls, which is one of the principal generic characteristics. Locality. Belle Plains Formation, Emily Irish grant, Baylor County, Tex. USNM 41774. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K - PLATE 18 ZONE 14, THE GIGANTOPTERIS FLORA. Ficur®E 1. 3, 4. 5, 6. PLATE 19 [All figures natural size] ZONE 15. ZONE OF THE YOUNGER GIG@GANTOPTERIS FLORA Gigantopteris n. sp. A. A fragment of the terminal part of a frond showing four distinct orders of venation. Locality: Medial part of the Lueders Limestone, Lake Kemp spillway, Baylor County, Tex. USNM 41775. . Gigantopteris n. sp. B. A dichotomously forked frond is shown. Note that there are only three orders of venation. Locality: Lower part of Vale Formation, south of Lawn, Taylor County, Tex. USNM 41776. ?Brongniartites sp. Two specimens are shown, figure 3 showing the apical part and figure 4, the basal part of the somewhat lobate pinnules. Locality: Lower part of Vale Formation, 2 miles east of Abilene, Taylor County, Tex. (figure 3); south of Lawn, Taylor County, Tex. (figure 4). Figure 3, USNM 41777; figure 4, USNM 41848. Callipteris cf. C. adzvensis Zallesky. Two specimens showing fragments of pinnae-bearing callipteroid pinnules. Locality: Lower part of Vale Forma- tion, 2 miles east of Abilene, Tex. Figure 5, USNM 41778; figure 6, USNM 41847. ?Compsopteris sp. A subapical fragment showing the broadly attached decurrent pinnules, the distinct midvein, and the acute lateral veins. - Locality: Lower part of the Vale Formation, south of Lawn, Taylor County, Tex. USNM 41779. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-K - PLATE 19 ZONE 15, ZONE OF THE YOUNGER GIGANTOPTERIS FLORA pe 73 26 r. yay: 4 1 7 xe e/ Stratigraphy of the Niobrara Formation at Pueblo, Colorado GEOLOGICAL SURVEYFPROFESSIONAL PAPER 454-L Stratigraphy of the Niobrara Formation at Pueblo, Colorado By GLENN R. SCOTT ard WILLIAM A. COBBAN SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L A report of an informal subdivision and faunal zonation of the Niobrara Formation UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page P O L1 | Stratigraphy-Continued Introduction 1 Smoky Hill Shale Member-Continued Previous 2 Upper chalky shale unit- L___________________ Stratigraphy c ccc. 4 Upper chalk unit- Fort Hays Limestone Member____________________ 6 Calcareous beds at base of Pierre Shale._________ C Fossils and age 7. Incorrect usage of the names Timpas Limestone and Disconformity at the base of the Fort Hays Apishapa Limestone 00 8 | Correlation Smoky Hill Shale 8 Boulder area, Colorado Shale and limestone unit_____________________ 8 East-central Lower shale 10 Wind River Basin, Lower limestone unit-. _L 11 Sweetgrass arch, Montana Middle shale unit-__________________________ 13 | References cited Middle chalk 17 | ILLUSTRATIONS [Plates 1-11 follow index] Prats 1. Inoceramus deformis Meek from shale and limestone unit of Smoky Hill Shale Member. 2. Fossils from Fort Hays Limestone Member. 8. Fossils from the lower shale and lower limestone units of Smoky Hill Shale Member. 4. Fossils from lower limestone and middle shale units of Smoky Hill Shale Member. 5-6 Fossils from lower part of middle shale unit of Smoky Hill Shale Member. 7. Fossils from upper part of middle shale unit of Smoky Hill Shale Member. 8. Stantonoceras pseudocostatum Johnson from upper part of middle shale unit of Smoky Hill Shale Member. 9. Inoceramus platinus Logan from middle chalk unit of Smoky Hill Shale Member. 10. Fossils from middle shale, middle chalk, and upper chalky shale units of Smoky Hill Shale Member. 11. Fossils from upper chalky shale unit and upper chalk unit of Smoky Hill Shale Member. Fraur® « Imd@® 0000000000000 000000000000 00000000000 neben en . Generalized geologic map of the Northwest Pueblo cc. . Fort Hays Limestone Member of Niobrara 00000000 . Shale and limestone unit of Smoky Hill Shale . Concretion subunit of middle shale unit of Smoky Hill Shale . Ridge formed by middle chalk unit of Smoky Hill Shale . Concretionary subunit of upper chalky shale unit of Smoky Hill Shale . Ridge formed by upper chalk unit of Smoky Hill Shale 1 2 3 4 5. Lower limestone unit of Smoky Hill Shale 00000 6 T 8 9 TABLES TaBtr 1. Nomenclature and probable equivalency of outcropping Niobrara strata in eastern Colorado and Kansas________ 2. Subdivisions of the Niobrara Formation at Loca i on 3. Correlation of the Niobrara Formation and its ve on o III Page L18 21 23 23 283 25 25 25 25 26 29 Page L2 4 6 9 12 14 18 19 22 Page L3 5 24 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY STRATIGRAPHY OF THE NIOBRARA F ORMATION AT PUEBLO, COLORADO By Gurnx R. Scorr and Wirrramn A. CorBarx ABSTRACT Eight lithologic units were mapped in the Niobrara Formation of Late Cretaceous age during a study of the engineering geology of the Northwest Pueblo quadrangle. The thin Fort Hays Limestone Member at the base is overlain by seven units in the thick Smoky Hill Shale Member, which, in ascending order, are: shale and limestone, lower shale, lower limestone, middle shale, middle chalk, upper chalky shale, and upper chalk. The Fort Hays is 40 feet thick. It is composed of thick beds of limestone with almost no shale and contains three character- istic fossil range zones-Inoceramus aff. I. perplezus Whitfield, I. erectus Meek, and I. deformis Meek. The overlying shale and limestone unit is 22 feet thick. It is composed of thick beds of limestone with much shale and contains Inoceramus deformis. The lower shale unit is 56 feet thick. It contains dark-yellow- ish-brown fissile calcareous shale and platy limestone and con- tains Inoceramus involutus Sowerby and other Inoceramus of unknown affinity. The lower limestone unit consists of a eyclic repetition, 37 feet thick, of light-gray limestone and gray shale beds and con- tains Inoceramus involutus Sowerby, Inoceramus stantoni Soko- low, Phlycticrioceras oregonense Reeside, Neocrioceras n. Sp., and Pseudobaculites Sp. The middle shale unit contains gray platy silty shale, a thin bed of light-olive-gray sandy shale, a limestone concretion sub- unit, and, in the upper part, thin beds of shaly limestone. It is 280 feet thick. In the lower few feet it contains Ncaphites depressus var. stantoni Reeside, 8. binneyi Reeside, Inoceramus stantoni Sokolow, 1. undulatoplicatus Roemer, and Proteaanites shoshonensis (Meek). The middle part is characterized by Clioscaphites sazitonianus (McLearn), Texanites americanus (Lasswitz), - Stantonoceras pseudocostatum Johnson, and Inoceramus cordiformis Sowerby. About 50 feet below the top it contains Clioscaphites vermiformis (Meek and Hayden). A few feet below the top it contains Clioscaphites choteauensis Cobban. The middle chalk consists of gray hard platy chalk, 28 feet thick, separated by beds of gray hard fissile chalky shale. It contains Clioscaphites choteauensis Cobban and Inoceramus platinus Logan. The upper chalky shale unit consists of pale-yellowish-brown fissile chalky shale, 270 feet thick, that contains many beds of bentonite and large concretionary masses of shaly limestone. Fossils in the lower part include, Inoceramus simpsoni Meek, I. patootensis de Loriol?, and I. platinus Logan; fossils in the upper part include Haresiceras placen tiforme Reeside, Scaphites cf. 8. hippocrepis (DeKay), and Baculites cf. B. haresi Reeside. The upper chalk unit consists of olive-black chalk, 8 feet thick, that contains Inoceramus simpsoni Meek and large smooth baculites. The names Timpas Limestone and Apishapa Shale have been abandoned, partly because they do not fit the natural lithologic division of the Niobrara as well as do the names Fort Hays and Smoky Hill and partly because they can not be recognized as widely. The Niobrara Formation of the Pueblo area is correlated with rocks at Boulder, Colo., in central Utah, in the Wind River Basin, Wyo., and on the Sweetgrass arch, Montana. At Boulder the rocks are nearly identical to those at Pueblo, except that they are less chalky. One different fossil, Haresiceras natro- nense Reeside?, was found at the base of the upper chalk unit at Boulder. In central Utah the rocks are composed of noncalcareous shale and beds of sandstone. The fossil sequence is the same as at Pueblo but, in addition, Desmoscaphites bassleri Reeside is found in rocks equivalent to the lower part of the upper chalky shale at Pueblo. In the Wind River Basin, correlative rocks are composed of shale, sandy shale, and sandstone. They contain one additional fossil, Haresiceras montanaense (Reeside), which is slightly older than H. placentiforme and which probably can be found in the middle of the upper chalky shale at Pueblo. On the Sweetgrass arch correlative rocks are composed of sandstone, calcareous and noncalcareous shale, siltstone, benton- ite beds, and limestone concretions. The fossil sequence is the same as at Pueblo except for the additional occurrence of Desmoscaphites erdmanni Cobban, D. bassleri Reeside, and Haresiceras mancosense ( Reeside) in beds correlative with the upper chalky shale unit at Pueblo. INTRODUCTION This paper presents the results of fieldwork in 1961 on the Niobrara Formation of Late Cretaceous age at Pueblo, Colo. The formation was subdivided and in- formal names were applied to seven units in the Smoky Hill Shale Member. Excellent exposures of nearly the entire formation made possible the measurement of a detailed stratigraphic section and the collection of hun- dreds of fossils most of which were previously un- known. Many of the fossils were found to be limited to zones whose boundaries coincide with the contacts of the lithologic subdivisions. Furthermore, many of the fossils are known from time-equivalent rocks in other parts of North America and Europe, and the Niobrara is correlated with these rocks. The contacts of the type Timpas Limestone and type Apishapa Shale were studied in order to decide which nomenclature should L1 L2 be used at Pueblo. As a result of this work, the exact relation of the Timpas Limestone and Apishapa Shale to the Fort Hays Limestone and Smoky Hill Shale Members of the Niobrara Formation was determined. Fieldwork on the Niobrara Formation was an essen- tial part of an engineering geologic study of Pueblo, Colo. (fig. 1). The Niobrara underlies about one-half of the city and one-third of the two 714-minute quad- Colorado Springs Carlile NORTHWEST PUEBLO pA eal QUADRANGLE g A TkanSa § no: O 38°00 - 03:- glfiffifi/‘x _../To'sb al fiwfl21_ \\\ g \7\\ E / -f | 6 HUERFANO / / we}. pWalsenburg I/ Trinidad 0 10 20 MILES [e renga oor b 2d 37°00" 1 FIGURE 1.-Map showing Northwest Pueblo quadrangle and other places mentioned in text. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY rangles that have been mapped. A detailed geologic map showing each unit of different lithology was need- ed so that the engineering characteristics could be cor- related directly with the map units. The objective of the work was then to measure a com- plete stratigraphic section, collect fossils wherever available, and establish a set of map units. The fossils were photographed by R. E. Burkholder. PREVIOUS WORK Although work on the Niobrara Formation dates back to 1862, the early papers were largely limited to the Niobrara in Kansas. The stratigraphic subdivi- sions described in these early reports are shown on table 1. Only the geologic reports that provide new information concerning the Pueblo area are reviewed here. Stanton (1893) reviewed the invertebrate fauna of the Colorado Group of which the Niobrara is the upper part. He identified a small Inoceramus, which he referred to as Inoceramus labiatus (Schlotheim), at the base of the Fort Hays Limestone Member at Carlile Spring, 15 miles west of Pueblo. R. T. Hill and G. K. Gilbert (in Gilbert's unpub- lished field notes, 1893) subdivided the Niobrara at Pueblo in considerable detail (table 1) on the basis of persistent lithologic units, especially scarp-forming limestone beds and valley-forming shale beds. Gilbert gave the scarp rocks informal names that were used by him and his associates in the mapping of most of the quadrangles near Pueblo. He made six collections of fossils from the Niobrara, including the first collection of Inoceramus undulatoplicatus Roemer from the west- ern interior of the conterminous United States. Gilbert later (1896, p. 566-567) subdivided (table 1) the Niobrara Group into a lower unit (Timpas Forma- tion, 175 feet thick) and an upper unit (Apishapa For- mation, 500 feet thick) but did not report the detailed subdivision that he and Hill had worked out in their field notes. Patton (1923) discovered that the lower boundary of the Timpas Limestone is gradational locally with the upper boundary of the Carlile Shale. He also noted the presence of a small Zmoceramus at the base of the Timpas, which, had been discovered earlier by Stanton (1893). Because it was identified as Inoceramus labiatus, Patton apparently assumed that there was a "passing of the lower group [Greenhorn Limestone] up into the higher group [Fort Hays Limestone]." Patton later (1924, p. 19-22) described the upper part of the Timpas Limestone as consisting of a lower unit of shale and thin limestone beds like those at the base of the formation, a middle unit of shale that weathers into thin papery leaves and scales, and an STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO 1 OPL 1J S19 1J O6F 1 09 1 08 1} 09 1 Of sruiofop € 6 11m 10s 10 -our £xfeqo moj op; ouoqsowr7 sep 110 © . Jog twa py ouo;sowy7 j.10,f (spaq tuntpododdif; 0 oddif;) ml auogsq 12.5ng -l@X Spmazhwaazv - auojsou1] spoq sien j40g uotstatp s4ep q404 '< 1404 1 SM feal a auojsouy| areys (pueq yorq) 12mo7 , . sling, mamada toe mmpain , , 2rd satpro f areys (pueq apt m) odd p ui sosua1 3o0.-[ Jog sipuni6 oreys 12mo7 pydoosordop; areys snydeosordep pudbssonts pus ( H auopsou| ny dnasopd vp M 19m07 (Addep) yoou dros 49moT spoq sajsipnar 'ouoz odouy, vvvvvv &= == Z, 3 z 3 z 8 § 4 § z 3 3 snypordoppmpun R 3 5. IPPIW 7 soreys aretpounoqu; | & rg tal® 3 I 3 s A 3 § ge 4 8 3 % 3 § aB 5 # 2 ha 5 € |&: [ & € £ o feel iS) te we g 3° & H= 1J 086 1J 008 1} OOL a 5 3 2 m fan rmim M 3 areys 4yreyo pus areyg Anton wzsnmumoimz 3. 7 & . @IPPIW UH Sows «0 ofdep) yoou dreos arppiy; 3 paugsq pus 't97 xrey> aqrym 03 Jing -oweip ufj}y piu pa joys - UIY,J, 334 P8 spoq £xpeyo pur areys edeysidy smuocadsap moped 'auoz uoj.10n xTEY> offa X qodoad areys soreys areag £xpeyo caddy doy xeou uoz xreyo aadd p (4224514) yoo dreos caddy -Loy codsef weyean (aaded (9681) (8681 'sorou (8681) (9681) (E68T) (LL8T) ueqqo; pug 1109g Pio poystqndun) qoqily 'y 'n uedso7 uides) aspnp Spsuny pup opp4010) uiagsna us vps ninigorny Burddouommo fo srqngoud pun ainppousuoy -T «7gy I, 1A upper unit of limestone layers that are yellow or pink- ish yellow. He described the Apishapa as consisting of dark bluish-gray shale at the base, overlain in order by papery-weathering shale, light-colored sandy shale, and-at the top-a dark calcareous shale unit. Johnson (1930) described an unconformity at the base of the Niobrara in the Pueblo quadrangle at Wild Horse Park. He suggested correctly that the lower limestone beds of the Niobrara are not everywhere of the same age. Dane, Pierce, and Reeside (1937, p. 220-224), in a reconnaissance of eastern Colorado, studied the Niob- rara along the Arkansas River. They chose to map the Hays (Fort Hays) Limestone and Smoky Hill Marl Members of the Niobrara, inasmuch as the upper lime- stone bed of the Timpas Limestone could not be recog- nized with assurance or mapped throughout the area. Dane and his associates, apparently included more beds 104°45" 28° 22' SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY in the upper part of the Fort Hays than are normally considered by others to be part of it as mapped along the Front Range. They stated that Imoceramus de- formis is limited to the Hays, whereas Z. deformis actu- ally ranges from 22 to 24 feet above the restricted Fort Hays Limestone Member of the Front Range. They apparently referred all large Inoceramus shells in the Smoky Hill to Inoceramus (Haploscapha) grandis Conrad. LeRoy and Schieltz (1958) studied the foraminiferal fauna above and below the Niobrara-Pierre contact at a locality near Canon City and concluded that the con- tact may be conformable. STRATIGRAPHY The Niobrara Formation at Pueblo contains eight lithologic units, as shown on the generalized bedrock map (fig. 2). Four units of ridge-forming limestone 104°07'30" EXPLANATION 30" Kp \o \"§6 ~ [» | Pierre Shale W Upper chalk Al * Kaus Upper chalky shale Knm P F A P < 2 S ® c 3 E - S Middle shale Smoky Hill Shale Member 4 CRETACEOUS Niobrara Formation Lower limestone § Ss Lower shale 7 Sy Shale and limestone y 3 s 6 "> ga y Knus \ Fort Hays Limestone® Member wN-a # Geology by Glenn R. Scott, 1961 UMM ZH ROCK Knls Z Kogg al CANYON, | , i a G Measure & section - s/ D% | ANTICLINE } 5-3 o 35K Keeg f 38° Kn Knf 7 15 R.66 W. R.65 W. 0 1 2 MILES oi e FIGURE 2. -Generalized geologic map of the Northwest Pueblo quadrangle, Colorado, Keeg © Carlile Shale, horn Limestone, and Graneros Shale, un differentiated Green - showing outcrop pattern of units in the Niobrara Formation. and chalk separate four other units of predominantly chalky, calcareous, or sandy shale. Each unit has a distinctive fauna of invertebrate fossils (table 2). These fossils are listed in the stratigraphic sections of each unit; many of them are shown on the accompany- STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO L5 ing plates, Fossil collections listed without localities are from measured sections; those with localities are from places other than measured sections, but they are placed as accurately as possible in the measured sections. Tapur 2.-Subdivisions of the Niobrara Formation at Pueblo, Colo. [Thicknesses are from measured sections] Standard stages Formation Member J Unit and thickness Fossils Campanian Lower Upper Upper part of middle Santonian Lower part of middle Lower Upper Coniacian Middle Lower Turonian Upper Niobrara Formation Upper chalk, 8 ft Inoceramus simpsoni, Baculites Sp. (smooth), Stramentum haworthi. Upper chalky shale, 264 ft Concretionary subunit Haresiceras placentiforme, Scaphites cf. S. hippocrepis, Baculites cf. B. haresi, Inoceramus sp. Inoceramus platinus, Ostrea congesta. Inoceramus simpsoni, Inoceramus cf. I. patootensis, Ostrea sp., Baculites sp. (smooth, small). Middle chalk, 28 ft Inoceramus platinus, Clioscaphites choteauensis, Baculites sp. (smooth), Ostrea congesta. Smoky Hill Shale Member, 700 ft Concretionary subunit --_________ =---_-________ I Concretion subunit Middle shale, 283 ft ) Sandy subunit Inoceramus sp. (quadrate species), Inoceramus platinus, Ostrea sp., Baculites Sp. (smooth), CHéoscaphites choteauensis. Oyster bed. Inoceramus platinus, Inoceramus cordiformis?, Clioscaphites vermiformis, Baculites codyensis. Inoceramus cordiformis, Inoceramus platinus, Ostrea sp. (erect), Anomia sub- quadrata, Lucina sp., Inoceramus cf. I. undulatoplicatus, Clioscaphites sazi- tonianus, Baculites asper, Baculites codyensis, Texanites americanus, Stan- tonoceras pseudocostatum, Placenticeras planum. Inoceramus platinus? Oyster bed. Inoceramus undulatoplicatus. Inoceramus cordiformis. Clioscaphites sazitonianus, Baculites codyensis. Inoceramus undulatoplicatus, Inoceramus cf. I. stantoni, Scaphites depressus, var. stantoni, Scaphites binneyi, Protezanites shoshonensis. Lower limestone, 38 ft Inoceramus (Volviceramus) involutus, Inoceramus stantoni (radial ribs), Pseudobaculites sp., Baculites codyensis, Baculites asper. Neocrioceras n. sp. Inoceramus stantoni (radial ribs), Phlycticrioceras oregonense. Inoceramus stantoni, Baculites codyensis. Lower shale, 56 ft Inoceramus (Volviceramus) involutus, Ostrea sp. Inoceramus stantoni. Baculites asper, Baculites codyensis. Inoceramus spp. (large and flat, and small and oval). Shale and limestone, 20 ft Inoceramus (Volvicgramm) involutus, Inpceramus deformis. Inoceramus deformis. Fort Hays Limestone Member, 40 ft Inoceramus deformis, Ostrea congesta. . Inoceramus erectus, Barroisiceras hobsoni. Prionocycloceras? Inoceramus aff. I. perplezus Whitfield. L6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Two members of the Niobrara Formation were mapped at Pueblo, the Fort Hays Limestone Member and the Smoky Hill Shale Member. FORT HAYS LIMESTONE MEMBER The Fort Hays Limestone Member (Mudge, 1877, p. 281-290; Williston, 1898, p. 109-110) of late Tur- onian and early Coniacian age is a ledge-forming unit, 40 feet thick, composed principally of gray hard lime- stone. It crops out west of Pueblo in a wide gently dipping, northwest-trending belt and forms a cliff that circles the Rock Canyon anticline (fig. 2). Individual beds are distinguishable only in cliffs or quarries (fig. 3) ; on gentle slopes the limestone weathers to 4- inch residual pieces that hide the bedding. The weath- ered and dissected ledges of limestone have a dendritic appearance on aerial photographs, and their relief in dissected areas is rough. The member consists of about 40 layers of gray dense, hard limestone separated by calcareous shale. Layers range in thickness from 1 to 26 inches, but they weather to thinner irregular yellowish-gray layers or flakes. The limestone in the upper part of the member is chalky and not as hard as in the lower part, but it does not slake upon weathering as a soft chalk does. Beds 3 to 4 feet above the base and just above the middle of the FIGURE 3.-Fort Hays Limestone Member of the Niobrara Formation in a slightly weathered quarry face in the SEUNEU see. 32, T. 20 S., R. 65 W., Pueblo County, Colo. -The uppermost and lowermost parts are not exposed and only two faunal zones are visible. The Jacob staff is 5 feet long. STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO member contain pseudomorphs of limonite after pyrite; pseudomorphs in the lowest bed are spheres bounded by well-formed crystals. The shale that separates the lime- stone beds is yellowish gray to dusky yellow, soft, and fissile to platy or blocky. It contains one grayish yellowish-green bentonite bed 34 feet above the base. The shale beds wash out readily along streams permit- ting large blocks of limestone to sag. FOSSILS AND AGB Fossils from the Fort Hays Limestone Member con- sist of Ostrea congesta Conrad, three species of Znocer- amus, and very rare fragments of ammonites. Three faunal zones, based on Z noceramus, are present. The lowest 1 foot of the Fort Hays is characterized by a small species of Zmoceramus (pl. 2, figs. 1-5) that resembles Z. perplerus Whitfield (1880, p. 392, pl. 8, fig. 3; pl. 10, figs. 4, 5), 7. incertus Jimbo as emended by Nagao and Matsumoto (1940, p. 10, pl. 3, figs. 1-5; pl. 10, fig. 2), and the forms figured by Fiege (1930, p. 35, pl. 5, figs. 3-11) as I. costellatus Woods. A very late Turonian age is assigned to this basal Fort Hays species of Inoceramus. Prionocycloceras ?, a large ammonite, was found 13.5 to 16.5 feet above the base. Inoceramus erectus Meek (1877 ) p. 145, pl. 13, figs. 1, 1a; pl. 14, fig. 3) characterizes the Fort Hays Limestone Member 19 to 24 feet above the base (pl. 2, fig. 6 this re- port). An impression of an ammonite, BRarroisiceras (Forresteria) hobsoni Reeside, was found associated with Z. erectus. (See pl. 2, figs. T , 8, for Reeside's type.) The presence of Barroisiceras establishes that this part of the member is early Coniacian in age (table 2). Inoceramus deformis Meek (187 1, p. 296; 1877, p. 146, pl. 14, figs. 4, 4a) is found in the upper 13 feet of the Fort Hays (fig. 3). The lowest specimen noted was about 4 feet above the highest collection of Z. erectus. Inoceramus deformis is considered early Coniacian in age because in the western interior it lies above Peroniceras. Fort Hays Limestone Member of the Niobrara Formation measured along the north side of the Arkansas River in E} sec. 82, T. 20 S., R. 65 W. Ft _ in 78s Mmestonel.. ..... 1 ef PE.. lon edie tne cine kL Pls l l_ TOsPhale: t st ___ WLOX 69. Limestong, shaly. tl - ar aan a ao a at e 67. Limestone, lower 2 in. softer and shaly; contains Inoceramus deformis Meek__________________ 1 po Y R- conn nc ner l eenes ai naal 65. OS Bhale: 2s eens n ollu. l illo 65: 1 Or Or N iA m o R b) ~T Or A 17. Fort Hays Limestone Member of the Niobrara Formation measured along the north side of the Arkansas River in E sec. 82, T. 20 S., R. 65 W.-Continued. Ft in 62. Shale; contains 4-in. bentonite layer 3 in. above a % cl. ol on. dunn sone ae ens nes dee aes phy 61. Limestone 60. !. - n oo u ns ee nn ae nne nan an bin ann an nae aaa s 59. Limestone; shaly parting in middle___________ 65. Bhale . 2 . .. 2 2 oy nl ll o o null nnn n ane mee hane naan 57. 850. 55. 1 84. Hhale. ... sn. ll ne nol oue o u'. aa do oo 53. Limestone 1 82. RHAIE -. .. on nul n onun nn ne a ue nee nn enn na ane a annees 51. Limestone, fossiliferous-______________________ USGS Mesozoic loc. D2988 ': Inoceramus deformis Meek Ostrea congesta Conrad 50. . o. o nll yl oon non non nen nn an enn bae nen a al's 1 A9. HMMESEQNOGL.: ns ee onne hn ene ane ch., 10 USGS Mesozoic loc. D2987: Inoceramus de- formis Meek 48. Shale; contains limonitic nodules._._____________ 6 A7 ¢ LAMeSEONO+ 22 .n no n on a nln no nn n nen nnn nl nne 8 40. RHAIG : .. . ou 2 ooo n oil oun nn naan ean ane nen an an we 4 45. Limestone; contains Inoceramus 2 : 2 £4. Shalt... ~.! _. no cold ene nn a anna e no buen ae nan n onl 1 483. Limestone 10 USGS Mesozoic loc. D3522: Inoceramus erec- tus Meek e:, PNAIG. sol ea ene ls nine ama seems linn b 1 41. Limestone; contains limonite nodules ___. _____ 10 USGS Mesozoic loc. D3521: Inoceramus erec- tus Meek 40. Shale; contains soft limonite nodules.___________ 89. .s 2.1... y 38. Shale; contains limonitic 87. lel. eit. Sor tti o abs c lus ula 1 USGS Mesozoic loc. D2984: Inoceramus erectus Meek (pl. 2, fig. 6) Barroisiceras hobsoni Reeside SAJBRAIG - . on cols on noen ne a n a amin we we ag ie al. 1 par ~ - nmi 1 0 USGS Mesozoic loc. D2983: Inoceramus erec- tus Meek 92s ... . 222 s oo o oul coon one e oon seine dee new al 1 31. Limestone, very light gray, hard; weathers light véllowish gray 0 1 .. 2 S0. BRAIlG ~ .o cell cas y on oin nes ena ntg 29. Limestone, has very smooth upper surface______ 6 USGS Mesozoic loc. D3924, NEM SWM see. 5, T. 21 S., R. 65 W.: Prionocycloceras? 28. _ ___ c: 27. HMmMmEStONOLL su oll ul l lll nll l l linia. 20. BHAMe_ 2 eo- lll loll ll illu nl BELL. ad 25. Limestone, contains limonite nodules 1 in. in iy 9 USGS Mesozoic loc. D3923, NE} SWM sec. 5, T. 21 S., R. 65 W.: Prionocycloceras? pa or bo i- R or co t bo sa K ih K wh 00 Hom st bo Ja & t No ! Fossil collections listed without sec., township, and range location are from the measured section. L8 Fort Hays Limestone Member of the Niobrara Formation measured along the north side of the Arkansas River in EV sec. 82, T. 20 S., R. 65 W .-Continued Fi _ in 24; SBalé: r ennensens oan ans ole 1 23. Limestone, contains long bifurcated dark-gray Wort tbe: 15 0 USGS Mesozoic loc. D3922, SEM SEM sec. 11, T. 21 S., R. 65 W.: Prionocycloceras? 22. ShAIG_ ilt 3 21. Limestone, contains long bifurcated dark-gray WOIM 1 » 0 20. 2 19. es) ) a o o e 2 17. Limestone, massive, hard, dense_______-------- 1° 6 16, 2 15. Limestone, very light gray, hard, massive; weathers light yellowish gray; contains nodules of limonite after pyrite_______________------ e 14. Shale, olive-gray; contains iron-stained gypsum . 3 13. Limestone; contains nodules of limonite after pyrite. - Base of quarry wall-________-_------- 1 _ 0 12, 1 11. 1. 3 USGS Mesozoic loc. D2982: Inoceramus sp. 10, NRAIG. 1 9. Limestone; tends to weather into irregular lenses; contains holes where weathered _______------ 10 8. Shale; contains small limonitic nodules-_-.------ 3 7. Limestone, hard, massive; contains tiny clusters of brown limonite crystals after pyrite -__- T G. Shale 2 5. Limestone, very light gray, very finely silty, hard, massive; weathers light yellowish gray; contains a few oysters in lower balf______---- 8 USGS Mesozoic loc. D2981: Ostrea sp. 4. Shale, calcareous-_._____________-__--------- 4 3. Limestone; contains some bits of oyster and inoceramid shells________________-_-__-__---- 8 2. Shale, calcareous; weathers light yellowish gray . 4 1. Limestone, very light gray, hard, massive, silty; weathers light yellowish gray; contains small borings filled with tan calcareous silt. Sparsely fossiliferous. On northeast side of Rock Canyon anticline, another 6-in. limestone bed lies below this at the base of the Fort Hays Limestone Member_________________-------- 1 : 0 USGS Mesozoic loc. D2980: Inoceramus aff. I. Whitfield (pl. 2, fig. 5) USGS Mesozoic loc. D3467, see. 26, T. 20 S., R. 66 W.: Rudistid USGS Mesozoic loc. D3468, M see. 20, T. 20 S., R. 65 W.: Inoceramus aff. I. perplezus Whitfield Total Fort Hays Limestone Member of Niobrara Formation. ______cc______----- 39 9 DISCONFORMITY AT THE BASE OF THE FORT HAYS LIME- STONE MEMBER The best evidence of a disconformity is found in the beds below the Fort Hays Limestone Member, although SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY some evidence of a disconformity is found in the basal beds of the Fort Hays. The basal beds of the Fort Hays, which are as much as 3 feet thick, locally con- sist of yellowish-gray fine-grained calcarenite or sandy limestone interlaced with worm borings; the filling of the borings is coarser than the matrix. The calcarenite forms rather massive, nearly unstratified deposits that seemingly were dumped into lenticular or rounded de- pressions on the sea floor. Where the calcarenite is thickest, the underlying beds are thinnest; locally the underlying bed consists only of 4-inch-thick lenses, 3 feet in diameter, although elsewhere in eastern Colo- rado it seems to be a continuous bed several feet thick. Fossils that elsewhere lie at the base of the Fort Hays lie above the calcarenite; this evidence suggests that a period of erosion or nondeposition preceded deposition of typical Fort Hays Limestone Member. SMOKY HILL SHALE MEMBER The Smoky Hill Shale Member (Cragin, 1896, p. 51-52) of Coniacian, Santonian, and early Campanian age is 700 feet thick and consists about equally of chalk and shale and a very small amount of limestone. It crops out in a broad belt that follows the Arkansas River and curves northwestward through Pueblo; a thin layer of the basal part caps the Fort Hays west of Rock Canyon anticline. Several beds in the Smoky Hill at Pueblo form low hogbacks whose relief is gentle because of the softness of most of the beds. The Smoky Hill is divided into seven units, in ascending order, as follows: shale and limestone, lower shale, lower lime- stone, middle shale, middle chalk, upper chalky shale, and upper chalk. SHALE AND LIMESTONE UNIT The shale and limestone unit of early and middle Coniacian age is a 20-foot-thick sequence of typical Fort Hays Limestone and soft calcareous shale that is transitional between the Fort Hays and the typical fissile Smoky Hill Shale. It forms gentle rock-strewn slopes parallel to the Fort Hays outcrop (fig. 2) ; indi- vidual beds are distinguishable only on steep slopes, as in the NEL sec. 32, T. 20 S., R. 65 W. (fig. 4). The unit contains 18 layers of limestone that are very similar lithologically to layers in the Fort Hays. The limestone is gray and massive. It weathers yellowish gray and shaly. Some beds are less indurated and more clayey than those in the Fort Hays. Individual beds range in thickness from 3 to 19 inches and average 6 inches. The shale is gray, calcareous, hard, and blocky. It weathers yellowish gray and soft. Shale layers average 7 inches in thickness. Beds near the base and near the top are gypsiferous. Bentonite beds lie 4 to 5 feet below the top. STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO LQ FiqUrRE 4.-Shale and limestone unit of Smoky Hill Shale Member along north valley wall of Arkansas River in the SENE 14 sec. 32, T. 20 S., R. 65 W., Pueblo County, Colo. FOSSILS AND AGE The shale and limestone unit contains Znoceramus deformis throughout. Specimens are large in the upper part of the unit (pl. 1), and we believe that Z. browni Cragin (1889, p. 65) was based on these. Cragin's name, however, is herein considered a syno- nym of Z. deformis. At Pueblo the top bed of the shale and limestone unit contains the lowest specimens of Inoceramus (V olviceramus) involutus Sowerby. The presence of Znoceramus deformis dates most of the unit as early Coniacian in age, but Znoceramus involutus suggests a middle Coniacian age for the topmost bed. Shale and limestone unit measured along north side of the Arkansas River in NEV sec. 82, T. 20 S., R. 65 W. Fit in 37. Limestone, gray, shaly 3 USGS Mesozoic loc. D3470, SWuNWuSW4 see. 4, T. 21 S., R. 65 W.: Inoceramus de- formis Meek (1 ft in diameter) (pl. 1) USGS Mesozoic loc. D3471, NW M see. 26, T. 18 S., R. 66 W., at Wild Horse Park: Inoceramus (Volviceramus) involutus Sowerby 36. Shale, gray, 3 35. Limestone, gray; shaly in lower part and upper ccc nln cece ccc, 1 _ 0 34. Shale, gray, calcareous; contains Inoceramus de- formis 3 33. Limestone, gray, shaly; contains Inoceramus de- formis Meek and Ostrea congesta Contrad______ 5 690-221 0O-64--2 Shale predominates over limestone. Shale and limestone unit measured along north side of the Arkansas River in NEV sec. 32, T. 20 S., R. 65 W.-Continued L 32. Shale, gray, mottled dark-yellowish-orange, soft, 5 31. Limestone, gray, massive; weathers in large plates; contains Inoceramus_________________ 10 7 30. Shale, gray; contains bentonite at top_________. 4 29. Bentonite, % 28. Limestone, gray, 3 27. Shale, hard, gray 4 % 26. Limestone, gray; has crossbedded appearance 3 25. Shale, gray 3 24. Limestone, gray; weathers blocky; contains Ino- 6 23. Shale, gray, calcareous-______________________ 8 22. Limestone, 6 21. Shale, yellowish-gray, hard __________________ 1 20. Limestone, gray, shaly_______________________ 4 19. Shale, gray, blocky, hard, calcareous___________ 1. 11 18. Limestone, gray; weathers shaly LL 3 17. Shale, gray, soft 3 16. Limestone, gray; weathers shaly; contains Ino- ceramus deformis Meek, Ostrea congesta Conrad. 3 15. Shale, gray, 1 14. Limestone, gray, soft, shaly in lower 3 in.; con- tains Inoceramus deformis Meek_____________ 8 13. Shale, gray, 1 4 12. Limestone, gray; weathers very light gray ; top 4 in. soft and 10 1 11. Shale, e 10. Limestone, soft, 6 L10 Shale and limestone unit measured along north side of 'the Arkansas River in NEV see. 82 T. 20 S., R. 65 W.-Continued Ft _ in 9. Shale, caleareous._______________________---- 1. 6 8. Limestone, soft, shaly. USGS Mesozoic loc. D3469, NWMSWMNEMH sec. 26, T. 20 S., R. 66 W.; contains Inoceramus deformis Meek ___ 3 7. sens 8 6. Limestone, soft, shaly___________-_------------ 5 5. Shale, gypsiferOous-________________-_-------- 5 4. Limestone; in two beds separated by half an inch of shale, contains Inoceramus deformis Meek. _ 9 3. Shalo. ss o 2. Limestone, soft, shaly, gypsiferous; contains Inoceramus deformis Meek____________------ 6 1; Shale_...2..._... _ LPHS HLL ident i wana 9 Total shale and limestone unit_______-_------- 20 - 5 % LOWER SHALE UNIT The lower shale unit of middle Coniacian age consists of 56 feet of shale and platy limestone ; this is the lowest unit that has a Smoky Hill aspect. The unit forms a shale slope and valley between the underlying hard beds and the overlying lower limestone unit; therefore, it is well exposed only in cliffs or in stream cuts, such as in the SWL, NW14 see. 16, T. 20 S., R. 65 W. Several of the limestone layers form minor ledges on steeper slopes. The unit is composed of pale-, moderate-, or dark- yellowish-brown shale with dark- or light-gray lime- stone layers. Dark-yellowish-brown earthy shale at the base of the unit contrasts sharply with the underlying gray shale and limestone. The shale layers are fissile to platy and weather to soft crumbly flakes. Limestone layers are more plentiful and more perfectly platy in the upper part of the unit. In a fresh exposure, plates of limestone more than 2 feet square and only a quarter of an inch thick can be broken out from the upper limestone layers. Selenite crystals, fibrous selenite (satin spar), and granular gypsum commonly form lenses in the lower beds and coatings on fossils near the middle of the unit. Many lenses of gypsum are stained dark yellowish orange by limonite. Bentonite beds lie 20 and 25 feet above the base. FOSSILS AND AGE The coiled pelecypod Inmoceramus (Volviceramus ) involutus Sowerby (1828, p. 160, pl. 583, figs. 1-8) is found in the lower shale unit and through the overlying lower limestone unit (pl. 3, fig. 4). We regard the fol- lowing names as synonyms of this species: I. umbon- atus Meek and Hayden (1858, p. 50), I. exogyroides Meek and Hayden (1862, p. 26), Z. concentricus Logan (1898, p. 490), Haploscapha grandis Conrad (1875, p. 23), H. eccentrica Conrad (1875, p. 24), H. niobrarensis Logan, (1898, p. 493), Inoceramus pennatus Logan SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 1898, p. 488, pl. 118, fig. 2) and possibly Z. undabundus Meek and Hayden (1862, p. 26). Two species of Inoceramus of unknown affinity are found with Z. (Volviceramus ) involutus in bed 19. One, which has a diameter of at least 12 inches, is thin, flat, and broadly ovate; the other is smaller, thin, fiat, and oval. Inoceramus stantoni Sokolow first appears in bed 24 of the lower shale, and it persists up through bed 7 of the middle shale unit. We regard the name Znocer- amus kleini Miller as a synonym of Inoceramus stantoni. Baculites asper Morton and Baculites codyensis Reeside first appear in bed 24 of the lower shale and con- tinue upward to bed 20 of the middle shale unit. Bacu- lites asper (pl. 3, fig. 5), which has small distantly spaced nodes, predominates in the lower part of this range, whereas Baculites codyensis (pl. 7, figs. 3, 4), which has closely spaced ribs, predominates in the upper part. The presence of ZInoceramus (V olviceramus) invo- Tutus dates the lower shale as about middle Coniacian (table 2). Lower shale unit measured along north side of Arkansas River in NEV, sec. 82 and NW sec. 88, T. 20 S., R. 65 W. Ft _ in 32. Shale, medium-gray, chalky, shaly; contains limo- nite-stained streaks of gypsum; yellowish gray where weathered 8 10 31. Shale, yellowish-gr@y L ---_--_-_-_--_---------------- TI- 4 30. Limestone, dark-gray, irregular, platy, hard ___... 5 29. Shale, pale-yellowish-brown, soft, fissile___------- 2 0 28. Limestone, dark-gray, hard, irregularly platy__--- 3 27. Shale, locally contains fossilif- erous limestone in middle_____--------------- 20 7 USGS Mesozoic loc. D3476: Inoceramus sp. Ostrea sp. Baculites asper Morton USGS Mesozoic loc. D3921, NEMUWNEL sec. 28, T. 21 S., R. 66 W.; Scaphites sp. 26. Limestone, light-gray, hard; forms minor ledge... 1 _ 0 25. Shale, pale-yellowish-brown, soft; contains limo- nite-stained gypsum which generally coats shells of Inoceramus on which Ostrea congesta are at- L2 3 8 24. Limestone, light-gray, platy-_______-------------- 5 USGS Mesozoic loc. D3474: Inoceramus (V olviceramus) involutus Sowerby Ostrea sp. Baculites asper Morton (pl. 3, fig. 5) USGS Mesozoic loc. D3475, SEMNWMH see. 16, T. 20 S., R. 65 W.: Inoceramus cf. I. stantoni Sokolow Baculites codyensis Reeside 23. Limestone, gray and pale-yellowish-brown, shaly, SOft, 10 STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO Lower shale unit measured along north side of Arkansas River in NEY sec. 82 and NWL4 sec. 88, T. 20 S., R. 65 W.-Continued Ft in 22. Limestone, medium-gray, hard, irregularly platy; contains limonite beds surrounding Inoceramus shells at 11-15 in. above base. Lower ledge shows flat joint faces in fresh eut-____-______________ 1 7 21. Shale, gray and dark-yellowish-brown, fissile, soft__ - 2 - 7 20. Bentonite, pale-yellowish-orange, soft, plastic, well- layered L 3 19. Shale, 3 8 USGS Mesozoic loc. D3473, SEMNWM see. 16, T. 20 S., R. 65 W.: Inoceramus sp. (large, thin shelled) I. sp. (small, thin shelled) I. (Volviceramus) involutus Sowerby (pl. 3, fig. 4) 18. Shale, 1 8 17. Bentonite, moderate-yellowish-brown ____________ 2 16. Shale, pale-yellowish-brown, fissile. 1° 4 15. Limestone, light-gray; minor ledge former________ 3 14. Shale, 9 13. Limonite and gypsum layer, moderate-yellowish- brown, lenticular 3 12. Shale, gray 3 11. Limonite and gypsum layer, moderate yellowish- j brown, 3 10. Limestone, light-gray, platy, hard; minor ledge 9 9. Shale, pale-yellowish-brown, platy, soft gypsif- : s on nn oy saol ee he een ain whe ania ae an a bo anne 's 6 10 8. Limestone, light-gray, platy; contains thin shale ccc I- <2 7. Shale, gray and dark-yellowish-orange, gypsiferous; contains Imoceramus L L LL 9 6. Limestone, dark-gray, platy; contains Inoceramus (Volviceramus) involutus Sowerby 1 1 5. Shale, dark-yellowish-orange; contains fibrous selenitel L 2 4. Shale and platy limestone, gray; hard in upper part- - 2 - 9 USGS Mesozoic loc. D3472, SEMNWMSWL see. 4, T. 21 S., R. 65 W.;: Inoceramus (Volviceramus) involutus Sowerby Ostrea congesta Conrad 3. Shale, yellowish-brown; layered with fibrous selenitel L cs 3 2. Shale, medium-light-gray, platy-________________ 2 1. Shale, dark-yellowish-brown; sharp lower boundary; contains light and dark speckles and Foraminif- era, fish scales, and fragments of inoceramid shells; has moderate-yellowish-brown layers of selenite erystals-___LLLLLLLLLLLLLLLLLLL______ 1 9 O Total lower shale unit. __ 56 LOWER LIMESTONE UNIT The lower limestone unit of middle and late Coniacian age is 37 feet thick and consists of limestone layers sep- arated by shale. The unit crops out in a broad band of gently dipping limestone that trends northwestward through the west side of Pueblo and encircles Rock Can- yon anticline (fig. 5). It forms a cliff along streams and a nearly white low ridge across flat areas, except where L11 it is buried by surficial deposits. Where weathered, in- dividual layers are hidden by yellowish-gray plates or chips of limestone. Farther south in the Raton basin in Colfax County, N. Mex., equivalent rocks are sandy. The unit is recognizable as far east as La Junta, as far north as Boulder and possibly beyond, and at least as far south as beyond Greenhorn Creek. The lower limestone unit is composed of about 16 distinguishable layers of gray hard slightly chalky platy limestone separated by beds of shale. The lower part of this sequence contains a cyclic repetition (fig. 5) of 6 layers of limestone, 7 to 11 inches thick, separated by 5 beds of shale, 14 to 22 inches thick. In addition, the laminae within some of the shale beds are cyclically banded; one bed contains dark laminae one-sixteenth of an inch thick that alternate with light laminae 14 to 5 inch thick. Shale beds in the unit are light olive gray, medium gray, or grayish brown and are calcar- eous, hard, and fissile to platy. They erode only a little more rapidly than do the limestone layers (fig. 5). The unit contains two persistent bentonite beds, a persistent limonite bed, and many lenses and nodules of gypsum stained by limonite. Most nodules of gyp- sum are 2 inches thick and 10 inches in diameter and commonly contain shells of Znoceramus; other nodules are 2 inches in diameter and contain septarian veins of gypsum. In addition to the limonite that stains the gypsum nodules, a persistent bed of limonite lies about 3 feet below the top of the unit. A bed of bentonite lies 4 inches below the top and another lies 6 feet below the top. FOSSILS AND AGE Inoceramus (V olviceramus) involutus, which con- tinues up from the underlying units, is larger in the lower limestone unit than in the underlying lower shale unit; also, specimens in beds 11 and 25 of the lower limestone have weak radial folds. Between beds 10 and 29 ZImoceramus stantoni, which also continues up from the underlying unit, is represented by a second form which has fine radial folds imposed across the concentric folds (pl. 4, figs. 1-3) ; the form without radial folds continues up into bed 7 of the middle shale. Neocrioceras n. sp. was found in bed 20 (pl. 3, figs. 1, 2). Pseudobaculites sp. was found in bed 25 with Zmoceramus stantoni, Inoceramus (V olviceramus) involutus, and Baculites asper. The topmost layer contains abundant worm borings. Fish remains were found in the middle of the unit at Williams Creek. The basal part of the lower limestone unit is prob- ably of middle Coniacian age, but the presence of Phlycticrioceras oregonense Reeside (pl. 3, fig. 3) and of radially ribbed Zmoceramus stantoni in all but the lower 10 feet suggests a late Coniacian age for most of the unit (table 2). This type of Z. stantoni is asso- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIQURE 5.-Lower limestone unit of Smoky Hill Shale Member overlying lower shale unit and shale and limestone unit in cliff along north valley wall of Arkansas River in the NWl4 see. 33, T. 20 S., R. 65 W., Pueblo County, Colo. Cyclic repetition of the limestone beds is well shown. ciated with Scaphites depressus Reeside, S. binneyi Reeside, PAlycticrioceras oregonense Reeside, Protex- anites shoshonensis (Meek), Neoccrioceras n. sp., and Pseudobaculites spp. in Utah and Wyoming. PAlycti- crioceras oregonense is associated with Baculites cody- ensis and Inoceramus stantoni in sandy beds in the Niobrara Formation in Raton basin in northeastern New Mexico. PAhilycticrioceras oregonense is closely related to P. douvillei described by Grossouvre (1893, p. 254, pl. 35, fig. 8) from the upper Coniacian of France. The American species differs from the French form by lacking clearly defined constrictions. Con- strictions were indicated by Reeside (1927, p. 3, pl. 1, figs. 6, 15) on his retouched photographs, but these are not definite on plaster casts of his types nor on specimens at hand from the western interior. Lower limestone unit measured along south side of Arkansas River in see. 88, T. 20 S., R. 66 W. Ft in 32. Limestone, light-olive-gray, hard, platy, speckled; locally weathers to shale; contains worm DOPIMG8 _ _ _ 4 31. Bentonite, dark-yellowish-orange______-_------- 2% 30. Shale, Olive-grAy L 10 29. Limestone, light-olive-gray, hard; weathers to irregular thin-edged plates-_____------------ 1. 6 USGS Mesozoic loc. D3483, SWMNEM see. 16, T. 20 S., R. 65 W.: Inoceramus - stantonit Sokolow - (radial folds) I. (Volviceramus) involutus Sowerby 28. Limonite, 1% 27. Limestone; contains worm borings, Inoceramus._. 4 26. Shale, 3 Lower limestone unit measured along south side of Arkansas River in WL sec. 88, T. 20 S., R. 65 W.-Continued 25. 24. 23. 22. 21. 20. 19. 18. 17. 16. 15. 14. 13. STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO L13 Limestone, dark-gray, hard __________________ USGS Mesozoic loc. D3481, SEMNWMH see. 16, T. 20 S., R. 65 W.: Inoceramus stantoni Sokolow (radial ribs) (pl. 4, figs. 1, 2) I. stantoni Sokolow I. (Volviceramus) involutus Sowerby Baculites asper Morton Pseudobaculites sp. USGS Mesozoic loc. D3484, NEMNEM sec. 82, T. 20 S., R. 65 W.: spiral burrows, 1%4-in. diameter, of unknown origin USGS Mesozoic loc. D3485, NWMSEM sec. 9, T. 20 S., R. 65 W.: Inoceramus stantoni Sokolow I. (Volviceramus) involutus Sowerby Baculites sp. USGS Mesozoic loc. D3486, SEXNEMSWH see. 5, T. 20 S., R. 65 W.: Inoceramus (Volvi- ceramus) involutus Sowerby USGS Mesozoic loc. D3487, see. 21, T. 20 S., R. 65 W.: Inoceramus (Volviceramus) involutus Sow- erby I. stantoni Sokolow Spiral burrows, same as in D3484 USGS Mesozoic loc. D3488, NE cor. sec. 8, T. 20 S., R. 65 W.: Inoceramus (Volviceramus) aff. I. involutus Sowerby (radial ribs) I. stantont Sokolow (radial ribs) (pl. 4, fig. 3) Bone Shale, 00 Limestone, shaly; contains Inoreramus (Volvi- ceramus) involutus Limestone, dark-gray, hard; contains I. (Volvi- ceramus) involutus Limestone, dark-gray, massive; weathers yellow- ish gray, shaly, and platy; where weathered, resembles beds 22-30. USGS Mesozoic loc. D3482, NEMkSEMNWH sec. 16, T. 20 S., R. 65 W.: Neocrioceras n. sp., 8 in. below top (pl. 3, figs. 1, 2) Inoceramus sp. Shale, medium-gray ~- 0 Limestone, yellowish-gray, shaly - _____________ Shale, medium-gray L_ USGS Mesozoic loc. D3480: Inoceramus (Vel- viceramus) involutus Sowerby Limestone, light-gray, shaly - _________________ Shale, medium-gray; weathers to VM4-in. chips; contains limonite-stained gypsum nodules 2 in. in diameter that contain septarian veinlets _ _ _ _ Shale, contains thin yellowish-gray and light- gray, fissile to platy limestone layers. Con- tains Limestone, yellowish-gray, platy; fissile and shaly in upper half; contains limonite-stained pyrite crystals. Contains ___ __ 24% Or to Lower limestone unit measured along south side of Arkansas River in SENW} see. 38, T. 20 S., R. 65 W.-Continued Ft in 12. Shale, light-olive-gray, hard; contains cyclic bedding consisting of alternating layers % in. and }s in. in thickness. Contains Inoceramus 27 in. in 1 9 11. Limestone, yellowish-gray, slabby, hard_______ 11 USGS Mesozoic loc. D3479: Inoceramus (Volviceramus) involutus Sow- erby (excellent example with radial ribs) Phlycticrioceras oregonense Reeside (pl. 3, fig. 3) 10. Shale, light-olive-gray, fissile, hard; contains limonite-stained gypsum lenses _____________ 1 10 USGS Mesozoic loc. D3478 (in lower part) : Inoceramus stantoni Sokolow (radial folds) I. (Volviceramus) involutus Sowerby 9. Limestone, yellowish-gray, platy _ 11 8. Shale, light-olive-gray, fissile to platy, hard; lower 6 in. commonly is thin platy limestone; con- tains 1 5 7. Limestone, yellowish-gray, slabby ; contains lami- nated limonite-stained fracture fillings and lenses of gypsum. 11 USGS Mesozoic loc. D3477, NW sec. 28, T. 20 8., R. 66 W.: Inoceramus stantoni Sokolow 6. Shale, light-olive-gray, platy to fissile; contains 1 8 5. Limestone, yellowish-gray ; forms two 5-in. layers where fresh; weathers to irregular plates; con- tains limonite-stained gypsum lenses_________ 10 4. Shale, light-olive-gray, fissile, hard; contains 1 3 3. Limestone, yellowish-gray, slabby; contains In- oceramus along bedding in limonite-stained gypsum lenses cL 8 2. Shale, light-olive-gray, fissile, hard ; contains 1 2 1. Limestone, yellowish-gray, hard, slabby ; contains Inoceramus along bedding and in limonite- stained gypsum lenses. _ __________________ T Total lower limestone unit_______________ 37 11% MIDDLE SHALE UNIT The middle shale unit of late Coniacian to middle Santonian age is the thickest unit of the Smoky Hill and contains the most variable lithology. It is about 280 feet thick at Pueblo, but thickens toward the south and thins toward the north. It consists principally of calcareous shale and some sandy shale, shaly or platy limestone, and limestone concretions. The unit is non- resistant and forms a broad shale valley that trends northwestward through the west side of Pueblo. Small parts of the unit crop out in stream valleys, but the whole unit does not crop out at any one place, and some parts of the stratigraphic section had to be in- ferred from poor outcrops. The middle shale is composed of light-olive-gray, medium-light-gray, pale-yellowish-brown, and yellow- L14 e %. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY § USGS Mesozoic loc. 2692 YX. FiGurE® 6.-Concretion subunit of middle shale unit of Smoky Hill Shale Member in valley of Dry Creek in the SW}4 sec. 3, T. 20 S., R. 65 W., Pueblo County, Colo. Concretions are more abundant but smaller at top of subunit. ish-gray shale that is platy, hard, and calcareous. It weathers to pale-yellowish-brown shale that is soft and fissile. In the lower 150 feet the shale contains hard platy layers of silty limestone that are ripped out of stream floors by flash floods and spread across the flood plain in blocks as much as 4 inches thick by 6 feet long. These weather to or can be split into large thin plates. From about 150 to 190 feet above the base are beds of platy light-olive-gray sandy shale- the sandy subunit-that contain thin hard plates cov- ered with the trails of worms and crustaceans. About 30 feet below the top of the middle shale is a concre- tion subunit that contains several layers of gray lime- stone concretions (fig. 6). Generally there are four layers of concretions in a shale interval 11 feet thick. The Jacob staff is 5 feet long. The top layer contains extremely hard somewhat flat pyritic concretions 2 to 6 inches long that are ovate or composite and shaped like peanut shells. The second layer contains more rounded concretions, and the lower two layers contain large flat concretions, as much as 14 inches in diameter, some of which formed in the hollows of ZInoceramus shells. These concretions also contain nodules of pyrite that are altering to limonite; some concretions contain a coating of gypsum. The upper 30 feet of the unit contains gray hard platy to shaly limestone and calcareous shale that weather dark yellowish brown and yellowish gray. Limonite-stained gypsum nodules or lenses of selenite crystals occur along with beds of limonite and one layer of bentonite. The shale at the top of the unit STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO is a concretionary subunit that contains lenticular con- cretionary masses, 2 feet in diameter, of gray platy limestone that is more resistant to weathering than the surrounding shale. FACIES CHANGES OF MIDDLE SHALE The middle shale varies more in thickness and li- thology than any other part of the Smoky Hill as it is traced away from Pueblo. Toward the south it be- comes thicker and sandier, and in Raton Basin in northeastern New Mexico contains several hundred feet of sandy beds with calcareous sandstone concre- tions. Toward the north in the Denver area it con- sists of only about 60 feet of yellowish-gray chalky fissile shale. FOSSILS AND AGE Fossils are common and varied in the middle shale unit. - In terms of the range zones suggested by Cobban and Reeside (1952) these fossils range from the upper part of the Scaphites depressus zone up into the Clio- scaphites choteauensis zone. The lower 25 feet (beds 1-7) contains Seaphites depressus var. stantoni Reeside ( pl. 5, fig. 2), 8. binneyi Reeside, Protemxamites shoshonensis (Meek) (pl. 4, fig. 4), Baculites asper Morton (pl. 5, fig. 3), B. codyensis Reeside (pl. 5, fig. 4), and the lowest occurrence of Inoceramus undulatoplicatus Roemer. The scaphites indicate the SNcaphites depressus Range Zone which is assigned to the upper Coniacian because of the presence of the uncoiled ammonite PAZycticrioceras in this zone in Wyoming and Utah and in the upper part of the Coniacian of France. Seitz (1956, p. 3, 4) assigned Inoceramus undulatoplicatus to the lower Santonian, but we found that this species overlaps the range zone of I. cordiformis and may have a different vertical range than in Europe. Olioscaphites sazitonianus (McLearn) (pl. 6, figs. 2, 3) first appears 30 feet above the base of the middle shale unit and ranges upward for 220 feet (beds 9-19). The great thickness of this zone compared to the thinness of the other scaphite zones in the Niobrara probably is the result of thickening of the middle shale unit by an incursion of sand and silt from the southwest. The lower part of the range zone of C. saxitonianus is prob- ably early Santonian in age because it lies between the top of the range zone of Scaphites depressus and the bottom of the range zone of Imoceramus cordiformis (table 2). Inoceramus cordiformis Sowerby (1823, p. 61, pl. 440) (pl. 7, figs. 1, 2) first appears 53 feet above the base of the middle shale unit and ranges up through L15 150 feet (beds 13-20). Seitz (1956), p. 3, 4) assigned this species to the lower part of the middle Santonian. We regard the following names as synonyms of this species: 7. gilberti White (1876, p. 113; 1879, p. 285, pl. 3, figs. la-c), Z. coulthardi Mclearn ( 1926, p. 121, pl. 21, figs. 1-4), and Z. McLearn (1926, p. 121, pl. 20, figs. 1,2). Inoceramus undulatoplicatus Roemer (pl. 5, figs. 1, 5; pl. 6, figs. 1, 4) is common in the lower 110 feet of the middle shale unit (beds 5-13) but may range up to 240 feet above the base. The highest occurring specimen at Pueblo that can be identified with this species is a frag- ment of a very large individual from bed 19 that differs from the older specimens by being smoother. In Raton Basin, northeastern New Mexico, a similar smooth form occurs with CHioscaphites vermiformis (Meek and Hay- den). Inoceramus platinus Logan (1898, p. 491, pl. 116, fig. 2) (pl. 9) first appears about 60 feet below the top of the middle shale unit and ranges up through the unit and into the upper part of the Smoky Hill Member. Some specimens attained diameters of more than 3 feet. The writers regard the following names of Logan (1898) as synonyms of this species: Zmoceramus pen- natus (pl. 120, fig. 2 only), I. truncatus, and I. sub- triangulatus. The bed of limestone concretions (bed 19, fig. 9) 30 feet below the top of the middle shale unit contains Inoceramus cordiformis, I. platinus, and I. cf. I. undula- toplicatus. Ammonites found in these concretions in the Pueblo area are Baculites asper (pl. 7, figs. 5, 6), 2. codyensis (pl. 7, figs. 3, 4), and CHoscaphites sawitoni- anus (pl. 4, figs. 7-9). These concretions contain Texanites americanus (Lasswitz) (pl. T, figs. 13, 14), Stantonoceras pseudocostatum Johnson (pl. 8), and Placenticeras planum Hyatt at USGS Mes. loc. 14305 near Trinidad about 20 miles south of Pueblo. The presence of Texamites americanus and Inoceramus cordiformis establishes that these concretions are mid- dle Santonian in age. Clioscaphites vermiformis (Meek and Hayden) (pl. T, figs. 10-12) marks a 6-foot zone, 11 feet above the limestone concretions and 20 feet below the top of the middle shale unit. A questionable specimen of Inoceramus cordiformis was found with this am- monite. A weakly ribbed form of Baculites codyensis is found here also. Olioscaphites choteauensis Cobban (pl. 10, fig. 6) is found in the upper 6 feet of the middle shale unit. It is associated with smooth baculites (pl. 10, fig. 4), Inoceramus platinus, and a quadrate species of Inocera- mus (pl. 10, figs. 3, 5). L16 Middle shale unit measured along the Arkansas River in the N4 secs. 88, 84, and 35, T. 20 S., R. 65 W. 27. Shale, light-olive-gray, soft, fissile; contains 4-in.-thick yellowish-gray nodular oyster bed locally 2 ft above base containing Ino- ceramus platinus Logan and Ostrea congesta Conrad; also contains hard gray concre- tionary limestone masses in middle and 6-in. lenses of iron-stained selenite crystals. About 6 ft below top of unit are olive-gray platy limestone beds that contain fossil mol- NIKE. _. L.. USGS Mesozoic loc. D3501, SWMNEM SWM sec. 10, T. 20 S., R. 65 W.: Inoceramus platinus Logan? Ostrea sp. Baculites sp. Clioscaphites choteauensis Cobban Inoceramus sp. (quadrate form with fold in shell) (pl. 10, figs. 3, 5) USGS Mesozoic loc. D3502, NWMNWMH sec. 27, T. 20 S., R. 65 W.: Inoceramus sp. (quadrate form with fold in shell). 26. Limestone, grayish-orange, shaly. Units 20- 26 form minor ledge___------------------ 25. Shale, grayish-orange, fissile, soft______-_----- 24. Limonite, dark-yellowish-orange_______------ 23. Limestone, yellowish-gray, shaly, medium hard. 02s sus selle ann an obs bse tt meme n oue ae oe mine ac 22. Bentonite, dark-yellowish-orange and yellow- ish-gray, 21. Limestone, - yellowish-gray, . shaly, medium ...s. Ile CRE ri arene aera aas 20. Shale, dark-yellowish-brown and yellowish- gray, platy to fissile; contains limonite- stained gypsum nodules; fossil mollusks are present 11 ft above uppermost limestone concretions of bed 19---________---------- USGS Mesozoic loc. D3500, sec. 10, T. 20 S., R. 65 W.: Inoceramus platinus Logan Inoceramus cordiformis Sowerby? Baculites codyensis Reeside (late form, weakly ribbed). Clioscaphites vermiformis (Meek and Hayden) (pl. 7, figs. 11, 12). 19. Shale, dark-yellowish-brown and yellowish- gray; contains gray hard pyritic or gypsi- ferous concretions in three or four layers at most outcrops; the top layer is hard and pyritic; lower layers are softer and gypsi- ccc cc USGS Mesozoic loc. D3495: Inoceramus platinus Logan Baculites codyensis Reeside USGS Mesozoic loc. D2692, NEMSW4H SW! see. 3, T. 20 S., R. 65 W.: Inoceramus cf. I. undulatoplicatus Roemer Inoceramus cordiformis Sowerby I. sp. I. platinus Logan Anomia sp. (concentric folds) Baculites codyensis Reeside Ft 12 16 11 in 10 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Middle shale unit measured along the Arkansas River in the NY secs. 88, 84, and 35, T. 20 S., R. 65 W.-Continued Clioscaphites sazitonianus (McLearn) USGS Mesozoic loc. D3496, NEMSWH sec. 10, T. 20 S., R. 65 W.: Inoceramus cordiformis Sowerby Anomia subquadrata Stanton USGS Mesozoic loc. D3497, NW HM sec. 25, T. 18 S., R. 66 W.: Inoceramus cordiformis Sowerby (pl. 7, figs. 1, 2) Anomia subquadrata Stanton Ostrea sp. (elongated) Lucina sp. Baculites codyensis Reeside B. asper Morton Clioscaphites sazitonianus (McLearn) crustacean 18. Shale, pale-yellowish-brown, platy, soft; silty in upper part; sandy and contains thin lamina of sandstone with worm trails and other markings in the lower 25 ft; contains oyster bed about 8 ft above base-___------ USGS Mesozoic loc. D3499, SWMNWH sec. 10, T. 20 S., R. 65 W. (from upper silty part) : Inoceramus platinus Logan? Inoceramus undulatoplicatus Roemer? Baculites codyensis Reeside Clioscaphites sazitonianus (McLearn) 17. Limestone concretion, yellowish-gray, sandy; lower surface has impression of Inoceramus undulatoplicatus Roemer, USGS Mesozoic loe. D&494.L........2. ...- - 16. Shale, light-olive-gray, platy; contains sandy layers covered with trails and borings__---- 15. Bentonite, dark-yellowish-orange, soft______ -- 14. Shale, light-olive-gray, platy; contains sandy layers covered with trails and borings--..-- 13. Shale, pale-yellowish-brown, platy, soft. Ino- ceramus undulatoplicatus Roemer, I. cordi- formis Sowerby, Ostrea congesta Conrad, and Baculites codyensis Reeside found in float of stream bed 40 ft above bentonite bed 12... 12. Bentonite, dark-yellowish-orange, soft, limo- RItIG. . . . ...n. se mn sos stn 11. Shale, dark-gray, platy, hard; weathers pale yellowish brown, platy, soft______-------- Section reconstructed from several isolated sections at this point. Total reported thickness of middle shale unit may be in error by as much as 50 ft less section than is present at the outcrop owing to possible miscorrelation of bentonite beds in this part of section. 10. Bentonite, light-gray and dark-yellowish- OrANG@, 9. Shale, medium-light-gray-____--------------- USGS Mesozoic loc. D3491, NEMSW!}4- NW! see. 21, T. 20 S., R. 65 W.: Inoceramus undulatoplicatus Roemer Pteria sp. Ostrea sp. Baculites codyensis Reeside Ft 90 10 63 35 in 1% STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO Middle shale unit measured along the Arkansas River in the NY secs. 33, 34, and 35, T. 20 S., R. 65 W.-Continued Ft in 9. Shale, medium-light-gray-Continued USGS Mesozoic loc. D3491-Continued Clioscaphites sazitonianus (MecLearn) (pl. 6, fig. 2) C. sazitonianus var. keytee Cobban (pl. 6, fig. 3) 8. Limonite, dark-yellowish-orange, and yellow- ish-gray 1 7. Shale, platy; contains iron-stained gypsum nodules. Best fossils are 4 ft above base__. 18 _ 6 USGS Mesozoic loc. D3490, NWMSEM see. 9, T. 20 S., R. 65 W.: Inoceramus undulatoplicatus Roemer (pl. 5, figs. 1, 5; pl. 6, figs. 1, 4) I. cf. I. stantoni Sokolow Baculites asper Morton (pl. 5, fig. 3) B. codyensis Reeside Scaphites binneyt Reeside S. depressus Reeside fish scales USGS Mesozoic loc. D3492, SEMSWH see. 21, T. 20 S., R. 65 W.: Inoceramus sp. Baculites codyensis Reeside Scaphites binneyi Reeside? USGS Mesozoic loc. 1289, NWMSEY sec. 9, T. 20 S., R 65 W.: Inoceramus undulatoplicatus Roemer Scaphites sp. Baculites codyensis Reeside Protexanmites shoshonensis (Meek) (pl. 4, fig. 4) USGS Mesozoic loc. D3493, SEMNWM see. 16, T. 20 S., R. 65 W.: Inoceramus undulatoplicatus Roemer Baculites codyensis Reeside (pl. 5, fig. 4) Scaphites depressus var. stantoni Reeside 6. Bentonite, dark-yeliowish-orange, gypsiferous; mealy clay le 5. Shale, medium-light-gray, hard, platy ; contains Inoceramus undulatoplicatus Roemer 2 ft above basel 5 0 . Clay, moderate-yellowish-brown, gypsiferous . Bentonite, yellowish-gray, soft______________ . Clay, moderate-yellowish-brown, gypsiferous._. Shale, light-olive-gray; platy, hard; weathers yellowish gray, fissile, soft; contains iron- stained gypsum nodules._________________ 7 - 0 USGS Mesozoic loc. D3489, NWXKSEX see. 9, T. 20 S., R. 65 W.: Scaphites depressus var. stantoni Reeside from 4 ft. below top (pl. 5, fig. 2). \e ve ae \ on ~ i bo 09 a 282 - 8% Total middle shale unit- ________________ MIDDLE CHALK UNIT The middle chalk unit of late middle Santonian age is a 28-foot unit of chalk beds separated by thin layers of hard chalky shale. The unit forms a low broad light-colored hogback that parallels Dry Creek for 5 L17 miles north of the Arkansas River (fig. 7). The entire unit is well exposed at many places, especially along a creek in the SW14 see. 15, T. 20 S., R. 65 W., and in the S14 see. 27, T. 20 S., R. 65 W. In the northern and southern parts of the Pueblo area, it is buried by sur- ficial deposits. The unit has been recognized in a low hogback at least as far north as Wyoming, as far south as Graneros Creek, and almost as far east as the Api- shapa River, beyond which it was not positively identi- fied. The middle chalk is composed of five or more distinct layers of gray hard platy to fissile chalk that are sep- arated by shale. The chalk contains small light-col- ored specks and consists partly of tests of Foramini- fera. It weathers to yellowish-gray irregular plates, a few inches in length. The shale is chalky and fissile but is softer than the resistant chalk which forms ledges (fig. 7). A limonite and a bentonite bed lie a little below the middle of the unit. Dark-yellowish-orange iron-stained selenite nodules are common in the upper part of the unit. Middle chalk unit measured along south side of Arkansas River in NWW sec. 35, T. 20 S., R. 65 W. 8. Chalk, very pale orange, platy; forms major ledge.. 3 - 9 7. Chalk, moderate-yellowish-orange and yellowish- gray, platy, chalky; contains dark-yellowish- orange selenite nodules. Contains fossils in lower 2 ft in large regular slabs of chalky yellowish-gray 12 0 USGS Mesozoic loc. D2693, NEMSWMSW !M sec. 3, T. 20 S., R. 65 W.; Inoceramus platinus Logan Ostrea sp. Baculites sp. (smooth) Clioscaphites choteauensis Cobban USGS Mesozoic loc. D3504, NWMNEMNWH see. 15, T. 20 S., R. 65 W.;: Inoceramus platinus Logan-more than 2 ft in diameter (pl. 9) Clioscaphites choteauensis Cobban Ostrea congesta Conrad 6. Limonite, dark-yellowish-orange, soft, ._. 2 5. Chalk, light-olive-gray; weathers yellowish-gray, platy. Contains Inoceramus platinus Logan and Ostrea comngesta 10 4. Bentonite, dark-yellowish-orange, hard, plastic, 1 3. Chalk, yellowish-gray, platy; forms part of ledge___ 1 0 2. Shale, light-olive-gray, hard, fissile. -_ ____________ 7 - 0 1. Chalk, yellowish-gray, platy; forms minor ledge____ 3 - 7 USGS Mesozoic loc. D3503, NEMNWMN WM see. 15, T. 20 S., R. 65 W.; Inoceramus platinus Logan Ostrea congesta Conrad Clioscaphites chotequensis Cobban (pl. 10, fig. 6) Total middle chalk unit- ___________________. 28 5 L18 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY FIGURE 7.-Ridge formed by middle chalk unit of Smoky Hill Shale Member along valley of a creek in the SE}4 sec. 16, T. 20 S., R. 65 W., Pueblo County, Colo. Middle bed of middle chalk unit is shown in foreground. - Ridge of upper chalk unit lies east of Dry Creek; upper chalky shale unit underlies valley between the two ridges. The Jacob staff is 5 feet long. FOSSILS AND AGE The middle chalk contains many specimens of Inoceramus platinus. Excellent impressions of speci- mens 2 feet or more in diameter are found in a platy limestone bed 13 feet below the top of the unit along Williams Creek (pl. 9). Ostrecq congeste Conrad is abundant. Closcaphites chotequensis (pl. 10, fig. 6) and a smooth baculite are also present. The writers regard the Clioscaphites choteaquensis Range Zone as late middle Santonian in age inasmuch as it lies above Inoceramus cordiformis of early middle Santonian age and below beds containing possible Znoceramus pa- tootensis de Loriol of late Santonian age (table 2). UPPER CHALKY SHALE UNIT The upper chalky shale unit of late Santonian and early Campanian age is a 264-foot sequence of shale with numerous beds of chalk, limonite, and bentonite. The unit forms a northward-trending belt along which Dry Creek flows through the west side of Pueblo. Most layers of the unit crop out along the south side of the Arkansas River in the NY see. 35, T. 20 S., R. 65 W., and at several places along Dry Creek and its small tributaries, but some parts of the unit are not exposed at Pueblo. It underlies a broad alluvium- covered valley between the hogbacks of the middle chalk and the upper chalk. The thickness of the unit is uniform at least as far north as Denver, but its thick- ness and extent are not as well known to the south or east. The upper chalky shale unit consists of pale-yel- lowish-brown, dark-yellowish-orange, olive-gray, and grayish-orange soft fissile chalky shale that contains STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO L19 op FIGURE 8.-Concretionary subunit of upper chalky shale unit of Smoky Hill Shale Member in valley wall of Arkansas River in the NE} see. 35, T. 20 S., R. 65 W., Pueblo County, Colo. The Jacob staff is 5 feet long. L20 a concretionary subunit and beds of chalk, limonite, and bentonite. Layers of chalk are most abundant near the base and the top and indicate that the deposi- tion of chalk diminished only slightly between deposi- tion of the middle chalk and the upper chalk. The chalk layers are yellowish gray; they are firm and platy where fresh but soften and wash away readily where weathered. Beds of soft dark-yellowish-orange limonite are abundant in the lower 65 feet. Many of them contain crystalline gypsum or crystals of selenite. Seventeen beds of dark-yellowish-orange granular soft plastic bentonite were observed; most of these lie be- tween 180 and 240 feet above the base of the unit. They serve as excellent marker beds in correlating small local outcrops of the unit. The concretionary subunit (fig. 8) is about 25 feet thick and consists of layers of olive-gray shale that contain hard dark-gray concretionary speckled lime- stone lenses and beds of bentonite. The limestone lenses are as much as 3 feet in diameter and 2 feet in thickness and one occurs laterally about every 10 feet. Because they are resistant to erosion, they project from banks of shale and stand as large disks on the floors of arroyos cut into shale. FOSSILS AND AGE Only two faunal zones are known from the upper chalky shale. A lower zone, which occurs in bed 10 only 30 feet above the base of the unit, contains /moce- ramus simpsoni Meek (pl. 10, fig. 1; pl. 11, fig. 5), smooth baculites (pl. 10, fig. 4), and a fragment of an Inoceramus that resembles Inoceramus patootensis de Loriol (pl. 10, fig. 2). The top of the zone of ZInmoce- ramus platinus (pl. 11, fig. 1) lies in bed 25. Many specimens of Z. platinus were collected from the upper part of bed 23; small individuals seem to be somewhat more regularly ribbed than specimens in the middle chalk bed. An upper faunal zone was found in the upper chalky shale 70 feet below the upper chalk along the Apishapa River in the Elder quadrangle 40 miles east of Pueblo but was not found at Pueblo, where its position in the upper chalky shale is unknown. The upper zone contains Haresiceras placentiforme Reeside (pl. 11, figs. 3, 4), Seaphites cf. S. hippocrepis (De- Kay), and Baculites cf. B. haresi Reeside which were found at USGS Mesozoic loc. D3266, NEV, SWL, NW! sec. 23, T. 23 S., R. 59 W., Otero County, Golo. Fish scales and bones are more abundant in the upper chalky shale than in any other part of the Niobrara. The lower part of the unit, which contains possible Inoceramus patootensis, is assigned to the late San- tonian. An early Campanian age is assigned to the upper part of the unit because of the presence of Haresiceras placentiforme Reeside (Cobban and others, 1962, p. B58). SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Section measured along south side of Arkansas River in NWW, SWVKN WW sec. 86, T. 20 S., R. 65 W. Ft Upper chalk unit: 1. Chalk, olive-black, blocky; weathers dark yellowish orange; forms a single bed with flat joint faces that is the most resistant bed on the cliff________-__-------------- USGS Mesozoic loc. D3510: Inoceramus simpsont Meek Baculites sp. (smooth) Stramentum haworthi Williston USGS Mesozoic loc. D3511, NWMSEM NEW see. 15, T. 20 S., R. 65 W.: Inoceramus simpsont Meek USGS Mesozoic loc. D3512, SEMSEM sec. 34, T. 20 S., R. 65 W.: Inoceramus simpsoni Meek Upper chalky shale unit: 70. Shale; weathers grayish orange, earthy... 69. Chalk, earthy, platy; weathers grayish or- ange, 68. Shale, grayish-orange, earthy -____-_------- 67. Chalk, yellowish-gray, irregularly platy -_. 66. Shale, light-olive-gray, gypsum veinlets _.. 65. Shale, light-olive-gray, earthy -____-_------- 64. Shale, light-olive-gray________------------ 63. Chalk, yellowish-gray, irregularly platy - --- 62. Shale, light-olive-gray, platy 61. Chalk, yellowish-gray, platy-__----------- 60. Shale, dark yellowish-brown and yellowish- orange, earthy; seamed with gypsum VeiDI@t§ L c 59. Shale, yellowish-gray; seamed with fibrous gypsum veinlets; shows flat joint faces on fresh 58. Shale, medium-gray; gypsum veinlets-___.. 57. Shale, medium-gray; seamed with fibrous gypsum veinlets; resistant to weathering.. 56. Shale, medium-gray; weathers dark-yellow- ish orange; concretionary about 4 ft above base; seamed with gypsum veinlets 55. Limestone, olive-gray, hard; forms ledge with flat joint faces______-_------------- BA. 53. Limestone, olive-gray, hard; forms ledge with flat joint faces-_____-_------------- 52. Shale, olive-black, hard, platy ------------ 51. Bentonite, moderate-yellowish-brown, soft, plastic; swells to 1 in. upon wetting.... 50. Shale, olive-black; weathers light olive gray; like bed 48 except harder______--------- 49. Bentonite, dark-yellowish-orange, stratified, sugary to floury; excellent marker bed AlONg Cliff _ 48. Shale, light-olive-gray speckled; weathers to irregular l-in. chipg-_____-------------- 47. Bentonite, dark-yellowish-orange and yel- lowish-gray, soft, plastic______-------- 46. Shale; same as bed 44--___-_------------- 45. Bentonite, dark-yellowish-orange, soft, plas- 44. Shale, light-olive-gray, fissile______------- 43. Bentonite, dark-yellowish-orange, stratified, bo 20 ~1 or to G0 Ot b) © im ~I hel a O STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO Section measured along south side of Arkansas River in sec. 86, T. 20 S., R. 65 W.-Continued 42. 41. 40. 39. 38. 37. 36. 35. 34. 33. 32. 31. 30. 29. 28. 27. 26. 25. 24. 23. 22. 21. 20. 19. Shale, light-olive-gray, fissile to platy; con- tains a few small concretionary lenses____ Shale, same as bed 27. (Top of concretion- ary shale subunit.) - _ ______LLLLLLL_____ Bentonite Shale; same as bed Bentonite, yellowish-gray, granular, soft _ _ _ Shale; same as bed 27..__________________ Bentonite, dark-yellowish-orange._________ Shale; same as bed 27....111____________._ Bentonite, dark-yellowish-orange_________. Shale, olive-gray; same as bed 27.________. Bentonite, dark-yellowish-orange, plastic, soft; contains selenite _________________ Shale, olive-gray ; same as bed 27._________ Bentonite, dark-yellowish-orange, plastic, Shale, olive-gray, platy, hard; contains hard concretionary lenses of limestone._______. Bentonite, dark-yellowish-orange, granular, ccc Shale, olive-gray, platy, hard; contains hard concretionary lenses of dark-gray speckled Bentonite, dark-yellowish-orange._________._ Shale, olive-gray, irregularly platy, hard. (Base of concretionary shale subunit.) Contains large concretionary limestone USGS Mesozoic loc. D3509, SEMANWM see. 15, T. 20 S., R. 65 W.: Inocer- amus platinus Logan, (pl. 11, fig. 1) Bentonite, dark-yellowish-orange, granular, Shale, dark-yellowish-orange and medium- gray, chalky, fissile; has texture of rotted wood; contains chalk at 74-84 in. and at many other places in overlying exposed part of section. Section is well exposed from 70 to 115 ft, where it consists of chalky shale and chalk weathered light brown and dark yellowish orange and contains fossil mollusks, fish bones, and scales. Also contains some hard dark- gray concretionary nonfossiliferous lime- stone masses near top as much as 3 ft in diameter and 2 ft thick _______________ USGS Mesozoic loc. D3506, NWMNEM see. 22, T. 20 S., R. 65 W.: Inocer- amus platinus Logan, Ostrea congesta Conrad USGS Mesozoic loc. D3507, SWMNWL SE! see. 10, T. 20 S., R. 65 W.: Inoceramus platinus Logan, Ostrea congesta Conrad USGS Mesozoic loc. D3508, SW! sec. 34, T. 19 S., R. 65 W.: Inoceramus platinus Logan Limonite and gypsum bed________________ Shale; same as bed 13-___________________ Bentonite, grayish-orange, fissile ._ ________ Shale, same as bed 18-___________________ 690-221 0O-64--3 Ft 3 2 115 in 2 © - ou c H & C> i 44 bo bo bo bo L21 Section measured along south side of Arkansas River in NWLASWL@NWL4 sec. 36, T. 20 S., R. 65 W.-Continued Ft _ in 18. Limonite and gypsum bed ________________ 2 17. Shale; same as bed 13-___________________ 3 0 16. Limonite and gypsum bed________________ 1 15. Shale; same as bed 18-___________________ 3 0 14. Bentonite, 1% 13. Shale, dark-yellowish-orange and medium- gray, chalky, fissile; has texture of rotted l oc 4 4 12. Limonite and bentonite bed, light-brown, 1 11. Shale, pale-yellowish-brown, soft, chalky, fissile; lower 6 feet? unexposed; contains several irregular platy speckled chalky limestone 14 8 10. Chalk, yellowish-gray, platy______________ 10 USGS Mesozoic loc. D3505, NWMSEM see. 10, T. 20 S., R. 65 W: Inoceramus simpsoni Meek (pl. 10, fig. 1; pl. 11, fig. 5) Baculites sp. (smooth) (pl. 10, fig. 4) Ostrea sp. Inoceramus cf. I. patootensis de Loriol (pl. 10, fig. 2) 9. Shale, pale-yellowish-brown, soft, fissile... 20 06 8. Limonite, dark-yellowish-orange__________. ¥ 7. Shale, pale-yellowish-brown, soft, fissile. __. 40 2 6. Limonite, dark-yellowish-orange, soft; con- tains selenite erystals__________________ 1% 5. Shale, pale-yellowish-brown, soft; contains 8-in.-thick chalky limestone in middle.. 4 _ 0 4. Limonite, dark-yellowish-orange, soft _ _____ 3 3. Shale, pale-yellowish-brown, soft; some thin platy limestone beds___________________ 11 _ 0 2. Chalk, yellowish-gray, platy; minor ledge former. - Inoceramus-__________________ 11 1. Shale, light-olive-gray, fissile_____________. 6 0 Total upper chalky shale ___ 263 10% UPPER CHALK UNIT The upper chalk unit of early Campanian age is an 8- foot-thick bed of massive chalk. The bed forms a nar- row sharp hogback that trends northward from the Fourth Street bridge across the Arkansas River just east of the Northwest Pueblo quadrangle along the east side of Dry Creek (fig. 9). The bed is well exposed in cliffs at many places along the hogback, but the best exposure is in the bluff along the Arkansas River in the NW!1@SW!,, NW!4 sec. 36, T. 20 S., R. 65 W. In the southern part of Pueblo the chalk is buried by sur- ficial deposits, A chalk bed of identical appearance crops out in a hogback as far north as Horse Creek on the east side of the Laramie Range, Wyo. The upper chalk extends eastward beyond the Apishapa River. It was not traced to the south. The upper chalk is a single massive blocky bed of olive-black chalk that weathers dark yellowish orange. Its description and stratigraphic position are shown in 1L22 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 65 W., Pueblo County, Colo. F1GURE 9.-Ridge formed by upper chalk unit of Smoky Hill Shale Member along east side of Dry Creek in the NE} see. 22, T. 20 S., R. Weathered upper chalk unit is shown in foreground. The Jacob staff is 5 feet long. STRATIGRAPHY OF NIOBRARA FORMATION, PUEBLO, COLORADO a stratigraphic section listed under the upper chalky shale. In a fresh exposure the chalk is difficult to dif- ferentiate from underlying and overlying chalky lay- ers. Where weathered, however, the chalky layers be- low and above are shaly, and only the 8-foot-thick upper chalk bed forms a hogback. The chalk is a weakly co- hesive rock composed of small light-colored specks of calcium carbonate, clay, and tests of Foraminifera. The content of calcium carbonate averages about 80 percent ; the remainder is clay and silt. FOSSILS AND AGE The upper chalk unit at USGS Mesozoic loc. D3510 and D3511 contains three fossil forms that characterize the unit but apparently are not limited to it. They are Inoceramus simpsoni Meek, large smooth baculites, and a barnacle, Stramentum haworthi Williston (pl. 11, fig. 2), which is attached to the baculites. This chalk unit is probably of early Campanian age. CALCAREOUS BEDS AT BASE OF PIERRE SHALE Calcareous shale that contains light-brown speckled chalky layers, moderate-yellowish-orange concretionary limestone, and bentonite beds continues 145 feet above the Smoky Hill Shale Member into the overlying un- named transition member of the Pierre Shale. These calcareous beds lie above the hogback-forming chalk along the Front Range at least from northern Colorado southward to Walsenburg. The contact between the calcareous and noncalcareous rocks is not mappable. Therefore, the top of the upper chalk unit, which is mappable, was chosen as the top of the Niobrara Formation. In the subsurface the top of the Niobrara is customarily picked at the break be- tween calcareous and noncalcareous rocks, and we want to emphasize that this boundary is considerably younger and 145 feet higher than the mappable top of the Nio- brara at Pueblo. Northward from Pueblo the calcare- ous rocks decrease in thickness at the base of the Pierre, but they are still nearly 100 feet thick near Denver. INCORRECT USAGE OF THE NAMES TIMPAS LIMKE- STONE AND APISHAPA SHALE The relation of the Fort Hays Limestone and Smoky Hill Shale Members of the Niobrara Formation to the Timpas Limestone and Apishapa Shale is discussed here in order to clear up a misconception, stated or im- plied repeatedly in the literature, that these formations are exactly equivalent to each other. As a result of the work at Pueblo, we find that the names Timpas and Apishapa are unnecessary and undesirable because they do not properly express the natural division of the rocks. Therefore, we abandon the names Timpas Lime- stone and Apishapa Shale. L23 Figure 2 shows that the type Timpas Limestone in- cludes beds from the base of the Niobrara to the top of the lower limestone unit; the Apishapa contains the rest of the Niobrara. The two names were used in the same sense as Gilbert (1896) intended them only in the early folios of the Geologic Atlas of the United States, such as the Nepesta, Apishapa, and Walsenburg folios, which were mapped by geologists who had worked with Gilbert or who knew exactly where he had placed the boundary between the Timpas and Apishapa. Since publication of the last of these folios in 1912, the Timpas has been almost invariably restricted to limestone beds 30 to 40 feet in thickness at the base of the Niobrara, which should correctly be called the Fort Hays Lime- stone Member. The enlarged Apishapa, as incorrectly applied, contains the upper part of the type Timpas and all the type Apishapa which together really equal the Smoky Hill Shale Member. In Kansas the type Fort Hays Limestone Member is the lower 55 feet of ledge-forming limestone at the base of the Niobrara. It is overlain by the type Smoky Hill, which contains about 550 feet of chalk and chalky shale. These two units are recognizable, and the contact be- tween them is readily mappable over nearly all the basin of Niobrara deposition. On the other hand, the contact between the Timpas and Apishapa is mappable only in a small area near Pueblo. The name Fort Hays has priority because it was pro- posed 3 years earlier than the name Timpas. The names Smoky Hill and Apishapa were proposed in the same year. Two sets of names are unnecessary to designate di- visions of the Niobrara. If the Pueblo area is con- sidered alone, either set of units could have been subdivided into the eight map units that are used in this report. We prefer, however, to abandon the names Timpas and Apishapa, partly because they have not been used as widely as the Fort Hays and Smoky Hill and partly because Fort Hays and Smoky Hill best fit the mappable units that crop out over most of the basin of Niobrara deposition. CORRELATION - The Niobrara Formation can be correlated with rocks of varied lithology throughout the western interior of the United States. Four areas (table 3) that are widely separated have been selected to show lithologic varia- tions in rocks equivalent to the Niobrara Formation at Pueblo. At Boulder, Colo., the rocks are calcareous but not as chalky as those at Pueblo. In central Utah, correlative rocks are noncalcareous shale and beds of sandstone. Rocks in the Wind River Basin, Wyo., and on the Sweetgrass arch, Montana, include sandstone, SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 124 snzofduod s18ua0409 Tye snuwnaasou;r sopydnog (qred) weuoing, saddp (jued) QMMMMWMJ “WWW—“ma ? $1309.49 uo J Jor} UOIA siey 1404 skep q 10 a pus sD42vis104Dg snun1a00ou] snsooquaraid J9MOT qy1un 49MOT suu1ofap wéEagm |-SUuo7sou0| snwn.4a90u] f pue arey; pue are4§ Wu yun arppIW § m W areys areys 19m07 snqnjoaut mswwwihww; oIPPIW m. wu Pod a m Areyg yang 3 |y snuwn.4200u] uemopoent - | go “Mu auogsou auo3sou| opens snssaidap n dodd SEN—Ed“: 5.) © 19MOT 2 19mOT 2, sopydoogy A ® \tp o o 3° w|§ w § m m 3 m w m snqnordopmpun 19m01 jun W. > L2 Smoky Hill Shale Member of Niobrara Formation................. 8,18, 17,18, 21,23 | TimpAS cece ccc ence}. 1,2, 4, 28 Stanton, T. W., e> 2 Stantonoceras pseudocostatum.. ___ 5, 15; pl. 8 | Upper chalk unit of Smoky Hill Shale Member of Niobrara Formation......... E Stramentum R@WorthiLL 5, 20, 23; pl. 11 | Upper chalky shale unit of Smoky Hill Shale Member of Niobrara Formation .. 18 .L. 2222 : @@St-C@NETALL L 2 2 22 0000000 cece eccen- neenee 25 Sweetgrass arch, 23, 25, 26 Virgell® S&MUStOMG.... .... coco cece cee eccen- 25, 26 Telegraph Creek 25, 26 Teranites 5, 15; pl. 7 ' Wind River Basin, cece 28, 25 O PLATES 1-11 PLATE 1 Inoceramus deformis Meek (p. L9). View of a very large specimen from the top of the shale and limestone unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3470 in the NWMSWH sec. 4, T. 21 S., R. 65 W. USNM 131488. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 1 6 INCHES INOCERAMUS DEFORMIS MEEK FROM SHALE AND LIMESTONE UNIT OF SMOKY HILL SHALE MEMBER PLATE 2 [All figures natural size] FrcurEs 1-5. Inoceramus aff. I. perplesus Whitfield (p. L7). 1-4. Views of four specimens from 2 feet above the base of the Fort Hays Limestone Member at USGS Mesozoic loc. D3514 in the SW}4 see. 22, T. 18 S., R. 68 w. USNM 131489-131492. 5. View of a specimen from the basal 1 foot of the Fort Hays Limestone Member at USGS Mesozoic loc. D2980 in the SWLANE}4 sec. 32, T. 20 S., R. 65 W. USNM 131493. 6. Inoceramus erectus Meek (p. L7). View of an average-sized specimen from 20 feet above the base of the Fort Hays Limestone Member at USGS Mesozoic loc. D2984 in the sec. 32, T. 20 S., R. 65 W. - USNM 131494. 7, 8. Barroisiceras (Forresteria) hobsont Reeside (p. L7). Front and side views of the holotype from the Fort Hays Limestone Member near Carlile Spring, Pueblo County, Colo. USNM 73762. After Reeside. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 2 FOSSILS FROM FORT HAYS LIMESTONE MEMBER PLATE 3 [All figures natural size] FicurES 1, 2. Neocrioceras n. sp. (p. L11). Side views of rubber casts of two impressions from the upper part of the lower limestone unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3482 in the see. 16, T. 20 S., R. 65 W. USNM 131495, 131496. 3. Phlycticrioceras oregonense Reeside (p. L11). Side view of a rubber cast of an impression of an adult whorl from the lower part of the lower limestone unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3479 in the SEL{ANW}4 see. 33, T. 20 S., R. 65 w. USNM 131498. 4. Inoceramus involutus Sowerby (p. L10). Right valve of a specimen from the middle of the lower shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3473 in the SEVMANW M sec. 16, T. 20 S., R. 65 W. USNM 131499. 5. Baculites asper Morton (p. L10). Side view of a crushed specimen from the middle of the lower shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3474 in the NEMNE}Y sec. 32, T. 20 S., R. 65 W. USNM 131500. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 3 FOSSILS FROM THE LOWER SHALE AND LOWER LIMESTONE UNITS OF SMOKY HILL SHALE MEMBER PLATE 4 [All figures natural size} FrcurEs 1-3. Inoceramus stantoni Sokolow (p. L11). 1, 2. Views of two specimens from the upper part of the lower limestone unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3481 in the SEMNW} see. 16, T. 20 S., R. 65 W. USNM 131502, 131503. 3. Both valves of a specimen from near the top of the lower limestone unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3488 in the NE cor. see. 8, T. 20 S., R. 65 W. USNM 131501. 4. Protexanites shoshonensis (Meek) (p. L15). Side view of part of a whorl from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. 1289 in the NWHMSE}4 see. 9, T. 20 S., R. 65 W. USNM 131497. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 4 FOSSILS FROM LOWER LIMESTONE AND MIDDLE SHALE UNITS OF SMOKY HILL SHALE MEMBER PLATE 5 [All figures natural size] FraurEs 1, 5. Inoceramus undulatoplicatus Roemer (p. L15). Views of a juvenile and a young adult from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3490 in the NWMSEM see. 9, T. 20 S., R. 65 W. USNM 131504, 131505. 2. Scaphites depressus Reeside var. stantoni Reeside (p. L15). View of rubber cast of part of a body chamber from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3489 in the NWMMSE}4 see. 9, T. 20 S., R. 65 W. USNM 131508. 3. Baculites asper Morton (p. L15). Side view of an incomplete specimen from the lower part of the middle shale unit of the Smoky Hill Shale Member at the same locality as figure 1. USNM 131509. 4. Baculites codyensis Reeside (p. L15). View of a rubber cast of an impression from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3493 in the SENW! see. 16, T. 20 S., R. 65 W. USNM 1831510. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 5 FOSSILS FROM LOWER PART OF MIDDLE SHALE UNIT OF SMOKY HILL SHALE MEMBER PLATE 6 [All figures natural size] Frcur®s 1, 4. Inoceramus undulatoplicatus Roemer (p. L15). Views of two specimens from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3490 in the NW14 SEL{ see. 9, T. 20 S. R. 65 W. USNM 131506, 131507. 2. Clioscaphites saxitonianus (McLearn) (p. L15). Side view of a crushed specimen from the lower part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3491 in the SWILNW!14 see. 21, T. 20 S., R. 65 W. USNM 131511. 3. Clioscaphites sazxitonianus var. keytei Cobban (p. L15). Side view of a crushed specimen from the same bed and locality as figure 2. USNM 131512. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 6 FOSSILS FROM LOWER PART OF MIDDLE SHALE UNIT OF SMOKY HILL SHALE MEMBER PLATE 7 [All figures natural size) Ficur®s 1, 2. Inoceramus cordiformis Sowerby (p. L15). Views of a right and a left valve from limestone concretions in the upper part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3497 in the NW}4 see. 25, T. 18 S., R. 66 W. USNM 131513, 131514. 3, 4. Baculites codyensis Reeside (p. L15). Side and ventral views of a specimen from a limestone concretion in the upper part of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. 14305 in see. 1, T. 32 S., R. 62 W., Las Animas County, Colo. USNM 131515. 5, 6. Baculites asper Morton (p. L15). Side and ventral views of a specimen from the same concretions and locality as figure 3. USNM 131516. 7-9. Clioscaphites sazitoniamnus (McLearn) var. keyte? Cobban (p. L15). Side, front, and top views of the holotype from the same concretions and locality as figure 3. USNM 106727. 10-12. Clioscaphites vermiformis (Meek and Hayden) (p. L15). 10. Side view of a crushed specimen from a limestone bed in the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D1714 north of Boulder in the SWNE} see. 7, T. 2 N., R. 70 W., Boulder County, Colo. USNM 131517. 11, 12. Side and rear views of two crushled specimens from the upper part of the middle shale unit at USGS Mesozoic loc. D3500 in the NESW! see. 10, T. 20 S., R. 65 W. USNM 131518, 131519. 13, 14. Texamites americanus (Lasswitz) (p. L15). Side and rear views of a specimen from the same concretions and locality as figure 3. USNM 131520. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 7 FOSSILS FROM UPPER PART OF MIDDLE SHALE UNIT OF SMOKY HILL SHALE MEMBER PLATE 8 retion at USGS USNM A con: diameter from a. limefifténe Hill Shale M R. 62 W., Las Animas County, Col mm in t of the Smoky ni ddle shale u . 82 8 (X 14) of the septate whorls 406 the upper part of the mi Mesozoic loc. 14305 in sec. 1, 131521. @ r- (Sl £ " o ® 3 ro € m view Side in. Stantonoceras pseudoc "3 GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 8 L 1 1 1 I 1 l T 1 12 INCHES STANTONOCERAS PSEUDOCOSTATUM JOHNSON FROM UPPER PART OF MIDDLE SHALE UNIT OF SMOKY HILL SHALE MEMBER 11 Shale Member at USGS Mesozoic loc. D3504 in the NEMNWHM USNM 131522. t of the Smoky Hi sec. 15, T. 20 S., R. 65 W. uni M o Mum o g $ E 3 49 § 3 A § 5] 3 [2] am I G co 3 o X As o > ies & Rs 'E a "6 E 2 i> & H & g & o H © S & 5 § wee GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 9 12 INCHES L 1 1 T L L I . 1 1 1 N 1 INOCERAMUS PLATINUS LOGAN FROM MIDDLE CHALK UNIT OF SMOKY HILL SHALE MEMBER FicurRE 1. 3, 5. PLATE 10 [All figures natural size] Inoceramus simpsonit Meek var. (p. 120). View of a broad variant that resembles the European I. balticus Boehm. From the lower part of the upper chalky shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3505 in the NWMSE!L4 sec. 10, T. 20 S., R. 65 W. USNM 131523. . Inoceramus cf. I. patootensis de Loriol (p. L20). Small fragment from the same locality as figure 1. USNM 131525. Inoceramus sp. (p. L15). From near the top of the middle shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3501 in the NEMSW!4 see. 10, T. 20 S., R. 65 W. 3. Rubber cast of parts of two valves having affinities with I. cordiformis Sowerby. USNM 131526. 5. View of a crushed specimen having a quadrate form. USNM 131527. Baculites sp. (p. L20). View of a rubber cast of two? specimens typical of the smooth form found in the lower part of the upper chalky shale unit of the Smoky Hill Shale Member at the same locality as figure 1. USNM 131528. . Clioscaphites choteauensis Cobban (p. L18). Side view of a crushed adult from near the base of the middle chalk unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3503 in the NWMNW!4 see. 15, T. 20 S., R. 65 W. USNM 131529. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 10 FOSSILS FROM MIDDLE SHALE, MIDDLE CHALK, AND UPPER CHALKY-SHALE UNITS OF SMOKY HILL SHALE MEMBER PLATE 11 [All figures natural size} FicurE 1. Inoceramus platinus Logan (p. L20). View of a specimen that has coarse and fine concentric folds. From the upper part of the upper chalky shale unit of the Smoky Hill Shale Mem- ber at USGS Mesozoic loc. D3509 in the SEMNW!4 see. 15, T. 20 S., R. 65 W. USNM 131533. 2. Stramentum haworthi Williston (p. L23). View of a rubber cast of two specimens attached to the side of a smooth baculite. From the upper chalk unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3513 in the NENW! sec. 23, T. 23 S., R. 59 W., Otero County, Colo. USNM 131530. 3, 4. Haresiceras placentiforme Reeside (p. L20). Views of two crushed specimens from the upper chalky shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3266 in the SW!4- NW! sec. 23, T. 23 S., R. 59 W., Otero County, Colo. USNM 131531, 131532. 5. Inoceramus simpsonit Meek (p. L20). View of a rubber cast of part of a specimen from the lower part of the upper chalky shale unit of the Smoky Hill Shale Member at USGS Mesozoic loc. D3505 in the NWMSEM see. 10, T. 20 S., R. 65 W. USNM 131524. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-L PLATE 11 FOSSILS FROM UPPER CHALKY-SHALE UNIT AND UPPER CHALK UNIT OF SMOKY HILL SHALE MEMBER SSLvHaLT ape peje [/Z ats? / A] Bedrock Valleys of the New England Coast as Related to Fluctuations of Sea Level GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-M OCT 22 1964 / A p Q Z science ust Bedrock Valleys of the New England Coast as Related to Fluctuations of Sea Level By JOSEPH E. UPSON erd CHARLES W. SPENCER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY SURVEY PROFESSIONAL PAPER 454-M Depths to bedrock in coastal valleys of New England, and nature of sedimentary fill resulting from sea-level fluctuations in Pleistocene and Recent time UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director The U.S. Geological Survey Library has cataloged this publication as follows : Upson, Joseph Edwin, 1910- Bedrock valleys of the New England coast as related to fluctuations of sea level, by Joseph E. Upson and Charles W. Spencer. Washington, U.S. Govt. Print. Off., 1964. iv, 42 p. illus., maps, diagrs., tables. 29 cm. (U.S. Geological Survey. Professional paper 454-M) Shorter contributions to general geology. Bibliography : p. 39-41. (Continued on next card) Upson, Joseph Edwin, 1910- Bedrock valleys of the New England coast as related to fluctuations of sea level. 1964. (Card 2) 1.Geology, Stratigraphic-Pleistocene. 2.Geology, Stratigraphic- Recent. 3.Geology-New England. I.Spencer, Charles Winthrop, 1930-joint author. II.Title. (Series) For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS @ «--- .= nar fotroducti0s - - - 22. .> e neal. ce ve Purpose of the investigation______________________ Acknowledements....2..>. _ Previous investigations '..._.__.__....__._________ Method of _ Ceneral geologic setWing......-....................... Location of sections and sources of data Configuration and depth of bedrock valleys and stratig- raphy of fill- ..= ..-. ran Bedrock valleys of coastal Connecticut.... General us Depth of bedrock thalwegs_._________________ Housatonic Quinnipiac River..........c.........l.. Connecticut Thames Unconsolidated deposits. ___________________. TM 3 2 os she ran eel ank s an alee s naaa a's ae and LIL o + ieee. ce on aca- nece n . Estuarine deposits.. :.-.-__._.l.l.:2l.l.... Deposits at Middletown-Portland Bridge.. Summary of features of Connecticut coastal VAllGY$-- i sagas» Narragansett -Bay General Depths of bedrock thalwegs.__.____._._______. Blackstone bedrock valley. ___.... Providence bedrock valley.. _____________._ Taunton-Sakonnet bedrock valley...... .. Unconsolidated Summary of features of Narragansett Bay area VAlley$>.~ e-- Page Mi Configuration and depth of bedrock valleys, ete.-Con. Buried valleys of the Boston area____.___________. Ceneral fCabUTCS- - <-- seers nace. Depth of bedrock thalwegs.___________________ Charles buried valley............_..______ Aberjona-Fresh Pond buried valley .._ ___. Malden buried valley.________.__________ Unconsolidated deposits.._..___..__________. Summary of features of the Boston Basin area buried Bedrock valleys near Portsmouth, N.H.___________. Bedrock valleys of the Maine coast...... General Depth of bedrock thalwegs._________________. Presumpscot buried valley________.___.___. Kennebec bedrock valley._____________._._._ Sheepscot River at Wiscasset____________. Penobscot River bedrock valley...... St. Croix bedrock valley (Passamaquoddy Pay). Unconsolidated deposits._.___.____________.. Till asp Marine clay and silt..........-_-....... Summary of features of Maine coastal bedrock ConcIusi0ns-.. .~... Depths and origin of the bedrock thalwegs--_-_... Stratigraphy of the depositional fill._._-_______.__. References Ched ic ans aun mee III Page M21 21 23 283 28 24 24 28 28 29 29 30 30 30 31 31 31 33 33 33 33 36 36 36 38 39 43 IV TaBurs 1-5. CONTENTS ILLUSTRATIONS [Plates are in pocket] . Sections of bedrock valleys of coastal Connecticut. . Sections of the Charles and Malden buried valleys in the Boston area, Massachusetts. . Sections of bedrock valleys along the Maine coast. . Map of the New England coast showing elevations of thalwegs of bedrock valleys. . Map of the New England coast showing elevations of the thalwegs of preestuarine valleys. . Index map of New England showing rivers, location of sections, and major structural basings......_....._.__. . Section of the Connecticut bedrock valley at highway bridge between Middletown and Portland, Conn... Sketch map of Narragansett Bay showing locations of bedrock valleys and sites of sections or where other data were . Profile of thalweg of Blackstone bedrock valley between Woonsocket and the city of Warwick, R.I_..._........- . Section of Taunton-Sakonnet bedrock valley at Tiverton, Sketch map of Boston area, Massachusetts, showing locations of buried bedrock valleys and of geologic sections. . Profile of thalweg of Aberjona-Fresh Pond and lower Charles buried valley8-_-_-_________-_-_-_-_------------- . Section of Malden buried valley at Malden, MA§§-______________________-________c___________________~~~- . Sketch map of the vicinity of Eastport, Maine, showing thalwegs of St. Croix bedrock valley and tributaries in the southern Passamaquoddy BAy TABLES Summary of: 1. Stratigraphy of unconsolidated deposits in New England bedrock 2. Information on bridge foundation borings at crossings of bedrock valleys in Connecticut.-.......«..... 3. Data on bedrock valleys at 10 sites in Narragansett Bay-_______________________c__________--_~- 4. Information on crossings of buried valleys in the Boston Basin area, Massachusetts-__--------------- 5. Information on crossings of bedrock valleys along the Maine COA8t_________________--------------- . Inferred elevations of thalwegs of New England coastal bedrock valléeys-__-._______________-_-__--__--------- . Generalized comparison of late Pleistocene and Recent stratigraphic units in bedrock valleys of the New ENgIANG Page M6 14 17 19 25 26 32 Page M65 15 29 37 38 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY BEDROCK VALLEYS OF THE NEW ENGLAND COAST AS RELATED TO FLUCTUATIONS OF SEA LEVEL By Josee E. Ursoxn and CHarurs W. Sprnorr ABSTRACT Test borings for bridges crossing 14 New England rivers or bays near the coast (including Narragansett and Passamoquoddy Bays) reveal information on depths to thalwegs of buried bedrock valleys and on the nature of contained unconsolidated sediments. An attempt is made to infer from these data some- thing of the time and rate of sea-level rise in late- or post- glacial time as one phase of the general problem of encroach- ment of salty ground water from the sea. Thalweg elevations near the coast range from about -95 feet msl (mean sea level) to about -420 feet msl. Virtually level reaches on the Blackstone buried valley at about -200 feet msl and on the Charles at about -250 feet msl suggest at least local base levels. The bedrock valleys were formed before the Wisconsin Glaciation, and the thalweg elevations are not considered to be a measure of sea-level decline at the Wisconsin maximum. The unconsolidated deposits within the bedrock valleys are of late and post-Pleistocene age, and differ systematically along the coast. In the valleys off the Connecticut coast, fluvioglacial outwash, possibly related to a stand of the ice at Middletown, Conn., is overlain in irregular contact by estuarine deposits extending to about present sea level. Valleys in the Boston area and in southern Maine contain mainly glacial- marginal marine clays, also overlain by estuarine deposits. Estuarine deposits of appreciable thickness apparently do not occur in eastern Maine. to BAY Tb J | f A $53 r 3 x77 i 4 C N A \ 10 3° / "A From U.S. Geological Survey: State base maps a 0 10 20 30 40 MILES FIGURE 1—Continued. accurate to within 10 feet. The data on the Quinnipiac River and on the Connecticut at the coast are not defini- tive; the thalweg depths are probably appreciably greater than the greatest observed depth at which the bedrock was penetrated. Some detailed comments follow. HOUSATONIC RIVER Data are available for several bridges across the Housatonic. The best are for State Route 15 (loc. 1, fig. 1) and for the Connecticut Turnpike (loc. o, 1). about 3.5 miles farther south. Some information on borings for the Washington Bridge, next bridge to the south, is available but is not used here because it adds little additional data. Plate 14 shows a section based on selected borings made for the State Route 15 Bridge (connecting the Merritt and Wilbur Cross Parkways) across the Housa- tonic between Stratford and Milford, Conn. The cross- ing is about 6 miles above the river mouth. The section extends across only about half the valley, but probably includes the buried thalweg. The deepest point in the section is -79 feet msl at boring 106-B. The deepest known point at this crossing is at boring 107-A, 60 feet north of 107-C, where the bedrock was penetrated at about -92 feet msl. f Plate 12 shows the subsurface conditions as inter- preted from logs of borings for the Connecticut Turn- pike bridge. For this section, the borings are numerous, and the bedrock is cored. The bedrock profile is con- sidered to be well controlled. The greatest known depth to bedrock is at boring 34-HR (about 80 ft north of boring 33-HR shown in the section), where the bed- rock surface lies at -115 feet msl. Accordingly, the bedrock is shown at this depth in plate 12. In addition to this main bedrock valley, borings numbered 9-HR through 21-HR, near the west end of the section, de- lineate a subsidiary buried bedrock channel. MS QUINNIPIAC RIVER Plate 1C shows the bedrock surface and lithology of unconsolidated deposits on the eastern side of the Quin- nipiac River bedrock valley at New Haven, Conn. The bridge is 350 feet northeast of the old Forbes Avenue- Water Street bridge and just south of the confluence of the Mill and Quinnipiac Rivers. The depth of the thalweg here is not known. The deepest bedrock shown in the section was penetrated at boring 99, where the surface lies at -171 feet msl. The best data on the deepest position of bedrock in the New Haven area were obtained from a log of a well drilled for the New Haven Clock Co., about 2,000 feet N. 21° W. of boring 82-D. Here the well went to 280 feet below sea level without reaching bedrock. Data on two other drill sites in the vicinity of Wallingford, about 12 miles west-northwest of New Haven, suggest that the bedrock is at depths of 243 and at least 190 feet below land sur- face, which is a few feet above high tide level. Thus, it is likely that this buried bedrock valley is considerably deeper than the maximum observed depth shown in plate 10. CONNECTICUT RIVER The Connecticut River heads in northern New Hamp- shire, and flows generally south between New Hampshire and Vermont. It crosses about the middle of Massa- chusetts, and continues south in Connecticut about to Middletown. (See fig. 1.) Here it changes abruptly to a nearly due easterly course, which it follows for about 5 miles, and then changes to a sinuous but gen- erally south-southeasterly course for about 22 miles to Long Island Sound. The course across Massachusetts and as far as Middletown in Connecticut lies in the structural basin, where here is underlain mostly by sand- stones and shales of Triassic age. Just below Middle- town the river crosses the eastern boundary of the basin. Thence downstream, the Connecticut occupies a rather narrow gorge cut in the much more resistant crystalline rocks, mainly gneisses. Because it is tidal as far up- stream as Hartford, the lowermost 15 to 20 miles of the stream is more like a long, narrow estuary than a river. The Connecticut River also has a buried bedrock val- ley which locally departs somewhat from the position of the present stream. - Within much of the Connecticut Valley Lowland, the thalweg of the bedrock valley lies a short distance east of the present stream (Flint, 1983; Cushman, 1960, fig. 2). Near Middletown the thalweg of the bedrock valley may swing eastward in a broad curve that cuts off the sharp right-angle bend of the present course. Thence to the southeast, the bedrock valley lies beneath and is part of the present Connecticut River gorge. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Data for two crossings of the Connecticut River and its bedrock valley are considered here. One crossing is at Middletown at the Middletown-Portland Bridge (loc. 6, fig. 1), and the other is near the river mouth at the Raymond E. Baldwin Bridge for U.S. Route 1 between Old Saybrook and Old Lyme (loc. 4, fig. 1). The bed- rock configuration is fairly well delineated at the Mid- dletown-Portland Bridge, but most of the borings for the Baldwin Bridge did not reach bedrock. The stra- tigraphy of the deposits in the bedrock valley at these two sites is markedly different. The difference sheds some light on the glacial history of the lower Connecti- cut River that is pertinent to the present paper. (See p. M12.) Figure 2 shows the configuration of the bedrock and lithology of the fill as interpreted from borings for the U.S. Alternate Route 6 and State Route 17 bridge be- tween Middletown and Portland, herein called the Mid- dletown-Portland Bridge (loc. 6, fig. 1). The lowest known elevation of bedrock here is -118 feet msl in boring 13-8. The bedrock may lie somewhat deeper because there is considerable area between boring 12-S and 13XS and between boring 12-8 and STA 110+18 that is unexplored. However, a conservative estimate is -120 feet msl. The Middletown-Portland bridge may not be over the thalweg of the main Connecticut bedrock valley which may follow the possible eastern cutoff of the sharp bend at Middletown. If the main bedrock valley follows the cutoff, it would pass about 3 miles east-northeast of Middletown. (See the Middletown and Middle Had- dam quadrangles, Connecticut, scale 1:31,680, and Cushman, 1960, fig. 2.) In the cutoff the lowest known elevation of bedrock is -112 feet msl, but it may be as low as -120 feet msl (R. V. Cushman, personal communication, 1959). This is comparable to the inferred elevation at the Middletown-Portland Bridge. Even if that bridge were over a tributary to the main valley, as Bissell (1925, p. 235) suggested, the maximum depth would still be about the same as on the main thalweg because the point of junction can not be more than a few miles away and the gradient is low. Plate 1D shows subsurface geology of the Connecti- cut bedrock valley as interpreted from lithologic logs of borings made for the Raymond E. Baldwin Bridge that crosses the river near Long Island Sound. This bridge, about 25 miles below Middletown, carries high- way traffic for U.S. Route 1, Interstate Route 95, and the Connecticut Turnpike over the Connecticut River between Old Saybrook and Old Lyme, Conn. (See loc. 4, fig. 1.) This section, unfortunately, shows comparatively little about the depth and configuration of the bedrock. 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F 13 «s A37 CEEVE JAOLLO 4 NN OI m y3% ny reruniyk _ o \ RCR E4 1 a LE m 1 & e to __ § w// 9 > ' - & I & w @ | s $+. &; § MN $. g 5 5 Op 2 i ff KL 1 -i} fmm =| § 5 A42 9s 'S 3 2 TE § ims f & s € $ oss dfs f s 2 gg %: sAz G. ® 3g % 2g sigs icf * 8 § 7VW in | $z" $f | o) £0 0 0 M10 Bedrock is close to the land surface at the east abutment of the bridge. The west abutment of the bridge is probably about over the middle of the bedrock valley because the nearest exposed bedrock on the west side of the river is about half a mile to the west. Within the bedrock valley, bedrock was penetrated in the fol- lowing five borings: 8-SW, 8-NW (not shown; about 85 ft north of 8-SW), 9-SE, 9-NE (not shown ; about 85 {t north of 9-SE), and 5-B, all on the east side. The lowest observed position of the bedrock surface is at boring 8-NW (about 85 ft north of 8-SW), at an ele- vation of about -132 feet msl. At boring 8-SW, the elevation is about -130 feet msl. The depth of the thalweg is not known. In the vicin- ity of East Haddam, which is along the river about 10 miles upstream from the Baldwin Bridge, data on a few water wells suggest that bedrock there is more than 100 feet below sea level. Another well drilled in the southeastern part of Middletown on the west side of the river and about 20 miles upstream from the Baldwin _- Bridge penetrated unconsolidated deposits to 155 feet below sea level without reaching bedrock. The thalweg beneath the Baldwin Bridge probably lies deeper than 200 feet below sea level. THAMES RIVER The Thames River is a narrow estuary that extends about 15 miles northward from Long Island Sound. Several streams come together at the head of the estuary. The bedrock beneath the tributaries is generally shal- low, and the thalweg of the valley system apparently deepens abruptly at the head of the estuary. Fairly complete data on the bedrock surface are avail- able from borings taken at the U.S. Route 1 bridge near the mouth of the estuary at New London. (See pl. 12.) The bedrock surface in this section is well controlled because nearly all the borings penetrated to bedrock. The present Thames is approximately centered over its bedrock valley whose profile is roughly symmetrical, although locally irregular, as shown at borings 9-K, 10-A, and 10-B. The lowest known elevation of the bedrock surface was found at boring 9-J, where the bed- rock surface is -174 feet msl. - On the basis of a pro- jection of slopes, the minimum inferred elevation is about -190 feet msl, although a somewhat lower eleva- tion would be reasonable. UNCONSOLIDATED DEPOSITS The unconsolidated deposits in the valleys of the Connecticut coast include for the most part three units which, from the base up, are identified as till, outwash, and estuarine deposits. These units each occur with slightly different characteristics or with somewhat dif- ferent thickness or extent in the valleys, but they are SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY all present. - Their characteristics and relationships are described in more detail in following paragraphs. In the section at the Middletown-Portland bridge are more units; these deposits are discussed separately (p. M12). TILL In all the sections many of the borings penetrated a layer of coarse-grained material at the base. This material is poorly sorted, generally consisting of coarse gravel, boulders, cobbles, and some clay. Many records indicate a high blow count for penetration of this layer, and in some sections the material is described as "hard." The coarse grain, poor sorting, and high blow count indicate that the layer is till. As it is not reported in all borings (see, for example (pls 1C and 17) ), the layer is probably discontinuous. At some sections, for example on the Thames (pl. 15), the till is clearly distinct from overlying material. In others, as on the Housatonic (pl. 12), the overlying material is also coarse grained and the distinction is not clearcut. Where doubtful material is believed to represent till, it is indicated by "till?" on the section shown in plate 1. In exposures near all the sections, a layer of till ranging from 1 to 20 feet in thickness can be observed locally resting on the bedrock. This basal till probably extends, at least discontinuously, down the sides of the concealed parts of the bedrock valleys. oUTWASH Above the till is better sorted material, consisting of sand and silt, some gravel, and a little clay. In the Houstatonic valley this unit is mostly sand and gravel, but the gravel is finer grained than the material below. Although this unit contains some clay locally, it is not described as "hard." Some clay also occurs in the unit in the Quinnipiac valley, as indicated by some boring records which report layered sand and clay and some sand partings. Al- though traces of bedding do not appear in most samples examined, one sample from boring 84 (70 ft northeast of boring 83, pl. 1C) is well-stratified pink-brown silt and clay interbedded with some very fine sand. The position of other reported stratification is shown on plate 1C by the lines indicating clay at several borings in the western part of the section. In the Connecticut and Thames valleys, this outwash unit is predominantly sand, although at some places it is gravelly in the upper part. Borings 1, 2-N, and West Abutment (pl. 17) start in sand, gravel, cobbles, and some silt; similar materials make up the stratified drift, which is exposed nearby. At greater depth some of these borings penetrate uniform sand and silt, as do borings 3, 4, 5, 6, 7, and 8-SW. This material, al- though fine-grained, is considered to be part of the BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS outwash unit. - Exposures of this unit farther upstream also have coarse-grained deposits in the upper part and fine-grained deposits in the lower (J. A. Baker, written communication, 1959). This unit underlies and forms terrace remnants whose surfaces are 20 or 30 feet above sea level at the Baldwin Bridge (pl. 17), and which are traceable for several miles upriver. In the vicinity of Middletown the ter- race surface stands at about 200 feet above sea level, and is the surface of the outwash mentioned by Flint (1953, p. 899) as marking the terminus of the read- vanced Cary ice tongue. Therefore, at least the upper part of this outwash is of the same age as the ice tongue at Middletown, which is Cary. In the Thames valley this outwash is predominantly sandy on the east side as shown by borings 10-E, 10-F, 11-A, and 11-B (pl. 15) but contains some clay and gravel in the west side of the section. Clayey sand and sand with some clay was found in borings 11-E, 11-F, and 12. The heterogeneous material may have been deposited near ice, and the predominantly sandy ma- terial may have been deposited some distance from the ite by melt-water streams or in lakes. No organic remains are reported to occur in this unit. Insofar as its characteristics are revealed by the records of borings, the outwash seems to be in each valley a single unit. However, its manner of deposition was probably complex. For example, Richard Gold- smith (1962) in discussing the surficial geology of the New London quadrangle indicated that the out wash de- posits as exposed at the east end of the bridge are older than those that form lower terraces, as for example at about sea level in New London, Conn. Although not differentiated in the section, the deposits that are the highest and the farthest from the river may have been deposited in part against stagnating ice that oc- cupied the central part of the bedrock valley. The lowest, central parts were deposited therefore after the ice had melted away. Thus, there may be local uncon- formities within the outwash. However complex its deposition, the outwash in the Connecticut valleys probably represents a single glacial retreatal episode. The complexity of deposition is shown in the logs of borings 97 and 99 in the Quinnipiac valley (pl. 10) where a few shells are reported. The log of boring 97 reports, "shells and mica in brown coarse to fine sand with little fine gravel" between -65 and -70 feet msl. This sample was not examined. A sample from boring 99 in the interval -105 to -106.5 feet msl was ex- amined and found to consist of very fine to coarse red-brown sand and to contain several white flakelike calcareous fragments. The largest fragment was 2X3 mm. These fragments are not clearly pieces of shell. M11 Furthermore, because they occur at only one place in each of two borings, they may have been carried down from above during the drilling. Except for the shell fragments, the material is predominantly sand like the rest of unit 2. Therefore, although the shells may mark an unconformity within the deposits (as indicated by the queried (?) dashed line in p! 1C), they are all considered to be out wash. The full thickness of the outwash is not penetrated by the borings, but it is certainly more than 100 feet in the Quinnipiac and Connecticut valleys. ESTUARINE DEPOSITS Above the outwash is the third unit, which is pre- dominantly fine grained and contains organic matter. The material is only slightly resistant to coring, and hence is "soft." In the Housatonic valley, it varies somewhat in grain size because it contains a good deal of sand, as well as some soft clay or mud. In the Quinnipiac valley, the unit is also sandy at some places, but the sand is mainly fine to medium. The material is gray in contrast to the brown or tan of the underlying outwash. Farther east the unit is predominantly of loose mud, clay, and silt. At most borings the clay and silt are described on the boring records as "dark" or "organic;" and in all the valleys the unit contains shells and shell fragments, and locally wood and woody organic matter. In the Connecticut valley, for example, the boring logs record the presence of "organic silt," "grass roots," and "rotted vegetation." Because of the fine grain, softness, and content of organic matter, these deposits are considered to be estuarine deposits. The basal few feet locally may be fresh-water swamp material. Material reported as "peat" is particularly conspic- uous in the Housatonic (pl. 12) and the Quinnipiac ( pl. 1C) valleys. In the Quinnipiac valley the peat occurs at the base or in the lower layers of the estuarine deposits. This basal peat probably represents swamp conditions shortly prior to the beginning of estuarine deposition at this place. : In the Thames valley section (pl. 12) the estuarine deposits range from 0 to about 110 feet in thickness. The deposits rest on an irregular surface which in the section appears to be channeled. This evidence sug- gests that this surface is an erosion surface formed on the underlying outwash. This topic is discussed more fully on page M13. The presence of peat at the base in the Quinnipiac valley (pl. 1C) and in the marginal part of the estua- rine deposits in the Housatonic valley (pl. 12) suggests that swamp or tidal marsh conditions prevailed at least locally throughout much of the deposition of the estua- M12 rine deposits and, therefore, that the deposits were formed at the margins of a rising sea. DEPOSITS AT MIDDLETOWN-PORTLAND BRIDGE The deposits penetrated by the borings for the Mid- dletown-Portland Bridge across the Connecticut River (loc. 6, fig. 1) are somewhat more varied than those near the coast. They appear to comprise six main units and two minor ones. These are, from bottom to top: (1) a basal till which may include some ice- contact deposits, (2) a unit of clay constituting lacustrine deposits, (3) a body of sand, which is prob- ably a coarse-grained facies of the lacustrine deposits, (4) till, (5) a body of glacial outwash, and (6) present- day river deposits. The two minor units are a local body of swamp deposits, penetrated by one boring (24-C), and artificial fill. These two units are shown on the section (fig. 2) but are not further discussed. The basal till is doubtless the clay, sand, and gravel penetrated at the bottoms of borings 12-S, 13-8, STA, 124+04 south, and 16-8. Borings 18-N, 24-C, and 27-C also penetrated material described as clay and gravel just above bedrock, which is considered to be till. This material, however, may not all belong to the basal till. The sand and gravel at the bottom on the west side of the river penetrated at borings 102+70, 104+47, 107+46, and 108+97 may be till, but the fact that the records do not mention clay suggests that the material may be stratified drift. If this material is drift, because it is directly on the bedrock, it is prob- ably of ice-contact origin and only slightly younger than the basal till. Every boring west of and including 16-S penetrated a variable thickness of nearly uniform red clay. One boring reportedly contained some gravel, and one con- tained some sand in the clay. This red clay is consid- ered lacustrine, and probably represents the Middle- town clay of Flint (1933, p. 968), which was deposited in a lake or lakes left when the retreating ice withdrew to some point north of Middletown. Above this lacustrine clay in the western part of the section is a body of material described in the logs of three of the four borings as "fine red sand, hard." In the fourth, it is simply "red sand." This unit is either a coarse-grained facies of the lacustrine deposits, glacial out wash from ice that lay to the north, or both. The unit is designated as a sand facies of the lacustrine deposits. The unit above is probably younger till. All the borings west of the Connecticut River penetrate a var- iable thickness of poorly sorted clay, silt, sand, gravel, SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY and boulders. The description of part of the mate- rial as "gravel hard pan'"-a term indicating com- pactness-and the heterogeneity of the material sug- gest that this unit is till. The unit overlies the sand facies of the lacustrine deposits at most borings but rests on the clay facies at the two westernmost borings. This unit reaches its greatest thickness, about 65 feet, at boring STA 101+17.5 and thins eastward. Similar, though more clayey material was penetrated at borings 13-$ and 16-S on the east side of the river, where it rests on the clay facies of the lacustrine deposits. A 3-foot thickness of "gravel and red clay" was penetrated at boring 12-S at the top of the lacustrine clay. This unit also probably represents the younger till layer. East of boring 16-S the unit disappears or cannot be distinguished from the basal till. This younger till may have been deposited by the re- advancing ice, which according to Flint (1983) over- rode and deformed the Middletown and Berlin lake clays. Its stratigraphic position above the lacustrine deposits is in accord with this view. As shown in the section, the younger till thickens westward and is ex- posed at the surface. West of the section it rests upon | the bedrock and is indistinguishable from the basal till. Also, certain wells a short distance north of the line of the section (R. V. Cushman, oral communication, 1960) apparently did not penetrate till at intermediate depth. Thus this material might be interpreted as a mass of the basal till that became detached from a larger body to the west and slid out across the lacustrine deposits. The body, however, seems to extend across almost the entire valley, and the writers tentatively consider it to repre- sent the readvancing ice. - Flint (1953, p. 898) suggested that this ice was of Cary age. Later Flint (1956, p. 277) presented evidence to show that the read vance took place more than 12,700 years ago, which is compatible with a Cary age. Above the younger till is a unit of varied stratified material. On the west side of the river, it is mostly sand and gravel with some clay; and on the east side it is predominantly sand. - This material forms and under- lies a terrace at an elevation of about 30 feet above sea level. It was evidently laid down during a late stage in the retreat of ice from the Connecticut valley. The sixth unit is known only from boring 12-S, in the middle of the river, which penetrated about 45 feet of material described simply as "coarse sand." - This unit extends to a depth of about 63 feet below mean low river level at the boring cited and is probably channel de- posits of the present-day stream. - This sand probably grades into the estuarine deposits that underlie the river farther downstream. (See pl. 1D.) BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS SUMMARY OF FEATURES OF CONNECTICUT CcoasTAL VALLEYS The Connecticut bedrock valleys coincide with the _ present stream valleys and their extensions into estu- aries. Near the coast the observed range in minimum elevations of these bedrock valleys is from about -115 to -174 feet msl ; the inferred range is from about -120 to more than -280 feet msl. The deposits within all the valleys have three recog- nizable stratigraphic units. At the base, discontinuous patches of till rest on the bedrock. Till also extends beyond the immediate vicinities of the bedrock valleys and at places forms thick or extensive ground moraine on the side of the valleys about sea level and on the ad- joining uplands. This till is probably the same strati- graphic unit everywhere throughout the Connecticut coastal region, at least within a few miles of the shore. The till is overlain mainly by fine- to coarse-grained sand and gravel that make up a unit of glaciofluvial outwash. Locally, this outwash extends above sea level and underlies terraces. These terraces are most clearly discerned along the Connecticut River, where they rise discontinuously upstream and terminate at a former ice border near Middletown. Along the other streams, the terraces are not so readily traceable, nor are their up- stream terminations so clearly marked. These terraces were deposited during ice retreat, and are probably gen- erally contemporaneous and of Cary age (p. M11). The outwash is overlain by estuarine deposits. Up- stream from the coast, the estuarine deposits are replaced by fluviatile deposits. The estuarine deposits grade up- ward and laterally into present-day tidal marsh de- posits, and probably formed during the last general rise of sea level in Recent time. Low points at the base of the estuarine deposits range from about -40 feet msl on the Quinnipiac to -130 feet msl on the Thames. In his discussion of the outwash terraces along the Thames River, Goldsmith (1960) said that sea level was low until late in the depositional sequence, and sug- gested that the irregular surface of the outwash may be due to subaerial erosion, to collapse upon melting of the underlying ice, or to both before the sea rose to its present position. - In this view, the now submerged sur- faces at the base of the estuarine deposits are not neces- sarily erosional and may not have been formed after an interval of higher sea level. However, the low points on this surface at the two crossings of the Housatonic and corresponding points in the other stream valleys of Connecticut do fit a pattern suggestive of subaerial ero- sion. Such erosion might have taken place either dur- ing a final phase of ice retreat and outwash accumula- tion and before completion of a sea-level rise, or later 728-774 0O-64--3 M13 after some epidode of higher sea level, traces of which either have been obliterated or are now submerged. NARRAGANSETT BAY AREA GENERAL FEATURES The complex of marine passages which form Narra- gansett Bay appears to cover three main buried bed- rock valleys. The locations of the thalwegs are given in figure 3. These are all extensions of known valleys that are present beneath the land areas mainly north of the bay. The westernmost of the main valleys is that of the Blackstone River. It has been traced along a course through Providence and Cranston to Greenwich Bay. The next valley to the east is herein called the Providence bedrock valley. This valley is mainly be- neath the bay, and is apparently the extension of a - buried channel beneath the Seekonk River estuary and Abbotts Run. The easternmost valley is called the Taunton-Sakonnet bedrock valley. It is a continuation of the Taunton River bedrock valley which extends southward from near Taunton, Mass. Details of geog- raphy and topography in these areas are shown on the U.S. Geological Survey 714-minute topographic quad- rangle maps listed in table 3, and also on the following maps, which are not listed: Pawtucket, Tiverton, and Sakonnet Point, Rhode Island or Rhode Island- Massachusetts. The courses of the bedrock valleys beneath the land areas and for part of the Bay area are based upon in- formation obtained from the files of the Ground Water Branch of the U.S. Geological Survey in Providence. This information was collected and interpreted in the course of cooperative ground-water investigations with the State of Rhode Island and Providence Plantations. Published information is given in maps and cross see- tions for reports on the geology and ground-water con- ditions in several Rhode Island quadrangles (Allen, 1956; Allen and Gorman, 1959; Bierschenk, 1954 and 1959; Hahn, 1959; Johnson and Marks, 1959; and Quinn and others, 1948). The courses of the valleys beneath the bay are based in part on bridge borings and geophysical surveys in the bay area outside the regions of current ground-water investigations. Narragansett Bay occupies a large part of the Nar- ragansett Basin, a structural depression composed of sedimentary and metasedimentary rocks mainly of Pennsylvanian age (fig. 1). (See also Quinn and Oliver, 1962, p. 62 and 66.) These rocks form a down- folded and downfaulted synclinorium within meta- morphic and igneous rocks, most of which are of pre- Pennsylvanian age. In general, the basin sediments are considerably less resistant to erosion than the surround- ing rocks. However, the metamorphic grade of the M14 71°30 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 7if15' 71°00 K 1 Fe # kWOONSOCKE’IJ § 42°00" > a M (if \\ & \\ , \\ C& -. cl AC | / y* Y & I[ -£ / 4 $s 7a, €" Xx / 5 C < \ 7 $ (root / [M l/ PROVIDENCE / 1 41°45" wESt ~ WARWICK ( 41°30" 10 MILES ) From Army Map Service Map NK 19-7 Series V501 Scale, 1:250,000 EXPLANATION CyA _L. Thalweg of buried valley Dashed where loca- tion is uncertain X ¥ Limits of profile shown in figure 4 f— Location an'd num ber of section de- scribed in text and listed in table 3 Trace of western boundary of Narrangansett basin FIGURE 3.-Sketch map of Narragansett Bay showing locations of bedrock valleys and sites of sections or where other data were obtained. Bedrock valleys are designated as follows: A, Blackstone ; B, Providence ; C, Taunton-Sakonnet. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS Pennsylvanian rocks increases to the south, and the rocks seem to become somewhat more resistant. From relatively unmetamorphosed less resistant shales in the northern part of the basin, the rocks gradually change southward to muscovite schist at the mouth of the bay (Quinn, 1953, p. 268). The structural trend of the bordering pre-Pennsyl- vanian rocks is roughly northwest and southeast (Quinn, 1953, p. 266), but the trend of the basin rocks in the vicinity of Narrangansett Bay is virtually north and south. The various passages of the bay are alined about north and south or slightly northeast and south- west, and the trends of the several bedrock valleys gen- erally coincide with these directions. Thus, they ap- pear to be generally controlled by the rock structure. Where detailed data are available, the courses are re- vealed to be somewhat sinuous, as in the vicinity of Providence and Pawtucket. Figure 3 shows, in addition to the courses of the buried bedrock valleys, 10 localities for which data on the depth of the bedrock were obtained from bridge borings and seismic or seismic reflection surveys. The M15 information is summarized in table 3. The data are referred to in the ensuing discussion of specifically identified valleys. DEPTHS OF BEDROCK THALWEGS BLACKSTONE BEDROCK VALLEY Approximate elevations of the thalweg of the Black- stone bedrock valley are known from several cross see- tions and scattered well data. Beneath the land area, the Blackstone valley has two different reaches. The upper reach is above New Pond, north of Pawtucket, where the bedrock valley approximately coincides with the course of the present river. Well records in this reach indicate that the thalweg lies generally at or above sea level. 'The lower reach extends from New Pond southward through Providence to the head of Greenwich Bay. In this reach the bedrock valley de- parts from the course of the present Blackstone River and lies beneath the concealing outwash west of Nar- ragansett Bay. Eight of the deepest wells drilled in Pawtucket, Providence, Cranston, and Warwick give TABLE 3.-Summary of data on bedrock valleys at 10 sites in Narragansett Bay, R1. Estimated lowest Local- Lowest bedrock elevation elevation of ity No. | Bedrock valley Location. Topographic Source of information estuarine Remarks on fig. 3 quadrangle deposits Figures are in feet below mean sea level 1 | Not named....| At Fox Point in Providence.... Five test borings...._. Deepest boring ended in till at -45 | U.S. Army Corps of Engi- Providence. -130. neers (1957, pl. E-1). 2 :.:. At Fields Point in _ |_____ s 2s ll Deepest boring ended in till at -55 . Army Corps of Engi- Providence. -123. neers (1957, pl. E-2). 3 | Providence.... Conimicut Point to ...}%... Eight test borings..__. Deepest boring ended in till at -85 | U.S. Army Corps of Engi- Nayatt Point. -158. neers (1957, 631. E-3). €.... do-.s:s.... Prudence Island to Prudence Island.] Four test borings... Deepest boring ended in gray -110 | U.S. Army Corps of Engi- Aquidneck Island, sandy silt at -158. neers (1957éafil. E-4, sec. C-C). | So-called "Middle Bay Site." do...s..... Conanicut Island to Newport........_. Seismic survey......_. Lowest computed elevation: |.__________. U.S. Army Corps of Engi- Newport Neck. -3820; actual lowest elevation neers (1957, pl. E-5). possibly -350. Seismic reflection survey by Woods Hole Oceano- graphic Institution sug- gests bedrock as deep as -350 feet msl.1 6 | Blackstone....| Pojac Point to East Greenwich Five test borings...._. At one boring, bedrock entered -40 | U.S. Army Con-PS of Engi- Patience Island. and Bristol. at -115; one well ended in meers (1957, pl. E-4, sec. gray silt at -118; actual lowest A-A). So-called "Middle elevation is deeper. Ba? Site." Tir oue s Quonset Point to Wickford and Seismic reflection One boring entered probable |.__________. Seimic reflection surveys by north end Conani- Prudence survey and 3 test bedrock at -130 feet msl. Woods Hole Oceanographic cut Island. Island. borings. Lowest elevation probably Institution. - Test holes somewhat deeper. contracted by U.S. Navy. Data from First Naval District, Public Works Office. Ber- ere Rome Point to Wickford__________ Seismic survey......__ Actual lowest elevation prob- Conanicut Island. ably somewhat deeper than lowest computed elevation of -167. Plum Beschto |_. | .____ recive 12 test borings......__. Deepest boring penetrated bed- -80 Bormgs made for Jamestown Conanicut Island. rock at -125. Bridge. .- The Bonnet to Narragansett Seismic survey...... Lowest computed - elevation |.___________ U.S. Army Corlps of Engi- Conanicut Island. Pier. -280. neers (1957, pl. E-6, seis- mic sec. 3). Seismic reflec- tion survey by Woods Hole Oceanographic Institution suggests bedrock at about -360 feet msl. 10 | Taunton- Sakonnet River Fall River, 16 test borings..._____. Deepest boring penetrated bed- -80 | Borings by American Drill- Sakonnet Bridge at Tiverton, Mass.-R.I rock at -370; lowest elevation ing Co. for C.A. Maguire RI. estimated at -400. iiklssfiocigtes. Section given g. 5. ! See footnote on p. M18. M16 bedrock elevations within the bedrock valley ranging from -164 to -200 msl. From the head of Greenwich Bay southward beneath Narragansett Bay, the bedrock valley swings east ward, passes through the section at locality 6 (fig. 3) where we know only that the bedrock is deeper than -115 feet msl, and then follows one of two possible courses to the south. The first guess would be that the Black- stone bedrock valley passes west of Hope Island and west of Conanicut Island. The maximum depths to bedrock in the section off Quonset Point (loc. 7, fig. 3) are not known, and the valley might go through it, though incomplete data suggest that bedrock there is not much more than -150 feet msl. The bedrock also appears to be too shallow farther south along the west side of Conanicut Island (loc. 8, fig. 3 and table 3). From a seismic survey made about a mile north of the Jamestown Bridge, an elevation for bedrock of -157 feet msl was computed (Johnson and Marks, 1959). The deepest boring for the Jamestown Bridge (fig. 3, table 3) reached bedrock at an elevation of about -125 feet msl. If these figures are close to the maximum thalweg depths for the passage west of Conanicut Is- land, the bedrock is not deep enough to be in the Black- stone bedrock valley, unless elevations deeper than -150 feet msl are due to overdeepening by glacial scour. Therefore, the valley probably lies east of Conanicut Island and presumably is tributary to the Providence bedrock valley which it joins somewhere south of Prudence Island. This course is shown on figure 3. Figure 4 shows an approximate profile of the thal- weg of the Blackstone bedrock valley from Woonsocket to the city of Warwick, R.I. Woonsocket is north of the area shown on figure 3, but the city of Warwick borders Greenwich Bay. The zero point of the profile is about 3 miles north of Greenwich Bay. (See Allen, 1956, section A-A' of pl. 1.) Upstream from about mile 13, most of the plotted points are for individual wells Below Ashton, one point represents two wells close together that penetrated | bedrock at about the same depth. In Woonsocket, a large number of wells and test holes have been drilled in several clusters along the river ; near the northwestern edge of the city several seismic measurements have been made. - For each cluster of wells, the lowest elevation of bedrock is plotted and the seismic shot point is shown. None of these points can be assumed to be exactly the lowest point of the thalweg for the locality. However, the valley in this reach is rather narrow, and the points cannot be too far from the deepest places. Also, longi- tudinally the points fall reasonable well along an even slope as indicated by the smooth thalweg curve drawn SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY slightly below the points. The thalweg, however, is probably more irregular than the curve. Downstream from about mile 13, the thalweg of the bedrock valley is drawn to follow the trough delineated by the bedrock contours shown in the Providence quad- rangle (Bierschenk, 1959, pl. 1) and East Greenwich (Allen, 1956, pl. 1) quadrangle reports on ground water. The points shown on the profile are for wells situated in the deepest parts of the bedrock valley, where there is perhaps less control than for the reach farther upstream, but the deepest wells show bedrock at elevations rang- ing from about -150 to about -200 feet msl, and several at about -190 feet msl. Longitudinally these eleva- tions also appear to be fairly uniform. The thalweg is indicated as being at about -200 feet msl and is prob- ably somewhat more irregular than shown. The data suggest reaches at two general elevations: one upstream rising from about sea level to 70 feet above, and the other downstream at about -200 feet msl and rising slightly upstream. The change between these two reaches is fairly abrupt and takes place about at the boundary of the Narragansett Basin. Downstream, beneath Narragansett Bay, some bed- rock elevations are deeper than -350 feet msl. The reach at -200 msl is so nearly level that one would ex- pect somewhere beneath the bay a rather abrupt change to the deeper elevations, but available data are insuffi- cient to show it. f PROVIDENCE BEDROCK VALLEY Providence bedrock valley is the name used in this report to designate the middle one of the three major bedrock valleys in the Narragansett Bay area (fig.: 8). Tt lies beneath the south end of the Seekonk River and beneath the Providence River. The valley passes east of Prudence Island and between Conanicut and Aquid- neck Islands; it reaches into Rhode Island Sound at Newport Neck. The presence of a buried valley in Providence and East Providence was first reported by Roberts and Brashears (1945, p. 9). The valley's location, approxi- mately beneath the Seekonk and Providence Rivers, is taken in part from that report and in part from later reports by Bierschenk (1959) and by Allen and Gorman (1959). The thalweg of this valley does not appear to pass through either the Fox Point or the Fields Point sections of the U.S. Army Corps of Engineers (1957) across the present Providence River (loc. 1 and 2, fig. 8). A more likely course was indicated by Bierschenk (1959, pl. 1). Roberts and Brashears (1945, p. 9) suggested that the valley may be 200 feet deep in this area. One well put down about a mile south-southeast of the con- fluence of the Providence and Seekonk Rivers pene- trated bedrock at -190 feet msl. Thus in this reach M17 BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS meq TH 'NOJIMIEM ;o 41> oy; pus joxo0sUu00M Uoamjoq Jo Jo otgoig-'p sunon § (2961 'uosuyor) gt dew salem punor9 uo umoys 12 10 aouapimorg ut gqgp 40 Sajip ay} ut are ooipaq uo 'uojsugi9 'eiqp pug faouapinoug '01g Rexyonmeq 'meq pug) 'wno fujoout7 'ur7 'com :smojJO; se 'sumo} Aq Sjjom Bunaqwnu jo wars4s pue;sj apoyy y3im proove ut are s1aqwnu ine; 49p1oq jo SIT | I i | O2 g ama uo umoys aut aftyord yo sqrutr7 A "X quod joys atustas wou; uoneaaj3 yooupog + uonzaato sty wey} y2o1pag "ke liom a10jaq sjoquifs "x01 aas 'ajyoid jo uotssnosip 104 :sajopy voneaoj uo Sty] 12 paje.ouad yooipag Id.l|.|I|||||l|.|dill]d|.%101|llmlllll.olllllloII// ? ox Lr/// NOILYNVTI4X3 & m Fa & ol =o ave m 8 Fra P W W 8 2 W W P P W 3 -Z -->> 24 a = = 22 15 = & o & l z < S gos Jonky auopmjong + = 909 0 !s. o I Cliclin <% § © £. & a &§25 2a Fe 3 £5 gs P 3 !f 5 58 S £ 5 & > < M~MMM s & 5. 8 & r forum " 40m 0,2 j a @ |G -Jnd c 5 © ==> £ Fils 2/8 B "s 3 ff gpip Fo § 2 These : & © s ® * 218 hot Qa g K w $18 A 2 co w a C m_MMM S § Sz .. | ® o ® 2. 9_ & ® A a:" th 8 2 3 a 8688 $ "%% 8 ajo = 'is alc § 8 o 0 no o 2 to &I C F/C ~ c |E c z & 0 x 3 & rams Adt s* . ~T $35; gli... :f i f:] 6 3° § N fol z lnd O =s & a l to " © Bl l S18 a $ 8 | 8 S $ \ 3+ 2 & 3 § S To 24 3!3 ® 5, ® ing 5 he R 22 2 £ & & =- $x s! _ Laxposnoom 2 o wo ® o ® a @ # fol 10 AID | @ 2 % St. oA a L2 C | ® 2 & w 8 j w a I 3 5 o 3 4 $ o S3TIW S2 M18 the depth is comparable to that of the Blackstone bed- rock valley in about the same latitude. South of locality 2, the suggested course of the Provi- dence bedrock valley beneath Narragansett Bay is as shown in figure 3. - Borings put down at, and northeast of, Conimicut Point (loc. 3, fig. 3, table 3) are probably in this valley, where the greatest depth was reached by one boring which ended in till at about -158 feet msl. Still farther south, at locality 4 (fig. 3 and table 3) one of four borings was drilled to - 158 feet msl but did not reach bedrock. - Lastly, at locality 5 near Newport Neck (fig. 8 and table 3) seismic data indicate an elevation of bedrock of at least -320 feet msl, and seismic reflection surveys ® made by Woods Hole Oceanographic Institu- tion suggest that it may be as deep as -350 feet msl. A buried valley mapped by Bierschenk (1954, pl. 1) and by Allen and Gorman (1959, pl. 1) southeast of East Providence reaches elevations deeper than -100 feet msl, and is probably a tributary to the Providence bedrock valley. The tributary appears to join the Prov- idence valley south of Conimicut Point. TAUNTON-SAKONNET BEDROCK VALLEY On the east side of Narragansett Bay is another bed- rock valley that extends south-southwestward beneath the Taunton River estuary. The valley begins far up- stream in Massachusetts, but how far is not now known. It apparently passes beneath the northwestern edge of the city of Fall River, Mass., and enters Mount Hope Bay (fig. 3). From the configuration of this bay the valley appears to continue southwestward toward Prud- ence Island, but borings for the Mount Hope Bay bridge near Bristol (Bierschenk, 1954, fig. 2) show that the lowest elevation of bedrock at the bridge is probably not much below -80 feet msl, whereas bedrock lies much deeper directly to the south beneath the bridge at Tiver- ton. - Therefore, below Fall River this valley probably swings southward and continues beneath the Sakonnet River estuary and thence to Rhode Island Sound. The writers propose to call this bedrock valley the "Taunton Sakonnet bedrock valley." Between Fall River and Tiverton, this valley is cut in sedimentary rocks of Penn- sylvanian age and is generally about 0.3 to 0.4 mile northwest of the nonconformable contact of the basal Pennsylvanian metasediments on pre-Pennsylvanian igneous rocks as determined by Foerste (1899, pl. 31). There is not much information about the depth of * These surveys were made by a seismic profiler-an instrument that uses low-frequency sound energy which is reflected and recorded from horizons in sediments below water somewhat as ocean depths are deter- mined with an echo sounder. The depth figures are preliminary because they are based on uncorrected values for the velocity of sound in the water and sediments. If the true velocity of sound transmission in the sediments is greater than that in water (W. O. Smith, 1958, p. 76 and 86), the true depths to bedrock may be appreciably deeper than indi- cated by the depth figures. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY this valley. Test borings made in Fall River, Mass., show that the thalweg there lies at least -157 feet msl (Allen and Ryan, 1960). - Figure 5 shows the configur- ation of bedrock in the Taunton-Sakonnet bedrock valley as determined from logs of borings made for the Rhode Island State Route 138 bridge over the Sakonnet River between Portsmouth and Tiverton, RI. (loc. 10, fig. 3). The bridge boring records are dated 1953 and 1954. In this section, the Sakonnet River estuary is fairly well centered over the axis of the bedrock valley. The deepest boring, boring D, entered bedrock at -370 feet msl, and-as shown on the section-the bedrock here may be as deep as -400 feet msl. Bedrock is exposed near both ends of the bridge. The bedrock cores ob- tained from borings A, C, D, F, G, and H were ex- amined by A. W. Quinn of Brown University. The rock in all these borings was found to be black shale and some sandstone of Pennsylvanian age. Bedrock penetrated by borings 1-1 and 1-1A was described in:: the original plans as "limestone rock." This "lime- stone" may actually be the cataclastic granite gneiss that crops out west of the bridge. UNCONSOLIDATED DEPOSITS The unconsolidated deposits in the bedrock valleys of the Narragansett Basin area contain the same three units as do the valleys of coastal Connecticut-till, out- wash, and estuarine deposits. Here, however, the out- wash is predominantly fine grained, and much of it could be classed as lacustrine or glaciolacustrine depos- its. - There may also be a body of till younger than the: basal till. Within the land area, the deposits in the Blackstone buried valley are the best known. - Most of them appar- ently represent the outwash unit, which exhibits a general decrease in grain size downstream. Above Providence, the material is mainly gravel or gravel and sand. - In the vicinity of Providence, fine to coarse sand predominates, whereas near Greenwich Bay fine sand predominates. - Available logs record little material to suggest the presence of till, although till discontinu- ously blankets the bedrock underlying the land surface outside all the valleys. Near Nayatt Point, some clay is known from well records or from exposures that were seen by workers in the area. (See Bierschenk, 1954, p. 21.) Schafer (1961), Smith, and others mapped outwash deposits in areas west of Narragansett Bay and sug- gested that at least the top layers were laid down by melt-water streams flowing from a lobe of ice in the Narragansett Basin and occupying successive retreatal positions. Thus the deposits probably actually com- prise several subunits of successively younger age. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS 20" SEA S A K 0 N N E T M19 |- 20° Portsmouth Tiverton RIVERSIDE DRIVE "3 p 0 - a | w RDV E R SEA LEVEL ram 20' CIH 40° "nt cg 60° 80' sp 100° 120" 140' 180' 200' 220' 240' 260" 280° Outwash 300° - x 320° 4 x 340° 4 360° - 380° - 500 FEET 100 100 300 x abl. ado cen ol alis 0 .s isl HORIZONTAL SCALE | LEveL - 20" - 80' |- 100" - 120" |- 140" Outwash |- 160 |- 180 |- 200" - 220' i- 240' |- 260" - 320° - 340" Sand - 360° » Ground-water level during drilling Gravel - 380° Borehole numbers are from original bridge plans - 400" Borehole logs shown are from within 35 feet of bridge center- line * - 420° FieurE 5.-Section of Taunton-Sakonnet bedrock valley at Tiverton, RI. Beneath Narragansett Bay the deposits are not well known, as available data are scanty in comparison with the size of the area. They may be extensions of the deposits beneath the land areas. For example, lami- nated clay and silt with scattered sandy layers pene- trated by borings at locality 3 (U.S. Army Corps of Engineers, 1951, pl. E-3) apparently extend westward beneath Conimicut Point and may grade into the de- delta (Bierschenk, 1954, pl. 3). posits beneath outwash plains mapped by Smith (1955). The laminated clay may also extend eastward and cor- respond with the thin clay beneath the Nayatt kame On the other hand, the deposits may constitute, at least in part, a younger body separated from the others by uncomformities, de- pending on the exact manner of withdrawal of the ice. For example, Schafer (written communication, 1961) M20 suggested that the outwash deposits west of the bay terminate in ice-contact slopes along or near the present shore. If so, the bay must have been occupied by ice, and the deposits in the bay were laid down after the ice had melted away. - The deposits must lie unconform- ably, then, against the outwash that occurs beneath the land. The outwash beneath the bay proper is there- fore here treated as a separate unit although it may not be. For the deposits beneath the bay, the following gen- eralized description is based mainly on records of bor- ings made by the U.S. Army Corps of Engineers (1957). The deposits have three recognizable units: till, pre- dominantly fine-grained outwash, and estuarine depos- its. - The fine-grained outwash may comprise more than one stratigraphic unit, and an intermediate body of till may occur at one locality. Borings at many of the localities shown on figure 3 terminated in material of pebbly or bouldery sand and clay whose compactness and poor sorting indicate that it is till. At some places bedrock was entered beneath this deposit, but at others it was not fully penetrated. Above this till is a considerable thickness of varied but mainly fine-grained material. - It consists mostly of clay, silt, and fine sand. Beds of gravel and sand are present locally, as indicated by the boring records, but they are usually described as silty or clayey and do not seem to occur in a particular depth range. As gravel seems to be more abundant in the marginal parts of the bay, it may merely be the interfingering edge of the coarse-grained facies upstream. At the Portsmouth-Tiverton Bridge (fig. 5) the en- tire thickness of deposits seems to be made up of varying amounts of silt, sand, and gravel, which contain some boulders in certain beds. There is practically no clay; hence, the deposits at this locality are generally coarser grained than the deposits beneath other parts of the bay. Much of the material is indicated in the original boring records as compact or cemented, which suggest that some of the material might be till. However, test pile penetration tests studied by Mr. F. C. Pierce (oral communication, 1958) of Charles A. Maguire and As- sociates indicated that the material was not cemented or unusually compacted. As to thickness, one boring, D (fig. 5), penetrated 326 feet of deposits, which except for the upper 20 feet, is probably all outwash. In contrast to the relatively coarse-grained material at the Tiverton Bridge, the deposits in much of the rest of Narragansett Bay are predominantly fine grained. Sections at localities 1, 2, 3, 4, and 6 and the Navy borings at locality 7 show a considerable thick- ness of material described as gray clay, silty clay, or silt and clay. There are also beds of silt and sand, or SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY sandy silt, and silty gravel and sand generally either above or below the clay. The clayey material is ordi- narily in recognizable beds a small fraction of an inch thick. The gray silt midway in the section at the Tiverton Bridge (fig. 5) may be the same body. Far- ther south, at localities 3 and 6, the material is pre- dominantly clay and silt in thin laminae. This predominantly fine-grained unit is classed as outwash because it rests on till, is probably derived from melt-water streams, and contains no organic re- mains. In a classification that has more subdivisions, it might properly be called lacustrine or glacio- lacustrine. It may grade continuously upward into the supposedly fresh water clays noted in the Barring- ton area (Bierschenk, 1954, p. 24 ff. and Smith, 1955b) and earlier reported by other geologists (Woodworth, 1896, p. 162, and Hyyppéi, 1955, p. 210). It was pre- sumably deposited in ponded water, but whether this water was dammed in some way by ice to form a lake (Schafer, written communication, 1961) or was in a marine embayment like the present Narragansett Bay, an interpretation favored by the writers, is not known. In the section of the Providence valley between Prudence Island and the northern part of Aquidneck Island (loc. 4, fig. 3 and table 3), a 10-foot interval in one boring showed "gray, silty, sandy gravel (Till- like)" and "gray, clayey sand (Till-like)" overlying a cored boulder. - This till-like material rests on at least 40 feet of "gray, clay." This is the only evidence of till stratigraphically higher than the basal till known in the deposits of Narragansett Bay. Elsewhere, the deposits above the clay and silt are the estuarine deposits. This uppermost unit in every section studied con- sists of material that is described as "loose." It con- tains plant remains and locally shell fragments, and rests on a channel-shaped surface apparently eroded in the underlying sand and gravel. The material varies in thickness within each section and also from one section to another. The unit is 25 to 50 feet thick and except for perhaps the uppermost few feet, at most places it consists of estuarine material deposited during a late Pleistocene or Recent relative rise of sea level. The approximate elevations of the lowest points on the pre-estuarine surface from section to section are summarized in table 3. They range from -45 feet msl at Providence to -110 feet msl near the middle of the bay. At locality 5, the water alone is about 160 feet deep (see U.S. Coast and Geodetic Survey chart 236), which is about 30 feet deeper than the base of the estuarine deposits in the Thames. (See p. M13.) However, there are no data on the subbottom sediments, BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS and this depth may be due in large part to scour by tidal currents. SUMMARY OF FEATURES OF NARRAGANSETT BAY AREA VALLEYS In the Narragansett Bay area, the lowest elevations of the bedrock valleys range from about sea level near Woonsocket to more than $50 feet below sea level beneath the eastern and southern parts of Narragansett Bay. The lowest elevation observed is about -370 feet msl. The best information on longitudinal profiles is for the Blackstone bedrock valley whose thalweg seems to have a nearly level reach at about -200 ft msl and a shallower reach in the part outside the N arragan- sett Basin. The upstream reach rises from about sea level to about 70 feet above in Woonsocket. Depths are greater downstream beneath the bay, but data are not at hand to indicate how nor where the elevation changes from -200 msl to the lower elevations farther south. The deposits are mainly stratified clay, silt, sand, and gravel, which are herein classed as outwash. Be- neath the stratified drift, till rests directly on the bedrock. Upstream from Providence, the outwash is mostly gravel, but downstream, except for the upper few feet, it is generally finer grained and composed of layers of sand, fine sand, and silt. The sand was de- posited in or beneath outwash plains described in the maps of the quadrangles surrounding Narragansett Bay. (See for example, J. H. Smith, 19552 and 1955b.) Beneath Narragansett Bay proper, inadequate data suggest that the sequence consists of ( 1) till resting on the bedrock, (2) a thick body of varied material, mainly fine grained, consisting predominantly of clays, silts, and fine sands, (3) possibly a body of till known at only one locality, and (4) estuarine deposits that rest on the fine-grained unit with erosional uncon- formity. The surface at the base of the estuarine deposits is probably an erosion surface. The elevations of the lowest points of these channels, -40 to -110 feet msl (table 3), suggest a gentle seaward gradient and are in the same depth range as the corresponding points in the coastal valleys of Connecticut. They are consid- ered also to result from subaerial erosion by a stream system that formed on the underlying deposits above water level. Schafer (written communication, 1961) suggested that the fine-grained outwash of Narragan- sett Bay was deposited in an ice-dammed lake. The postulated erosion then would have occurred after the dam disappeared and when sea level was lower than at present. - It is also possible that the exposure occurred because of a decline of sea level. ( See p. M39.) M21 BURIED VALLEYS OF THE BOSTON AREA GENERAL FEATURES The Boston area, for purposes of this report, is an area of about 400 square miles bordering Boston Harbor on the north and west. It is occupied by parts of the present-day Charles, Mystic, Malden, and Neponset Rivers. In comparison with such rivers as the Con- necticut or the Kennebec, these are insignificant streams; however, the bedrock valleys associated with them reach considerable depth. The bedrock valleys have been studied by geologists of three generations, and considerable data are available. The most comprehensive and the most recent works on the geology of the Boston area are those of Billings (1929) and La Forge (1982). As described in these reports, the Boston Basin is a structural depression, like the Narragansett Basin, and is underlain by com- plexly folded and faulted sedimentary and volcanic rocks which Billings (1929, p. 106) considered to be of Pennsylvanian (?) and Permian age. These rocks are separated by fault contacts from older igneous and metamorphic rocks that range in age from Precambrian to Devonian(?). In general, the younger rocks are less resistant to erosion than the older ones and, having been more extensively and deeply dissected, form a topographic as well as a structural depression. A major fault marks the north boundary of the basin. This fault was named the Northern Border Fault by Billings (1929, p. 107, fig. 2), and was further described by La Forge (1932, p. 63). The parts of the valleys that are north of the fault are appreciably shallower than the parts to the south. Also, at places the valleys or their tributaries seem to have been localized along the fault zone itself. The unconsolidated sediments that rest on the bed- rock are virtually all glacial deposits or marine and fluviatile deposits formed in association with glacia- tion. La Forge (1982, pl. 2, p. 79-86) mapped the glacial deposits of the Boston area in moderate detail, and Judson (1949) made a rather thorough study of the subsurface deposits as revealed by borings and founda- tion excavations for certain large buildings in Boston. For most areas discussed in this paper, the term "bedrock valley" is preferably used. In the Boston Basin area, however, the valleys are so extensively filled, or buried, that most of them have no surface expres- sion. They are often referred to in the older literature as "buried," and the one beneath Fresh Pond has the word "buried" in its name. Therefore, the bedrock valleys of the Boston area are generally referred to in this part of the text as "buried valleys." (See p. M4.) Figure 6 shows the approximate outline of the buried valley system that probably underlies the Boston area 71°10' --f s ¥ ©Cambridge Base by Commonwealth of Massachusetts, 1957 River p fl I=" "ys. 3 \ ; NMS - aand nie t s HRCI O0 DCs S SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 71°00" ___ ___ ff o-- EXPLANATION | tra s Thalweg of bedrock valley | Dashed where location uncertain | | yy> | | ® | | Locality number | | | Bar indicates alinement of cross sections ‘ > \ shown in plate 2 and figure 8 ‘ | | | | 1 Trace of Northern Border fault 3 MILES & 'C =a & Location of buried valleys by C. W. Spencer; modified from Crosby, 1937; and Halberg and Pree, 1950 FIGURE 6.-Sketch map of Boston area, Massachusetts, showing locations of buried bedrock valleys and of geologic sections. and the locations of the sections given in plate 2 and figure 8. In subsequent paragraphs, localities referred to by number are shown on figure 6. Most of the buried valleys lie approximately as shown by I. B. Crosby (1937) although the courses are slightly different, as in- dicated by work done by Halberg and Pree (1950, fig. 3) and by data collected in the course of the present study. The thalweg of the Aberjona-Fresh Pond buried valley is from Chute (1959, pl. 14) but is modified slightly in part on the basis of test-well data furnished by H. N. Halberg (oral communication, 1959). Table 4 lists the localities for which sections are drawn and the source of the data for each. 'The names of most of the buried valleys used in this paper are the names of the present streams. Some explanation however, is desirable. W. O. Crosby (1899, p. 302) postulated that the ancestral Merrimack River (fig. 1) followed a valley southeastward from New Hampshire to a position beneath the present Aberjona and Mystic Rivers (fig. 6) and thence to Boston Harbor. I. B. Crosby (1937) at first adopted this postulate but later evidently modified the view, as he wrote (1989, p. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS TABLE 4.-Summary of information on crossings of buried valleys in the Boston Basin area, Massachusetts Local- Purpose for which Agency for which Date Buried valley | ity No. borings were made borings were made of on fig. 6 plans Charles.......... 4 | Main drainage sewer | Metropolitan District | 1954 tunnel at Columbus Commission. Park, Boston. 3 | Proposed water sup- |___. Ost. laila se 1937 ply tunnel loop (south line), in Boston. Do-l..ellle. 2 | City water tunnel _ |_____ 10-1 regan icing.. 1958 extension between Boston and Cam- bridge. Do.:....s.. 1 | Pressure aqueduct Metropolitan District | 1939, between Weston Water Supply 1947 and Newton (see- Commission. tions 6 and 7). Aberjona-Fresh 5 | Proposed loop water |.... os Pond. tunnel in Cam- bridge. Malden......._.. 7 | Main drainage sewer | Metropolitan Dis- 1953 tunnel in Boston. trict Commission. 6 | Spot Pond Brook __ |.... PO cie cu 1956 Flood Control Pro- ject in Malden. 374), "The valley coming from the north is in line with the projection of the buried valley of the Merrimack, and these valleys will be described as the pre-glacial Merrimack-Mystic Valley, although it is not yet proved that these were one continuous valley." La Forge (19832, p. 79) stated that there is no evidence that the Merrimack extended as far south as the Aberjona River, a view supported by more recent seismic surveys (Lee and others, 1940) and investigations of ground-water conditions near Lowell, Mass. (J. A. Baker, oral com- munication). Thus the name "Merrimack" should not be used. Halberg and Pree (1950, p. 209-210) showed that the main stem of the buried valley beneath the Aberjona River continues southward, passing beneath the Mystic Lakes, and instead of following the present Mystic River continues more nearly southward beneath Spy Pond and Fresh Pond. Thus, although I. B. Crosby used the name "Merrimack-Mystic," the use of "Mystic" is also incorrect. Halberg and Pree (1950, p. 209) used the term "buried Aberjona valley" infor- mally, and also (1950, p. 211) the name "Aberjona- Fresh Pond buried valley." Subsequently, Chute (1959, p. 189) formally applied the named "Fresh Pond buried valley." Fresh Pond lies above the extreme southern part of the buried valley, and use of this name ignores the greater, or northern, part of it beneath the Aberjona Valley. Accordingly, in this report the writers use the name, "Aberjona-Fresh Pond buried valley" as it is more descriptive and has some precedence in former usage. f For the most part, the Charles buried valley follows the course of the Charles River except in Boston proper where it lies several miles to the south. This valley, because of its possible upstream continuation in an M23 ancestral Sudbury River (I. B. Crosby, 1937) is consid- ered to be the major buried valley of the Boston area. Halberg and Pree (1950, p. 208-211) also briefly de- scribed the other valleys beneath the Malden and Neponset Rivers. Only the one beneath the Malden, herein called the "Malden buried valley," is further described in this report. DEPTH OF BEDROCK THALWEGS CHARLES BURIED VALLEY The sections in plate 2 show a progressive downstream deepening of the bedrock thalweg of the Charles buried valley. At locality 1 (pl. 24) the thalweg is probably at about -100 feet msl. It is not located within close limits, but is thought to be just west of boring 6-2, which entered bedrock at about -82 feet msl. About 4 miles down the buried valley from this section a test boring put down by the Metropolitan District Water Supply Commission near the south side of the present Charles River penetrated bedrock at about 97 feet below sea level. Still farther downstream, about at the confluence of the Charles and Aberjona-Fresh Pond buried valleys (pl. 22), the lowest observed position of bedrock is at about -145 feet msl at boring 160-16. The depth of the thalweg itself is estimated indirectly as follows: Assuming a smooth curve between the Fresh Pond area of the Aberjona-Fresh Pond buried valley (p. M24) where the lowest elevation is about -1"70 feet msl, and the Columbus Park section (loc. 4 and pl. 27), where the lowest elevation is about -240 feet msl, the lowest ele- vation at locality 2 (pl. 28) would be about -210 feet msl. The sections, plate 2C and 2D, show the bedrock sur- face well controlled, and the positions of the thalweg to be at about -244 and -243 feet msl, respectively. At the section shown in plate 2C, most of the borings penetrate rock recognized as typical of the Boston Basin formations, but two borings (30-A and 31) penetrated several hundred feet of material reported as gray-white shale and some sandstone, which is unusual. Pearsall (1937, p. 178) suggested that this gray-white shale may be sediment of Cretaceous or Tertiary age filling a "pre- glacial gorge." In any case, it seems to be part of the preglacial bedrock. ABERJONA-FRESH POND BURIED VALLEY There are considerable scattered data on the bedrock depth in this valley, but the best section lies about east- west just north of Fresh Pond in Cambridge. (See loc. 5, fig. 6.) This section, not reproduced here, was published by Halberg and Roberts (1949, fig. 2). It shows the lowest elevation of the thalweg to be about M24 -165 feet msl. One boring, about 0.9 mile north of Fresh Pond and on a proposed Loop Water Tunnel of the Metropolitan District Water Supply Commission, penetrated bedrock at about -170 feet msl. The low point at this section may be as low as -180 feet msl. Several borings also suggest the presence of buried bench, or terrace, remnants at an elevation of about -80 feet msl. (See Chute, 1959, p. 189.) Interpre- tive sections prepared by Chute (1959, pl. 16) show the lowest elevation of bedrock near Fresh Pond to be about -170 msl. A well and a test boring 5 to 7 miles up- stream from Fresh Pond entered the bedrock at -145 and -137 feet msl, respectively. A seismic profile made on the east side of Spy Pond (about 1 mile north of Fresh Pond in Cambridge) gave a lowest bedrock ele- vation of -270 feet msl (Chute, 1959, fig. 33, and p. 198). Figure 7 shows an approximate profile for the thal- weg of the Aberjona-Fresh Pond and lower part of the Charles buried valleys. The profile is based on data presented in plate 2, table 6, and in the text. Assuming that the thalweg is likely to be at least a few feet lower than the observed elevations (more for a single well) no matter how well controlled the sections seem to be, the thalweg line is drawn slightly below the plotted points. Note that the Spy Pond seismic profile point seems to be excessively deep. If the seismic data permitted an ac- curate interpretation, this depth probably indicates local overdeepening by glacial erosion-perhaps plucking or scour along the Northern Border fault. This profile indicates reaches of the thalweg at two elevations, one at somewhat above -200 feet msl and rising upstream, and the other beneath the lowland part of the basin and nearly level at an elevation of about -250 feet msl. MALDEN BURIED VALLEY The Malden buried valley extends southward through Melrose and Malden and then swings southeastward to join the Charles buried valley apparently at the north edge of Boston Harbor. (See fig. 6.) Two sections are shown across this valley : one at locality '/ beneath Boston Harbor (pl. 22), and one in the upstream part at locality 6 (fig. 8). The borings shown in figure 8 are along a line that is almost parallel to the Malden valley axis at a place where the valley crosses the Northern Border fault of the Boston Basin. On the basis of bedrock exposures, the borings in the northern half of this section are ap- parently along the flank of the buried valley and thus probably did not penetrate the bedrock at its maximum depths. From water-well data in the files of the U.S. Geologi- cal Survey in Boston, the Malden bedrock valley in the SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY upland north of the section may be as deep as about 40 feet below sea level. Here the valley is apparently cut in pre-Pennsylvanian igneous and metamorphic rocks, which are generally relatively resistant to stream ero- sion. Near boring SPT 6-B (fig. 8) the slope of the longitudinal profile begins to steepen and drops from an estimated level of about -60 feet msl (this place is west of the line of section) to about -195 feet msl beneath the Malden River. This drop, which amounts to 1830 feet in a little more than 1,300 feet, occurs about at the north border of the Boston Basin where the thalweg crosses from the resistant upland rocks to the less resistant Cambridge Slate. The zone of the Northern Border fault doubtless passes through the section at about this place. The ap- parently crushed nature of the bedrock cored in boring SPT-3, which is described as "soft and broken," "broken bad," "bad and soft," and "soft broken and clay seam," suggests that at least one fracture intersects this boring. The lowest elevation of the bedrock surface along the line of section was -193 feet msl at boring SPT-4. The bedrock penetrated by this boring is described as "shale argillite." - The elevation is also about the lawest point of the thalweg, which may have been overdeepened somewhat by glacial erosion along the Northern Border fault zone. Other subsurface data in this vicinity sug- gest that bedrock valleys tributary to the Malden, whose approximate positions are shown in figure 6, may extend some distance along the fault zone here. The second cross section of the Malden buried valley is near Deer Island in Boston Harbor (loc. 7, fig. 6). Plate 25 shows the configuration of bedrock at this place. The bedrock valley thalweg here is probably at least 230 feet below sea level and may be deeper. The deepest bedrock reported on the boring logs was at -212 feet msl at boring 195-HS3A. A fault zone was penetrated near the bottom of the boring. Bedrock was described on all of the boring logs as argillite, pre- sumably the Cambridge Slate. UNCONSOLIDATED DEPOSITS The unconsolidated deposits within the buried valley system of the Boston Basin are complex locally, but- as revealed by the sections examined in this study- seem generally to conform to the sequence observed by Judson (1949). They are separated into five major units: (1) till at the base, probably the Boston Till of Judson (1949, p. 12), (2) a thick body of marine clay and silt, the Boston Clay of Judson (1949, p. 16), (3) outwash, which interfingers with the clay around the margins of the Basin, (4) a unit of sand and gravel that overlies the marine clay and silt at most places, prob- ably the Lexington outwash of Judson (1949, p. 23) M25 BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS poring sori¥yu; omor pus puog Jo Somreq} ;o WHODL ¢: t T T h 9 aindy uo umoys se sAajjeA yooipaq sauieyy pue T T T i anon T Pomo mmm T T tres T T T T T G Ot St aruustas wou; x uapjep jo uonoun{ wou; sai Bur10q 3807 10 [Jom 12 ya04pag | 0 | poreumso uonsaala yoo1paq 'uon2ag uorpeoo| ajewixoiddy Linvs #30ax408 ZIMIFEOZ_ + | 14811 qnoge uonsaato yo04paq 'uonaag 100€ - y. "d A6 |- .00€ Se eved woes na ine mel aes cece mee cel SL cold ee hane woe ee Ince ms pe- --- -~ -~ 22 AT Cm woz - f ig Lup Te _._ _ _._. |- 1002 9 G ig ene. pad oo. caa 1001 7 + ~ ,001 a 13a37 vas 1337 vas kajjea paunq saueyo _ Kajjen paring puog ysaig-euofiaqgy 3 p 3 Pa m & LogiDf; uogsog- ® 4 m_ m $ 'f = 2% Fa fd 2 a # % K - e 8 W $ W _ W 3 W 63 =o & 3 i § 3 5 a o & a to s & a. a < o 5 § 5 o 0 &. & tn = 97° o md a 7 g.. 3 [J o $ oS 5 8 vo o 2g ® a Ce 8 o - § & 8 <3 § & o a 0 me 8 B & ~ 3 3 % 6 32 7 € @ & & ®. % s a 8 8 T ro ro ro 8 n o sR & et 20 o 3 g 4 § g % ~ 8 5. & B $ ® & ro a SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY M26 'g oin@g 'q 41ftedot 09s Jo UOf}800] Jof 'SSEPT 1% 4ot¥A poring Jo Buijjup Suunp jono! peianco senew 09¢ | Jarem-puno18 aBeraAy _ yooupaq jo yidag Jnery pueg Keo I4 reoyniy p 08 # ; - - & I ore \\N P =< } 1 bez 13437 vas NY3W SI Wnivd mm -me -ma 1334 0001 009 '00¢ 0 10¢ suejd jouun} jeuiBuo wou} aie suoneuBisap ajoya10g 02 if A oat 4 (b a1qe4 aas) suepd jouuny # jeuiBu0 wos st ajyoud puno48 arewixorddy et 4 auruejueo jouuny | jo j99} / uiyyim are umoys s8oj ajoya10g 3 | { m Eo r-- --r ---+ a © : 8 ov Or 13a37 |_ - vss vas s " ig & m o [3] bs t s $ a s HA % o i>" - E op - f % 7 * § a C, a 5 ad Pa ® - : f { € & my D o t w p © o & "= L 5 Y 5 & & f C ~ | = % = % ~ ~ ; hd 7 ¢ h Z a- p s _ W & 3 a # eas 2 = is 98 A a m 9 P & a 2 0 BJ E < as ° & 2 3 8 m » o ® 8 6 N 3 $ 3 BB 3 5 S 5 m a 50 m m A mo m ~ H 22 4 aE d BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS and at least partly correlative with unit (3) above, and (5) a unit composed of several deposits not fully differ- entiated, including silt and clay, peat, and other plant remains. This last unit is herein called estuarine de- posits. It includes the lower peat, the marine silt, and the upper peat of Judson (1949, p. 27-32). Judson (1949, p. 10) recognized the presence of a till older than the Boston Till ; and recently Kaye (1961, p. 73-(6) described a complex sequence of glacial de- posits exposed in the excavation for the Boston Com- mon garage, in which he recognizes four drift layers separated by three marine clays. Of these, the lower three drift layers underlie Clay III (Kaye, 1961, p. B-i5), which is probably the Boston Clay of Judson. Kaye (p. B-75) considered that the deposits below this clay are early Wisconsin and older, and that Clay III is of middle Wisconsin, or Tazewell, age. This age estimate is based on indirect evidence, and may not be final. However, not only may there be middle and lower Pleistocene glacial deposits locally in the Boston area, but the Boston Clay itself is possibly older than most of the deposits considered in this report. Nevertheless, the identity and age of the last period of lower sea level is significant. Both Judson (1949, p. 20, 27) and Kaye (1961, p. B-75) recognized that the sea level was relatively low following the deposition of both the Boston Clay and the Lexington outwash, although whether or not there were two separate epi- sodes of lower sea level is not known. In any event, there was a period during which the level of the sea rose following deposition of the Lexington outwash and __ during which the sequence of peat, marine silt, and peat of Judson was laid down. This period corresponds to the episode of estuarine deposition described in this report. The several sections shown in plate 2, especially those across the Charles Buried valley, show the general se- quence fairly well (sees. 7 2, C, D, at locs. 2, 3, and 4, respectively). Till occurs generally at the base and is overlain by the marine clay. There may be more than one unit of clay deposits, but the available data do not show it. In none of these sections does the clay extend above sea level. At the site shown in plate 2C the clay body contains a lens or lenses of fine sand shown by symbol for out- wash. This sand constitutes the only apparent break in the uniformity of the clay body, except at the mar- gins of the Boston Basin, and thus probably is a slightly coarser grained facies resulting from local depositional conditions. In the section at locality 7 (pl. 22) across the Malden buried valley, the deposits are undescribed except at boring 194-1C on Deer Island. This boring penetrated M27 sand and gravel at the top, and then entered compact poorly sorted clay, sand, and gravel considered to be till. The deposits in this section probably consist mostly of the marine clay known to occur elsewhere in the area. Around the margins of the basin, the deposits are different. For example, at locality 1 (fig. 6 and pl. 24) they consist almost entirely of sand and gravel, and constitute a body of outwash. This outwash rests on a discontinuous layer of heterogeneous material above the bedrock, evidently till. A body of clay and silt penetrated by borings 6-1 and 6-2 at the base of the outwash may be a tongue extending westward from the main body of marine clay or may represent lacus- trine deposits in an arm of glacial Lake Sudbury as postulated by I. B. Crosby (1939, p. 381). In the upstream part of the Malden buried valley (fig. 8), the deposits are mostly sand and gravel, as in the upstream section of the Charles (pl. 24). There seems to be till at the bottom, overlain by predomi- nantly sandy material, some of which contains gravel and some of which contains silt and clay. Possibly the gravel penetrated by borings SPT-6 and SPT-6D (fig. 8) is outwash, but the silt and clay penetrated by borings SPT-2 to 5 may be a basal coarse-grained facies of the marine clay unit. In about the middle of the section (vertically) and penetrated by borings SPT-1 to SPT-5 is a body of stiff gray clay, containing inter- bedded silt and silty clay and some pebbles. This body of clay is probably a tongue of the Boston clay. The top of this body is irregular and may have been eroded before deposition of the succeeding material. The deposits above the clay are mainly sand and gravel and, for the most part, are probably outwash. However, some of the boulders and gravel that contain clay, such as those penetrated by borings SPT-2, 3, 4, and 5 above the clay unit, may be till. For example, at boring SPT-3, material above the clay is described as "sand, clay, and rock particles, very compact." In the central part of the basin, where the estuarine deposits occur, the deposits above the marine clay are varied, and different units cannot be clearly distin- guished from one another. The greatest diversity seems to be at locality 2 (pl. 2B), where a body of sand and gravel rests on the clay and is in turn overlain by a body containing silt, peat, and other plant remains. The sand and gravel probably represents the Lexington outwash of Judson, and the unit containing organic remains probably represents the post-Lexington unit of marine and marsh deposition. In the north end of the section and along the Charles River is a body of estuarine deposits which probably lie unconformably on the sand and gravel. These estuarine deposits may M28 be correlative with the peat and plant remains in the central part of the section. Estuarine deposits, resting unconformably on the ma- rine clay, are also shown in plate 20. On the original record, these deposits are shown simply as "silt" and it is not known whether they represent the outwash that lies above the clay, or the marine silt of Judson (1949, p. 29), but are probably the latter. These deposits are shown here as estuarine deposits because of the lith- ologic description as "silt." They may represent the out wash because they appear to be overlain by sand and gravel (boring 34) and because some sand and gravel were penetrated in the upper part by shaft B. Judson (1949, fig. 1 and p. 21) presented data on the erosion of the Boston Clay and suggested that the streams that dissected the Boston Clay before the dep- osition of Lexington outwash were graded to a base level 90 to 100 feet below present sea level. This depth range may be correct, but whether it is for a pre- Lexington or a pre-estuarine erosion surface is not known. More dependable information is probably af- forded by the depth of the lower peat, the lowermost part of which is herein called the estuarine deposits. Barghoorn (1949, p. 73), referring to this lower peat, stated that it is clearly a fresh-water accumulation, and "probably the basin in which it formed was periodi- cally affected by brackish invasions from the Charles River estuary." Thus the lower peat was probably approximately at the sea level of the time. Barghoorn's inference was based upon examination at the Boylston Street fishweir site, where the base of the peat is nearly 30 feet below sea level (Judson, 1949, p. 31). Boston City base is -5.75 feet msl at the Boston Navy Yard. Judson (1949, p. 27) reported that buried peat, pre- sumably the same as that at the Fishweir site, occurs elsewhere in the Boston area as low as about -50 feet msl (45 ft below Boston base). «Therefore, sea level during pre-estuarine time was probably at least 50 feet lower, with respect to the land, than it is at present. This elevation is given on plate 5 as the low point of the pre-estuarine surface, though farther seaward it may have been lower. SUMMARY OF FEATURES OF THE BOSTON BASIN AREA BURIED VALLEYS The lower reaches of the thalwegs of the bedrock valleys of the Boston Basin area lie between -230 and -245 feet msl. The elevations at about -243 feet msl on the Charles Buried valley in Boston (pl. 2C), at about -244 feet msl on the Charles at Columbus Park (pl. 27), and at -230 feet msl at the lower end of the Malden buried valley indicate a very low grade which may represent a local base level somewhat below -240 msl, at say -250 feet msl. Such a level, however, may SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY represent adjustment to varying rock resistance and not necessarily indicate any position of sea level. The data do not indicate any systematic elevations for the upper reaches of these thalwegs. The thalweg of the Malden buried valley rises abruptly upstream to an estimated elevation of about -60 feet msl north of the Northern Border fault. The upper part of the Aberjona-Fresh Pond buried valley is lower, about -145 feet msl in Winchester (p. M24), perhaps be- cause it was the valley of a larger stream. The inter- mediate levels between -165 and -180 msl feet near Fresh Pond and Spy Pond probably represent a rapids between the deep reach to the south and a shallower reach north of the Northern Border fault. The terrace remnants mentioned by Chute (1959, p. 189) at about -80 feet msl may also represent a shallower base level. (See also p. M24 this report.) Perhaps the bench on the Charles buried valley in Newton, at about -80 feet msl (pl. 24), represents the same level. The unconsolidated deposits in these valleys indicate a complex sequence of events culminating in a relative rise of sea level accompanied by deposition of estuarine and marsh deposits, some in fresh and some in salt wa- ter. The elevation of the preceding position of sea level may have been 90 to 100 feet below present level, but this estimate is perhaps confused with an earlier episode of lower sea level. In other words, there must have been a decline of sea level at some time after the deposition of the last marine clay, but whether or not there was an actual decline following the deposition of the Lexington outwash is not known. A lower peat deposit at the base of the estuarine deposits reaches a depth of about -50 feet msl in the Boston area, and that elevation is plotted in plate 5. BEDROCK VALLEYS NEAR PORTSMOUTH, N.H. A rather intricate system of drowned river mouths in the vicinity of Portsmouth, N.H., marks the bed- rock valleys of the Piscataqua River and its tributaries. (See Dover and York quadrangles, New Hampshire- Maine, scale 1: 62,500; and the more up-to-date Ports- mouth and Kittery, N.H.-Maine 7i4-minute quad- rangles, scale 1: 24,000.) Data on the crossings of the Piscataqua River at Portsmouth, if available, were not obtained. However, borings for modern bridges be- tween islands southeast of Portsmouth, give refusal depths, probably near bedrock, of about -55 feet msl. About 514 miles northwest of Portsmouth the Scam- mel Bridge for U.S. Route 4 crosses the Bellamy River between Cedar Point and Dover Point in the City of Dover, NH. At this place the Bellamy River is a. sizable tidal estuary which joins the Piscataqua about 4 miles above Portsmouth. In 1933, seven wash borings BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS were made at this crossing for the New Hampshire Toll Bridge Commission. 'The borings penetrated un- consolidated deposits until they struck either bedrock or a boulder too large to be broken or driven aside. The deepest point of refusal is near the middle of the crossing at an elevation of -91.5 feet msl. This eleva- tion is probably close to the bedrock surface and the thalweg of the valley is plotted as -95 feet msl in plate 4. This locality is a few miles inland, and the bedrock thalweg may deepen downstream. The water depth alone in the Piscataqua at Portsmouth is as much as -70 feet msl. From the description of the deposits given on the records, the borings penetrated four depositional units, from the top : (1) silt, fine sand, and shells, (2) a thick and fairly uniform body of very soft blue clay and sand, (3) a body of variable thickness of sharp gray sand, which is "hard" in some borings and "loose" in others, and (4) hard gray gravel and sand, with some clay reported at one or two of the borings. Refusal points are in or at the base of this gravelly unit. Unit 2 is the marine clay and silt which is exposed in the vicinity and which is similar to the marine clay in the Portland area to the north (p. M34). The uppermost unit, No. 1, is evidently the estuarine deposits found in other areas. The lowest observed M29 point at the base of these deposits is -36.5 feet msl. This elevation is considered to be approximately the lowest point, and is shown as -36 feet msl on plate 5. BEDROCK VALLEYS OF THE MAINE COAST GENERAL FEATURES The Maine coast is highly indented, marked at most places by many islands and long narrow estuaries. The coast reflects the structural alinements of the bedrock, which consists chiefly of folded and more or less metamorphosed sediments and intrusives of Paleozoic age. The full explanation for the detailed indentation of the Maine coast is doubtless complex, involving the nature of the bedrock, amount of marine submergence, amount of crustal recovery from ice load, crustal de- formation if any, and previous erosional history. Most of the rivers enter the sea through estuaries that extend many miles inland and mainly are extensions of buried bedrock valleys. The Maine coast valleys discussed are those of the Presumpscot River, the Kennebec, and Sheepscot, the Penobscot, and the St. Croix including its continuation through Passamaquoddy Bay (fig. 1). Representative sections are given in plate 3. Table 5 gives nontechni- cal information about the sites and sources of data on borings. 5.-Summary of information on crossings of bedrock valleys along the Maine coast Locality Date of | Topographic quadrangle Bedrock valley No. on Purpose of borings Agency for which borings were made plans maps on which the sites fig. 1 and vicinities are shown Presumpscot........ 8 | Veterans Memorial Bridge (U.S. | Maine State Highway Com- 1952 Portland West. Route 1) over Fore River between mission. Portland and South Portland. Do:........... 7 | Maine Turnpike in Portland_____. Maine Turnpike Authority___| 1953 Do. 10 | U.S. Route 1 bridge between Bath | 1926 | Bath. and Woolwich. 9-A | Highway bridge between Rich- | Directors of the Maine Ken- 1930 Gardiner. mond and Dresden. nebec Bridge.! 9 | Augusta Memorial Bridge, U.S. | Maine State Highway Com- 1945, | Augusta. Route 202, in Augusta. mission. 1949 Sheepscot-........_. 11 | U.S. Route 1 bridge between Wic- |____. 10. i: teenie 1931 | Wiscasset and casset and Davis Island in Boothbay. Edgecomb. Penobscot..::.._:.. 10 | U.S. Route 1 between Prospect | 1930 Bucksport, and Verona. 12 | Highway bridge between Bangor | Maine State Highway Com- 1953 Bangor. and Brewer. mission. \ Passamaquoddy Bay . 14 | Proposed tidal dam across Head | Sonar investigation for U.S. 1952 (@). Harbor Passage between Deer Army Corps of Engineers. and Campobello Islands, New Brunswick, Canada. 15 | Proposed tidal dam between Estes | U.S. Army Corps of Engi- 1936 Eastport. Head in Eastport and Treat neers. Island, in Lubec. i Data obtained from Maine State Highway Commission. 2 U.S. Coast & Geodetic Survey chart 801. M30 DEPTH OF BEDROCK THALWEGS The crossings of the buried bedrock valleys of the Maine coast are all either about at the heads of the estu- aries of the rivers, or several miles upstream where the valleys are narrow. Some information has been ob- tained about the Passamaquoddy Bay part of the St. Croix bedrock valley by sonar exploration. Each of these valleys is different, or there is some special prob- lem involved ; hence, the respective bedrock depths are discussed separately in the following paragraphs: PRESUMPSCOT BURIED VALLEY The present-day Presumpscot River is the largest of several streams that cross the lowland around the city of Portland, Maine. Except for the prominent hill on which much of the city is built, the area has moderate relief. Low hills, underlain mainly by bed- rock, rise short distances above a blanket of glacial de- posits. The bedrock consists of more or less strongly metamorphosed sedimentary rocks whose foliation has steep dips and a northeasterly strike. The Presumpscot River originates at Sebago Lake (fig. 1) and flows directly southeastward for about 12 miles as if to enter the sea at the south side of Portland. Instead, it turns abruptly northeastward for about 4 miles, and then turns east-southeastward again to enter Casco Bay north of Portland. Hitchcock (1874) sug- gested that the Presumpscot River fomerly continued southeastward all the way to the sea. If so, this course is now completely buried. The bedrock profiles at localities 7 and 8 (pls. 3 A and B), however, appear to show a valley along this trend. The small Stroud- water River now lies approximately along this course, which is considered to be that of an ancestral Presump- seot River. Plate 34 shows the subsurface geology at the Maine Turnpike crossing over the Stroudwater River (loc. 7, fig. 1). Most of the borings shown in this section penetrated the unconsolidated deposits only until they encountered some obstruction; that is, the point of refusal. The obstruction may have been a boulder, very compact till, or bedrock. For lack of other sub- surface data, the assumed bedrock surface is shown at about the point of refusal of the borings. The depth to bedrock at this section is not everywhere well established. Boring 23-05, the deepest, extended to about -56 feet msl, and ended in "gray wet compact silty fine sand, some gravel." The lowest elevation of the bedrock surface here is not known but is prob- ably at least -60 feet msl and could be substantially deeper. For example, a 2-foot-thick boulder at -18.83 to -20.3 feet msl was penetrated by boring 23-05. Had this obstruction not been penetrated, the depth SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY would have been reported as refusal and the elevation would have agreed with the positive bedrock depth at boring 23-14 and the point of refusal at boring 23-67A. Hence, at least locally, bedrock may be appreciably deeper that the assumed bedrock surface shown. Plate 3B shows a section across the Fore River estuary at the southwestern tip of Portland. All bor- ings were stopped at refusal; probably most holes ended within a few feet of bedrock. Based on the refusal depths, the bedrock surface has a minimum observed elevation of about -115 feet msl. Some older borings (p. M35) approximately along the same line reached refusal: one at -129.8 feet msl and another at 128.4 feet msl. KENNEBEC BEDROCK VALLEY The Kennebec is one of the largest rivers in Maine. It rises at Moosehead Lake and follows an irregular, but generally southerly, course through Augusta, and thence to the sea at Merrymeeting Bay. From Augusta south, the bedrock channel is several tens of feet below river level. The alinement of the bedrock ridges, is- lands, and promontories south of the 44th parallel sug- gests that the buried course of the Kennebec would continue about southwestward to the northeastern part of Casco Bay. However, the data on the rather fully concealed bedrock are insufficient either to determine or to disprove the presence of a buried bedrock valley in that area. On the other hand, the course of the pre- Wisconsin Kennebec may have been about the same as that of the present river. The only section surely on the ancestral Kennebec is at Augusta (loc. 9, fig. 1), about 24 miles upstream from the middle of Merrymeeting Bay. At four borings (Nos. 5, 14, 16, and 27) the bedrock was cored, and its elevation accurately determined. The lowest point on the bedrock reported in the logs was at boring 27 which penetrated "granite ledge" at about -76 feet msl. The thalweg of the bedrock valley here may be -80 feet below msl. Boring 26 (not shown), about 50 feet south of boring 27, entered bedrock at about -65 feet msl, which is the basis for drawing the bedrock shelf shown on the cross section just southwest of boring 27. At Bath, Maine, about 35 miles downstream from Augusta, the U.S. Route 1 toll bridge crosses the estuary part of the Kennebec River (loc. 10, fig. 1). The rec- ords do not indicate whether or not bedrock was actually cored, but they do report "hardpan" at the bottom, sug- gesting that a more positive identification of the base of the deposits was made than simple "refusal." If so, the bedrock depth figures are reasonably accurate. The lowest bedrock elevation is at boring 30, 188.4 feet below "mean water level," probably close to the lowest bedrock BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS elevation in the section. The figure used is -140 feet o SHEEPSCOT RIVER AT WISCASSET A few miles east of the mouth of the Kennebec is the estuary of the Sheepscot River. A set of records from wash borings for the bridge at locality 11 (fig. 1) are illustrated in plate 35. Records of two borings are also available for the subsidiary bridge from Davis Island eastward to the mainland. At the main bridge, locality 11, the minimum elevation of the bedrock, based on refusal depths in fairly closely spaced borings, is about -150 feet msl. The minimum elevation plotted is -160 feet msl. PENOBSCOT RIVER BEDROCK VALLEY Within the coastal region under consideration in this report, the Penobscot River extends northward as a narrow estuary from Penobscot Bay about to Bangor. The head of Penobscot Bay (taken as the southern tip of Vinalhaven Island) is about 34 miles from the sea, and Bangor is about 20 miles farther. The depth to bedrock beneath Penobscot Bay is not known, and ap- preciable data for along the river itself are available at only two places. One location is where the U.S. Route 1 bridge crosses between Prospect and Verona, about 4 miles upstream from the head of the Bay (loc. 13, fig. 1) and the other is at Bangor (loc. 12, fig. 1). There is some question as to whether or not either locality 12 or 13 is actually on the course of the ancestral Penobscot. Bastin in Barrows and Babb, 1912, p. 12) suggested that the bedrock valley of the Penobscot near Bangor passes some 4 to 5 miles west of the Bangor business center. J. M. Trefethen (oral communication) and students are now working to delineate the former course of the Penobscot in the vicinity of Bangor. Far- ther south, about 5 miles upstream from locality 13 (fig. 1), the South Branch Marsh River joins the Penobscot after flowing directly northward for several miles in a broad marsh-floored steep-walled valley. Trefethen made a rod sounding in this valley about a mile from the Penobscot estuary to -190 feet msl with- out reaching refusal, and suggested (oral communica- tion, 1958) that the South Branch Marsh River valley may mark a former course of the Penobscot. The suggestion that the course passes west of Bangor may be valid, but a possible outlet for a deep buried val- ley beneath the South Branch Marsh River other than along the present Penobscot is not readily apparent from field examination in the area. Nevertheless, the sections at localities 12 and 13 are either on some preglacial or early glacial course of the Penobscot or on tributaries thereto. M31 The section at Bangor shows cored bedrock at a mini- mum elevation of about -43 feet msl, overlain by strati- fied sand and gravel. The information on the Prospect- Verona bridge site is sketchy. The deepest and lowest of four borings below sea level penetrated 96 feet of clay containing gravel and boulders to an elevation of -124 feet msl. Bedrock was not reached. If the 190- foot minimum elevation reported by Trefethen a few miles to the north is in a tributary to the main Penobscot buried valley, and is not due to glacial over- deepening, the elevation of the bedrock surface at lo- cality 13 could be at least -200 feet msl. The depth is considerably greater farther southeast beneath Penobscot Bay. In fact, the water alone is deeper than 400 feet in the area just south of the narrow part of the passage between the west side of Vinalhaven Island and the mainland (U.S. Coast and Geodetic Sur- vey, chart 1203). This depth is comparable to the depths in the outer parts of Passamaquoddy Bay to the north. ST. CROIX BEDROCK VALLEY (PASSAMAQUODDY BAY) The St. Croix River heads in Canada, and the lower 95 miles of its course forms the boundary between Maine in the United States and New Brunswick in Canada. It enters an arm of Passamaquoddy Bay a few miles down- stream from Calais, Maine, and thence exists as a nar- row channel trending south-southeast in an almost straight line for about 19 miles. This course lies be- neath Western Passage, the channel that forms the southern outlet of Passamaquoddy Bay. (See fig. 9.) Nearly east of Eastport, the channel turns abruptly northeastward and passes in a broadly curving course through Head Harbor Passage around the north end of _Campobello Island, New Brunswick, to the Bay of Fundy. At Eastport, the St. Croix bedrock valley is joined by a tributary channel from Cobscook Bay to the south and west, probably a continuation of the Pen- namaquan River valley that enters Pennamaquan Bay. The bedrock geology of the Passamaquoddy Bay area has been described by Bastin and Williams (1914), Perry and Alcock (1945), and Alcock (1946). The rocks consist of some more or less metamorphosed, and some unmetamorphosed, sedimentary rocks of Paleozoic age associated with igneous rocks, mainly extrusive. There are two major fault zones. One of these, in- ferred, lies beneath the Western Passage and strikes northwest parallel to the alinement of the passage. The other, likewise inferred, is a northerly extension of one of the faults mapped by Bastin and Williams (1914) between Lubec Neck and Seward Neck. This fault probably continues northward east of Eastport and be- neath Head Harbor Passage west of Campobello Island. M32 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 67°10 f 3 67°05" 67°00 66°55" 45°00 v 45°00 44°55" 44°55" 44°50" 44°50 2 MILES as 67°10 67°05" 67°00 66°55" FIGURE 9.-Sketch map of the vicinity of Eastport, Maine, showing thalwegs of St. Croix bedrock valley and tributaries in the southern Passamaquoddy Bay area. Segments shown by dashed lines are taken from 1951 sonar survey (Smith, Upson, and others, 1952) ; those shown by dotted lines are estimated. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS Probably other faults in the region have trends that diverge from those described. The alinement of the sea passages herein discussed appears to be broadly controlled by these fault zones, along which erosion took place more readily than in the adjacent blocks. Deeply buried bedrock valleys along the lower part of the St. Croix River and the Cobscook Bay tributaries are revealed by subsurface investigations made by the U.S. Army Corps of Engineers since 1930 in connection with plans for the International Passamaquoddy Tidal Survey aided by sonar studies carried out by the U.S. Geological Survey in 1951. The results of the earlier work are in reports by the corps, and the results of the later work are in a preliminary report by Smith, Upson, and others (1952) and a paper by Upson (1954). The results of more recent work, done in 1958 by the corps aided by Fairchild Aerial Surveys sonoprobe, are sum- marized in a report by the International Passama- quoddy Engineering Board (October 1959). The most complete information pertinent to the present discussion on the configuration of the bedrock and the nature of the sediments is in the report by Smith, Upson, and others (1952). Largely on the basis of sonar surveys the bedrock channel beneath the Western Passage lies slightly below -400 feet msl. A little more than 4 miles downstream, about opposite Green Island in Head Harbor Passage, the bedrock thalweg also lies a little below -400 feet msl. A figure of -420 feet msl, considered to be ap- proximately correct, is used. These depths are approx- imate because the velocity of sound transmission used was not specifically determined for the area. Also, it was difficult at places to recognize the bedrock reflection in the recorder trace. The results of the 1958 investi- gations are not closely comparable with the 1951 results but are not inconsistent with the depths herein men- tioned. The Western Passage reach is alined, in gen- eral, with the direction of glacial ice movement, whereas the Head Harbor Passage reach lies athwart the direc- tion of ice movement. It would be expected that, of the two, the former would be deepened more by glacial erosion. The fact that the depths at these places are . about the same suggests that glacial erosion was not the principal agent in forming the valleys, although there may have been some scour or plucking in either or both reaches. Bedrock depths beneath other channels in the area agree with the concept of a major bedrock valley for an ancestral St. Croix River, which was perhaps graded to some level lower than 400 feet below present sea level. This depth is appreciably greater than that known or inferred for any other bedrock valley on the New England coast except for Penobscot Bay (p. M31) M33 and part of the Taunton-Sakonnet valley in Naragan- sett Bay (p. M18). UNCONSOLIDATED DEPOSITS The unconsolidated deposits in the bedrock valleys of the Maine coast comprise altogether five units, of which only three or four occur in any one valley. In general the units are: (1) till at the base, (2) local bodies of ice-contact deposits classed as outwash, (3) marine clay and silt, (4) late glacial outwash or fluvia- tile deposits, and (5) estuarine deposits. TILL Till, designated as unit 1 in the sections shown in plate 3, occurs discontinuously on the bedrock surface in all the valleys. It is recognized in the boring records as poorly sorted material composed mainly of gravel plus varying amounts of clay, silt, and sand. It is compact, or hard, is sometimes described as "hardpan," and causes a markedly higher blow count than any of the overlying deposits At most places it is 10 to 20 feet thick, but at others (pl. 34) it may be 40 feet or more. Till is not recognized everywhere, as the sections (pl. 3) show; it might be present as a thin layer of pebbles or be only a few feet thick, as in some exposures, but was not noted during drilling or boring. Some of the material, generally in the upper few feet, is less compact and comprises gravel and sand. This material may actually be thin outwash but is not differentiated in the sections. ouTtwask There are no extensive outwash deposits above the till such as there are in the valleys of Connecticut. In the valleys of coastal Maine, outwash, designated as unit 2 in plate 3, mainly occurs as local bodies of fine to coarse sand with some gravel or boulders. The material contains little clay or silt and is not hard, although at places it is described as "compact." Be- cause it contains no appreciable clay or silt and because it occurs locally along the valley sides, it is probably an ice-contact deposit and is herein classed as outwash. Examples of this outwash are at the south sides of the Presumpscot buried valley (pl. 34) and of the Kenne- bec valley at Augusta (pl. 30). MARINE CLAY AND SILT The predominant deposit in the Maine coastal valleys is marine clay and silt (unit 3 shown in pl. 3). (See Goldthwait 1951; Katz, 1913.) This deposit is usually gray, but locally blue, mostly compact clay and silt. At places it contains some sand. Locally, it contains shell fragments, but ordinarily no other organic matter. At most places it is tough or compact, but at some M34 places it is soft and in some borings is reported as stratified. Locally, it contains scattered pebbles. The unit is as much as 120 feet thick (pl. 35). - Perhaps the best subsurface characterization of this deposit is found in the boring records for the Presumpscot buried valley (pl. 34, B), where the material is variously described as "gray silty clay," "clay and silt," "silt and traces of clay," or "gray silty clay and traces of sand." These deposits are entirely below sea level at some of the sections, but in the vicinity of Portland (pl. 34, B) and Augusta (pl. 3C) they extend above sea level where their observed characteristics are the same as those herein described from boring records. In the vicinity of Portland, the deposits are continuous with the Presumpscot Formation of Bloom (1959). In the Sheepscot valley (pl. 35), the marine deposits form a thick unit that, in all but six of the boring records, is designated "blue clay." In one it is desig- nated "soft blue clay," and in five the material is not named, but the symbol used on the drawing is the same as where blue clay is named. This material reaches a maximum thickness of more than 120 feet in the deepest part of the bedrock valley. It is doubtless the marine formation of clay and silt that occurs along the entire coast and that is exposed farther inland. The records of the borings across the Sheepscot do not indicate whether or not this clay comprises more than one stratigraphic unit. Two units of clay, how- ever, are indicated by records of two borings and a "soils profile" drawn by the State Highway Commis- sion for the subsidiary bridge between Davis Island and the mainland to the east. - The lower clay is gray silty clay described as having "medium consistency." The upper, which appears to occupy a channel eroded in the gray silty clay, consists of "soft sensitive clayey silt with a few sea shells." - The channel, if present, extends down to about -95 feet msl. - However, the lowest ele- vation of probable estuarine deposits is about -30 feet msl. (See p. M35). Whether these are two divisions of the marine clay or whether the younger unit here represents the estu- arine deposits that are present in other valleys farther south is not known. - The upper material has sea shells, but apparently no plant remains, and the authors con- sider it to be older than the estuarine deposits in the buried valleys of the Presumpscot and Kennebec Rivers. The deposits in the Penobscot are not well known. The section at Bangor shows mostly stratified sand and gravel that is actually younger than the marine clay. At the Prospect-Verona Bridge (loc. 13, fig. 1) the available boring records report primarily clay with varying amounts of gravel. The data are not adequate to define the stratigraphy, but the deposits appear to consist mainly of clay and silt. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY In the St. Croix buried valley system, the marine clay and silt occur for the most part in the broad shallow bays west of Eastport and Lubec (fig. 9) (Upson, 1954). They are similar to the Presumpscot Formation of Bloom, but they may not be the same formation. Within Passamaquoddy Bay proper, the marine clay and silt deposits are widespread. - Whether or not they are cov- ered with an appreciable thickness of estuarine deposits is not known. The deposits have been examined in detail south of Eastport, Maine, beneath the sea passages north of Treat Island and south of Dudley Island (fig. 9). De- tailed descriptions of samples taken during test drilling in these channels were made by geologists of the U.S. Army Corps of Engineers. The material penetrated was marine clay and silt. The descriptions suggest a possible differentiation between an upper "soft clay" and a lower "stiff clay." - The "soft clay" contains shells and some silt and sand ; the lower stiff clay is, in general, described as banded. Thus a significant difference is suggested. However, in a few holes "soft clay" occurs below "stiff clay," and in one or two holes banding is noted in the lower part of the "soft clay." Locally, the "stiff clay" also appears to grade upward into the "soft," and the two are not separated by any clear-cut uncon- formity. Therefore, the upper clay is considered part of the glacial marine sequence, and not of the nonglacial estuarine deposits like the soft shell-bearing estuarine deposits of the Connecticut coastal valleys, Narragansett Bay, and the harbors of Portland and Boston. How- ever, if the marine clay and silt unit does comprise two subdivisions, the distinction may be related to different relative positions of land and sea. During decline from its highest position (Upson, 1954, p. 293), the postglacial sea near Eastport apparently stood against the land. for an appreciable length of time at a level now about 90 feet above sea level. - Possibly the lower beds of the ma- rine clay unit were deposited when the sea was higher, and the upper beds were deposited while and after the sea was at a level that was 90 feet higher than it is at present. In summary, the deposits herein designated marine clay and silt rest on the till and at places directly on the bedrock where the till is missing. Locally, they over- lap bodies of outwash. They occur along the coast from Portsmouth, N.H., to Eastport, Maine, and beyond, and they extend inland up the major stream valleys as much as 75 miles from the coast. They appear to be equivalents throughout, but it is not certain that they are entirely. The surface of the marine clay and silt was eroded in the Presumpscot valley near Portland and in the lower part of the Kennebec at Bath, but farther east evidence BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS of erosion is slight. It may have been channeled slightly in the Sheepscot River at Wiscasset but ap- parently was not channeled in the vicinity of Eastport, Maine. Above the marine clay and silt is a fourth unit, con- sisting of estuarine deposits, that occurs every where ex- cept in the northeastern part of the coast. As exempli- fied by the top unit beneath the Fore River (pl. 32), the deposits are soft, loose material, in which the bore casing settled under its own weight. They are described as soft silt, or river mud. At some borings (for example, D-20) traces of shells are recorded, and in some borings plant organic material was penetrated. According to the borings used for the section shown in plate 32, the base of the estuarine deposits extends to about -40 feet msl. However, older borings (p. M30) made along the same line by the Edw. F. Hughes Co. of Boston in the period August 1946 to November 1947 show material that appears to be the underlying marine clay and silt but that contains organic material down to an elevation, at two borings, of nearly -90 feet msl. Except for some pieces of decayed wood in the interval -41.5 to -50.5 feet msl at one boring, the organic mat- ter is undescribed and presumably consists of pieces or seams of carbon or perhaps finely disseminated carbon. The strata that contain this organic material are sep- arated from overlying shell-bearing clearly estuarine material that reaches about -40 feet msl by beds of clay, silt, and sand without organic material. Woody organic material apparently is not charac- teristic of the Presumpscot Formation of Bloom, whose rather full description (1959, p. 55-61) mentions only shells or shell fragments at a few places. Either the organic material reported in the older borings is a mis- identification of some other dark material, or organic material was not recognized in the later borings. If the organic material is present, the sediments probably rep- resent a post-Presumpscot estuarine deposit; and thus there may have been two periods of post-Presumpscot down cutting and filling in this area, the older one reach- ing a depth of about 90 feet below sea level. The evi- dence at present is considered inconclusive. At Bath, Maine (pl. 3D), the unit consists of sand, and sand and gravel. Rotten wood is reported at boring 16 and "sound spruce drift" at boring 11, but otherwise no plant remains or shells are indicated. This unit may be the equivalent of estuarine deposits in other areas, although the reported coarse grain size suggests that the material is composed of outwash. In the Sheepscot valley, the deposits consist of ma- terial described as "mud" or "soft mud." At most borings this material is reported to be 4 feet thick; at one it is reportedly 16 feet thick. This is probably M85 present-day bottom mud. However, it rests on an ir- regular surface that may have been formed by sub- aerial erosion, and thus may be partly estuarine mate- rial and correlative with estuarine deposits in the Maine valleys farther south. The base of the deposits extends to about -30 feet msl. Upstream, these deposits apparently merge with more sandy material, at least in some stream valleys. For example, along the Kennebec at Augusta (pl. 3G) the uppermost unit lies beneath the river, and also extends about 15 feet above river level on the east side to form a low terrace. Beneath the river this unit is sand and gravel generally less than 5 feet thick. Beneath the terrace it reaches a thickness of about 20 feet and consists mostly of sand and silt. Locally, its surface is covered by artificial fill. The original log of boring 3 (pl. 8C) reported "boulders or logs embedded in sand" near the bottom of the unit at -3.99 to -0.99 feet msl. The overlying material is decribed as "medium brown sand, soft silt and very fine sand, sawdust and rotten wood." From inspection of the site, the authors be- lieve that at least the upper part of boring 3 penetrated artificial fill. This material appeared to have been excavated from the silty sand and sandy silt deposits exposed nearby. The writers also believe that this unit, except for the artificial fill, is late fluviatile alluvium. At least the part beneath the river currently must be subject to cutting and filling with variations in river- flow. The unit is clearly not estuarine but may be the time equivalent of estuarine deposits farther down- stream. The lower part of the deposits beneath the terrace may be a fine-grained late outwash. There appear to be no estuarine deposits in the valleys of Passamaquoddy Bay, at least south of Eastport, ex- cept perhaps for a few feet of present-day bay mud. In the Presumpscot valley and in the Kennebec at Bath, estuarine deposits rest on a surface which, be- cause it is irregular and has a channellike shape and because it is on marine deposits, is probably an erosion surface formed subaerially by streams. The low point, or thalweg, of this pre-estuarine unconformity lies at about -40 feet msl (possibly -90 ft msl) at the Fore River bridge at Portland, and apparently about -94 feet beneath the Kennebec at Bath. This thalweg may have been as low as -95 feet msl beneath the Sheep- scot River at Wiscasset (p. M34), but probably not deeper than -30 feet msl. Suggested channeling within the deposits to depths of about 90 to 95 feet is considered to mark variations within the marine clay and silt, although it may indi- cate a pre-estuarine unconformity extending to such depths. M36 SUMMARY OF FEATURES OF MAINE COASTAL BEDROCK VALLEYS The bedrock thalwegs of most of the Maine coastal valleys range from about 95 (the Piscataqua at Ports- mouth, N.H., or Kittery, Maine) to about 160 feet beneath the Sheepscot River at Wiscasset. The sub- merged thalweg of the St. Croix in Passamaquoddy Bay reaches a level of about -420 feet msl. The deposits in these valleys consist for the most part of glacial-marginal marine clay and silt separated from the bedrock by a thin discontinuous layer of till. The marine clay and silt reaches a maximum thickness of more than 100 feet. In the valleys of southern Maine the marine clay and silt are overlain unconformably by estuarine deposits that occur above erosional chan- nels. The lowest places on these channels reach at least -40 feet msl and possibly -90 to -95 feet msl. This unconformity either is not present or is not recognizable with existing data in the Penobscot valley, and the clays in the vicinity of Eastport do not seem to have been channeled at all. CONCLUSIONS The conclusions are divided into two main categories, corresponding to the main topics discussed in the re- port: (1) depths and origin of the bedrock thalwegs, and (2) . inferences drawn from the stratigraphy of the glacial deposits in the valleys, especially the uncon- formity at the base of the estuarine deposits. DEPTHS AND ORIGIN OF THE BEDROCK THALWEGS One of the objectives of the current study was to obtain an idea of the time of origin of the bedrock valleys and to ascertain their relationship, if any, to lowered sea level accompanying glacial stages or sub- stages of the Pleistocene Epoch. Table 6 shows the inferred depths of the thalwegs below sea level at the localities examined. - The significant depths are plotted for the entire coast on plate 4. Examination of the map shows that there is no obvious pattern for the thalweg depths along most of the coast. However, one or two general features are revealed. The depths on the Thames River in Connecticut (elev -190) on the Blackstone buried valley in the Narragansett Basin (eley -200) and the valleys in the Boston area (elev -250) are all within the same general range which may indicate that they represent a single general level of erosion. - However, the rough correspondence of depths may be simply fortuitious. At two places the thalweg elevations are substantially lower. One is Narragansett Bay where some elevations are around -350 feet msl level and the other in Passa- maquoddy Bay where elevations are a little lower than SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY -400 feet msl. A recent report by Woods Hole Oceano- graphic Institution (Hersey and others, 1961) indicates that bedrock thalweg elevations in the southern part of Narragansett Bay may be more than -400 feet msl. The bedrock in the outer part of Penobscot Bay is also more than -400 feet msl. These elevations are within a limited range, and an erosional level at -350 to -400 feet msl may be indicated. However, only in the Passamaquoddy Bay area is there indication that such a level is at all extensive longitudinally. Also, there is not enough information to show whether or not such elevations are a consistent feature of the whole coast. Most of the thalweg depths along the Maine coast are appreciably shallower. Even if the elevations at about -200 to -250 feet msl and at about -350 to -400 feet msl should repre- sent segments of erosional levels, such levels may reflect merely local base levels due to varying rock resistance. The depth of drowning of the bedrock topography, and variations in the depth are then largely an expression of the relative amounts of local erosion that preceded the drowning, and they are not controlled by a coast- wide base level such as sea level would be. Also, the amount of glacial erosion-by scour, plucking, or by subglacial streams-is not known. Although possible, it seems unlikely to the writers that the thalweg depths below sea level are wholly, or even in major part, the result of deepening by glacial erosion. More detailed studies of the longitudinal bedrock profiles might reveal critical evidence. Because of the lack of a consistent depth pattern, and 'because some of the isolated depths may be the result of appreciable glacial erosion, it seems that with present knowledge, the thalweg depths probably do not repre- sent positions of lower sea level accompanying glacial stages, and hence do not indicate the magnitude of eustatic lowering. Furthermore, the bedrock valleys, in general, have a veneer of Wisconsin till that extends down the valley sides and at many places appears on the valley bottoms. Unless, of course, the ice itself is the main agent of erosion, this relationship suggests that the valleys were already in existence before at least the Wisconsin ice reached the present coastal region. If these thalwegs, below sea level, are not related to eustatically lowered stages of sea level, the question arises as to why they are below sea level at all. The reason must be either that the crust is still recovering from Wisconsin glacial loading or that the crust itself has been warped downward during Pleistocene and Re- cent time. Consideration of this problem is outside the scope of this report. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS M37 TaBu® 6.-Inferred elevations of thalwegs of New England coastal bedrock valleys [Elevation: >, below indicated elevation] Locality Data . Inferred Minimum eleva- | Inferred | minimum Relative tion of bedrock | elevation | elevation compe- from well, test | of thalweg | of uncon- | Approximate tency of Bedrock or buried boring, or seismic | of bedrock | formity at | distance up- | bedrock: valley data valley base of stream from | resistant No. Shown on- Type Reference estuarine coast (miles) | (R); non- deposits resistant (N) Feet above (+) or below (-) mean sea level Coastal valleys of Connecticut Housatonic... 2 | Figure 1____| Cross section _______. Plate 1B... -115 -115 -65 5.8 | R ... do.........~... Plate 14 ._.. -92 -92 -43 6.6 | R Quinnipiac... 3 12 ;~ Q-: c seus Plate 1C___. -171 | > -280 -40 4.0 | N Connecticut.... 4 do....sl...s... Plate 1D.__. -182 -92 3. 5 | R DOs. irl cl. en ene nan Water welllat .-- > +100: 22.9 | R Maromas, in Middletown, Conn. _________ 6 |__.do._._-_..-] Cross section._..___.| Figure 2.___ -118 -120 -66 29.3 | N Thames........ 5 Plate 1E.___ -174 -190 -130 8.7 | R Narragansett Bay area Blackstone... 6 | Figure See table 3... > =115 {s... ..:. -40 15.0 | N Doree ese n Water wells in War-_|____________ -165-- 200 -200 16. 4-32. 5 | N wick, Providence, and Pawtucket, ? RL. Dou. lel Test boring for See figure 4. +28 +18 |.._._.._._. 38.4 | R bridge at Ashton, in Cumberland, RL Providence_____. 5 | Figure 3.:..:l-..l..s...il._.l.l.l.. See table 3__ ~>-820 | * -350 |_._.____._. 1.8 | N Do.......s. e ks ae we ces creak ana sn ius. J>-I188 |.....:. -110 12. 3 | N Do:..:..... o {r 0. =s reale den cn ea ... J>-168 |........ -85 18. 8 | N Taunton- 10 |- <2} -~.:..... 15. N Aberjona- O |< ere len ene ae naan ies a noe aan See p. M24 -170 -180 |...... 8.9 | N Fresh Pond in text Dol Water well in Win- |____..._.._. -145 =160. [-..--... 141 | R chester, Mass. Test well in Win~ -137 =-140 15.8 | R chester, Mass. ann Washington Street |____________ Er TO |_ 16. 2 | R over Aberjona River in Woburn, Mass. Malden..__.._. .._ 7 | Figure 6-___| Cross section-. ____. Plate 26.._.__ -212 -290 24. |N OE CA: c alo ae an clans s man ane als Mystic River Bridge |___________._ A 120 |« 5.7 | N oston. Dos lcs Revere Beach Park- |____________ A100 |. canes ale ln iew 7.1 I °N way over Malden River between Medford and Everett, Mass. f Malden... ._. 6 | Figure 6-_-__| Cross Figure 8.___ -193 195 |.._...... 9.3 | N DO.: reticle bre Water well in Mel -|.-__.____.__. A w40 10. 5 | R rose, Mass. 0... c isi ic asl 10 | -l. reece 2s 11.8 | R See footnotes at end of table. M38 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY TABLE 6.-Inferred elevations of thalwegs of New England coastal bedrock valleys-Continued [Elevation : >, below indicated elevation] Locality Data \ Inferred Minimum eleva-| Inferred | minimum Relative tion of bedrock | elevation | elevation compe- from well, test | of thalweg | of uncon- | Approximate | tency of Bedrock or buried boring, or seismic | of bedrock | formity at | distance up- | bedrock valley data valley base of stream from | resistant No. Shown on- Type Reference estuarine coast (miles) | (R); non- deposits resistant (N) Feet above (+) or below (-) mean sea level Vicinity of Portsmouth, N.H. Bellamy River.. 6A | Figure 1-___] Wash boring near See p. M28 -91. 5 -95 -36 10. 5 ? Scammell Bridge in text. for U.S. Route 4. Maine coast Presumpscot. .-- 8 | Figure 1____| Cross Plate 3B... -115 -130 -40 3. 1 4 Do..::....<% a.-... Plate 34... y=b0 -38 5. 9 ? Kennebec....... 10 }-:.do......._.... do.-.>>.=...==<- Plate 3D. .- -138 -140 5 -94 13. 0 Do:i~.-...% 9-& |;: «s- Table 5... -70 :- . 26.9 | R 9. {:..do......-. Cross section____.._.. Plate 3C.___. -76 -80 -10 43. 4 | R Sheepscot... 11 O..: Plate 3E.___. 4 -150 -160 -30 16. 0 Penobscot. ..... 13 ].._do....-.. Route | Bridge >-124 |>-124 |________ 38. 5 | R between Prospect and Verona, Maine. Do... ..: Seepage M31 Jp =100 45.2 | R in text. 12) Figure See table 5... - 48 40 |_c...... 59.1 | R St. Croix (Pas- 14... , ? samagquodd, -420 Bay. ¥ 1 See A. W. Quinn and others (1948); W. H. Bierschenk (1954, 1959). *See A. W. Quinn and others (1948). 3 From seismic reflection survey by + Figure is refusal depth; at most borings probably close to bedrock. $ At base of outwash or fluviatile deposits; may not be pre-estuarine unconformity. STRATIGRAPHY OF THE DEPOSITIONAL FILL The glacial deposits in the several valleys discussed in this report are highly varied and were deposited under different conditions in the different valleys. They are broadly correlative in the sense that they are all pleisto- cene, but they are not closely correlative. For example, certain deposits in the lower part of the section in the Boston Commons garage excavation were considered by Kaye (1961, p. B75) to be early Wisconsin or older. The outwash in the Connecticut valleys, though probably Cary, may be somewhat different in age from the ice-marginal clays along the Maine coast. And those clays themselves may be progressively younger northward, or those in eastern Maine may be younger than the others. A generalized comparison, not a cor- relation chart, is given in table 7. However, all the valleys except those in eastern Maine have an upper- most unit of estuarine deposits, and related peat, swamp, and marsh deposits, which rest unconformably on the underlying glacial deposits. Woods Hole Oceanographic Institution. Depths are preliminary because based on uncorrected velocity values. TABLE 7.-Generalized comparison of late Pleistocene and Recent deposits in bedrock valleys Maine coastal valleys Boston Basin area Connecticut | Narragansett | (after Judson, 1949 and Kaye, 1961) Southern Eastern (Bloom, 1959)| (Upson, 1954) Peat and marsh Estuarine Estuarine deposits Estuarine deposits deposits Marine silt deposits Peat Unconformity | Unconformity Lower sea level Uncen: formity “figmkm Iv Outwash outwash| of Outwash (Including | Erosion and lower Presumpscot | Ice-marginal marine (?) sea level formation marine clay and (Marine) clay and silt) silt Boston Clay (marine) (Clay III of Kaye) Thin outwash Ground Ground Boston Till (Also Ground Ground moraine moraine older clays and moraine moraine drifts of Kaye) In all the sections from southern Maine to Connecti- cut, the surface at the base of the estuarine deposits is curving, somewhat irregular, and convex downward. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS The low point on this surface at each of the localities studied is probably the thalweg of a pre-estuarine val- ley and is plotted on plate 5. The possibility that the pre-estuarine surface in the Connecticut valleys is not a surface of fluvial subaerial erosion has been previously mentioned (p. M13). It is also conceivable that the corresponding surface in Narragansett Bay is not of subaerial origin. However, the elevations in Narragansett Bay, as has been pointed out (p. M21), suggest a gentle seaward slope and in the same sense correspond to elevations in the valleys of the Connecticut coast. Thus, these elevations seem to fit a possible drainage system that could have ex- tended seaward off the eastern end of Long Island. The lowest point of this system would be at least -130 féet msl and perhaps somewhat lower. The elevations at Boston Harbor and farther north do not fit so obviously. They are north of Cape Cod, and hence were probably on a different drainage system, or systems, than those south of Cape Cod. However, they are all less than -94 feet msl and thus are of the same order of magnitude. Especially in southern Maine, where the channels occur on the marine clay and silt, which must have been deposited beneath the sea, the channels are not likely to be ice-block de- pressions, and exposure must have occurred after a decline of sea level with respect to the land. As stated previously (p. M35), evidence for an ero- sional interval seems to be lacking in the Passama- quoddy Bay area, and in general the unconformities may become increasingly shallow northward. If so, this gradation may signify that at the time of sea-level decline some northward-increasing crustal recovery was still to take place. The thalwegs of valleys formed at the time would have been initially shallower with re- spect to the lower sea level, and now, with full crustal recovery, would stand higher to the north. In extreme eastern Maine, the land may have been so deeply sub- merged that an eustatic decline of sea level was not enough to expose the land, thus accounting for the apparent absence of erosion there. It is possible, how- ever, that the whole coast was exposed to subaerial erosion at the same time. It is certainly reasonable to suppose that the estuarine deposits, representing evidently the last depositional episode in the coastal valleys, are approximately of the same age everywhere and were formed during a single rise of sea level along the whole coast. The underlying surface, on the other hand, may not be the same age every where, and may not have been formed in the same way everywhere. However, except possibly for the Boston area, it does seem to have been formed every- M39 where on glacial deposits of Cary age. In the Connect- icut valleys the outwash is considered to be of Cary age (Flint, 1953, p. 899) ; the Lexington outwash in the Boston area is said by Kaye (1961, p. B75) to be of Cary age; and MacClintock (1954, fig. 2, and p. 382) suggested that the uppermost drift in Maine is of Cary age. Therefore, if the pre-estuarine surface does repre- sent a general episode of erosion, this episode evidently is post-Cary in age and could correspond to lowered sea level accompanying the ice advance next younger than Cary, which would be of Mankato or of Valders age. (See Flint, 1957, p. 346-347; and Leighton, p. 847-550.) . Regardless of the detailed manner and exact time of formation of the pre-estuarine surfaces, the deposition of the estuarine deposits resulted from the rise in sea level which accompanied the waning and retreat of the ice in Recent and late Pleistocene time. Sea level was at least 130 feet lower than the present (as at the Thames River). According to radiocarbon dating, the retreat of the Valders ice began about 8,500 B.C. 10,500 B.P., Flint, 1957, table 20-B, p. 347). If the low point coincided with the beginning of Valders retreat, sea level rose at least 130 feet in 10,500 years, or at least 0.012 foot per year. Organic material near the base of the estuarine de- posits in the Quinnipiac valley at New Haven (see pl. 1C) at a depth of -30 to -31.5 feet msl has a carbon-14 age of 5,900 years +200 B.P. (Upson and others, 1964.) (Sample W-945.) This date indi- cates a much slower average rate of rise in the last 5,900 years. The estuarine deposits discussed in this paper pre- sumably have correlatives in the estuaries elsewhere along the Atlantic coast. Identification of the correla- tives south of the glaciated area, and especially the underlying erosion surfaces, might lead to more precise estimates of the rate of late or postglacial sea-level rise. Thus far, the estuarine deposits in the New England valleys would seem to be correlative of either unit C or D as defined by Hack (1957, p. 821, and figs. 4 and 5) in the Susquehanna valley system. REFERENCES CITED Alcock, F. J., 1946, Geologic map of Campobello sheet, New Brunswick: Canada Geol. Survey Map 964A. Allen, W. B., 1956, Ground-water resources of the East Green- wich quadrangle, Rhode Island : Rhode Island Devel. Coun- cil, Geol. Bull. 8, 56 p. Allen, W. B., and Gorman, L. A., Ground-water map of the East Providence quadrangle, Massachusetts-Rhode Island : Rhode Island Water Resources Coordinating Board, Ground Water Map 4. MA4O Allen, W. B., and Ryan, D. J., 1960, Ground-water map of the Fall River quadrangle, Massachusetts-Rhode Island : Rhode Island Water Resources Coordinating Board, Ground Water Map 7. Barghoorn, E. S., 1949, Paleobotanical studies of the Fishweir and associated deposits, in Barghoorn, E. S., and others, The Boylston Street Fishweir II: Andover, Mass., Robert S. Peabody Foundation, v. 4, p. 49-83. Bastin, E. S., 1912, in Barrows, H. K., and Babb, C. C., Water resources of the Penobscot River Basin: U.S. Geol. Survey Water-Supply Paper 279, p. 11-12. 4 Bastin, E. S., and Williams, H. S., 1914, Description of the East- port quadrangle [Maine]: U.S. Geol, Survey Geol. Atlas, Folio 192. Bierschenk, W. H., 1954, Ground-water resources of the Bristol quadrangle, Rhode Island-Massachusetts: Rhode Island Devel. Council, Geol. Bull. 7, 98 p. 1959, Ground-water resources of the Providence quad- rangle; Rhode Island: Rhode Island Water Resources Co- ordinating Board, Geol. Bull. 10, 104 p. Billings, M. P., 1929, Structural geology of the eastern part of the Boston Basin: Am. Jour. Sci., v. 18, no. 104, p. 97-137. Bissell, M. H., 1925, Pre-glacial course of the Connecticut River near Middletown, Conn., and its significance: Am. Jour. Sci., ser. 5, v. 9, no. 51, p. 233-240. Bloom, A. L., 1959, Late Pleistocene changes of sea level in south- western Maine: Office of Naval Research duplicated rept., 148 p. Brown, J. S., 1925, A study of coastal ground water, with special reference to Connecticut: U.S. Geol. Survey Water-Supply Paper 537, 101 p. 1928, Ground water in the New Haven area, Connecticut : U.S. Geol. Survey Water-Supply Paper 540, 206 p. Chute, N. E., 1959, Glacial geology of the Mystic Lakes-Fresh Pond area, Massachusetts: U.S. Geol. Survey Bull. 1061-F, 216 p. Clapp, F. G., 1901, The geological history of the Charles River in Massachusetts: New England Water Works Assoc. Jour.. v. 53, no. 3, p. 872-383. Crosby, I. B., 1922, Former courses of the Androscoggin River : Jour. Geology, v. 30, no. 3, p. 232-247, 5 figs. 1937, Ground-water conditions of parts of Middlesex, Worcester, and Norfolk Counties in the buried valleys of the preglacial Merrimack, Sudbury and Charles Rivers: Massachusetts Dept. Pub. Health Ann. Rept. year ending Nov. 30, 1937, Commonwealth of Massachusetts Pub. Doc. 34, p. 219-224. 1939, Ground water in the pre-glacial buried valleys of Massachusetts: New England Water Works Assoc. Jour., v. 53, no. 3, p. 372-383. Crosby, W. O., 1899, Geological history of the Nashua Valley dur- ing the Tertiary and Quaternary periods: Technology Quart., v. 12, p. 288-324. 1903, A study of the geology of the Charles River estuary and the formation of Boston Harbor: Boston Rept. of the Comm. on the Charles River Dam, p. 345-369. Cushman, R. V., 1960, Ground water in north-central Connecti- cut : Econ. Geology, v. 55, p. 101-114. Denny, C. S., 1956, Wisconsin drifts in the Elmira region, New York, and their possible equivalents in New England : Am. Jour. Sci., v. 254, p. 82-95. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Ewing, John, and others, 1960, Sub-bottom reflection measure- ments on the continental shelf, Bermuda Banks, West Indies Arc, and in the West Atlantic Basins: Jour. Geophys. Re- search, v. 65, no. 9, p. 2849-2859. Ewing, M. E., and others, 1960, Revised estimate of Pleistocene ice volume and sea level lowering [abs.] : Geol. Soc. America Bull., v. 71, no. 12, p. 1860. Fairbridge, R. W., 1958, Dating the latest movements of the Quaternary sea level: New York Acad. Sci. Trans., ser. 2, v. 20, no. 6, p. 471-482. Flint, R. F., 1930, The glacial geology of Connecticut: Connecti- cut Geol. Nat. History Survey Bull. 47, 294 p. 1933, Late Pleistocene sequence in the Connecticut Valley : Geol. Soc. America Bull., v. 44, p. 965-988. 1953, Probable Wisconsin substages and late-Wisconsin events in northeastern United States and southeastern Can- ada : Geol. Soc. America Bull., v. 64, p. 897-920. 1956, New radiocarbon dates and late-Pleistocene stra- tigraphy : Am. Jour. Sci., v. 254, p. 265-287. 1957, Glacial and Pleistocene Geology: New York, John Wiley & Sons, Inc., 553 p. Foerste, A. F., 1899, Geology of the Carboniferous strata of the southwestern portion of the Narragansett Basin, with an account of the Cambrian deposits, in Shaler, N. S., and others, Geology of the Narragansett Basin: U.S. Geol. Sur- vey Mon. 83, p. 223-895. Goldsmith, Richard, 1960, Surficial geology of the Uncasville quadrangle, Conn.: U.S. Geol. Survey Geol. Quad. Map GQ-138. 1962, Surficial geology of the New London quad., Conn.- N.Y.; U.S. Geol. Survey Geol. Quad. Map GQ-176. Goldthwait, Lawrence, 1951, Marine clay of the Portland- Sebago, Maine, region: Marine State Geologist Rept., 1949- 50, p. 24-84. Hack, J. T., 1957, Submerged river system of Chesapeake Bay : Geol. Soc. America Bull., v. 68, p. 817-830. Hahn, Glenn W., 1959, Ground-water map of the Narragansett Pier quadrangle, Rhode Island: Rhode Island Water Re- sources Coordinating Board, Ground Water Map 5. Halberg, H. N., and Pree, H. L., 1950, Ground-water resources of the Greater Boston area, Massachusetts: Boston Soc. Civil Engineers Jour., v. 87, no. 2, p. 204-230. Halberg, H. N., and Roberts, C. M., 1949, Recovery of ground- water supplies by pumping from water-table ponds: Am. Geophys. Union Trans., v. 30, p. 285. Hersey, J. B., Nalwalk, A. H., and Fink, D. R., 1961, Seismic reflection study of the geologic structure underlying south- ern Narragansett Bay, RI.: Woods Hole Oceanographic Inst., duplicated rept., no. 61-19, 24 p. 16 figs., 21 pls. Hitchcock, C. H., 1874, The geology of Portland: Am. Assoc. Advancement Sci. Proc., pt. 2, p. 163-175. Esa, 1955, On the Pleistocene geology of southeastern New England: Geologinen Tutkimuslaitos, Comm. Geol. Finland Bull. 167, 225 p. International Passamaquoddy Engineering Board, 1959, Investi- gation of the International Passamaquoddy Tidal Power Project, Report of the International Joint Commission: Washington, D.C. and Ottawa, Ontario, app. 1, 11 p., and app. 2, 58 p. Jahns, R. H., 1947, Geologic features of the Connecticut Valley, Massachusetts, as related to recent floods : U.S. Geol. Survey Water-Supply Paper 996, 158 p. Johnson, D. W., 1931, Stream sculpture on the Atlantic slope: New York, Columbia Univ. Press, 142 p. BEDROCK VALLEYS OF NEW ENGLAND COAST AS RELATED TO SEA-LEVEL FLUCTUATIONS Johnson, K. E., and Marks, L. Y., 1959, Ground-water map of the Wickford quadrangle, Rhode Island : Rhode Island Wa- ter Resources Coordinating Board, Ground Water Map 1. Johnson, K. E., 1962, Ground water map of the Rhode Island parts of the Attieboro, Blackstone, Franklin, Oxford, and Uxbridge quadrangles: Rhode Island Water Resources Co- ordinating Board, Ground Water Map 19. Judson, Sheldon, 1949, The Pleistocene stratigraphy of Boston, Massachusetts, and its relation to the Boylston Street fish- weir, in Barghoorn, E. S., and others, The Boylston Street Fishweir II: Andover, Mass., Robert S. Peabody Founda- tion, v. 4., p. 7-48, and fig. 1. Katz, F. J., 1913, Clay in the Portland region, Maine: U.S. Geol. Survey Bull. 530, p. 202-206. Kaye, C. A., 1961, Pleistocene stratigraphy of Boston, Massa- chusetts, in Geological Survey Research 1961: U.S. Geol. Survey Prof. Paper 424-B, p. B-73-B-76. Krynine, P. D., 1950, Petrology, stratigraphy and origin of the Triassic sedimentary rocks of Connecticut: Connecticut Geol. Nat. History Survey Bull. 78, 247 p. La Forge, Laurence, 1932, Geology of the Boston area, Massa- chusetts : U.S. Geol. Survey Bull. 839, 105 p. Lee, F. W., and others, 1940, The seismic method for determining depths to bedrock as. applied in the Lowell quadrangle, Massachusetts: Massachusetts Dept. Pub. Works-U.S. Geol. Survey Coop. Geol. Proj. Spec. Paper 3, 46 p. Leighton, M. M., 1960, The classification of the Wisconsin glacial stage of north-central United States : Jour. Geology, v. 68, no. 5, p. 529-552. MacClintock, Paul, and Richards, H. G., 1936, Correlation of late Pleistocene marine and glacial deposits of New Jersey and New York: Geol. Soc. America Bull., v. 47, p. 289-338, 2 pls., 5 figs. MacClintock, Paul, 1954, Leaching of Wisconsin glacial gravels in eastern North America : Geol. Soc. America Bull., v. 65, p. 369-384. Oliver, J. E., and Drake, C. L., 1951, Geophysical investigations in the emerged and submerged Atlantic coastal plain, pt. 6, The Long Island area: Geol. Soc. America Bull., v. 62, p. 1287-1296. ' Pearsall, C. S., 1937, Report on the geological features along the Pressure Tunnel in Special Report of the Metropolitan Dis- trict Water Supply Commission and Department of Public Health relative to improvements in distribution and to adequate prevention of pollution of sources of water supply of the Metropolitan Water District: Commonwealth of Massachusetts, House Doc. no. 262, app. D, p. 174-183. Perkins, E. H., 1927, The evolution of the drainage of the Water- ville region (Maine) : Am. Jour. Bei., ser. 5, v. 14, p. 852- 364. Perry, S. C., and Alcock, F. J., 1945, Geologic map of St. George sheet, Charlotte County, New Brunswick: Canada Geol. Survey, prelim. map 45-1. Quinn, A. W., 1953, Bedrock geology of Rhode Island : New York Acad. Sci. Trans., ser. 2, v. 15, p. 264-269. M41 Quinn, A. W., and Oliver, W. A., 1962, Pennsylvanian Rocks of New England in Pennsylvanian System in the United States : Tulsa, Okla., Am. Assoc. Petroleum Geologists, p. 60-73. Quinn, A. W., and others, 1948, The geology and ground-water resources of the Pawtucket quadrangle, Rhode Island: Rhode Island Port and Indus. Devel. Comm., Geol. Bull. 3, Ground Water Map. Roberts, C. M., and Brashears, M. L., Jr., 1945, Progress report on the ground-water resources of Providence, RI.: Rhode Island Port and Indus. Devel. Comm., Bull. 1, 35 p. Rodgers, John, and others, 1956, Preliminary geologic map of Connecticut: Connecticut Geol. Nat. History Survey Bull. 84. Schafer, J. P., 1961, Surficial geology of the Wickford quad- rangle, Rhode Island : U.S. Geol. Survey Geol. Quad. Map GQ-136. Sharp, H. S., 1929, The physical history of the Connecticut shore line: Conn. Geol. Nat. History Survey Bull. 46, 97 p., 29 figs., 8 pls. Smith, J. H., 1955a, Surficial geology of the East Greenwich quadrangle, Rhode Island: U.S. Geol. Survey Geol. Quad. Map GQ-62. 1955b, Surficial geology of the Bristol quadrangle and vicinity, Rhode Island-Massachusetts: U.S. Geol. Survey Geol. Quad. Map GQ-70. Smith, J. H., 1956, Surficial geology of the Providence quad- rangle, Rhode Island : U.S. Geol. Survey Geol. Quad. Map GQ-84. Smith, W. O., 1958, Recent underwater surveys using low- frequency sound to locate shallow bedrock: Geol. Soc. America Bull., v. 69, no. 1, p. 69-98. Smith, W. O., Upson, J. E., and others, 1952, Preliminary re- port on the Passamaquoddy bedrock survey-July-August 1951: U.S. Geol. Survey open-file rept., 49 p., 23 figs., 10 pls. Swarzenski, W. V., 1963, Hydrogeology of northwestern Nassau and northeastern Queens Counties, Long Island, New York: U.S. Geol. Survey Water-Supply paper 1657. (In press). Tuttle, C. R., Koteff, Carl, and Hartshorn, J. H., 1960, Seismic investigations in the Connecticut River Valley, southern Massachusetts: Geol. Soc. America Bull., v. 71, no. 12, pt. 2, p. 1994. U.S. Army Corps of Engineers, 1957, Hurricane Survey, Interim report, Narragansett Bay area, Rhode Island, Massachu- setts: Boston Mass., unpublished report, 74 p. plus ap- pendices. Upéon, J. E., 1949, Late Pleistocene and Recent changes of sea level along the coast of Santa Barbara County, California : Am. Jour. Sci., v. 247, p. 94-115. 1954, Terrestrial and submarine unconsolidated de- posits in the vicinity of Eastport, Maine: New York Acad. Sei. Trans., v. 16, no. 6, p. 288-295. Upson, J. E., Leopold, E. B., and Rubin, Meyer, 1964, Post- glacial change of sea level in New Haven Harbor, Con- necticut: Am. Jour. Sci., v. 262, p. 121-132. Woodworth, J. B., 1896, The retreat of the ice sheet in the Narragansett Bay region: Am. Geologist, v. 18, p. 150-168, 891-392. A Page RUH GC. +- 10+ enc cee nave eo. Mis ADCNJORRAIMVET Y-...» .o s ibs 22, 23 Aberjona-Fresh Pond buried valley. 22, 88, 28 Acknowledgments.... ANHUVIUMZ £. /-1- sre A -- cdb bes 35 Androscoggin River. 2 Aquidneck Island...._..........__... ss «696 Augusta, 34, 35 B BARGOF, cabe, 31 Barghoorn. 'E. S., quoted..........._...._.... 28 BATTINETOUN MBS. 20 Basal Pennsylvanian metasediments.. 18 Bat) : ~- 30 35 Bedrock DrORIGS. e- 30 Bedrock thalwegs, depth of.. 6, 15, 23, 30, 36 ecs cond» 86 Bedrock valleys, buried.........._.._..__._.. 8 CORRBEUPRLION: 222200 200000000 20022 evans e . 5 20s sess et 4, 21 dures 5 formation... 4 MAINGCICORSb.... .... cc. cesses 29, 36 -c 20 Portsmouth, 28 Presumpscof 29, 31 Frovidence.........._......_. .. 18, 16, 18 $t.Crolx.......... -- 20, 30, 31 Sheepscot. ...... i.. 20 summary of data. . z 15 Taunton-Sakonnet. -.. 18,18 Bellamy River...... * 28 Berlin lake clay. R 12 BIDHOGTADHY-s cerccco- co cen cone 39 DIACK _ ceo 18 Blackstone bedrock valley. Borings, Connecticut Turnpike bridge........ 7 Raymond E. Baldwin Bridge. 8 State Route 15 Bridge.... 7 U.S: Route Ibridge......:............... 10 Washington 7 Boston area, Massachusetts buried valleys.... 4, $1 Boston 3, 21, 28, 37 buried ¥AllGY6:1 0. 211 IIE. 28 Boston 24, 27, 28 Boston Commons garage excavation.......... 38 Boston 21, 22, 24, 39 Boston Till... ...... Cary glacial stade, events of. .c rece Cataclastic granite gneiss. ........___________. Charles buried valley.................. 23, 24, 27, 28 INDEX [Italic page numbers indicate major references] Page RIVET. - » « seres ade ces Mx¥1, 27 ...... 10, 12, 19, 24, 33, 36, 38 Coastal plain deposgite........_............_._ 3 CODSCOOKE BAY :c. :n 31 Conanicut 16 Conclusions. ..... 36 Conimictit 18, 19 Connecticut coastal valleys. ...._..._.__... 5, 18, 37 Connecticut River........__....__...:.. 5, 8 Connecticut State Highway Department. 5 Connecticut Valley Lowland.......___...... 3 5, 8 Cranston, R.1......._.... 15 Crogby, W. O., tited .. ... 22 D DSS; Of} +2 e 6 Davis Island... 31 Deer Island ... a 24, 27 Dover, N.H 28 30 Dudley Island .-..... .... code 34 E Bast Haddam; Conti. . .._... East Hartford, Conn.. Eastport, Maine.. .. Frogion, @ladial-.__.:__.__:............. 4, 24, 33, 36, stream ece 4 Estuarine deposits.... ..._......._... 4, 10, 11, 13, 18, 20, 21, 27, 28, 29, 33, 34, 35, 36, 38, 30 F Fairchild Aerial Surveys sonoprobe............ 33 Fall RIVET .... 18 Fall Zone 3 FANG. os- seas s Fil.. 5, 88 Fluviatile deposits............. - 13, 21, 33 Fore Fore River bridge. < 85 Fore River estuary. ... s 30 .. . .. .cc 44, 28 G Geologic setting, general.. Glacial deposits. ........ 4, 21, 38, 39 Glaciolacustrine deposits. .. Goldsmith, Richard, quoted. HLOUSALONIC RIVEF. -: o... .e een oo 5 7,10 Housatonic valley........._.-...ccll....l...l 10,11 Hughes, Edw. F. 022000 cee. .... 35 I Ice-contact depogits........................._. 12 Ice movement 33 IgnoOUs FOCK®: .. cools uc 3, 18, 21, 24, 31 Page TAfrOGUCHION . . : ..: : . coon Cece ie en Mi Investigation, method of.....___...._......... 2 .. . - .so 1 . o. sous 2 1 J Jamestown 16 K Kennebec bedrock valley..................... 20, $0 RIVET. 2, 30 Kennebet Valloy.-..-1 :.. os 33 L Lacustrine deposits........_.....__._______ 12,18, 27 Lake Sudbury.... 27 Lexington outwagh..........___..._.... 24, 27, 28, 39 Limestone rock...... 18 Logs Of eres. 7, 8, 24, 35 M Maguire, Charles A., and Associates.......... 20 Malden buried valley. 24, 27, 28 Maldon 24 MAIGden RIVET - .. ci 21, 24 Mankato glacial stade. Marine deposits. .... RIVET. .¢.. - 22 Merrimack-Mystic Valley. 23 Merrymecting Bay.-.:..._ci:cl.cclllclll.... 30 Metamorphic rocks..._..._..__.._._..__._.. 3, 21, 24, 290 Metasedimentary rocks........._....._...... 13,18 Metropolitan District Water Supply Com- : eer ce eee viene 23 12 Middletown, 8,11 Middletown-Portland Bridge........_........ 8, 12 Moosehead Lake._._..._.._..... =. 80 Mount Hope Bay......... s 18 Mount Hope Bay Bridge ah c 38 MYSHC-BIVEF-.... ...... .._ 21, 22 N Narragansett Basin....._..._.......... 3, 13, 16, 21, 36 Narragansett Bay.... 13, 15, 16, 19, 20, 21, 34, 36, 37, 39 Neponset River. .. 21 New Haven, Conn..._._.._._... - > B New Haven Harbor............. a 2 New London, Conn. = 11 New Pond.......:..... 15 Newark Group.......... 5 Northern Border Fault.................... (21, 24, 28 \~O 'OFERRIC IBEGTIAL . .. 2... eee ines 39 OUEWAGH . . .. o. och e needed ie lan sree 10,12, 13, 15, 18, 20, 21, 24, 27, 33, 34, 35, 38, 39 P Passamaquoddy Bay.............. 2, 30, 31, 35, 36, 39 Passamaquoddy Tidal Survey................ 33 M43 M44 Page PaWEUCKt, RL. M15 ... cs 11, 28 Pennamaquan 31 Pennamaquan River valley. ...........~----- 31 PeNObSCOt BAY. 31, 36 P enobscot valley. Portsmouth, N.H......-- Portsmouth-Tiverton Bridge...............-- 20 Presumpscot buried valley. ........------- 30, 33, 34 Presumpscot Formation .. 35 Presumpscot River... 30 Prospect-Verona 31, 34 Providence, RI.... . 15,18 Providence River.... 16 Prudence 20 Q Quinnipiac 2, 3, 5, 8 Quinnipiac valley. ..........._.....__~.----«-- 11 QUONS@t 16 R Radiocarbon dating. .._....................-- 39 Raymond E. Baldwin Bridge. 5 Red 12 Rhode Island Sound..........- 18 Rhode Island State Route 138 bridge. ...... 18 INDEX Page River M12 Rocks, crystalling...._.._...........~«~.----- 5 8 St. Croix buried valley......................- 34 St. CrOiX River. 33 SaKORNGt River. 18 SANG. 12, 24, 20 Scammel Bridge.... 28 SeDAEO 30 Sections, location of...... as 5 Sedimentary rocks....... - 13, 21, 31 Triassic...... a § / Seekonok River. .......--- - 13, 16 Shale argillite. . ......----- s. Sheepscot River. - 31, 35 Sheepscot valley.........--~--- e 34 we. B0 _ 24, 29, 33, 36 South Branch Marsh River........---------- 31 SDY 24, 28 Stratigraphic correlations...........~--------- 3 SHTAtIGTADRY. . . . 5,38 Stroudwater River....___......-.--- S 30 Sudbury River.... 23 Swamp 12 T 'TAUNtON, 13 'TESt DOFIMGS............_____.____««_--«««««~~ 18, 23 Page Thames River........__.._____...__...«.«... M5, 10 Thames 11 Tidal marsh deposits. 13 2, 4, 10, 12, 13, 18, 20, 24, 27, 33, 34, 36 Tiverton Bridge......_._...___...__...._..... 20 Treat Island.... 34 Triassic rocks. 3 U Unconformity. ......._...._....._.cc....., 11,19, 36 Unconsolidated deposits.... 2, 4, 8, 10, 18, 21, 24, 28, 33 U.S. Army Corps of Engineers...........---- 33, 34 v Valders glacial stade....................------ 39 VOICAMIG 21 w Wallingford, 8 WArWitk, RI. 15,16 Well OAA. . ...... 24 Western Passage.. - 31,33 WOORSOCKet, 16, 21 Wiscasset, Maine..._..._.._._..-.......-«---- 35 Wisconsin glacial stage. . 36 Wisconsin 36 Wisconsin till....._........_...___...._..._-- 36 Woods Hole Oceanographic Institution...... 18, 36 U.S. GOVERNMENT PRINTING OFFICE : 1964 . O-723-774 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-M PEATE 1 40" 7 40" fm: 40 ao * SEA SEA LEVEL LEVEL SEA SEA LEVEL LEVEL 40" 40! 40° 40: 8o' 80" so' Bol 120' 120' 4. HOUSATONIC-RIVER AT STATE: ROUTE 15 NEAR B. HOUSATONIC RIVER AT CONNECTICUT TURNPIKE, BETWEEN MILFORD. CONNECTICUT LOCALITY: 1 STRATFORD AND MILFORD; CONNECTICUT. LOCALITY 2 C Fe © w E wee . " 80' - f 40 4 #. = 5 42 PV © E SEA 10.4% 3 ng C j‘ 40° LEVEL <: S9 . & SEA SEA 40" LEVEL LEVEL S9 aoh l - chess. - 1) ve ops Nares i Tams Ate 1 s, 100 i e ia one ae fe ces s d aro oral as lg 120" go' - $4 Se 160 4 Bedrpck not penetrated T ; 17 - 160" 120% Bedricfilcrhnga iitiitgted ( 13p in these borings Till VO§ C. QUINNIPIAC RIVER AT CONNECTICUT TURNPIKE IN D. CONNECTICUT RIVER AT RAYMOND E. BALDWIN BRIDGE (US ROUTE 1). NEW HAVEN, CONNECTICUT. LOCALITY 3 OLD SAYBROOK, CONNECTICUT... LOCALITY 4 EXPLANATION 40 mate Fill or "made land" Outwas te. Mainly fine. to. medium sand with % f. c g. varying amounts of gravel and LEVEL REVEL LI 3 - some silt and clay Estuarine deposits v S 40' - AQ" Mostly mud or soft sand with some silt and sand. Locally contain plant Bedrock remains and shells, as shown 80 - ~ 80° dares Orientation of all sections is about west to east. °;°J-°_1(3-4 Localities of cross sections are shown in Til figure 1. Numbers of boreholes are those f hi 120" 4 120 Hard sa.nd and gravel or boulders; some SgréedcrflTSS of ageney for which -borehgles silt or clay at most borings 160" - "160" 72 g Numbers identify units described in text; queried names are used where identification is un- Peat or woody material certain 200" 200' E. THAMES RIVER ROUTE I., NEW LONDON, CONNELTICUT-EOCALITY: 5 CROSS SECTIONS OF BEDROCK VALLEYS OF COASTAL CONNECTICUT 400 0 400 800 £200. FEET mq == r I & 100 0 100 200 300. METERS m- rm 723-774 O - 64 (In pocket) NITED STATES DEPARTMENT OF THE INTERIOR PROFESSICSEQEEEPQPER 454-M GEOLOGICAL SURVEY r 80' - 80 160" £ § 160 « i > $ | C prat so SEA LEVEL =- SEA LEVEL go' g of. iss | &D BEA LEVEL SEA LEVEL 80' -+- so" 80 ' € os > |- 80" 160" 7 160" Borings projected to \ Borings projected to line of section line of section tes, \ | | 160' 240" b- i 240" | 1 I 1 1 1 AND NEWTON, LOCALITY 1 CAMBRIDGE, LOCALITY 2 EXPLANATION UWitimin Fill Estuarine deposits Mainly silt and sandy silt with some clay and peat; contain salt-marsh deposits at places 80' r 80" Peat anmemains SEA LEVEL SEA LEVEL tear: 2g Outwash c .80" Mainly sand with some gravel and boulders; minor clay and silt. Includes some estuarine deposits locally 160' 160" Marine clay 240' U @ S809 Soft to stiff gray clay, silt, or silty clay; some fine sand and scattered pebbles 320' J , : , 320' 1 I I I 1 I C. CHARLES BURIED VALLEY IN BOSTON, LOCALITY 3 Gravel or boulders and sand, at places compact; with various amounts of clay and silt I5 Bedrock Numbers identify units described in text; queried Note difference in scale in plates 1 and 3. names are used where identification is un- Sections are oriented about west to east or certain south to north. Localities of cross sections are shown by number on figure 6 805 c 3 & 3. '@ <% -'~§ § & & 807K C3 in t ee . & ~ 9 gr 80° TOU cou f as I IC I "IC © "~I: xr 1 C SEA LEVEL MLL f Mrs : SEA LEVEL i is 5:7 g' - i g‘ Fat §$g S B 0% T. O'N Z A =- mA RB OR 2.2 r - A main SEA LEVEL ep *l-y>/- SEA LEVEL 8o' - so- 80' - 160" L mep! \ > 16057 \ |- 160" 240" - a ze f 240 N 240' - Borings projected to \ - 240" line of section 320° 320 D. CHARLES BURIED VALLEY AT COLUMBUS PARK, 4 I BOSTON, LOCALITY 4 E. MALDEN BURIED VALLEY IN BOSTON HARBOR, LOCALITY 7 CROSS SECTIONS OF THE CHARLES AND MALDEN BURIED VALLEYS IN THE BOSTON AREA, MASSACHUSETTS 800 0 800 1600 2400 FEET m= m I = ee === 200 0 200 400 600 METERS T235774 O - 64 (In pocket Es- 4 F--- TED STATES DEPARTMENT OF THE INTERIOR 80 ~-, 40" 7 GEOLOGICAL SURVEY 80' 40" SEA SEA LEVEL 40' - 40" 40' 7 - 40" JEA LEVEL 40" 8o' 120 40' > l- ag" |-<80' g» 120' LEVEL SEA LEVEL PROFESSIONAL PAPER 454-M PLATE 3 120" p 120 8so' go' 401 40 SEA LEVEL SEA LEVEL 40' 40" so' 80" C. KENNEBEC RIVER AT MEMORIAL BRIDGE, US ROUTE 202, IN AUGUSTA, LOCALITY 9 st SEA LEVEL fl SEA LEVEL «-d 3 Q Wood ? z* 80' i- 80° 120' - 120' Borings projected to line of section 160" 160" B. PRESUMPSCOT BURIED VALLEY AT VETERANS MEMORIAL BRIDGE OVER FORE RIVER, sOUTH PORTLAND, LOCALITY 8 44 +56 D). KENNEBEC RIVER AT US ROUTE 1 BETWEEN BATH AND WOOLWICH, LOCALITY 10 EXPLANATION 40" 47 +31 48 +75 49 +87 50 +63 52+19 54+52.5 56+67 SEA LEVEL 120- 40" 8o' 120' 160" 160" E. SHEEPSCOT RIVER AT US ROUTE 1 BRIDGE BETWEEN WISCASSET AND DAVIS ISLAND, LOCALITY 11 00 3 + C f??? ENEL Fill exe Estuarine and fluviatile deposits Mud, soft mud, or silt; fluviatile sand and gravel along Kennebec River may be outwash;scat- tered shell fragments, some wood 5g. Marine clay Blue or gray clay and silty clay; locally contains sand in basal part Numbers identify units described in text; queried names are used where identification is un- certain CROSS SECTIONS OF BEDROCK VALLEYS ALONG THE MAINE COAST 400 0 400 800 1200 FEET 100 0 100 200 300 METERS Outwash Fine to coarse sand, some silt, and, at places, gravel in various amounts Mainly compact gravel or sand and gravel; locally contains clay. Described as "hardpan" in some borings ss Bedrock Bedrock surface based mainly on refusal depths Sections are oriented about southwest-north- east. Locality numbers are those given in figure 1 723-774 O - 64 (In pocket) OOOOOOOOOOOO PAPER 454-M PPPPPP 7 //////////////7 F Ff F 4/ I ///%/////////??//;// /////////7//¢/ T f/ 7 // 5 7 f T T /// // // P 7 I W T P F a 7 W /7/ é/ t aar JV d F 66°00' " 7 TIT o T Pf / ¥ 7/ W ///7f'4f5//// P r N2 ) W // ////////////Z////{f///j// EASTEO/RT GGP / 7 T I /// 4 I STL LIZ T T »La ACEC waa yg /%/é// 7 p J A P 4 23" M, // /A" ' z a Piscataqua K - Kennebec eeeeeeeee / - 6 / 7 4 lf/ 160 I ) RZ 00" f * "*~G RRRRRR , AS FoLLows: 7 }%Z/’% 2 7 w?" H - Housatonic , £4. | Q 811mm?“ t P P // P LAfi/D { 3g 0 $ nnnnnnnn 7 / 7 7 TTTTTT WY W H Ly E y /;/ /////////;// - ////;; 65, V/ _ _ ___ T PROVIDENCE L A00 | 3 & 0 8C Crape Bay) T IP l o & 8 / 60° 300\ jw 10°00. 66°00 00 MAP OF THE NEW ENGLAND COAST SHOWING ELEVATIONS OF THALWEGS )F BEDROCK VALLEYS PROFESSIONAL PAPER 454-M | GEOLOGICAL SURVEY EXPLANATION 74°00" UNITED STATES DEPARTMENT OF THE INTERIOR T NT /// T T S \ A Ww & R 40 _L. Lowest elevation of the estuarine deposits _ In feet below mean sea level; bar shows S S S S //// ///wP,/ \ | location of section // S S \ f 7 / Z Lf TF W 7 J T F 7 7 7 waoo/ Ocean-bottom contour In feet below mean low water; contour interval. 800 feet RIVERS, AS FOLLOWS: LETTER s¥yMBOLs besicnatE. [/ F' Fore River (Presumpscot buried valle H- Housatonic Q Quinnipiac C - Connecticut T - Thames Pa Piscataqua K- Kennebec S . Sheepscot Pb Penobscot S °O0' @] 0 o C A 0 66°00 70°00" 74°00 Base and contours from USC&GS chart 1000 MAP OF THE NEW ENGLAND COAST SHOWING ELEVATIONS OF THE THALWEGS OF PRE-ESTUARINE VALLEYS 723-774 O = 64 (In pocket) ¢£75 L Z6 p roos o Miocene Floras from Fingerrock Wash Southwestern Nevada GEOLOGICAL SURVEY PROFESSIONAL PAPER 454 -N Miocene Floras from Fingerrock Wash Southwestern Nevada By JACK A. WOLFE SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N Description of fossil plants from the southern Great Basin, with emphasis on their significance to phytogeography and floristic evolution UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page | Systematiecs-Continued Page - "ro- nen cunt dant ahd k a aie uns N1 Class N16 Introduction 1 Subclass Monocotyledones. 16 Geologic 1 Order glumiflor l 16 Floral composition and interpretation _ _ _ ______________ 3 Subclass chotIy 16 FingerrOCK fIOP&. c c cc. 4 Order _ 16 8 jags M Order Garryales- 19 Systematic list of the Fingerrock flora. ________ 4 rger yaies om r e W 5 Order Juglandales_____LL________________ 20 Po « s Order Fagales-___LLLLLLLLLLLLLLLLLLL___ 20 Floristic relationships. LL _________LLLLL______ 5 rger 8 . Order 22 Stewart Spring T Order 23 Systematic list of the Stewart Spring flora. ___ 7T Order ROSAI$. 23 con?" 951t10n 7T Order Sapindales- L 28 Floristic relationships L L _ _L_________________ 9 Order 30 Floral provinces in the Barstovian..______________ 10 Order 30 12 Order 31 SySb@MAtiG§ 13 Incertae sedigc c 81 Class 14 | References cited 32 Order 14 | 33 ILLUSTRATIONS [Plates 1-12 follow index] PratEs 1-5. Fingerrock flora. 6-12. Stewart Spring flora. Page Fraurm 1. Index map of the Fingerrock WASh N2 2. Composite stratigraphic section of part of the Tertiary rocks on the west flank of Cedar Mountains.______ 3 3. Distribution map of Picea breweriana, Quercus chrysolepsis, and Chamaecyparis nootkatensis_______________ 9 4. Sketch map of the Great Basin showing location of some Neogene 11 l oo 14 oi O o 16 7-12. Marginal venation of- T. 22020 e 0020 enne neenee enne ene eee nene eee ee ene eee nee ee ee eee eee ee ee 17 o 19 O. cc lenee nene neenee nene neenee neenee nene eee e eee ee eee nene eee 20 o 21 11. beeen ee 24 12. 000000000000 0000000000 en eee nene neenee ee ee en eee ee ee ene nen en noi. 25 13. Distribution map of fO8Sil CERCOC@FDPUS-_ ___ ccc cc ccc. 26 14. Marginal venation Of 000000 26 15. Venation Of cece ccc ccc. 27 16. Distribution map of fo§Sil LYOMOIR@GMMUS- _L 2222 2222222222222 ccc 00002 27 17-20. Marginal venation of- 17. eee 27 a oo 28 19. WOCMMMSL 2200000000000 0000000 eee nene nee eee en neenee neenee eee eee eee eee e 29 pe b O o 29 21. Apical venation Of 2222222222222 ccc cnc ccc nn een cence 30 22. Marginal venation Of _c ccc eee 31 TABLES Page TaBur 1. Numerical abundance of FiNG@PrOCK _ ccc nene enne nene ene enne nnn enne. N5 2. Numerical abundance of Stewart fOSSil$ . _ _ 2222222222222 cc cnn nnn nnn nen nnn nnn nnn nn nnn 22 7 3. Comparison of relative abundance of spruce, live oak, and cedar in the Nevada Barstovian and Clarendonian cnn lll enne lenee nn nnn nnn nee eee ee ee eee 8 4. Correlation of some Neogene floras of the Great 13 III SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY MIOCENE FLORAS FROM FINGERROCK WASH, SOUTHWESTERN NEVADA By Jack A. Wours ABSTRACT Two floras of Miocene age, the Fingerrock and Stewart Spring, are found in a stratigraphic section that also contains fossil mammals. The Fingerrock flora occurs in beds below the Stewart Spring local fauna of transitional Hemingfordian- Barstovian (middle-late Miocene) age, and the Stewart Spring flora occurs above that fauna but below the Cedar Mountain local fauna of Cerrotejonian (earliest Pliocene) age. The late Hemingfordian Fingerrock flora was dominated by the live oak, Quercus chrysolepis, but most of the flora is com- posed of species found in contemporaneous floras of the Columbia Plateau. These species include lobed Quercus, Carya, Ulmus, Zelkova, Platanus, and Acer. The lack here of certain other species found in this association to the north indicates that the Fingerrock flora lived in a drier climate than prevailed at the same time on the Columbia Plateau. Nevertheless the Fingerrock flora was a warm-temperate mesophytic flora. Twenty-four species are described from the Fingerrock flora, none of which are new. The early, or more probably middle, Barstovian Stewart Spring flora is, besides the expected lacustrine element, dom- inated by Quercus chrysolepis, Picea breweriana, and Chamae- cyparis nootkatensis. This assemblage is typically found only in western Nevada and is further restricted to floras of Bar- stovian and Clarendonian age. Most of the species in the Stewart Spring flora appear to be descended from northern mesophytic forms, although the flora has a subhumid aspect different from the northern floras. Only a small element in the Stewart Spring flora may contain species of southern origin. Several phylads in the Stewart Spring flora are now found on the margins of and in the Great Basin. The Stewart Spring flora contains 42 described species, 9 of which are new. INTRODUCTION The Miocene floras of the southern Great Basin are of interest because it was in this region during the Miocene epoch that the subhumid flora first became dominant (Axelrod, 1958). Axelrod (1956, 1958) de- seribed and discussed some of the "Mio-Pliocene" floras of the southern Great Basin. With the exception of the middle Miocene Tehachapi flora (Axelrod, 1939), how- ever, knowledge of middle and early late Miocene floras from this area is singularly lacking. In 1960, vertebrate paleontologists from the Univer- sity of California discovered several new plant lo- calities in the Stewart Valley of southwestern Nevada. This region is already well known for numerous verte- brate fossils, and the plant localities can be related stratigraphically to the mammalian geochronology. One locality occurs several hundred feet lower than an early Barstovian fauna and is therefore considered to be Hemingfordian (middle Miocene) at the youngest. The other localities occur in paper shales between the beds containing early Barstovian and Clarendonian mammals, and thus this flora can be considered of mid- dle or late Barstovian age. The paper shales mentioned above are not only no- table for the abundant and well-preserved leaves, seeds, and flowers but also for numerous fossils of insects and fishes. Exhaustive collecting in the future will prob- ably bring these paper shales the same prominence as the famed paper shales near Florissant, Colo. The paper-shale locality was first found by Mr. S. D. Webb of the University of California ( Berkeley). Other vertebrate paleontologists have assisted in the collection of the fossil plants and in the discussion of mutual problems, and I particularly wish to thank Prof. D. E. Savage and Mr. J. R. Mawby, both of the University of California (Berkeley). Dr. H. D. Mac- Ginitie has contributed in the discussion of paleo- botanical problems. GEOLOGIC OCCURRENCE The fossil plants occur in a sequence of volcanic rocks lying in a north-south basin on the west flank of the Cedar Mountains (fig. 1). The lower part of the se- quence is composed primarily of basaltic and rhyolitic flows with interbeds of tuffaceous sediments. There is no evidence in the lower part of widespread lacustrine conditions, and the sediments appear to have been de- posited in rivers and ponds. The Fingerrock flora (USGS paleobotancial loc. 9882) occurs in the lower part of this section, in a buff- colored water laid tuff that crops out for a lateral extent of about 150 yards. On weathering the tuff is white. To the south, the sedimentary rocks dip under a series of rhyolitic flows. About one-quarter of a mile to the south of locality 9882, tuffaceous rocks containing mam- mals (the Stewart Spring local fauna) rest on top of N1 N2 f SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 56" 117254" 118°00' 38°38" - 36 |- 34! xfi 2 sa>~! 0 1 2 ? MILES FIGURE 1.-Index map of the Fingerrock Wash area showing fossil localities. MIOCENE FLORAS FROM FINGERROCK WASH the rhyolites. There appears to be at least one fault in the -rocks in the strata that separate the mammals and plants, but the displacement along the fault is prob- ably only a few feet. | Above the mammal beds, the section is composed of, thin-bedded fine-grained shales, so-called paper shales (fig. 2). Plants from these shales have been collected from 75 feet (locs. 9697, 9698) and 200 feet (loc. 9696) above the mammals. The floras from the individual localities do not appear to differ and hence all are in- cluded in the Stewart Spring flora. Locality 9696 has furnished the most abundant flora. Collections were made for about a mile along the outcrop of this bed which was traced for at least an additional 2 miles. The extent of the shales indicates that the lake in which they formed had dimensions of at least 7 by 4 miles. flora Cedar *< ** local fauna t :_A- Tuffs I ., 4A :—_—__:—: a Paper shales [f TC Stewart Spring (J: TT ITC IRC Stewart Spring _|. ; } Tufts local fauna Flows -200 Fingerrock- flora 300 FieURE 2.--Composite stratigraphic section of part of Tertiary rocks on west flank of Cedar Mountains. N3 Above locality 9696, the shales are sparingly fossilif- erous and grade into a sequence of sandy tuffs. About 400 feet above locality 9696 is the horizon that 16 miles to the southeast contains Clarendonian mammals (D.E. Savage, oral communication, 1960). Rocks lithologically similar to those in the upper part of the Stewart Valley section have been called the Es- meralda Formation (Turner, 1900). The type Esme- ralda is more than 50 miles south of Stewart Valley, however, and no continuity can be demonstrated at this time. Axelrod (1956) designated a similar lacustrine sequence 50 miles east of Stewart Valley, the Aldrich Station Formation. In addition, the paleontologic evi- dence indicates that the upper part of the Stewart Valley section is correlative with Axelrod's Aldrich Station Formation. The lithologic similarities appear, however, to be due more to a similar environment of deposition in isolated basins than to remnants of a once continuous and large basin. N aming of rock units in the Stewart Valley should await the availability of large-scale topographic maps so that meaningful de- tailed geologic maps can be made and the relations of the various rock units worked out. FLORAL COMPOSITION AND INTERPRETATION The floristic relationships of a fossil flora depend largely on the taxonomic, that is morphologic, relation- ships of the member species. In early Tertiary floras, the taxonomic relationships of the species to extant species are generally so obscure that the floristic rela- tionships are of a general nature. For late Tertiary floras, the resemblance to extant floras is more appar- ent, and inferences deal with geographically more re- stricted modern floras. Early Tertiary communities bear little, if any, resemblance to extant communities; the Miocene warm-temperate mesophytic flora has more specific relationships to floras of eastern Asia and eastern North America, although the communities are not closely comparable. It is difficult, at best, to attempt a reconstruction of the communities represented in fossil floras. Even modern communities are variable in content; for ex- ample, the redwood community has only one plant on which the concept is based, Sequoic sempervirens. Throughout much of its range, the redwood is asso- ciated regularly with species such as Acer macrophyt- lum, Alnus rubra, Umbellularia californica, and Co- rylus californica. But in some parts of the redwood's range one or more of its "typical associates" are lack- ing; the community in these parts is no less a redwood community. Similarly, in southern Oregon, most of the redwood's associates may be present but the red- wood is not, and this community cannot therefore be called a redwood community. Extant plant communi- N4 ties are of only limited use in the interpretation of fossil floras. At an early date, Chaney (1986) attempted to trace the redwood community through time. This attempt was a failure because of the misidentification of Meta- sequoia as Sequoia (Chaney, 1952), but even the sub- stituted concept of a Metasequoia community is mean- ingless unless the age and geographic area are also defined. Metasequoia glyptostroboides [= M. occiden- talis (Newberry) Chaney] occurs in definitely tropical early Tertiary floras with Menispermaceae, TIcacinaceae, Lauraceae, Sapindaceae, and Dilleniaceae; this species is also found in the late Miocene Hidden Lake flora with Abies, Picea, Liriodendron, Amelanchier, and Acer. As Mason (1947, p. 204) has written: It therefore becomes necessary, in tracing floristic records through time, to re-define the flora repeatedly in terms of the changed associates of some of the more persistent character- istics. Mason (1934, 1944) has also shown that in the short period of time from the Pleistocene to Recent, such ap- parently well defined communities as the closed cone pines have undergone considerable change in composi- tion. In a region that has had a relatively stable cli- mate, soil, and topography, communities may have re- mained similar over considerable periods of time, but in a region such as western North America all three factors have been rapidly changing. Hence, we can- not expect plant communities in this region to remain unchanged. The only reasonable method for inferring communities in fossil floras is on the basis of the fossil flora itself. The communities based on the extant flora should have little value in floristic interpretations of the fossil flora. Mason (1947, p. 204) considered the problems of the duration of communities: Because of the differences in genetic constitution and in phys- iological capacity between the various species of the community and because of the operation of different genetic mechanisms, it is hardly to be expected that any two or more species of such a community will follow precisely the same historical pattern even for a relatively short time. Through careful taxonomic work in both fossil and extant plants, it is possible to infer how the plant asso- ciations, both fossil and extant, have come about. These inferences ultimately rest on the morphologic re- lationships of the plants themselves. For example, if most of the species in two distant floras are conspecific or closely related (vicarids), we infer that the orga- nisms in these floras are descended from common ances- tors in a relatively recent epoch. Whether we think that the ancestors migrated from one region to the other or migrated into both regions from another is another inference for which we need sequences of floras in the intervening area. - If the morphologic relationships are SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY more distant, or only compose a small part of the flora, then the floral connection may have been in the distant past or may have involved only a few members of the flora. - In addition, it is possible that similar floras may be the result of parallel evolution in regions with simi- lar environmental histories. FINGERROCK FLORA SYSTEMATIC LIST OF THE FINGERROCK FLORA Tracheophyta Pteropsida Gymnospermae Coniferales Pinaceae Abies concolor Lindley Picea magna MacGinitie Pinus monticola Douglas Pinus ponderosa Douglas Cupressaceae Chamaecyparis nootkatensis (Lambert) Spach Taxodiaceae Glyptostrobus sp. Angiospermae Monocotyledones Glumiflorae Cyperaceae Cyperacites sp. Dicotyledones Salicales Salicaceae Populus lindgremi Knowlton Juglandales Juglandaceae Carya bendirei (Lesquereux) Chaney and Axelrod Fagales Betulaceae Alnus relata (Knowlton) Brown Betula thor Knowlton Fagaceae Quercus chrysolepis Liebmann Quercus simulata Knowlton Quercus pseudolyrata Lesquereux Urticales Ulmaceae Uimus newberryi Knowlton Zelkova oregoniana (Knowlton) Brown Ranales Berberidaceae Mahonia reticulata (MacGinitie) Brown Rosales - Platanaceae Platanus bendirei (Lesquereux) Wolfe, n. comb. Rosaceae Amelanchier subserrata Smith Cercocarpus antiquus Lesquereux Sorbus harneyensis Axelrod Sapindales Aceraceae Acer bolanderi Lesquereux Acer macrophyllum Pursh Ericales Ericaceae Arbutus traini MacGinitie MIOCENE FLORAS FROM FINGERROCK WASH N5 TABLE 1.1-Numerical abundance of Fingerrock fossils Number of __ pey. Species specimens cent Quercus chrysolepis_________________LL_L_LLL_L___ 119 43 PICO HAH 2. - s .. .. cl Pan aoc n enne ous nl eames s 26 9 Quercus simulata___________LLLLLLLLLLLLLLLLLL__ B56 p Acer macrophyllum_______LLLLLLLLLLLLLLLLLL___ 16 6 Glyptostrobus 13 5 Uimus 11 4 Zelkova oregomniamna_______________LLLLLLLLL_____ 11 4 Pinus 9 3 Platanus bendirei______LLLLLLLLLLLLLLLLLLLLL___ 9 3 Carya bendireic___LLLLLLLLLLLLLLLLLLLLLLLLLL___ 8 8 Quercus pseudolyrata___________________________ 8 8 Mahonia reticulata_____________LLLLLLLLLLLLL____ 4 1 Abies concolor-_______LLLLLLLLLLLLLLLLLLLLLLLL__ 8 1 Arbutus 3 1 Acer 2 1 Pinus monticola____________LLLLLLLLLLLLLLLL____ 2 1 All 8 Bj TOTAL 277 100 COMPOSITION The numerical abundance of the various fossils are listed in table 1. From this table, it is apparent that the dominant trees near the site of deposition were the three oaks, Acer macrophyllum, Zelkova, Ulmus, Picea magna, Pinus, Glyptostrobus, Platanus, and Carya. It is assumed that all these plants grew in proximity to one another and hence can be thought of as a natural association. It is possible that some of the rarer fos- sils, for example the Cercocarpus, may have been part of another association, but it is equally probable that the Cercocarpus was just a rare shrub in the forest. The general similarity of the Fingerrock association to that in contemporaneous Miocene floras in Oregon is apparent. All these floras have an association of Quercus pseudolyrata, Carya bendirei, Zelkova ore- goniana, Ulmus spp., Quercus simulata, Platanus ben- direi, and Arbutus traini. One noticeable difference in the Fingerrock Quercus pseudolyrata assemblage is the lack of Fagus, Liquidambar, and Pterocarya, all of which are of common occurrence in the northern parts of the association. < An unusual feature of the Fingerrock flora is the rarity or lack of what are considered typical fluviatile or lacustrine species. Fossils of Populus, Alnus, and Betula are present but are rare, and Saliz is completely lacking. This indicates that the fossil assemblage may be the result of some depositional selectivity, with the more delicate leaves of plants such as Populus and Saliz being destroyed. Most of the preserved leaves are relatively thick and resistant, for example, Quercus chrysolepis, Mahonia, Cercocarpus, and Arbutus. On the other hand, large twigs of G@lyptostrobus and a com- plete leaf of Sorbus would be unusual in this context. The coniferous element of Abies, Picea, and Pinus was apparently a part of the Quercus pseudolyrata as- sociation. This element is only present in floras of at least moderate altitude (above 2,000 ft) as in the Hidden Lake (Oregon Cascades), Blue Mountains, Stinking Water, and Thorn Creek floras. The in-place stumps in the Stinking Water basin (Chaney, 1959, p. 92) indicate that a spruce was directly associated with the oaks. Hence, the occurrence in the Fingerrock flora of Pinaceae indicates a moderate altitude for this region. The lack of Liquidambar, Fagus, lobed white oaks, and Pterocarya is probably significant in regard to the climate. In addition, the Fingerrock lacks any of the plants of subtropical affinities (Cinnamomum, Persea, Lindera, and Magnolia) that are found in contempo- raneous floras to the north. These differences are in my opinion too numerous to be due only to local habitat differences. It is more reasonable to suggest that the Fingerrock flora lived under greater temperature ex- tremes and less precipitation than Chaney (1959, p. 56-60) postulated for the Mascall flora. FLORISTIC RELATIONSHIPS Nearly all the Fingerrock species are known in older and contemporaneous floras to the north in Oregon. The two exceptions are Cercocarpus antiquus and Sor- bus harneyensis. The recorded occurrence of S. har- neyensis from the Fingerrock is the oldest known and hence for present considerations this species is valueless. Cercocarpus antiquus, however, appears to be descended from a new species in the early Miocene of Oregon. Thus the obvious relationship of the Fingerrock flora is to the northern floras. What type of flora preceded the Fingerrock in southwestern Nevada is unknown. The bulk of the northwest Miocene flora is derived from the subtropical Oligocene flora of the northwest and from warm-temperate Oligocene flora of the Cor- dilleran region. It is likely that the Fingerrock flora was developed simultaneously from the same or similar sources. Of direct concern here is the concept of the Arcto- Tertiary Geoflora, which is used to explain the floristic relationships between eastern North America, north- western North America during the Miocene, eastern Asia, and western Europe during the Miocene. The Arcto-Tertiary concept infers the existence of a warm- temperate Eocene (perhaps even Cretaceous) boreal flora virtually similar to the extant east Asian and east North American floras. In response to cooling cli- mate, this flora migrated southward into middle lati- tudes during the Oligocene and Miocene. In the west- ern parts of Eurasia and North America, most of the species of this flora became extinct, but the flora has N6 maintained its composition or identity in the eastern parts. The A rcto-Tertiary theory has much to recommend it in its simplicity of explaining the floristic similarities mentioned above. On the other hand, the theory does not explain: (1) the floral sequence in Alaska, or (2) the floral dissimilarities between eastern Asia and western North America. - Concerning the first point, I have elsewhere briefly discussed (MacNeil and others, 1961) the Alaskan floras. The mesophytic warm-tem- perate flora is first recorded in Alaska in the middle and late Oligocene rocks; the earlier floras known in Alsaka contain abundant cycads, palms, Lauraceae, Menisper- maceae, Alangium, and other taxa indicative of sub- tropical if not tropical climates. - Peculiarly, the early Tertiary Puget flora of Washington (Wolfe and others, 1961) contains more "warm-temperate" genera than are known from our admittedly meager Alaskan Eocene; among these are: Carya, Pterocarya, Juglans, Alnus, Betula, Quercus, Ulmus, Zelkova, Cercidiphyllum, T et- racentron, Liquidambar, and Platanus. Lacking are some of the more characteristic temperate taxa such as the lobed black and white oaks, Rosaceae, Aceraceae, and Salicaceae, but these are lacking or rare in Paleocene and Eocene floras throughout the Northern Hemisphere. At apparently the same time, in the later half of the Oligocene, recognizably warm-temperate floras com- posed of Juglandaceae, Fagaceae, Rosaceae, Aceraceae, Salicaceae, and Betulaceae first appear, not only in Alaska but also at middle latitudes in North America (MacGinitie, 1953; Becker, 1961) and Eurasia (Krys- tofovich, 1956). Some plant migration is probably in- volved, for this is the most reasonable explanation for the spread of Cercidiphyllum erenatum. This species first appeared in the Oligocene of Washington (Wolfe, 1961) (probably descended from C. elongatum and by late Oligocene was present throughout most of Eurasia. Nevertheless, extensive migrations as demanded by the Arcto-Tertiary concept appear to be unreasonable. The species of this Oligocene warm-temperate flora do not appear to show any greater relationships be- tween North America and Eurasia than now prevail, although more work is needed to fully validate this con- clusion. The Kazakhstan flora has a few identical or closely related species to the Kenai flora of Alaska, but there are even fewer closely related species in the Ruby Valley flora of Montana. The Miocene flora of the northwestern conterminous United States, although similar to the extant east Asian flora, has significant differences. From the early Mio- cene flora of the Oregon Cascades, more than 150 species of presumably woody plants are known. Some of these SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY species are closely similar to extant east Asian species and indicate some floral continuity. On the other hand, there is a large group of species in the following genera, that show no correspondence to the Asian flora : Colu- brina, Lyonothammus, Cercocarpus, Arbutus, Juglans (Rhysocaryon), Quercus (Erythrobalanus), Platanus, RSecuridaca, and Acer. Other species belong to genera that today survive only in east Asia, but their morpho- logic relationships to east Asian species are as distant as, for example, the relationship between Acer macro- phyllum and the extant east Asian maples. Some of the close comparisons that can be drawn between the west American Miocene and extant east Asian flora are in Carya and Pterocarya. The Ameri- can Miocene species in these genera, however, can gen- erally be placed in phylads that extend back into the tropical Eocene floras. Probably most of the strong floristic similarity between the Miocene of western North America and the Recent of east Asia is due to parallel evolution in related phylads in response to sim- ilar environments. These genera do not appear to have formed their own characteristic association in the Eocene and older epochs; rather, they probably were members of the tropical and subtropical floras in both North America and Eurasia. The Fingerrock association of species of Carya, Zel- kova, Ulmus, lobed Quercus, Populus, Platanus, Acer, and Glyptostrobus is due to the coincidence of toler- ances of these species. That these tolerances have changed, or rather that phylads have undergone sig- nificant physiologic evolution in conjunction with mi- gration and morphologic evolution is evident. The Puget individuals of Alnus, Carya, Uimus, and Gly pto- strobus, although possibly ancestral, almost certainly had tolerances different from those of the Fingerrock individuals of the same phylads. The evolution of the warm-temperate mesophytic floras of the Northern Hemisphere still needs much more elucidation. From the preceding discussion it is evident that the concept of the Arceto-Tertiary Geoflora does not fully explain and is partly contradicted by the fossil record. On the basis of a consideration of the salient features of living plants, Mason (1947, p. 205) came to the same conclusion : It is difficult * * * to envisage such floristics as an Arcto- Tertiary flora (Chaney 1936) in contrast to a Madro-Tertiary flora (Axelrod, Mss.) as accounting for floristic sources and centers of origin during Tertiary time. Such concepts of flo- ristic organization and development demand unity and stability of communities in time and space beyond what is possible in the light of the nature of floristic dynamics such as are bound up with the genetics of the population, the physiology of the individual, and the diversity and fluctuation of the environment. MIOCENE FLORAS FROM FINGERROCK WASH NZ STEWART SPRING FLORA SYSTEMATIC LIST OF THE STEWART SPRING FLORA Tracheophyta Pteropsida Gymnospermae Coniferales Pinaceae Abies concolor Lindley Abies sp. Lariz occidentalis Nuttall Picea breweriana S. Watson Picea magna MacGinitie Pinus ponderosa Douglas Tsuga heterophylla Sargent Cupressaceae Chamaecyparis nootkatensis (Lambert) Spach Juniperus nevadensis Axelrod Angiospermae Monocotyledones Glumiflorae Gramineae Poacites sp. Cyperaceae Cyperacites sp. Dicotyledones Salicales Salicaceae Populus cedrusensis Wolfe, n. sp. Populus tremuloides Michaux Populus trichocarpa Torrey and Gray Populus washoensis Brown R Populus sp. Saliz pelviga Wolfe, n. sp. Garryales Garryaceae Garrya azelrodi Wolfe, n. sp. Juglandales Juglandaceae Juglans major Torrey Fagales Betulaceae Betula sp. Fagaceae Quercus cedrusensis Wolfe, n. sp. Quercus chrysolepis Liebmann Ranales Berberidaceae __ Mahonia reticulata (MacGinitie) Brown Rosales Saxifragaceae Philadelphus nevadensis Condit Ribes webbi Wolfe, n. sp. Ribes sp. Rosaceae Amelanchier cusicki Fernald Cercocarpus antiquus Lesquereux Holodiscus fryi Wolfe, n. sp. Lyonothamnus parvifolius comb. Peraphyllum vaccinifolium (Knowlton) Wolfe, n. comb. Prunus sp. Rosa sp. Sorbus sp. (Axelrod) Wolfe, n. Tracheophyta-Continued Pteropsida-Continued Angiospermae-Continued Dicotyledones-Continued Sapindales Anacardiaceae Astronium mawbyi Wolfe, n. sp. Rhus integrifolia Bentham and Hooker Schinus savage Wolfe, n. sp. Sapindaceae Sapindus sp. Rhamnales Rhamnaceae Colubrina sp. Myrtiflorae Elacagnaceae Elaeagnus cedrusensis Wolfe, n. sp. Ericales Ericaceae Arbutus traini MacGinitie Arctostaphylos masoni Wolfe, n. sp. TABLE 2.-Numerical abundance of Stewart Spring fossils Number of Species or genus specimens Percent PiHG@® 49 15 Quercus chrysolepis________________________ 47 14 Lyonothamnus parvifolius___________________ 43 12 Grass 28 8 Populus 22 7 Chamaecyparis nootkatensis_________________ 22 4 Tsuga heterophylla_________________________ 13 4 Pinus ponderosa________________LLLLLLLLL___ 9 3 Arbutus 8 2 Abtes comeolor-___________LLLLLLLLLLLLLL___ 8 2 Ribes webbi______LLLLLLLLLLLLLLLLLLLLLL____ T 2 Sali T 2 Peraphyllum vacceinifolium__________________ 6 2 Mahonia 6. 2 Lariz occidentalis__________________________ 6 2 Cercocarpus antiquus_______________________ 6 2 All 47 14 ToOtAIS-________LLLLLLLLLLLLLLLLLL_L 334 100 COMPOSITION The mixture of Pinaceae with dicotyledons is more pronounced in the Stewart Spring flora than in the Fingerrock flora. Pinaceae form a conspicuous ele- ment of the Stewart Spring flora, both in variety and numerical abundance, indicating that they were com- mon forest trees. The dicotyledon flora is also rich, with a large lacustrine and (or) fluviatile element. The abundant remains of Populus and Saliz are con- sonant with the present habitats of species of these genera. The abundance of complete leaves of the Lyonotham- nus is indicative of a lacustrine habitat for this species. However, as with Quereus chrysolepis and the gymno- sperms, Lyonothamnus was probably a common forest tree. Other species that, judged from their numerical abundance, were numbers of the forest association are Ribes webbi, Mahonia reticulata, Cercocarpus antiquus, Elaeagnus cerdrusensis, and Arctostaphylos masoni. Fossils of all these species were collected for more than N8 a mile along the outcrop of the main leaf-bearing bed. Nearly all extant species of these genera are shrubs, rather than trees, and it is reasonable to assume a similar habit for the fossil species. Although remains of grass are abundant in the shales, the affinites of the grass or grasses are unknown. The common remains of grass could be interpreted as in- dicating a lacustrine habitat or a very great abundance in the forest. The Stewart Spring flora shows considerable simi- larity to the Aldrich Hill and Horsethief Canyon floras (Axelrod, 1956) about 60 miles to the west. There are somewhat lesser similarities between the Stewart Spring and the Middlegate, Fallon, and Chloropagus floras (Axelrod, 1956) to the north and the Esmeralda flora to the south. As discussed later, most of these other floras are younger than the Stewart Spring. All these floras in western Nevada have a large number of species TaBus® 3.-Comparison of relative abundance in percentage of spruce, SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY in common in two or more floras. A group of three species, Picea breweriana, Quercus chrysolepis, and Chamaecy paris nootkatensis is, however, the only group that all the floras have in common. This association of spruce, live oak, and cedar is the most characteristic feature of these floras. The oak and spruce fossils are everywhere abundant, but the cedar is typically rare. In table 3 the abundance of these three forms in the various floras is compared. In both the Horsethief Canyon and Stewart Spring floras, the representation of these species is conspicuously lower, but this can be correlated with the comparatively high representation of Populus, Saliz, and other probable lacustrine genera. Other genera that are frequently found in the spruce- live oalk-cedar association are Lyonothammus, Frazinus, Amelanchier, Cercocarpus, Arbutus, Mahonia, Sequoia- dendron, and Juniperus. live oak, and cedar in the Nevada Barstovian and Clarendonian floras Species Stewart Spring! Horsethief Aldrich Hill | Chloropagus Fallon Middlegate Canyon PiCe@ L __ cc 15 3. 6 25. 4 64. 3 83. 5 84. 3 Quercus Chry8O1@D18_ _ ___ 14 9. 6 28. 2 2. 2 ir . 6 Chamaecyparis nootkQ@LMSLS-__________________-_-------- 7T .9 . 4 2. 8 1 .1 TObALL L 36 14. 1 54. 0 69. 3 84. 3 85. 0 Floras with the dominant association of spruce, live oak, and cedar are restricted to western Nevada (fig. 3). The Barstovian, Upper Cedarville flora (LaMotte, 1936), the Trout Creek (MacGinitie, 1933), and the Clarendonian Goose Creek floras from the northern Great Basin are typical northwest mesophytic assem- blages. No Neogene flora is known from the eastern Great Basin. The climate under which the spruce-live oak-cedar association lived is best described as subhumid and warm temperature. _ A pronounced climatic change may have taken place in the late Hemingfordian-early Barstovian interval if the differences between the Fin- gerrock and Stewart Spring floras are indicative. Axelrod's (1956, fig. 13) suggestion of 20-35 inches of annual rainfall is a reasonable estimate, although it is unlikely that the lower figure was approached until well into the Claredonian. In the northern Great Basin, the persistence of species such as Quercus deflexi- loba and Zelkova oregoniana into the the Hemphillian indicates a considerably greater amount of precipitation. The occurrence of Picea, Quercus, and Chamaecy paris in the same floras is contrary to their Recent distribu- tion (fig. 3). Although Picea breweriana and Quercus chrysolepis do have an overlap in ranges, the overlap is small. P. breweriana is restricted to the southern Oregon Coast Ranges and the Trinity, Siskiyou, and Klamath Mountains of northern California. In Ore- gon, the individuals of P. breweriana occur as low as 4,000 feet, but in California they occur at altitudes of 5,500-8,000 feet. Q. chrysolepis apparently overlaps the lower range of P. breweriana in the Trinity Mountains, but typically the canyon live oak is found at lower altitudes. - Along the west slope of the Sierra Nevada, Q. chrysolepis is typically found up to 6,000 feet. Chamaecyparis nootlkatensis is, compared with the other two species, of northern distribution. From coast- al southeastern Alaska, individuals of C. nootkatensis are found at increasingly higher altitudes to the south. Isolated southern outliers are found at altitudes of 2,500-6,100 feet in the central Oregon Cascades. Thus, at no place today is C. nootkatensis found in associa- tion with Picea breweriana or Quercus chrysolepis. The comparatively large area of overlap in ranges of the three species in the Neogene (fig. 3) indicates that the tolerances of the extinct individuals were consid- erably different from those now living. Moreover, all three species occupied a greater area in the past. The present range of Chamaecyparis noothkatensis indicates that it is adapted to a cool moist climate; the Nevada occurrences must have been adapted to a considerably different climate. This does not necessarily indicate MIOCENE FLORAS FROM FINGERROCK WASH that lineages of C. nootkatensis have adapted through time to a different climate, for specimens of the species are also known in the Neogene floras of the Oregon Cascades. The Nevada occurrences probably represent extinct physiologic races. Quercus chrysolepis has also been restricted through time. Specimens are known from decidedly mesic floras in the late Miocene of the Puget lowland, as well as in a mesic early Barstovian flora from the Mac- Kenzie River basin of the Oregon Cascades. The Oregon occurrence is interesting because of the associa- ation with Liriodendron, Pterocarya, Sophora, and Liquidambar. The record of Picea breweriana is somewhat less cer- tain because of the difficulty in determining seeds of Picea. Nevertheless, it is apparent that P. breweriana was widely distributed from the Oregon Cascades south into central California and east into Nevada. In general aspect, the Stewart Spring flora does not appear to be closely related to the Fingerrock flora or the Miocene mesophytic floras of the northwest. As 128° 46° Ln a2> E o,,/ ea "Booy * (pg _ 7/ _ - c s a \ 7-4, A / ~~ |, ~ el, 34° EXPLANATION _- Picea breweriana Quercus chrysolepis 30° |I Chamaecyparis nootkatensis FicurE 3.-Distribution map of Picea breweriana, Quercus chrysolepis, and Chamaecyparis nootkatensis. Patterned areas are Recent distri- bution ; fossil occurrences denoted by P, Q, or C, respectively. 695-377 O-63--2 NQ FLORISTIC RELATIONSHIPS was pointed out previously, the live oak-spruce-cedar association is constant in western Nevada and has no closely comparable association prior to Barstovian or after Clarendonian. Nineteen of the Stewart Spring species are either poorly known or are not known to be related to any older species; the significance of these is of necessity minimized in the present discussion. Of the remaining 23 species, 3 groupings can be made: (1) species con- specific with or descended from species in the Finger- rock flora, (2) species conspecific with or descended from species in the northwest Miocene flora, and (3) species related to or possibly descended from species in the Oligocene flora of the Cordilleran region. The first group, species, or phylads common to the Fingerrock and Stewart Spring floras contains: Abies concolor Picea magna Pinus ponderosa Chamaecyparis nootkatensis Sorbus sp. Quercus chrysolepis Mahonia reticulata Amelanchier cusicki Cercocarpus antiquus Arbutus train The second group, species, or phylads common to the northwest Miocene and Stewart Spring flora is: Abies concolor Picea breweriana Picea magna Pinus ponderosa Tsuga heterophylla Chamaecyparis nootkatensis - Populus tremuloides Populus trichocarpa Populus washoensis Colubrina sp. Saliz pelviga Juglans major Betula sp. Quercus chrysolepis Mahonia reticulata Ribes webbi Amelanchier cusicki Cercocarpus antiquus Lyonothamnus parvifolius Arbutus traini The third group, Stewart Spring species with phylads in the Oligocene of the central and northern Rocky Mountain region, is: Picea magna Pinus ponderosa Populus trichocarpa Saliz pelviga N10 Astronium mawbyi Colubrina sp. Quercus chrysolepis Amelanchier cusicki Cercocarpus antiquus Sapindus sp. Arctostaphylos masoni These lists demonstrate that a large part of the Stewart Spring flora is of basically northwest meso- phytic derivation. The only species that might be of more southerly origin are: Populus cedrusensis Garrya axelrodi Rhus integrifolia Elaeagnus cedrusensis Quercus cedrusensis The Garrya is particularly significant because the family is endemic to southwestern North America today and has never been recorded from the mesophytic floras of the Northwest or the Cordilleran region. Similarly, the Quercus, Populus, Rhus, and Elaeagnus may have come into southwestern Nevada from a southerly or southeasterly direction; however, only the RAus has a close relative in the Tehachapi flora. Garrya azelrodi and Quercus cedrusensis have strong similarities to species in both central California and northern Mexico. Populus cedrusensis shows about the same degree of differentiation from its Baja California relative as the Garrya and Quercus do from their Mexi- can relatives. Juglans major might be thought to indicate a Mexican derivation, but investigations of Tertiary Juglandaceae indicate that the immediate an- cestor of J. major lived in the Northwest, where PAyso- caryon evolved from Cardiocaryon. It is possible that the southern Rocky Mountain region was analogous to the northern Rocky Mountain region in containing in the Oligocene ancestors of many of the warm-temperate subhumid species of the Neogene of the southwestern United States. Nevertheless, it is still evident that at least half of the Stewart Spring species are derivatives of mesophytic Oligocene and earlier Miocene species. The Stewart Spring flora contains several species whose descendants have survived with little or no modi- fication in the Great Basin or its western and northern margins. These species are: Abies concolor Picea breweriana Pinus ponderosa Juniperus nevadensis Arctostaphylos masoni Populus tremuloides Populus trichocarpa Amelanchier cusicki Cercocarpus antiquus. Elaeagnus cedrusensis Peraphyllum vacceinifolium SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Some of these species adapted to the drier habitats of the Great Basin proper, but others are found only in the moister mountains bordering the region. From the preceding discussions (see also p. N5-N6), certain basic conclusions can be drawn. The flora of a region at any particular time has the strongest rela- tionship with the preceding flora of the same region. That is, through the processes of adaptation, lineages have continued in western North America through much of the Cenozoic. On the other hand, the com- munities, associations, and floras that we construct from these lineages are quite different through time. We cannot correctly say that the flora evolves; environ- mental, that is natural, selection operates only on a series of individuals. Through time these lineages of individuals have changing tolerances and (or) differ- ent areas of occupation, and in conjunction with extinc- tion, the flora "changes." Concomitant with the changing environment, the plants have changed, both physiologically and morphologically. Mason (1953, p. 155) has aptly written : "Environmental elaboration over area and morphological elaboration occur together in time and in space and are the result of the same phylogenetic processes." FLORAL PROVINCES IN THE BARSTOVIAN The middle Miocene Fingerrock flora is in the same province as the northwest mesophytic flora, as shown by the large number of species in common. The floral continuity between the southern Great Basin and the Northwest during the Miocene is considerable, except for the lack in the south of probable highly mesophytic species. - As interpreted here, the southern Great Basin and the Northwest were in the same floral province during the middle Miocene (Hemingfordian). By late Miocene (Barstovian), the southern Great Basin floras, as represented by the Stewart Spring, have relatively few species in common with floras to the north. Not only is the Stewart Spring dissimilar to floras on the Columbia Plateau, but it is just as dis- similar to floras in the northern Great Basin. Early Barstovian floras such as the Payette and Succor Creek in Oregon and Idaho are dominated by the lobed black and white oaks, Acer, Platanus, and other clearly mesophytic groups that are lacking in the Stewart Spring. Later Barstovian northern floras (Upper Cedarville, Stinking Water, and Thorn Creek) still maintained the mesophytic aspect. Indeed, only re- cently have we come to realize that Clarendonian floras (Goose Creek) of the northern Great Basin are basi- cally mesophytic. Even a Hemphillian flora from southern Idaho (Brown, 1940) contains wood of Quer- cus, Carya, Acer, and Picea. Of the Hemphillian and early Blancan floras, only the Alvord Creek and Cache Creek lack the typical mesophytic species (fig. 4). 120°00' 44°00' CALIFORNIA 36°00" FIGURE 4.-Sketch map of Great B 4, Trout Creek ; 5, Bruneau; Fallon ; 13, Middlegate ; 14, C Esmeralda. MIOCENE FLORAS FROM FINGERROCK WASH 112°00' IDAHO -- _- ___ 2 NEVADA asin showing location of some Neogene floras. 6, Goose Creek ; 7, Cache Valley ; 8, Alturas ; oal Valley ; 15, Aldrich Hill and Horsethief ARIZONA 1, Lower Idaho ; 2, Stinking Water ; 3, Alvord Creek $ 9, Upper Cedarville ; 10, Chloropagus ; 11, Verdi; 12, Canyon ; 16, Fingerrock ; 17, Stewart Spring; and 18, N11 N12 To the west in the Sierra Nevada region, the meso- phytic flora dominated. Both the Table Mountain (Condit, 1944a) and the Remington Hill (Condit, 1944b) floras are evidence to this interpretation. The age of the Remington Hill is uncertain, but it appears to be Barstovian. Significant mesophytic elements are Quercus columbiana, Q. deflexiloba (=@Q. pseudolyrata of Condit), Uimus newberryi (=U. californica of Con- dit), Liquidambar, Platanus dissecta (=P. pauciden- tata, in part of Condit), Crataegus, and Carya (=Aesculus preglabra of Condit). This flora is highly similar to late Barstovian floras from northern Oregon. The Table Mountain flora is dated by mam- mals as early Clarendonian. Significant elements here are: Platanus dissecta, Crataegus, Persea, Carya, Cercis, Ulmus, Berchemia, Cornus, Rhododendron. Once again, similarities may be noted to more north- erly floras, as well as to the contemporaneous but more subtropical Neroly flora on the coast. It is apparent that the Stewart Spring is distinct floristically from the known Barstovian and Clarendonian floras to the west in California. The middle Pliocene (Hemphillian) floras of central California, however, do show relationship on the ge- neric level to the Stewart Spring flora. The Mulholland (Axelrod, 1944a) and the Oakdale (Axelrod, 1944b) floras contain : nonlobed live oaks, Mahonia, Ribes, Sa- pindus, and Lyonothammus. On the species level, however, the resemblance is small, and the derivation of these Hemphillian floras was probably distinct from the Nevada floras. This is further indicated by the presence of several species related to or conspecific with species in the "Madro-Tertiary Geoflora." To the south, the Hemingfordian Tehachapi (Axel- rod, 1939) and the Clarendonian Ricardo (Webber, 1933) floras have very little in common, particularly on the species level, with the Stewart Spring. Hence, it may be concluded that at least since the Hemingfordian the southern Great Basin was in a floral province dis- tinct from the area to the south. To the west and north, no floral dissimilarity is apparent until the Barstovian. The almost complete lack of Neogene floras in Utah and eastern Colorado does not allow a statement as to the eastward extent of the southern Great Basin floral province. ( BIOSTRATIGRAPHY The presence of associated mammalian fossils facili- tates the age determination of these floras. The Ste- wart Spring flora occurs in beds about 400 feet strati- graphically below Clarendonian (early Pliocene) mam- mals of the Cedar Mountain local fauna (Fish Lake Valley local fauna of Wood and others, 1941) and 200 feet stratigraphically above the Stewart Spring local SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY fauna (Wood and others, 1941). Although the age of the latter fauna has been somewhat uncertain, recent work demonstrates an age equivalent to the Mascall fauna (S. D. Webb, oral communication, 1960), that is, early Barstovian (late middle or early late Miocene). The distance that the Fingerrock beds lie below the Stewart Spring fauna is uncertain, and, because of the possible intervening unconformity, this fauna only fixes the upper age limit of the Fingerrock flora. Hence, the age of the Fingerrock flora must rest pri- marily on paleobotanical evidence. Two species agree with the mammalian evidence on an upper age limit. Quercus pseudotyrata and Platanus bendirei are not known in beds younger than early Barstovian, after which their descendant species, Q. deflexiloba and P. dissecta, are found. Q. pseudolyrata also determines a lower age limit of probable early Hemingfordian, that is, equivalent to the Latah flora. The problem then be- comes the determination of whether the Fingerrock flora is of early (Latah) or late (Mascall) Hemingfordian age. Two species, Cercocarpus antiquus and Arbutus traini, are more typical of later Miocene floras and thus indicate that the Fingerrock flora is more likely of late Hemingfordian age. Various other Nevada floras have been considered to be of "Mio-Pliocene" age (Axelrod, 1956), that is latest Barstovian and early Clarendonian (Cerrotejonian of Savage, 1955). Included in these floras are the Aldrich Hill and Horsethief Canyon floras which have been included together as the Aldrich Station flora (Axel- rod, 1956). Considering the relatively great strati- graphic separation (875 ft; Axelrod, 1956, p. 24), the two floras combined may represent a considerable seg- ment of time. The upper flora, the Aldrich Hill, oc- curs 2,625 feet below fossil mammals (Axelrod, 1956). According to Axelrod (p. 55), the mammals include Nannipus tehonmensis, which dates them as Cerrote- jonian. - The occurrence of the Aldrich Hill and Horse- thief Canyon floras a few thousand feet lower than the mammals in a section composed primarily of thin- bedded shale and diatomite indicates to me that both floras are no younger than middle Barstovian. That is, both floras would be approximate correlatives of the Stewart Spring, or perhaps slightly older. Certainly the three floras are similar, but the occurrence in the Aldrich Hill and Horsethief Canyon floras of Zelkove and Ulmus may indicate that they are older than the Stewart Spring. The floras found in the Carson Sink region all appear to be younger than the Aldrich Hill, Horsethief Can- yon, and Stewart Spring floras. The Chloropagus and Fallon floras typically lack the warm-temperate and presumably older forms such as Lyonothamnus, Sapin- dus, Astronium, Zelkova, and Ulmus. The methods of dating by climatic interpreta (Axelrod, 1956) are fully as a of generic analysis (Wolfe an these floras, on any method, ar donian age. tions or floristic evolution pproximate as the method d Barghoorn, 1960). All e of Barstovian or Claren- From stratigraphic evidence, it is known that the Chloropagus flora is older t han the Fallon but how much older is problematic. The composition of the two floras does indicate that they are of nearly the same age (Axelrod, 1956, p. 155) and are either latest Barsto- vian or early Clarendonian. Unfortunately, neither the Clarendonian Esmeralda (K nowlton, 1901) nor Coal Valley (Berry, 1927) floras are well-enough known for purposes of correlation. The age of the Middlegate flora rests, in part, on frag- mentary mammals. gate Formation of Axelrod slightly higher than the flora but R. W. Wilson (in Axelrod The mai mmals from the Middle- 1956) came from a bed (Axelrod, 1956, p. 204), , 1956, p. 204) stated that MIOCENE FLORAS FROM FINGERROCK WASH "* * * the material appears to represent Aphelops. It suggests a Late Barstovian or Early Clarendonian age * * *" The stratigraphic significance of even well- preserved Neogene rhinocerotids is not certainly known. Fragmentary ls stratigraphically more N13 than 3,000 feet above the Middlegate flora were "tenta- tively" regarded as Hemphillian (Tedford in Axelrod, 1956, p. 205). Thus, the mammals do not aid signifi- cantly in the age determination of the Middlegate flora. From the paleobotanical standpoint, the Middlegate is probably older than the Fallon and Chloropagus floras. Because of the occurrence in the Middlegate flora of Acer macrophyllum, Acer columbianum, Platanus dissecta, typical forms of Quercus simulata, Persea, and Betula vera, I am inclined to regard this flora as at least as old as the Stewart Spring. The Middlegate flora may be even older, and in particular the maples and sycamore indicate this. None of the known Clarendonian or Barstovian floras from central Nevada have these species in them, although they are present in the Fingerrock flora. On the other hand, the Middlegate lacks Carya and Quercus pseudolyrata and hence is probably younger than the F ingerrock. Thus the Middlegate flora appears to be transitional between the Fingerrock and Stewart Spring, that is, transitional Hemingfordian-Barstovian. The age relationships of several Great Basin Neogene floras are summarized in table 4. TABLE 4.-Correlation of some Neogene floras of the Great Basin Mammalian provincial Cedar Mountain Wassuk Range Reno-Carson Sink area Warner Range Steens Mountains Snake River basin age Coaldale area Blancan Cache Valley Hemphillian Verdi Alturas Alvord Creek Bruneau Montediablan Goose Creek Cerrotejonian Esmeralda Coal Valley Fallon Lower Idaho Barstovian Stewart Spring Aldrich Hill Chlorapagus Upper Horsethief Cedarville Canyon Hemingfordian Fingerrock SYSTEMATICS isolated organs; what assurance, therefore, do we have In this paper the taxonomi species differs from current p c treatment of numerous ractices in North Ameri- can Tertiary paleobotanical work. This difference is the result of the concept of taxa based solely on morpho- logic not on age criteria. Alt and Asian workers have not h plied to extant plants for foss ers have been reluctant to do tl hough several European esitated to use names ap- ils, most American work- iis. Hence, in La Motte's catalog (1952) not one Recent species is found below the Quaternary. The practice of setting up separate names for fossils, no matter how similar to Recent plants, is based largely on the idea that in the fossil record we are dealing with that in the case of identical fossil and extant leaves (or any other organ) that the rest of the organs were also identical? This is an admittedly important question. In fact, we have no such assurance, but we can demon- strate in extant plants that foliage is diagnostic to the generic level, and hence we use generic names of extant plants for fossils It is equally valid, therefore, to extend epithets of Recent plants into the fossil record if foliage is diagnostic to the specific level. In many genera of extant plants, the seeds and (or) foliage are specifically diagnostic, and I have thus placed fossils not distinct from the same living organs in Recent species. N14 The practice of using names of extant species for fos- sils has the advantage of indicating the rates of mod- ernization in several groups. For example, most of the middle Miocene conifers are still extant. Most middle Miocene species of dicotyledons, on the other hand, are extinct. By late Miocene (Barstovian), a large num- ber of living species was present, even among the dicot- yledons. Of the 22 specifically identified Stewart Spring dicotyledons, 7, or 32 percent, are extant. In the Clarendonian Goose Creek flora, this reaches 50 percent. It should be noted that the dicotyledons are almost certainly woody, and the percentages for her- baceous dicotyledons may be considerably different. The application of the concept of "ecospecies" to taxonomy has been rejected here; size of foliage is not considered to be a valid taxonomic criterion. The drawings of marginal venation include the venation only to the level of tertiaries. Specimens are deposited in the U.S. National Mu- seum (USNM) or in the University of California Mu- seum of Paleontology, Berkeley (UCMP). Class GYMNOSPERMAE Order CONIFERALES Family PINACEAE Genus ABIES (Tourn.) Linnaeus Abies concolor Lindley Plate 1, figure 10; plate 6, figures 1-3, 6, 10, 11 Abies concolor Lindley, 1850, Jour. Hort. Soc. London, v. 5, p. 210. Discussion.-The seeds, needle, and bract from the Stewart Spring localities figured here can be matched by the respective organs of the extant Abies concolor. Probably some specimens assigned to A. concoloroides Brown by various authors also represent A. concolor, but the former species contains a variety of types, most of which are closer to extant species other than 4. concolor. The Fingerrock specimen here assigned to Abies con- color appears to have a less rectangular wing than is typical of seeds of that species. More specimens may indicate that this difference is consistent and would hence form the basis for a new species. Abies concolor has not yet been certainly recorded from the middle Miocene. Hypotypes: USNM 42025, 42032-42037, UCMP 8600-8603. Occurrence: Fingerrock, Stewart Spring. Abies sp. Figure 5 Discussion.-This fragmentary seed, with the sharply expanded and relatively large wing, is similar to seeds SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY of the extant Abies magnifica var. shastensis Lemmon. More fossil material, however, is needed in order to establish the specific relationship. Specimen: USNM 42031. Occurrence: Stewart Spring. FiGurE 5.-Abies sp. USNM 42031, X 1. Genus LARIX Tourn. ex Adanson Larix occidentalis Nuttall Plate 6, figures 23, 28, 29 Lariz occidentalis Nuttall, 1849, Sylva North Am., v. 3, p. 143. Discussion.-The twigs and seed figured here repre- sent the first validated record of Lariz in the Tertiary of North America. The whorled decurrent and sparsely spaced needles are characteristic of foliage of the genus; as well, the elongated winged seed with the round seed is typical of Z. occidentalis. The general lack of Lariz in western Tertiary rocks is surprising in view of the large representation of other of the larch's living associates. The only other possible rec- ord is on the basis of wood of unknown age (Beck, 1945). Hypotypes: USNM 42040, 42041, UCMP 8604. Occurrence: Stewart Spring. Genus PICEA Link Picea breweriana S. Watson Plate 6, figures 4, 5, 8, 9, 13, 14, 19 Picea breweriana S. Watson, 1885, Proc. Am. Acad., v. 20, p. 378. Discussion. -Representatives of Picea breweriana that occur as fossils have been given the name of P. sonomensis Axelrod, although the fossils are in- distinguishable from seeds from extant plants of P. breweriana. As noted above, the former distribution of P. breweriana was much wider than at present; P. breweriana is truly relictual today. Mason (1947, p. 209) noted the close relationship between P. brew- eriana and P. engelmanni of the Rocky Mountains and suggested a common ancestry. - Of interest in this con- nection is a small collection of probable Neogene age from the Camelo Hills of Arizona ; the only two species present are P. engelmanni and Chamaecyparis noot- katensis. This association is, of course, apparently MIOCENE FLORAS FROM FINGERROCK WASH analogous to that of P. breweriana and C. nootkatensis in Nevada. Hypotypes: USNM 42042-42048, UCMP 8605, 8606. Occurrence: Stewart Spring. Picea magna MacGinitie Plate 1, figures 3 and 5; plate 6, figures 7, 12, 17, 18, and 22 Picea magna MacGinitie, 1953, Carnegie Inst. Washington Pub. 599, p. 83, pl. 18, figs. 5-7. Discussion. -MacGinitie (1953, p. 83) noted that Picea magna is a large-coned spruce unrelated to the extant American species but related to species in east- ern Asia. P. magna is one of the oldest known mega- fossil species of spruce in North America; it is first known in the Oligocene but app during the Clarendonian. Hypotypes: USNM 42027, 42028, 8608. Occurrence: Fingerrock, Stewart S arently became extinct 42049-42053, UCMP 8607, pring. Genus PINUS Linnaeus Pinus monticola Dougla Plate 1, figures s ex Lamb 2, 9 Pinus monticol« Douglas ex Lamb, 1832, Gen. Pin., v. 3, p. 87. Pinus latahensis Berry, 1929, U.S. Geol. Survey Prof. Paper 154, p. 238, pl. 49, fig. 7. Pinus monticolensis Berry, 1929, U.S. Geol. Survey Prof. Paper 154, p. 238, pl. 49, figs. 5, 8. 1934, U.S. Geol. Survey Prof. Paper 185, p. 104. Pinus tetrafolia Berry, 1929, U.S. Geol, Survey Prof. Paper 154, p. 238, pl. 49, fig. 6. Pinus quinifolia Smith, 1941, Am. p. 490, pl. 2, figs. 2, 8. | Pinus wheeleri auct. non Cockerell. C Carnegie Inst. Washington Pub. Axelrod, 1956, California Univ. Pu pl. 4, fig. 23 ; pl. 12, figs. 17, 18. Discussion.-All western Tert the extant Pinus monticola have b resent the same fossil species only tionship (Chaney and Axelrod, Ginitie (1953, p. 79), however, because two fossils have the same fossils do not necessarily belong idland Naturalist, v. 25, haney and Axelrod, 1959, 617, p. 148. bs. Geol. Sci., v. 33, p. 277, ary fossils related to een considered to rep- y because of this rela- 1959, p. 143). Mac- pointed out that just living equivalent, the to the same species. All the specimens on which the above citations are based are indistinguishable from of the extant P. monticola. Hypotypes: USNM 42016, UCMP 8609. Occurrence: Fingerrock. the respective organs Pinus ponderosa Douglas Plate 1, figures 1, 4; plate 8, Pinus ponderosa Douglas ex Lawson, 1 figures 32, 33 836, Agr. Manual, p. 354. N15 Pinus florissanti Lesquereux, 1883, U.S. Geol. Survey Terr. Rept., v. 8, p. 138, pl. 21, fig. 13. MacGinitie, 1953, Carnegie Inst. Washington Pub. 599, p. 84, pl. 19, fig. 2; pl. 20, figs. 1, 3, 4. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 276, pl. 4, figs. 19, 20 ; pl. 17, figs. 10, 11. Axelrod, 1958, California Univ. Pubs. Geol. Sci., v. 34, p. 126, pl. 17, fig. 8. Pinus macrophylla Berry, 1929, U.S. Geol. Survey Prof. Paper 154, p. 238, pl. 49, fig. 9. Discussion.-The correspondence of fossil seeds, needles, and cones often found in the same beds to the comparable organs of Pinus ponderosa is so close that the fossils should be assigned to the extant species. Hypotypes: USNM 42017, 42026, 42038, 42039, UCMP 8610. Occurrence: Stewart Spring, Fingerrock. Genus TSUGA Carriere Tsuga heterophylla Sargent Plate 6, figures 15, 16, 20, 21, 24 Tsuga heterophylla Sargent, 1895, Silva North Am., v. 7, p. 73. Discussion.-Numerous seeds found in the paper shales are referrable to the extant Tsuga Acterophylla, This species is today a mesophyte ; in the Cascade Range it increases in abundance relative to Pseudotsuga to the north. Hypotypes: USNM 42053-42057, UCMP 8611. Occurrence: Stewart Spring. Family CUPRESSACEAE Genus CHAMAECYPARIS Spach Chamaecyparis nootkatensis (Lambert) Spach Plate 6, figures 27, 30, 31, 34-37 Chamaecyparis nootkatensis (Lambert) Spach, 1842, Hist. Veg., v. 11, p. 333. Thuja dimorpha auct., non (Oliver) Chaney and Axelrod. Axel- rod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 279. pl. 4, fig. 24; pl. 12, figs. 1-4; pl. 18, figs. 1, 2; pl. 25, figs. 2, 3. Discussion.-Numerous cupressaceous shoots and cones can be matched by those of the extant Chamaecy- paris nootkatensis. The foliage of the long shoots can be confused with that of Thuja dimorphae (fig. 6B), but in the latter species the scales of the short shoots have the same shape and pattern of insertion as the long shoots. The short shoots of C. nootkatensis (fig. 6A) are distinct, with short and unflattened scales. The specimen figured as plate 6, figure 36, has attached cones which are clearly those of Chamaecyparis. Today Chamaecyparis nootkatensis is confined to the area west of the crest of the Cascades. Although southwest Nevada was probably more mesic in the Mio- cene than today, it is apparent that it was not as mesic as the area currently inhabited by C. mootkatensis. N16 Hence, it is reasonable to consider that the Nevada indi- viduals of this species represent a distinct ecotype. Hypotypes: USNM 42019-42024, UCMP 8613, 8614. Occurrence: Fingerrock, Stewart Spring. A B C 6.-Cupressaceae. A, Chamaecyparis nootkatensis (Lambert) Spach, hypotype USNM 42024. B, Thuja dimorpha (Oliver) Chaney and Axelrod, USNM 42059. C, Juniperus nevadensis Axelrod, hypo- type UCMP, X 10. Genus JUNIPERUS Juniperus nevadensis Axelrod Plate 6, figure 26 Juniperus nevadensis Axelrod, 1940, Washington Acad. Sci. Jour., v. 30, p. 170. 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 278, pl. 12, figs. 9-12; pl. 18, figs. 3, 4. Sabina linquaefolia auct. non (Lesquereux) Cockrell. Knowl- ton, 1928, U.S. Geol. Survey Prof. Paper 131, p. 187. Discussion.-Juniperus nevadensis specimens can be matched by at least two species of extant juniper. Hence, Axelrod's species is retained for fossil shoots indistinguishable from those of J. californica Carr. and J. utahensis (Engelm.) Lemm. Hypotype: UCMP 8612. Occurrence: Stewart Spring. Genus GLYPTOSTROBUS Endlicher G@lyptostrobus sp. Plate 1, figures 8, 11 Discussion.-Several shoots bearing axially arranged triangular leaves occur in the Fingerrock flora; these shoots are identical to those of @/lyptostrobus oregonen- sis from the Miocene of Oregon. Until associated or attached cones are found, however, no certain specific assignment can be made. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Specimens: USNM 41933, 41934. Occurrence: Fingerrock. Class ANGIOSPERMAE Subclass MONOCOTYLEDONES Order GLUMIFLORAE Family GRAMINEAE Genus POACITES Brongniart Poacites sp. Plate 7, figure 1 Discussion.-Remains of the vegetative parts of grass are abundant in the paper shales. It is possible that sev- eral types of grass are present, but the lack of attached reproductive structures precludes assignment to other than a form genus. Specimens: USNM 41973-41975, UCMP 8618, 8619. Occurrence: Stewart Spring. Family CYPERACEAE Genus CYPERACITES Schimper Cyperacites sp. Plate 1, figure 6 Discussion.-This specimen represents either a sedge or grass but is otherwise indeterminate. Specimen: USNM 41976. Occurrence: Fingerrock. Cyperacites sp. Plate 7, figure 2 Discussion.-The specimen figured represents a clump of a sedgelike plant, complete with roots in the original soil. Specimen: USNM 41972. Occurrence: Stewart Spring. Subclass DICOTYLEDONES Order SALICALES Family SALICACEAE Genus POPULUS Linnaeus Populus cedrusensis Wolfe, n. sp. Plate 7, figures 4, 5, 8, plate 8, figure 4; figure T Populus sonorensis Axelrod. - Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 284, pl. 5, figs. 5, 9-11. Description. simple, palmate ; shape broadly to narrowly ovate; length 3.5-5.0 em, width 1.5-4.0 em ; base narrowly to broadly rounded, apex acute to acu- minate; three primary veins, but one or both laterals often weakly developed and extending 14-14 the length of lamina ; three to five pairs of central secondaries de- parting at an angle of 35°%-60°, undulatory and looping at the margin but sending strong craspedodrome ter- tiaries into teeth; three to five lateral secondaries; ner- villes irregularly forking ; areoles irregularly polygonal, typically 2 mm across, intruded by dendroid compound freely ending veinlets; margin irregularly serrate, with one to seven sharp triangular teeth; petiole 2.0-2.7 em long. Discussion.-Several leaves in the Aldrich Station and Stewart Spring floras most closely resemble those produced by the extant Populus brandegeei Schneid. of Baja California. Similarities between leaves of the latter species and P. cedrusensis are the frequently aparallel and undulatory secondaries and the irregu- larly spaced sharp triangular teeth. Differences are in shape, which is typically only broadly ovate in P. bran- degeei, and in more numerous teeth of the extent species. Along the margin below the end of the lateral primaries, P. brandegeei has five to nine teeth, but in P. cedrusen- sis the maximum number is seven and often there are none. There are even fewer resemblances between leaves of Populus sonorensis and P. cedrusensis. The former species has leaves with relatively straight subparallel secondaries, blunt teeth, and a blunt rounded apex. It is questionable if P. sonorensis is closely related to either P. cedrusensis or P. brandegeei. Holotype: USNM 41876 P 4050, 4052, 4053. Paratypes: USNM 41877-41879; UC Occurrences: Stewart Spring. A B FrguRE 7.-Marginal venation of Populus. A, P. cedrusensis Wolfe, paratype USNM 41877. B, P. brandegeei monticola Wiggins, Recent, X 5. MIOCENE FLORAS FROM FINGERROCK WASH N17 Populus lindgreni Knowlton Plate 1, figure 12 Populus lindgreni Knowlton, 1898, U.S. Geol. Survey 18th Ann. Rept., p. 725, pl. 100, fig. 3. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 151, pl. 17, figs. 1-8. Discussion.-Chaney and Axelrod (1959) have shown that Populus lindgreni is not an aspen but is an extinct species related to P. heterophylla L. It should be noted, however, that even this relationship is distant. Hypotype: USNM 41947. Occurrence ; Fingerrock. Populus tremuloides Michaux Plate 8, figures 5, 6, T Populus tremuloides Michaux, 1803, Flora Boreali-Americana, v. 2, p. 243. Populus pliotremuloides Axelrod, 1937, Carnegie Inst. Washing- ton Pub. 476, p. 169, pl. 4, figs. 1-3. Condit, 1944, Carnegie Inst. Washington Pub. 553, p. 41. Axelrod, 1950, Carnegie Inst. Washington Pub. 590, p. 53, pl. 3, fig. 4; p. 201. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 34, p. 128, pl. 22, figs. 5-8. Populus lindgreni auct. non Knowlton. MacGinitie, 1933, Car- negie Inst. Washington Pub. 416, p. 49 [in part]. Discussion.-All the specimens on which the above citations are based are indistinguishable from leaves of the extant Populus tremuloides. There is a prevalent idea that leaves of P. tremuloides (or pliotremuloides) differ from those of P. voyana only by size; there are also several valid characters which separate these two species. In P. voyana the teeth are sharp, numerous, and glandular tipped, whereas in P. tremuloides they are crenate to simple rounded bumps, few, and glandu- lar tipped only near the apex, if at all. There are seven primary veins in P. voyanae, although the basal pair may be inconspicuous; in P. tremuloides there are five primaries although a rudimentary sixth is rarely pres- ent. The marginal areoles in P. tremuloides are in- truded, always admedially, by the freely ending vein- lets; marginal areoles are intruded both ab- and ad- medially by the veinlets in P. voyana. The stratigraphic relationship between Populus tremuloides and P. voyana appears to be clearcut. The latter species is known only from rocks of Arikareean and Hemingfordian ages, and P. tremuloides first ap- pears in the Barstovian. Hypotypes: USNM 41880, 41881, UCMP 8620. Occurrence: Stewart Spring. N18 Populus trichocarpa Torrey and Gray Plate 8, figures 3, 11, 12 Populus trichocarpa Torrey and Gray ex Hooker, 1836, Icones Plantarum, p. 878. Populus eotremuloides Knowlton, 1898, U.S. Geol. Survey 18th Ann. Rept., p. 725, pl. 100, figs. 1, 2; pl. 101, figs. 1, 2. Brooks, 1935, Carnegie Mus. Annals, v. 24, p. 282. LaMotte, 1936, Carnegie Inst. Washington Pub. 455, p. 114, pl. 5, figs. 7, 9. Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 169, pl. 47, fig. 1. Smith, 1941, Am. Midland Naturalist, v. 24, p. 496, pl. 3, fig. 4; pl. 4, fig. 7. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 282, pl. 18, figs. 7, 8; pl. 26, fig. 5. Populus alezanderi Dorf, 1930, Carnegie Inst. Washington Pub. 412, p. 75, pl. 6, figs. 10, 11; pl. 7, figs. 2, 3. Chaney, 1938, Carnegie Inst. Washington Pub. 476, p. 215, pl. 6, figs. 1, 5. Axelrod, 1944, Carnegie Inst. Washington Pub. 553, p. 281, pl. 48, fig. 4. Brown, 1949, Washington Acad. Sci. Jour., v. 39, p. 226, fig. 19. Axelrod, 1950, Carnegie Inst. Washington Pub. 590, p. 199, pl. 4, fig. 6. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 282, pl. 6, fig. 9, pl. 13, figs. 1, 2. Axelrod, 1958, California Univ. Pubs. Geol. Sci., v. 34, p. 128, pl. 19, figs. 1-11. Populus emersoni Condit, 1938, Carnegie Inst. Washington Pub. 476, p. 255, pl. 4, figs. 1, 2. Populus lindgreni auct. non Knowlton. Oliver, 1934, Carnegie Inst. Washington Pub. 455, p. 17 [part]. MacGinitie, 1933, Carnegie Inst. Washington Pub. 416, p. 49. Discussion. -All specimens of Barstovian or younger age previously referred to Populus eotremuloides and P. alexanderi prove to be identical with leaves of the extant P. trichocarpa. An undescribed species from the early and middle Miocene of the Oregon Cascades appears to be ancestral to P. trichocarpa. Hypotypes: USNM 41882-41884, UCMP 8621, 8622. Occurrence: Stewart Spring. Populus washoensis Brown Plate 7, figures 6, 7 Populus washoensis Brown, 1937, Washington Acad. Sci. Jour., v. 27, p. 516. Smith, 1939, Torrey Bot. Club Bull., v. 66, p. 467, pl. 10, fig. 1. Smith, 1941, Am. Midland Naturalist, v. 25, p. 496, pl. 3, figs. 1, 2, 6. Axelrod, 1944, Carnegie Inst. Washington Pub. 553, p. 98, pl. 22, figs. 1, 2. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 152, pl. 18, figs. 6-8 only. Populus booneana Smith, 1941, Am. Midland Naturalist, v. 25, p. 494, pl. 2, figs. 14, 15. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Populus subwashoensis Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 284, pl. 6, figs. 1-4; pl. 13, figs. 13, 14 only. 1958, California Univ. Pubs. Geol. Sci., v. 34, p. 128, pl. 22, figs. 1-4. Populus lindgreni auct. non Knowlton. Inst. Washington Pub. 455, p. 17. LaMotte, 1936, Carnegie Inst. Washington Pub. 455, p. 115, pl. 4, fig. 1. Cebatha heteromorpha auct. non (Knowlton) Berry. LaMotte, 1936, Carnegie Inst. Washington Pub. 455, p. 126, pl. 9, fig. 1. Populus pliotremuloides auct. non Axelrod. Chaney, 1938, Carnegie Inst. Washington Pub. 476, p. 214, pl. 6, fig. 4; pl. 7, figs. 1¢, 14. Brown, 1949, Washington Acad. Sci. Jour., v. 30, p. 226, figs. 20-22. Oliver, 1934, Carnegie Discussion.-Not considering - small-leafed "eco- species" valid taxonomic species, I have united Populus subwashoensis with P. washoensis. Examination of the Populus leaves in the Cache Creek flora (Brown, 1949) shows them to be conspecific with P. washoensis, as suggested by Axelrod (1956, p. 285). The leaves of Populus washoensis have a highly vari- able number of teeth, from two per side to as many as ten. No other species, fossil or extant, has both leaves with a few large crude teeth and leaves with an evenly and moderately finely serrate margin. The latter variation is found in leaves of P. grandidentata Michaux, which also resemble leaves of P. washoensis in shape and general venation pattern. An even closer match can be noted in the leaves of the Asian P. bonatt Levl. Populus washoensis has not been reported from any pre-Barstovian flora. The youngest occurrence is in the early Blancan Cache Creek flora. Hypotypes : USNM 41885, 41886, UCMP 8623, 8624. Occurrence: Stewart Spring. Populus sp. Plate 7, figure 3 Discussion.-This specimen is a catkin of some species of Populus although which of the four species known from leaves the catkin represents is problematic. Most of the capsules are three parted, although a few are two parted. Specimen: USNM 41937. Occurrence: Stewart Spring. Genus SALIX Linnaeus Salix pelviga Wolfe, new name Plate 8, figures 1, 2, 8; figure 8 Myrica lanceolata Knowlton, 1898, U.S. Geol. Survey 18th Aun. Rept., pt. 3, p. 724, pl. 99, figs. 5,6. Raliz knowltoni Berry, 1927, U.S. Natl. Mus. Proc., v. 72, p. 9, pl. 2, fig. 1. Saliz hesperia auct. non (Knowlt n) Condit. Axelrod, 1956, California Uniy. Pubs. Geol. Sci., v. 83, p. 285, pl. 25, fig. 11. Discussion.-By synonymizing Myrica lanceolata with Saliz knowltoni, Berry (1927) automatically made his new species a junior synonym. A new com- bination, 8. lanceolata, however, would be a homonym, and hence a new name must be given for this species. Axelrod (1950, p. 254) is of the opinion that one of the types from the Payette is the same as his Saliz payettensis from the Alvord Creek. Both types of Myrica lanceolata, however, represent a relatively broad-leafed willow with numerous teeth, whereas S. payettensis is a narrow-leafed form with few teeth. The specimens called 8. Znowltoni by Axelrod (1956, p. 285) are entire margined, short and often obvate leaves unlike the types of either 8. pelviga or S. know!- toni. Neither Berry's description or figure of the latter species show that the type actually has distinct and sharp teeth, although they reveal that the specimen is a' more linear leaf than any of Axelrod's specimens. The closest species to Saliz pelviga is 8. truckeana Chaney from the Dalles Formation. This latter form appears to be a considerably more linear leaf, although there may be an overlap in this feature. Hypotypes: USNM 41958, 41959, UCMP 8625, 8626. Occurrence: Stewart Spring. A B 8.-Marginal venation of Saliz. A type USNM 41958. Saliz pelviga Wolfe, hypo- B, S. nigra Marsh, Recent, X 5. MIOCENE FLORAS FROM FINGERROCK WASH N19 Order GARRYALES Family GARRYACEAE Genus GARRYA Douglas Garrya axelrodi Wolfe, n. sp. Plate 12, figure 4, figure 9 Description.-Leaves simple, pinnate; shape oval; length 3.8-9 cm, width 24.5 em; apex narrowly rounded, but spinetipped ; base cuneate, decurrent along petiole; eight or nine pairs of secondaries, departing from midrib at an angle of 30°-40°, curving apically, undulatory, forking about two-thirds the distance to the margin, forming a series of irregularly shaped loops; tertiaries and quaternaries forming marginal loops; intersecondaries frequent and conspicuous; ner- villes irregularly branching, departing from the basal sides of the secondaries perpendicular to midrib and from the apical sides perpendicular to the secondaries ; areoles irregularly polygonal, less than 0.5 mm in diam- eter, intruded by once or twice branching freely end- ing veinlets; margin entire; petiole not complete, but at least 0.6 mm long. Discussion.-The undulatory forking secondaries and the irregular series of marginal loops indicate that these fossils are referrable to Garrya. The closest extant species to G. azelrodi is G. elliptica Dougl. from north- ern and central California. The primary difference between leaves of the two species is in shape-in @. axelrodi the length to width ratio is 2:1 but in G. elliptica the ratio is typically 1.5 :1. Axelrod (1944c, p. 204) noted that Garrya elliptica leaves are entire, rather than revolute or undulate, in the more mesic parts of this species' range, and only entire-margined leaves of G. axelrodi are known. Three other records of fossil Garrya are known. G. masoni Dorf has been reported from the middle and late Pliocene of California (Dorf, 1930, p. 104; Axel- rod, 1944c, p. 204). None of the leaves on which these records are based can be separated from leaves of G. elliptica. Holotype: USNM 41935. Paratype: USNM 41936, UCMP 8627 (counterpart). Occurrence: Stewart Spring. N20 B C FicurB 9.-Marginal venation of Garrya. A, G. agelrodi Wolfe, holo- type USNM 41935. B, @. laurifolia Hartw., Recent. C, G. elliptica Dougl., Recent, X 5. Order JUGLANDALES Family JUGLANDACEAE Genus CARYA Nuttall Carya bendirei (Lesquereux) Chaney and Axelrod Plate 1, figure T Carya bendirei (Lesquereux) Chaney and Axelrod, 1959, Car- negie Inst. Washington Pub. 617, p. 155, pl. 19, figs. 1-5. Rhus bendirei Lesquereux, 1888, Proc. U.S. Natl. Mus., v. 11, p. 15, pl. 9, fig. 2. arya bendirei is the most widespread and abundant hickory in the Miocene of the north- western United States This occurrence is the most southerly for the species. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Although Carya bendirei has been thought to be re- lated to the east American species of Zucarye (Chaney and Axelrod, 1959, p. 155), details of the ultimate and marginal venation and of the teeth indicate that this species and its relatives are most closely related to the subtropical Asian C. tonkinensis LeComte. The phylad to which C. bendirei belongs extends back into the Eocene of Washington and British Columbia. Hypotype: USNM 41943. Occurrence: Fingerrock. Genus JUGLANS Linnaeus Juglans major (Torrey) Heller Plate 8, figures 9, 10 Jugins major (Torrey) Heller, 1900, Muhlenbergia, v. 1, p. 50. Manning, 1957, Arnold Arbor. Jour., v. 38, p. 136 (see synonymy). Carpinus grandis auct. non Unger. Axelrod, 1944, Carnegie Inst. Washington Pub. 553, p. 254, pl. 43, fig. 6. Discussion.-Both the Stewart Spring specimens and the one described from Alvord Creek as Carpinus can be matched by leaflets of the extant Juglans major. The Alvord Creek specimen has numerous campto- drome secondaries and cannot be Carpinus ; the truncate base and short petiolule are features more frequently found in forma stellate Manning than in typical J. major (Manning, 1957, p. 139). Hypotypes: USNM 41960, 41961, UCMP 8628. Occurrence: Stewart Spring. Order FAGALES Family BETULACEAE Genus ALNUS Linnaeus Alnus relata (Knowlton) Brown Plate 1, figure 13 Alnus relatus (Knowlton) Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 49, figs. 1-6. Phyllites relatus Knowlton, 1926, U.S. Geol. Survey Prof. Paper 140, p. 48, pl. 28, fig. 8. Discussion.-E. P. Klucking (oral communication, 1959) stated that Almus relata, as conceptualized by Brown (1937) and Chaney and Axelrod (1959), con- tains a heterogeneous assortment of species. Until the time that Klucking's revision of Tertiary Betulaceae of North America is published, little stratigraphic sig- nificance should be attributed to A. relata. Hypotype: USNM 41969. Occurrence: Fingerrock. MIOCENE FLORAS FROM FINGERROCK WASH Genus BETULA Linnaeus Betula thor Knowlton Plate 1, figure 14 Betula thor Knowlton, 1926, U.S. Geol. Survey Prof. Paper 140, p. 35, pl. 17, fig. 8. Betula fairii auct. non Knowlton. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 160, in part, pl. 23, fig. 1 only. Discussion.-The similarity of the Fingerrock speci- men to the Mascall specimen called Betula fairit and to the type of B. thor is considerable, but without examin- ing the specimens from the Blue Mountains flora I hesi- tate to place them in synonymy. Some of the latter appear to have basally pointing teeth and would there- fore be Alnus. The types of B. fairii are all Alnus on the character of the teeth. Hypotype: USNM 41971 Occurrence: Fingerrock. Betula sp. Plate 9, figure 1; figure 10 Discussion.-One incomplete specimen has secondary veins bending apically near the ends of the teeth; this is characteristic of leaves of Betula (E. P. Klucking, oral communication, 1959). Although the specimen appears to be conspecific with Betula lacustris MacG., specific determination should await a more complete specimen. Apecimen: USNM 42008, UCMP 8629. Occurrence: Stewart Spring. FiGURrE 10.-Marginal venation of Betula. B. sp., USNM 42008, x 5. 695-377 0O-63--3 N21 Family FAGACEAE Genus QUERCUS Linnaeus Quercus chrysolepis Liebmann Plate 2, figures 1-10, 14; plate 9, figures 2, 3, 5-7, 12, 16 Quercus chrysolepis Liebmann, 1854, Danske Vidensk selsk. Forh., p. 173. Discussion.-Numerous leaves of oak clearly related to the extant Quercus chrysolepis have been reported from the Neogene of western North America under the names of Q. conveza Lesq., Q. brown Brooks, and Q. hannibali Dorf. The type specimens of Q. convexa are Castamopsis, which can be readily distinguished from Quercus on the basis of ultimate venation. It should be noted that the extant American species of Castamnopsis are the only ones that can be so distinguished on ulti- mate venation. In addition, some of the Stinking Water specimens of Quereus Aannibalé (Chaney and Axelrod, 1959, p. 168) are also referable on the basis of ultimate venation to CGastaenmnopsis. Probably most specimens of Q. Aannibali are Q. chrysolepis, but the solution to this problem will have to await a thorough study of west American fossil nonlobed oaks. The suites from both the Fingerrock and Stewart Spring floras can be matched in all characters by Q. chrysolepis leaves. Leaves either identical with or closely resembling those of Q. chrysolepis are found in abundance in the Neogene of central British Columbia. This indicates that Q. cArysolepis or an ancestor was present in the northwest mesophytic flora, and that, when conditions approached aridity, the live oak assumed a more domi- nant role in the flora. Hypotypes: USNM 41887-41904, UCMP 8630-8639. Occurrences: Fingerrock, Stewart Spring. Quercus cedrusensis Wolfe, n. sp. Plate 9, figure 15 Description.-Leaf simple, pinnate; shape oval; length 6.9 cm, width 4.2 em; base narrowly cordate, apex acute; 11 pairs of subparallel secondaries, depart- ing at an angle of 50°%-90°, straight until forking near margin, craspedodrome; no intersecondaries; nervilles irregularly percurrent, 1-2 mm apart; areoles 0.3-0.5 mm in diameter, irregularly polygonal, either lacking freely ending veinlets or with linear simple veinlets; margin with conspicuous marginal vein, and seven small dentate-spinose teeth; petiole more than 0.3 em long. Discussion.-In grosser aspects of venation and mar- gin, as well as in ultimate venation, this fossil is similar to the leaves of the extant Quercus agrifolia Nees. This latter species, however, has leaves typically with six N22 pairs of secondaries and a correspondingly greater num- ber of intersecondaries; in addition, the intercostal ven- ation is irregular with the nervilles about 4 mm apart. Another extant species, Q. fulva Liebm., has leaves that are more similar to Q. cedrusensis in intercostal vena- tion and numbers of secondaries. Q. fulva, however, lacks teeth in the basal half of the lamina and the see- ondaries typically depart at an angle of 40°. Holotype: USNM 41968. Occurrence: Stewart Spring. Quercus pseudolyrata Lesquereux Plate 3, figure 1 Quercus pseudolyrata Lesquereux, 1878, Harvard Coll. Mus. Comp. Zoology Mem., v. 6, no. 2, p. 8, pL. 2, figs. 1, 2. 1888, U.S. Natl. Mus. Proc., v. 11, p. 17, pl. 10, fig. 1. Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 48. Berry, 1931, U.S. Geol. Survey Prof. Paper 170, p. 34. Chaney and Axelrod, 1959, (in part). Carnegie Inst. Wash- ington Pub. 617, p. 169, pl. 38, figs. 1-3 only. Quercus pseudolyrata acutiloba Lesquereux, 1888, Harvard Coll. Mus. Comp. Zoology Mem., v. 6, No. 2, p. 17, pl. 11, fig. 2. Quercus pseudolyrata brevifolia Lesquereux, 1888, Harvard Coll. Mus. Comp. Zoology Mem., v. 6, No. 2, p. 18, pl. 10, fig. 2. Quercus pseudolyrata latifolia Lesquereux, 1888, Harvard Coll. Mus. Comp. Zoology Mem., v. 6, no. 2, p. 18, pl. 12, fig. 1. Quercus pseudolyrata obtusiloba Lesquereux, 1888, Harvard Coll. Mus. Comp. Zoology Mem., v. 6, no. 2, p. 18, pl. 10, fig. 3. Quercus merriami Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 49, pl. 6, figs. 6, 7 ; pl. 7, figs. 4, 5. Berry, 1929, U.S. Geol. Survey Prof. Paper 170, p. 34. Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 172. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 169, pl. 27, figs. 3-8. : Quercus duriuscula Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 50, pl. 8, fig. 2. Berry, 1934, U.S. Geol. Survey, Prof. Paper 185, p. 109. Quercus ursina Knowlton, 1902, U.S. Geol, Survey Bull. 204, p. 51, pl. 7, figs. 2, 3. Berry, 1929, U.S. Geol. Survey Prof. Paper 154, p. 246. Berry, 1938, Torrey Bot. Club Bull., v. 65, p. 92, text fig. 8. Discussion.-It is the opinion of Chaney and Axelrod (1959) that Q. pseudolyrata and Q. merriami are dis- tinct species, but the intergradations of morphologic characters displayed by specimens from the Mascall Formation indicates that the two species should be syn- onymized. If there were two distinct populations or species present, a statistical analysis of morphologic characters should indicate this by values clustering about two norms.. However, two characters selected for analysis (degree of dissection of the lamina and numbers of lobations) indicate that we are dealing with one population. Thus far, Quercus pseudolyrata is known only from beds of Hemingfordian or early Barstovian age. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Younger specimens show a considerably greater dis- section of the lamina, a greater number of lobations, and more leaves with compound lobations. These speci- mens will be referred to Q. deffexiloba Smith. Older specimens from the Eagle Creek and equivalent forma- tions vary from Q. pseudolyrata in the opposite direc- tion, and form the basis for a new species. Hypotypes: USNM 41905, 41906, UCMP 8640. Occurrence: Fingerrock. Quercus simulata Knowlton Plate 2, figures 11-13 Quercus simulata Knowlton, 1898, U.S. Geol. Survey 18th Ann. Rept., pt. 3, p. 728, pl. 101, fig. 4; pl. 102, figs. 1, 2. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 171 (see synonymy), pl. 30, figs. 2, 3, 5-8; pl. 31, figs. 1-4. Discussion.-Most authors have related Quercus sim- wlata to the extant Asian Q. myrsinaeflora Blume. Al- though the resemblances of the foliage of the two species recommends itself to such a relationship, there are some doubts. The group of oaks to which Q. myrsinaef olia belongs has, by some authors, been segregated into a dis- tinct genus, Cyelobalanopsis. This distinction is based, in part, on the peculiar acorn cupule which has its scales fused into a series of overlapping cups. This type of cupule would be readily recognized as a compressed fossil, but none of the several hundred cupules found associated with Q. simulata leaves are of that type. If just the entire-margined leaves of Quercus simu- lata were known, they would be related to the linear varieties of Q. chrysolepis Liebm. Therefore, consider- ing the lack of substantiating ecupules, as well as foliar morphology, Q. simulata is here considered to represent an extinct line distantly related to Q. chrysolepis. Hypotypes: USNM 41938-41940, UCMP 8641. Occurrence: Fingerrock. Order URTICALES Family ULMACEAE Genus ULMUS Linnaeus Ulmus newberryi Knowlton Plate 3, figures 4, 6, Uimus newberryi, Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 54, pl. 9, fig. 4. Discussion.-Leaves of Ulmus newberryi are charac- terized by their narrowly rounded base and oval shape, as opposed to those of U. speciosa which are broadly cordate and ovate. Hypotypes: USNM 41942, UCMP 8642, 8643. Occurrence: Fingerrock. MIOCENE FLORAS FROM Genus ZELKOVA Spach Zelkova oregoniana (Knowlton) Brown Plate 3, figures 2, 3, 5 Zelkova oregoniana (Knowlton) Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 173, (see synonymy), pl. 51, figs. 11-15. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 174, pl. 31, figs. 5-8. Myrica oregoniana Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 33, pl. 3, fig. 4. Discussion.-In the Great Basin, Zelkove has not been demonstrated to occur in strata younger than Bar- stovian, but west of the Cascades it is known in the Troutdale flora (Chaney, 1944) of probable Claren- donian age. The fragmentary specimens called Z. ne- vadensis Axelrod do not appear to differ specifically from Z. oregoniana. Hypotypes : USNM 41944-41946, UCMP 8643. Occurrence: Fingerrock. Order RANALES Family BERBERIDACEAE Genus MAHONIA Nuttall Mahonia reticulata (MacGinitie) Brown Plate 4, figure 3; plate 9, figures 8-10 Mahonia reticulata (MacGinitie) Brown, 1987, U.S. Geol. Sur- vey Prof. Paper 186, p. 175, pl. 52, fig. 4. Smith, 1939, Michigan Acad. Sci. Papers, v. 24, p. 114. Axelrod, 1944, Carnegie Inst. Washington Pub. 558, p. 255, pl. 43, fig. 7. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 296, pl. 8, fig. 16; pl. 14, figs. 3, 4, pl. 21, figs. 1-3; pl. 29, fig. 5. Chaney and Axelrod, 1959, Carnegie Inst. Washington Pub. 617, p. 176, pl. 33, figs. 1, 4. Clematis reticulata MacGinitie, 1933, Carnegie Inst. Washing- ton Pub. 416, p. 54, pl. 6, fig. 4. Odostemon hollicki auct. non Dorf. MacGinitie, 1933, Carnegie Inst. Washington Pub. 416, p. 55, pl. 7, figs. 1, 3, 5. Odostemon simplex auct. non (Newberry) Cockerell. Berry, 1934, U.S. Geol. Survey Prof. Paper 185, p. 112, pl. 23, fig 1, only. - Dorf, 1936, Carnegie Inst. Washington Pub. 476, p. 118. Mahonia hollicki (Dorf) of Arnold (non-typic), 1936, Michigan Univ., Mus. Paleontology, Contr., v. 5, p. 61, pl. 2, figs. 3-8; pl. 3, figs, 5, 7, 9. Discussion.-Thus far, Mahonia reticulata has been substantiated only to the east of the Sierra-Cascade axis. The one western slope record (Axelrod, 1950, p. 60) is based on a fragmentary specimen that appears to be Mahonia repens (Lindl.) Don. The most closely related extant species is Mahkonic repens. Leaflets of this latter species, however, are neither entire margined nor as cuneate as those of M. reticulata. Hypotypes: USNM 41951-41953, UCMP 8644. Occurrence: Fingerrock, Stewart Spring. FINGERROCK WASH N23 Order ROSALES Family SAXIFRAGACEAE Genus PHILADELPHUS Linnaeus Philadelphus nevadensis condit Philadelphus nevadensis Condit, 1944 Carnegie Inst. Washing- ton Pub. 553, p. 79, pl. 16, fig. 2. Philadelphus bendirei auct. non (Knowlton) Chaney. Axel- rod, 1939, Carnegie Inst. Washington Pub. 516, p. 104. Discussion.-Leaves of Philadelphus nevadensis are typically 114 to 2 times as long as broad in contrast to those of P. lewisi Pursh which are typically as long as broad. In addition, the most basal pair of secondaries depart, in P. nevadensis, almost at the base of the leaf, but in P. Zewisi they depart above the base an eighth to a quarter of the length of the lamina. Hypotype: USNM 41907. Occurrence: Stewart Spring. Genus RIBES Linnaeus Ribes webbi Wolfe, n. sp. Plate 9, figures 13, 14, 17, 18 Description.-Leaf simple, palmate ; shape orbicular ; apex rounded, base truncate to cordate; length 0.8-1.8 cm, width 1-2.2 em; seven primary veins spreading out in a fanlike fashion, giving off one to three secondary veins; secondaries craspedodrome; tertiary venation obscure; margin with three to five lobes, which are compoundly serrate; petiole 1 cm long. Discussion.-These fossils are nearly identical to leaves of the extant Ribes cereum Dougl. The only major difference is that the margin of the latter is more finely divided (compoundly serrate) than in leaves of R. webbi. This species is named in honor of Mr. S. David Webb. Holotype: USNM 41908. Paratypes: USNM 41909-41911, UCMP 8645, 8646. Occurrence: Stewart Spring. Ribes (Grossularia) sp. Plate 9, figure 11 Discussion.-The one leaf figured is deeply incised and has a few compoundly serrate teeth; hence it is referable to Grossularia. Foliage of extant species of this subgenus does not, in general, appear to be specifi- cally diagnostic on the basis of a single leaf. It may be noted, however, that the fossil can be matched by some leaves of Ribes californica (H. and A.) Cov. and Britt. Specimen: UCMP 8647. Occurrence: Stewart Spring. N24 Family PLATANACEAE Genus PLATANUS Linnaeus Platanus bendirei (Lesquereux) Wolfe, n. comb. Plate 4, figures 1, 2, 4 Acer bendirei Lesquereux, 1888 [in part], U.S. Natl. Mus. Proc., v. 11, p. 14, pl. 5, fig. 5; pl. 6, fig. 1; pl. 7, fig. 1. Discussion.-The description of Acer bendirei makes clear that Lesquereux was describing primarily those leaves with closely spaced scalloped sinuses, rather than the one discordant specimen of Acer macropAyllum. Hence, I have resurrected the epithet of "bendire?" to apply to the sycamores in the Mascall and equivalent beds. Platanus bendirei is distinguished from the younger P. dissecta Lesq. by features of margin and shape. No leaves of P. dissecta are known to have the finely and compoundly serrate margin common in P. bendirei. In addition, P. bendirei is typically three lobed. Hypotypes: USNM 41941, UCMP 8648, 8649. Occurrence: Fingerrock. Family ROSACEAE Genus AMELANCHIER Medicus Amelanchier subserrata H. V. Smith Plate 5, figure 1 Amelanchier subserrata H. V. Smith, 1941, Am. Midland Natur- alist, v. 25, p. 514, pl. 18, fig. 1. Amelanchier dignate auct. non (Knowltén) Brown. Smith, 1941, Am. Midland Naturalist, v. 25, p. 514, pl. 13, fig. 2. Prunus cove@ auct. non Chaney. Smith, 1941, Am. Midland Naturalist, v. 25, p. 516, pl. 13, fig. 10. Amelanchier scudderi auct. non Cockerell. Berry, 1928, U.S. Geol. Survey Prof. Paper 154, p. 252, pl. 55, fig. 4. Amelanchier grayi auct. non Chaney. MacGinitie, 1933, Car- negie Inst., Washington Pub. 416, p. 58. Discussion.-T wo phylads of Amelanchier -can be rec- ognized in the western Tertiary: the A. cove@ and 4. seudderi phylads. The latter phylad is known in the middle Oligocene and is represented by the following successively younger species: 4. gray?, A. dignata, A. alvordensis, and the Recent A. florida. The nervilles of the A. scudderi group's leaves are, when compared to those of the A. cove@ phylad, less numerous (about half as many), depart from the secondaries at a higher angle (normally 60°-90° rather than about 45°), and are straighter and less branching. The A. type of leaf is known in A. subserrate and A. alnifolia Nutt. Chaney and Axelrod (1959) synonymized A. subser- rata and A. covea, but the latter has leaf bases that are consistently cuneate, whereas A. swbserrate has a broad typically cordate base. Both species, however, SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY have small often denticulate teeth; this character dis- tinguishes both from A. almifolia with its large coarse teeth. The Mascall specimen assigned to A. by Chaney and Axelrod is too poorly preserved and in- complete for familial determination. Hypotype: USNM 41954. Occurrence: Fingerrock. Amelanchier cusicki Fernald Plate 10, figure 9; figure 11 Amellanchier cusicki Fernald, 1899, Erythea, v. 2, p. 121. Discussion. -Leaves of Amelanchier cusicki differ from those of other west American species of the genus by having an acute apex and, frequently, a few large teeth. - All other Neogene records in the Western United States represent the phylads with a rounded apex and numerous teeth. However, early Miocene members of A. subserratqa do occasionally have an acute apex, as does the Oligocene A. seudderi. Hypotype: USNM 42009. Occurrence: Stewart Spring. FIGURE 11.-Marginal venation of Amelanchier. A. cusicki Fernald, hypotype USNM 42009, X 5. Genus CERCOCARPUS Humboldt, Bonpland, and Kunth Cercocarpus antiquus Lesquereux Plate 5, figure 2; plate 10, figures 2, 3; figure 12 Cercocarpus antiquus Lesquereux, 1878, Harvard Coll. Mus. Comp. Zoology, Mem., v. 6, no. 2, p. 37, pl. 10, figs. 6-11. Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 176, pl. 57, fig. 6. Condit, 1944, Carnegie Inst. Washington Pub. 553, p. 82, pl. 16, fig. 3. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 299, pl. 28, figs. 1, 12-14. Discussion.-Several citations of Cercocarpus anti- guus, for example Axelrod's (1944d, p. 256), are based on specimens that have comparatively small teeth and a linear decidedly obovate shape, as contrasted with the typic specimens that have large teeth and are dia- MIOCENE FLORAS «FROM FINGERROCK WASH mond shaped. Therefore, I do not think that all the citations synonymized by Axelrod ( 1956, p. 299) with C. antiquus should be considered one species. After examining all materal of Cercocarpus from the Table Mountain locality, I cannot agree with Axelrod (1956, p. 299) that obovate as well as oval leaves are present. Cercocarpus is one of the genera most typical of the flora of southwestern North America. Species are found as far north as southern Oregon and as far south as northern Mexico. Today all the species are found in subhumid to semiarid climates. However, the fossil record of broad-leafed serrate Cercocarpus indicates that the genus or more accurately the member species of the genus had a wider range, both geographic and physiologic. The first record is C. myricaefolius, a large-leafed species represented in the middle Oligocene Florissant flora of central Colorado (Mac- Ginitie, 1953, p. 115). Another species is found in the correlative or slightly younger Ruby Valley flora of western Montana (Becker, 1961, p. 71). In both of these floras, Cercocarpus was apparently a common plant, associated with Sequoia, M. etasequoia, Chamae- eyparis, and mesophytic dicotyledons. In the Codil- leran region, however, as judged by these two described floras, the climate became drier to the south. In the early Miocene of the Oregon Cascades, a species belonging to the Ruby Valley lineage is well represented in a decidedly mesic flora. By the Barstovian, a decend- ant species, C. anfiquus, is found from southwestern Nevada north to northeastern Oregon and west into California. It is from C. antiquus that the extant C. betuloides is probably derived. Thus, this phylad has become adapted to progressively drier conditions. In the Neogene of the Great Basin, Cercocarpus hot- mest first appears. Axelrod (1944d, p. 257) related this species to the extant C'. paucidentatus, C. brevifiorus, and C. eximinus. Although this relationship is close, it is not likely that any of the western or northern Great Basin populations are phylogenetically related to the populations of the extant species. The occurrence of C. hotmesi in the Creede flora of Colorado indicates that the Cordilleran populations were more likely ancestral to the Recent ones. The relationship of C. Aolmesi is with the northern group of Cercocarpus that occurs in the Florissant and Ruby Valley floras. The Tertiary record is very poor in Arizona and northern Mexico. In view of the above history of Cer- cocarpus, however, it is likely that the phylads of the extant species of northern Mexico were differentiated in the later Oligocene and Miocene of the southern Cordil- leran region. Hypotypes: USNM 41912-41914, UCMP 8650, 8651. Occurence: Fingerrock, Stewart Spring. N25 A B Ficuc®E 12.-Marginal venation of Cercocarpus. A, C. antiquus Lesque- reux, hypotype USNM 41913. B, C. betuloides Nutt., Recent, X 5. 128° 120° 112° 46° 42° 38° 34° 30° |_ FIGURE 13.-Distribution map of fossil Cercocarpus. N26 Genus HOLODISCUS Maxim Holodiscus fryi Wolfe, n. sp. Plate 10, figures 8, 12; figure 14 Description. -Leaf simple, pinnate; shape orbicular ; apex rounded, base cuneate with lamina decurrent along petiole; length 1.0-1.3 em, width 0.9-1.2 em; three or four pairs of straight craspedodrome secondaries; one or two craspedodrome tertiaries departing from the basal side of the basal secondaries; mesh not preserved ; margin compoundly serrate, with three rounded pri- mary teeth, petiole 0.5 cm long. Discussion.-These leaves are similar to those of Holo- discus dumosus (Nutt.) Heller. In the living species, the leaves typically have four primary teeth, and the secondaries depart at a lower angle. Holotype: USNM 41915, UCMP 8674 (counterpart). Paratype: USNM 41916, UCMP 8652 (counterpart). Occurrence: Stewart Spring. Genus LYONOTHAMNUS A. Gray Lyonothamnus parvifolius (Axelrod) Wolfe, n. comb. Plate 10, figures 1, 14, 15; plate 11, figures, 1, 3-6; figure 15 Comptonia parvifolia Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 287, pl. 8, figs. 13-15 ; pl. 28, fig. 10. Discussion.-This species is abundantly represented in the paper shales by numerous compound leaves. The identity of these specimens with those of Axelrod's Comptonia is clear, although only his Middelgate speci- men (his pl. 28, fig. 10) shows, by the alate rachis, that it was part of a compound leaf. One certain feature that distinguishes leaves of Comptonia from those of Lyonothammus is that those of the latter are compound and those of Comptonia are simple (and hence could not have an alate rachis). Another distinguishing fea- ture is in the venation of the leaflet lobations ; in Lyono- thammus, the most apical secondary terminates at the tip of the lobation. In Comptonia, the secondary that goes to the tip of the lobation is centrally located and there is at least one other, more apical, secondary in the lobation. Leaves of Lyonothammus parvifolius can be readily distinguished from those of the extant L. fZoribundus A. Gray by the fewer number of leaflets in the latter species (five as opposed to seven or nine in the fossil species). Moreover, the individual lobations of the leaflets are nearly square in L. fZoribundus (fig. 15), SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 9p, FIGURE 14.-Marginal venation of Holodiscus. H. fryi Wolfe, holotype USNM 41915, X 5. but in L. parvifolius the lobations are elongated in a direction perpendicular to the midrib. The past distribution of Lyonothamnus is in interest- ing contrast to the present endemism on the Channel Islands (fig. 16). The first known record of the genus is in a flora of early Miocene age from the Oregon Cas- cades. Although this flora contains other genera of "Madro-Tertiary" type, for example Cercocarpus, Ar- butus, and Colubrina, the flora has a highly warm-tem- perate mesic aspect. This same species is known from the mesic Latah flora of Washington. L. parvifolius is closely related to, and probably descended from, this earlier species. Hence, L. parvifolius appears to be another subhumid derivative of a mesic species. On the other hand, the middle Miocene Lyonotham- nus mohavensis (Axelrod, 1939, p. 107) is closely related to the extant L. foribundus. - This phylad is thus recog- nizable as distinct from the northern one by middle Mio- cene. Such a distribution in space and time indicates that Lyonothammus was a member of the Cordilleran flora in the Oligocene, and, following the renewed up- lifting of that region in the later Oligocene, two popula- tions or groups of populations became isolated. The southern one contains the lineage leading to the insular L. floribundus, whereas the northern one became extinct at the close of the Miocene. Thus, the occurrence of Lyonothamnus in a flora should not necessarily be interpreted as indicating en- vironmental conditions similar to the present area of L. floribundus. It is evident that lineages have under- MIOCENE FLORAS FROM FINGERROCK WASH N27 A B FicUurE 15.-Venation of Lyonothamnus. A, L. parvifolius (Avelrod) 46° 42° 38° 34° 30° Wolfe, hypotoype USNM 42060. B, L. floribundus A. Gray, Recent, X 5. 0 FIGURE 16.-Distribution map of fossil Lyonothamnus. 695-377 0 - 63 - 4 gone considerable physiologic evolution since the Oli- gocene. Hypotypes: USNM 41917-41928, UCMP 8653, 8656. Occurrence: Stewart Spring. Genus PERAPHYLLUM Nuttall Peraphyllum vaccinifolium (Knowlton) Wolfe, n. comb. Plate 10, figures 4-6; figure 17 Saliz vaccinifolia Knowlton, 1901, U.S. Geol. Survey 21st Ann. Rept., pt. 2, p. 212, pl. 30, fig. 8. Saliz knowltoni auct. non Berry. Axelrod, 1956, California Univ. Pubs. Geol. Sci., v. 33, p. 285, in part, pl. 7, figs. 1, 2; pl. 13, figs. 6, 7. Discussion.-Of Knowlton's type material for this species, one specimen (his pl. 30, fig. 20), which Axel- rod (1989) placed in Saliz kernensis, is lost. The origi- nal figure of this specimen is so poor that the citation of 8. kernensis in the Esmeralda flora should be dis- carded. Another unfigured specimen has numerous sharp teeth and venation typical of S. succorensis. Knowlton's other figured and unfigured specimens, however, are similar in being linear-oval to obovate, having steeply ascending and angularly looped second- aries and an entire margin. The coarse pattern of the nervilles and the highly angular secondary loops of the fossils can be matched by the leaves of the extant Peraphyllum ramosissimum Nutt. This Recent species has leaves with a remotely toothed margin ; the fossils do not appear to have any definite teeth, although a few specimens have small undulations on the margin. Hypotypes: USNM 41965-41967, UCMP 8657. Occurrence: Stewart Spring. FIGURE 17.-Marginal venation of Peraphyllum. _ P. vaccinifolium (Knowlton) Wolfe, hypotype USNM 41967, x 5. N28 Genus PRUNUS Linnaeus Prunus sp. Plate 10, figures 11, 13 Discussion. -Two fragmentary leaves with percur- rent nervilles, camptodrome secondaries, and a finely serrate margin can be confidently assigned to Prunus. Without more complete specimens, the specific relation- ships of the species represented must remain specula- tive. However, these leaves do resemble the leaves of Prunus harneyensis Axelr. from the Alvord Creek flora. Specimens: USNM 41949, 41950. Occurrence: Stewart Spring. Genus ROSA Linnaeus Rosa sp. Plate 10, figure 7; figure 18 Discussion. -The difficulty of separating isolated leaflets of extant species of Rose makes determination of this one fossil speculative. It may be the same species as the leaflet called Rose miocemica (Axelrod, 1939, p. 111, pl. 8, fig. 12), but I prefer to maintain a conservative approach. The Stewart Spring leaflet also superficially resembles Rosa alvordensis (Axelrod, 1944d, p. 259, pl. 44, fig. 5), but on examining and clean- ing the holotype of that species, it proved to have a long petiole and to be a variant of Amelanchier alvordensis. Specimen: USNM 41924. Occurrence: Stewart Spring. FIGURE 18.-Marginal venation of Rosa. R. sp., USNM 41924, X 5. Genus SORBUS Linnaeus Sorbus sp. Discussion. -An incomplete specimen lacking a base has the margin and venation of leaflets of Sorbus. Specimen: USNM 41925. Occurrence: Stewart Spring. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Sorbus harneyensis Axelrod Plate 5, figure 3 Sorbus harneyensis Axelrod, 1944, Carnegie Inst. Washington Pub. 553, p. 259, pl. 44, figs. 6, 7. Discussion.-As Axelrod (1944c, p. 259) noted, the leaflets of Sorbus harneyensis are similar to those of the extant 8. scopulina Greene. The compound leaf fig- ured here has at least 13 leaflets and is thus in this respect also similar to 8. scopulina. Hypotype: USNM 41977. Occurrence: Fingerrock. Order SAPINDALES Family ANACARDIACEAE Genus SCHINUS Linnaeus Schinus savagei Wolfe, n. sp. Plate 12, figure 10; figure 19 Description. -Leaflet pinnate; shape oval; apex rounded, base rounded ; length 2 em, width 1.2 em ; eight pairs of straight to undulatory secondaries, forking submarginally, sending tertiary branches into teeth, and forming weak loops; nervilles branched, percur- rent; mesh with large polygons intruded by freely end- ing veinlets; margin simply and coarsely serrate; teeth rounded ; apetiolulate. Discussion.-This solitary leaflet has the undulatory forking secondaries typical of Schinus. Some species of Frazinus are also similar to the fossil, but in the latter genus the tertiary veins enter the teeth along the apical margin as opposed to the central entry in Schinus. The most closely related species is Schinus gracilipes Johnston, as evidenced by the foliar similarity. The fossil, however, has fewer secondaries and a broader shape than the extant leaves. Holotype: USNM 41926, UCMP 8658 (counterpart). Occurrence: Stewart Spring. Genus RHUS Linnaeus Rhus integrifolia (Nuttall) Bentham and Hooker Plate 12, figure 2 Rhus integriflora Bentham and Hooker, 1874, in Wheeler, Geog. and Geol. Explor., Rep. Botany, p. 84. Discussion.-The one Stewart Spring specimen of Rhus is an entire folded leaf; the counterpart has been cleaned to show the other side of the lamina. This spec- imen is indistinguishable from leaves of the extant Rhus integrifolia, except that the latter do not typically have a base as broadly rounded as the fossil. However, MIOCENE FLORAS FROM FINGERROCK WASH FrGURE 19.-Marginal venation of Achinus. $. savagei Wolfe, holotype USNM 41926, x 5. on the basis of one specimen, it is not possible to deter- mine whether this type of base is typical of the Stewart Spring form. Rhus integrifolia appears to be descended from the middle Miocene 2. preintegrifolia, which is found in the Tehachapi flora. R. integrifolia is the only definite "Madro-Tertiary" species in the Stewart Spring flora. Hypotype: USNM 42011, UCMP 8659 ( counterpart). Occurrence: Stewart Spring. Astronium mawbyi Wolfe, n. sp. Plate 12, figure 7; figure 20 Description.-Leaflet pinnate; shape asymmetrical, ovate; length 2.0 em, width 1.2 em; base asymmetrical and cuneate, apex acuminate; 13 pairs of secondaries, departing at an angle of 45°%-50°, straight but curving apically near margin to enter teeth; nervilles branch- ing, departing perpendicular to secondaries; tertiaries craspedodrome; mesh not preserved ; margin finely ser- rate with narrowly triangular teeth ; apetiolulate. Discussion.-This solitary leaflet has the asymmet- rical V-shaped base found in Astronium truncatum (Lesq.) MacG. A. mawbyi differs from leaflets of that species by being less asymmetrical, less linear, and more finely serrate. It is possible, however, that A. mawbyi is descended from A. truncatum. This species is named in honor of Mr. John Mawby. Holotype: USNM 41948. Occurence: Stewart Spring. N29 FrqurR 20.-Marginal venation of Astronium. A. mawbyi Wolfe, holo- type USNM 41948, x 5. Family ACERACEAE Genus ACER Linnaeus Acer bolanderi Lesquereux Plate 5, figure 7 Acer bolanderi Lesquereux, 1878, Harvard Coll. Mus. Comp. Zoology, Mem., v. 6, no. 2, p. 27, pl. 7, figs. 7-11. Chaney and Axelrod, 1959, p. 192 (see synonymy), pl. 39, figs. 7-12 ; pl. 40, fig. 7. Discussion.-This one seed appears referable to Acer bolanderi. This species is known from the late Heming- fordian through Barstovian. A closely related species is A. minutifolia Chaney from the early Miocene of Oregon. Hypotype: USNM 41955. Occurrence: Fingerrock. Acer macrophyllum Pursh Plate 5, figures 4-6 Acer macrophyllum Pursh, 1814, Fl. Am. Sept., v. 1, p. 267. Acer oregonianum Knowlton, 1902, U.S. Geol. Survey Bull. 204, p. 75, pl. 13, figs. 5, 7, 8. Jennings, 1920, Carnegie Mus., Mem., v. 8, p. 423, pl. 32, fig. 3. Oliver 1934, Carnegie Inst. Washington Pub. 45, p. 24. Chaney and Axelrod, 1959, Carnegie Inst. Washington 617, p. 195, pl. 41, figs. 11-14. Acer septilobatum Oliver, 1934, Carnegie Inst. Washington Pub. 455, p. 25, pl. 4, figs. 1, 2. Acer bendirei auct. non Lesquereux. Brown, 1937, U.S. Geol. Survey Prof. Paper 186, p. 179, pl. 58, figs. 20-22. Smith, 1938, Torrey Bot. Club Bull., v. 65, p. 561. Acer merriami auct. non Knowlton. MacGinitie, 1933, Car- negie Inst. Washington Pub. 416, p. 61, pl. 10, fig. 1. Lamotte, 1936, Carnegie Inst. Washington Pub. 455, p. 135, pl. 12, fig. 7. N30 Acer chaneyi auct. non Knowlton. MacGinitie, 1933, Carnegie Inst. Washington Pub. 416, p. 61. Discussion.-No paleobotanist has yet shown what characters distinguish recent seeds and leaves of Acer macrophyllum from the specimens on which the above citations are based. I also concur that the fossils and recent specimens are indistinguishable and have hence included them under the same epithet. Although Acer alvordensis Axelr. is clearly a maple of the macrophyllum-type, the deep dissection of the lamina, often into a compound leaf, is a feature not typically found in the living members of A. macro- phyllum. Axelrod (1944d, p. 261) noted that in the drier parts of its range A. macrophyllum is more deeply dissected, although not as deeply as in 4. alvordensis. Hypotypes: USNM 41956, 41957, UCMP 8660, 8661. Occurrence: Fingerrock. Family SAPINDACEAE Genus SAPINDUS Linnaeus Sapindus sp. Plate 12, figure 1 Discussion.-The specimen figured here is not suf- ficiently well preserved to make certain the generic ref- erence. The highly falcate shape of the leaflet, the revolute margin, and the looping secondaries, however, are features typically found in leaflets of Sapindus. Several leaflets possibly conspecific with the above specimen have been recorded from the Pliocene of Cali- fornia under the name of Sapindus oklahomensis Berry. All these specimens are linear in shape, but the Okla- homa material is typically linear-ovate and probably represents a separate species. Specimen: USNM 41970, UCMP 8662 (counterpart). Occurrence: Stewart Spring. Order RHAMNALES Family RHAMNACEAE Genus COLUBRINA Richard Colubrina sp. Plate 12, figure 3 Discussion.-One fragmentary palmate specimen has the coarse teeth with glands on the lamina that is characteristic of leaves of Colubrina. This specimen appears to be conspecific with a new species from the early Miocene of Oregon. Specimen: USNM 41927, UCMP 8663 (counterpart). Occurrence: Stewart Spring. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Order MYRTIFLORAE Family ELAEAGNACEAE Genus ELAEAGNUS Linnaeus Elaeagnus cedrusensis Wolfe, n. sp. Plate 12, figures 6, 8, 9; figure 21 Description. -Leaves simple, pinnate; shape oval to linear-oval; length 3.0-4.5 em, width 0.8-1.6 cm; base cuneate to broadly rounded with lamina decurrent along petiole; apex broadly to narrowly rounded ; mid- rib thick near base, thinning and forking before reach- ing apex; six to nine pairs of irregularly spaced sec- ondaries, departing at angles of 40°-90°, undulatory, forking in the broader leaves, looping apically in the linear leaves; intersecondaries numerous; nervilles irregularly branching and forming a coarse polygonal pattern ; areoles about 0.2 mm wide, intruded by once or twice branching freely ending veinlets; margin entire; petiole thick, 0.3-0.9 em long. Discussion.-In gross aspects of venation and shape these fossils resemble the leaves of the extant AZaeagnus utilis Nels. One peculiar feature of both fossil and Recent leaves is the tendency for the midrib to fork before reaching the apex. - No stellate trichomes, which are characteristic of the extant species, have been de- tected on the fossils, but the size of the individual hairs is about same as the grain size of the matrix and hence might not be preserved. The areoles in Z. utilis are about 0.5 mm wide in contrast to the width of 0.2 mm in E. cedrusensis. - This is the first authentic fossil record of Elaeagnus from North America. Holotype: USNM 41962, UCMP 8664 (counterpart). Paratypes: USNM 41963, 41964, UCMP 8665, 8666. Occurrence: Stewart Spring. < A B FiGuRB 21.-Apical venation of Elaeagnus. A, E. cedrusensis Wolfe, holotype USNM 41962. B, E. utilis Nels., Recent, X 5. MIOCENE FLORAS Order ERICALES Family ERICACEAE Genus ARBUTUS L. Arbutus traini MacGinitie Plate 5, figures 8, 9; plate 12, figures 11-14 Arbutus train MacGinitie, 1983, Carnegie Inst. Washington Pub. 416, p. 64, pl. 12, fig. 3; pl. 13, figs. 1, 2. Discussion.-The Stewart Spring specimens are typical of Arbutus traini in being either entire mar- gined or sharply serrate. The much broader leaves of the extant A. menziesi Pursh are, except in shape, simi- lar to the fossils. Whether A4. train? is directly ances- tral to A. menziesi is uncertain, although the fact that the former species is apparently older than A. menzies? does indicate such a relationship. Late Miocene speci- mens of A. traini from the Cascades are slightly broad- er than the Great Basin specimens, and this could be interpreted to mean that the coastal members of A4. train gave rise to A. menziesi. Today the distribution of the latter species is primarily along the western slopes of the Sierra-Cascade axis. Hypotypes: USNM 41928-41932, UCMP 8667-8669. Occurrence: Fingerrock, Stewart Spring. Genus ARCTOSTAPHYLOS Adanson Arctostaphylos masoni Wolfe, n. sp. Plate 11, figure 2 ; figure 22 Description.-Leaves simple, pinnate; oval to obo- vate; length 2.4-3.3 em, width 1.1-1.6 cm ; base cuneate, apex rounded to acuminate and spine tipped; six to eight pairs of secondaries departing at an angle of 30° 50°, curving apically, looping but giving off strong tertiary loops; marginal tertiaries forming a series of ladderlike loops with margin, often forking just sub- marginally; intersecondaries numerous and weak; ner- villes irregularly branching; ultimate venation not pre- served ; margin entire. Discussion.-The fossils have the unusual ladderlike marginal tertiaries (see fig. 22) characteristic of leaves of Arctostaphylos. In general features of shape and venation, A. masoni most closely resembles the extant A. nevadensis Gray, which has been recorded as a fossil under the name of A. verdiana (Axelrod, 1958, p. 133). A. masoni differs from A. nevadensis by having leaves FROM FINGERROCK WASH N31 that occasionally have a rounded apex and that have more numerous secondaries. Holotype: USNM 42000. Paratypes: USNM 42001, UCMP, 8670. Occurrence: Stewart Spring. A B FicurE 22.-Marginal venation of Arctostaphylos. A, A. masoni Wolfe, holotype USNM 42000. B, A. nevadensis A. Gray, Recent, X 5. INCERTAE SEDIS INDETERMINED LEAF Plate 12, figure 5 Discussion.-This leaf has a prominent mesh of large areoles intruded by much-branched freely ending vein- lets. The marginal venation is formed of a series of regularly shaped loops. The nervilles are irregularly branching. As yet, I have not seen any Recent leaf comparable to the fossil. There are superficial resem- blances to some leaves of Lauraceae, but the fossil lacks the basal secondaries characteristic of that family. Specimen: USNM 42012, UCMP 8673 (counterpart). Occurrence: Stewart Spring. INDETERMINED FLORAL REMAINS Plate 10, figures 10, 16-19 Discussion.-Several fossils of different types of in- florescences have been found. As impressions or com- pressions, most floral remains are difficult to determine because the three-dimensional relationship of the various parts is not known. - Suggestions as to the taxo- nomic relationships can be made, for example the four- parted calyx (pl. 10, fig. 19) could be Cruciferae, but even these suggestions are of dubious value. Specimens: 42013-42015, 42029, 42030. N32 REFERENCES CITED Axelrod, D. I., 1939, A Miocene flora from the western border of the Mohave desert: Carnegie Inst. Washington Pub. 516, 129 p., 12 pls. '- 1944a, The Mulholland flora : Carnegie Inst. Washington Pub. 553, p. 103-146, 8 pls. --- 1944b, The Oakdale flora: Carnegie Inst. Washington Pub. 553, p. 147-165, 2 pis. 1944c, The Sonoma flora: Carnegie Inst. Washington Pub. 553, p. 167-206, 6 pls. 19444, The Alvord Creek flora: Carnegie Inst. Washing- ton Pub. 553, p. 225-262, 7 pls. 1950, Studies in late Tertiary paleobotany : Carnegie Inst. Washington Pub. 590, 360 p., 19 pls. 1956, Mio-Pliocene floras from west-central Nevada : California Univ. Pubs. Geol. Sci., v. 83, 322 p., 32 pls. 1958, The Pliocene Verdi flora of western Nevada : Cali- fornia Univ. Pubs. Geol. Sci., v. 34, p. 91-160, pls. 13-28. Beck, G. F., 1945, Tertiary coniferous woods of western North America: Northwest Sci., v. 19, no. 8, p. 67-69. Becker, H. F., 1961, Oligocene plants from the upper Ruby River basin, southwestern Montana: Geol. Soc. America Mem., v. 82, 127 p., 32 pls. Berry, E. W., 1927, Flora of the Esmeralda formation in west- ern Nevada : U.S. Natl. Mus., Proc., v. 72, art. 28, 15 p., 2 pls. Brown, R. W., 1937, Addition to some fossil floras of the west- ern United States: U.S. Geol. Survey Prof. Paper 186-J, p. 163-206, pls. 45-63. --- 1940, A bracket fungus from the late Tertiary of south- western Idaho: Washington Acad. Sci. Jour., v. 29, p. 422- 424. 1949, Pliocene plants from Cache Valley, Utah: Wash- ington Acad. Sci. Jour., v. 89, p. 224-229. Chaney, R. W., 1936, The succession and distribution of Ceno- zoic floras around the northern Pacific Basin in Essays in Geobotany in honor of William Setchell: California Univ. Press, Berkeley, Calif., p. 55-85. 1944a, The Dalles flora : Carnegie Inst. Washington Pub. 553, p. 285-321, 5 pls. 1944b, The Troutdale flora: Carnegie Inst. Washington Pub. 553, p. 823-351, 11 pls. 1952, Conifer dominants in the middle Tertiary of the John Day Basin, Oregon: Paleobotanist, v. 1, p. 105-113. 1959, Miocene floras of the Columbia Plateau, Part I. Composition and interpretation: Carnegie Inst. Washing- ton Pub. 617, p. 1-134. Chaney, R. W. and Axelrod, D. I., 1959, Miocene floras of the Columbia Plateau, Part II. Systematic considerations: Carnegie Inst. Washington Pub. 617, p. 135-237, 44 pls. Condit, Carleton, 1944a, The Remington Hill flora: Carnegie Inst. Washington Pub. 553, p. 21-55, 12 pls. 1944b. The Table Mountain flora : Carnegie Inst. Wash- ington Pub. 553, p. 57-90, 9 pls. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Dorf, Erling, 1930, Pliocene floras of California : Carnegie Inst. Washington Pub. 412, p. 1-108, 13 pls. Krystofovich, A. N., ed., 1956, Oliogotsenovalaia flora Gory Ashutas v Kazahtstane [Oligocene flora of Mount Ashutas in Kazakhstan]: Akad. Nauk SSSR Inst. Botanicheskii Komarova Trudy, ser. 8, Palaeobotanica, v. 1, 179 p., 61 pls. Knowlton, F. H., 1901, Fossil plants of the Esmeralda forma- tion: U.S. Geol. Survey 18th Ann. Rept., pt. 2, p. 200-222, pl. 30. Lamotte, R. S., 1936, The Upper Cedarville flora of northwest- ern Nevada and adjacent California: Carnegie Inst. Wash- ington Pub. 455, p. 57-142, 14 pls. 1952, Catalogue of the Cenozoic plants of North America through 1950: Geol. Soc. America Mem. 51, 381 p. MacGinitie, H. D., 1933, The Trout Creek flora of southeastern Oregon: Carnegie Inst. Washington Pub. 416, p. 21-68, 16 pls. 1953, Fossil plants of the Florissant beds, Colorado: Carnegie Inst. Washington Pub. 599, 198 p., 75 pls. MacNeil, F. S., Wolfe, J. A., Miller, D. J., and Hopkins, D. M., 1961, Correlation of the Tertiary formations of Alaska: Am. Assoc. Petroleum Geologists, Bull., v. 45, p. 1801-1809. Manning, W. E., 1957, The Genus Juglans in Mexico and Central America: Arnold Arbor, Jour., v. 38, p. 121-150. Mason, H. L., 1934, Pleistocene flora of the Tomales formation : Carnegie Inst. Washington Pub. 415, p. 81-179, 11 pls. --- 1944, A Pleistocene flora from the McKittrick asphalt deposits of California: California Acad. Sci. Proc., v. 25, p. 221-233. 1947, Evolution of certain floristic associations in west- ern North America: Ecol. Monographs, v. 17, p. 201-210. 1953, Plant geography in the delimitation of genera in Plant genera-their nature and definition-a symposium : Chronica Botanica, v. 14, no. 3, p. 154-159. Savage, D. E., 1955, Nonmarine lower Pliocene sediments in California-a geochronologic-stratigraphic classification : California Univ. Pubs. Geol. Sci., v. 31, no. 1, 26 p. Turner, H. H., 1900, The Esmeralda formation, a freshwater lake deposit : U.S. Geol. Survey 21st Ann. Rept., pt. 2, p. 191- 208. Webber, I. E., 1933, Woods from the Ricardo Pliocene of Last Chance Gulch, California: Carnegie Inst. Washington Pub. 412, p. 113-134, 5 pls. Wolfe, J. A., 1961, Age of the Keechelus Andesitic Series of the Cascade Range, Washington: art. 231, U.S. Geol. Survey Prof. Paper 4240, p. ©228-C230. Wolfe, J. A., and Barghoorn, E. S., 1960, Generic change in Tertiary floras in relation to age: Am. Jour. Sci., v. 258-A, p. 388-399. Wolfe, J. A., Gower, H. D., and Vine, J. D., 1961, Age and cor- relation of the Puget group in King County, Washington : art. 232, U.S. Geol. Survey Prof. Paper 4240, p. ©230-C232. Wood, H. E., Chaney, R. W., Clark, John, Colbert, E. H., Jepson, G. L., Reeside, J.B., and Stock, Chester, 1941, Nomenclature and correlation of the North American continental Tertiary : Geol. Soc. America Bull., v. 52, p. 1-48, 1 pl. A Page Abies. 222 cocco ccc coco ccc ccc cnl N4,5,14 concolor... ________________ 4, 5,7, 9, 10, 14; pls. 1, 6 comcoloroides. . .___________________________ 14 magnifica shastensis. ______________________ 14 SD nono oo oo nnn ono noon noo 7,14 00000002 --- 1, 4, 6,10, 29 alvordensis .. con- 30 24, 29 4, 5, 29; pl. 5 30 columbiamum. . 13 macrophyllum... - 3, 4, 5, 6, 13, 24, 29, 30; pl. 5 -- 29 minutifolia...__________________ - 29 o o e 20 septilobatum. . ._ __________________________ 20 Aceraceae....____________________ - 6, 4, 29 acutiloba, Quercus pseudolyrata ___ - 22 Aesculus preglabra_.______________ - 12 agrifolia, Quercus. 21 0200000000000 00002 6 Aldrich Hill 8,12 Aldrich Station flora.... 12 Aldrich Station Formation. 3 alezanderi, Populus__________________________ 18 alnifolia, Amelanchier.________________________ 24 Almusc 222222222222 2222222202 22222222 5, 6, 20, 21 4, 20; pl. 1 20 PUDTQL c 2222 nn nn noon nnn ccc ccc 3 Alvord Creek flora....._______________________ 10 alvordensis, Acer.. 30 Amelanchier.____________________________ 24, 28 28 Amelamchier...________LLL____LLLL___________ 4,8, 24 24 4, 24; pl. 5 Anacardiaceae.___________________ ___ 7,28 Angiospermae. .._____________________ oo-- 4, 7,16 antiquus, ... 4, 7, 9, 10, 24, 25; pls. 5, 10 ._. 13 Arbutus... 5, 6, 8, 26, 31 31 4, 5, 7, 9, 12, $1; pls. 5, 12 Arctostaphylos. .______________________________ 31 ULC 7, 10, 31; pl. 11 mevadensis. c 31 verdiama...___________________ - 31 Arcto-Tertiary flora. ..___________ 6 5, 6 12 -- 7, 10, 29; pl. 12 trumeatum{ 29 azelrodi, Garrya--..______________. 7, 10, 19; pl. 12 B Barstovian fauna. ..._________________________ 1 Barstovian flora.._________________ 8, 9, 10, 12, 13 INDEX [Italic page numbers indicate descriptions] Page Barstovian mammals...______________________ N1 bendirei, Acer. 24, 20 4, 5, 20; pl. 1 Berberidaceae......_________________________ 4, T, 28 12 DETM ccc ll l lol nlc onn 13 conn 7, 9, 21; pl. 9 4, 6, 7, 20 betuloides, Cercocarpus..._____________________ 25 Biostratigraphy......________________________ 12 Blancan 10 Blue Mountains flora.. ..____________________. 5 bolanderi, Acer...____________________ 4, 5, 29; pl. 5 bonatti, Populus... .. 18 booneana, Populus... __. 18 brandegeei, Populus... ._______________________ 17 breviflorus, Cercocarpus. 25 breweriana, Picea. . --- 1, 7, 8, 9, 10, 14, 15; pl. 6 browni, Quercus... 21 C Cache Creek flora..._.._______________________ 10 californica, Corylus..._________________________ 3 Juniperus. ._.... 16 23 12 3 10 20 grandis. .._ 20 1, 5, 6, 10, 12, 13, 20 bendirei_________________LLLL______ 4, 5, 20; pl. 1 tomkimensis.._.___________________ 20 21 Cebatha heteromorpha....._____________________ 18 Cedar Mountain local fauna_.._______________ 12 cedrusensis, Elaeagnus.______________ 7, 10, 30; pl. 12 7, 10, 16, 17; pls. 7, 8 10, 21, 22; pl. 9 CercidiphyMum. .... -6 6 6 L 22222 lool ccc 12 Cercocarpus__________________. 5, 6, 8, 24, 25, 26 antiquus. . 4, 7, 9, 10, 12, 24, 25; pls. 5, 10 betuloides. . . 25 breviflorus. . .. 25 eximimaie 25 holmesi. .._. 25 25 25 cereum, Ribes. .. 23 Chamaecyparis._____________________.______ 8, 15, 25 nootkatensis .. - 1, 4, 7, 8, 9, 14, 16; pl. 6 haneyi, Acer ___ - - 30 Chloropagus flora.________________________ 8, 12, 13 chrysolepis, Quercus 1, 4, 5, 7, 8, 9, 10, 21, 22; pls. 2, 9 Page Cinmamomum . N5 Clarendonian flora. -_ 12, 13 Clarendonian mammals. . - 1,8 Clematis reticulata_....________________________ 23 Coal Valley floral __________________________ 13 6, 26, 30 SD-_______ -- 7, 9, 10, 26, 80; pl. 12 columbiama, Quereus __________________________ 12 columbic m, Acer __ - 13 Composition of the Fingerrock flora. .._______. 3 Composition of the Stewart Spring flora. .. ___. 7 25, 26 concolor, Abies. ... 4,5, 7, 9, 10, 14; pls. 1, 6 comcoloroides, Abies..._________________________ 14 4, 7, 14 conpera, Quercus. al Cornus. ..________ 12 Corylus californica . . 3 covea, Amelanchier..._________________________ 24 PPUMUSLLL 22222222200 24 Le oo i 12 crenatum, Cercidiphyllum. 6 Cruciferae..__________ 31 Cupressaceae. 4,7,15 cusicki, Amelanchier..._____________ 7, 9, 10, 24; pl. 10 ccc 6 Cyclobalamopsis.._____________________________ 22 Cyperaceae..___... 4,16 Cyperacites...._______________ = 16 SD 4,7, 16; pls. 1, 7 D Dalles Formation...__________________________ 19 defleziloba, Quercus._._______ dicotyledones...__.._______. dignata, Amelanchier..________________________ Dilleniaceae. . 4 dimorpha, Thuja___________. ___ 15 dissecta, Platamus..___________ 12, 13, 24 dumosus, Holodiscus . - 25 duriuscula, Quercus. ._________________________ 22 E Elacagnaceae..__________________.. - 780 Elaeagnus... .. ___ 10, 80 cedrusensig. ______________________ 7, 10, 80; pl. 12 2 ccc cc - 30 elliptica, Garrya._. ___. 19 elongatum, Cercidiphylum . 6 emersoni, Populus. ... 18 engelmanni, Picea_..__________________________ 14 FEOC@n@ 6 eotremuloides, Populus________________________ 18 Eri __ 4,7, 31 BTICAIGS. . . . . 4,7, 81 (Erythrobalanus), Quercus....________________ 6 Esmeralda flOrA......_________________________ 8, 13 Esmeralda Formation. 3 Eucarya_._________ 20 eximinus, Cercocarpus...______________________ 25 F F oon coo 4, 6, 7, 21 FA@AI®S.. 4,7, 20 Fagus. 5 N34 Page fairii, N21 Fallon flora... ~ 8,12, 13 fauna, - 1 Mascall.......- - 12 Stewart Spring. 12 Fingerrock flora. 1, 4, 5, 7, 8, 9, 10, 12 floristic relationships of. ....____________-- D Fish Lake Valley local fauna.....________---- 12 flora, Aldrich Hill...___________.. - 812 Aldrich Station-.._____________________._.- 12 Alvord Creek 10 Arcto-Teritiary...______________-- -_- 6 Barstovi@n..__..________________- 8, 9, 10, 12, 13 Blancan-.---- 10 Blue Mountains 5 Cache Creek.... 10 ChloropagU8. -_____.______________..--- 8, 12, 13 Clarendonian..._______________________..-- 12, 13 Coal Valley. - 13 6 ESMeFrAIGA....._______________________---- 8, 13 - 8, 12, 13 Fingerrock________________- 1, 4, 5, 7, 8, 9, 10, 12 GooS@ Cr@@K.____________________________-- 8, 14 Hemingfordian.._____________________.--- 12 10, 12 Hidden Lake...... Horsethief Canyon. KazakKRStAN. . .______________________----- 6 KAI 6 Madro-Tertiary .. ______________________-- 6 8, 13 oo 5, 6, 9 Mio-Pl0C@N@.______________________------ 1 Mulholland. 12 Neogene.._____..... Neroly...________.- Nevada.. 12 OlGOC@N@_.________________________-_--- 5, 6, 9 Paleoceng. ...__________----- 6 Pay@tt@. .. _________________.--.- 10 Puget. 6 Remington Hill.. .._______________------- 12 RICAPGO. . ._ no- 12 Ruby Valley...__________----- 6 Stewart Spring.__________----- Stinking Water Succor Creek.. Table 12 Tehachapi....____.____----------- 1, 2 TertiArY.._______________-------- 3 Thorn Creek. -_ 5,10 TrOUE ---> 8 Upper Cedarville..._____._____._.__..._----- 8, 10 Floral composition and interpretation. . ...... 8 Floral provinces in the Barstovian....._...~~- 10 floral remains, indetermined... 81 floribundus, Lyonothammus . . 26 florida, Amelanchier.... .. 24 florissanti, Pimnus...._____.. 15 Floristic relationships of the Fingerrock flora.. 5 Floristic relationships of the Stewart Spring 9 2222 cee ces 8, 28 fryi, 7, 25; pl. 10 JUIDQ, QUETCU® ... . 22 G e e 10, 19 @gelrodi . .cc. - 7, 10, 19; pl. 12 __ 19 - 19 Garryaceae. __________________-- - 7,19 INDEX Page Geoflora, N5, 6 Madro-Tertiary....__________.___.-------- 12 Geologic occurrence...._________.-.--- Glumiflora®.....-__.----------------- glyptostroboides, Metasequoia . Glyptostrobus oregonensis..._________.....-.---- 16 SD c ece 4,5, 16; pl. 1 Goose Creek flOrA...__________________-------- 14 gracilipes, 28 GTAMNN@R@. . . ._ co- 7,16 grandidentata, - 18 grandi$, 20 GFASS... eon 7 grayi, 24 Grossularia.. ...-... 23 GymnoSp@MMAQ@.....___________.____~_--.-- 4,7, 13, 14 H hammibali, QUEPCUS . 21 harneyensi8, PPURUS. ... 28 Sorbus. .._______--- - 4,5, 28; pl. 5 Hemingfordian flOrA. 12 Hemphillian flOrA.....________-__-----------«- 10, 12 ReSDEri@, SQUZ. . .. 19 hetermorpha, Cebath@...____._____...-_-------- 18 heterophylla, POPUUS. . ._______._________---~-- 17 Tsuga_...__________--- - 7,9, 15; pl. 6 Hidden Lake 4,5 hollicki, M@hOMiQ._..____________________------ 23 Odost _- 23 holmesi, CerCOC@rPUS..___________________----- 25 25 L.. __ _c no 25 fryil.... 7, 25; pl. 10 Horsethief Canyon 8,12 I TCACINACERO. ._____________________------- 4 Incertae sedis...______---- 31 Indetermined coniferous pl. 6 Indetermined floral remains. ..._________----- 31 Indetermined inflorescences......___...- __ pl. 10 Indetermined leaf._______________--------- 31; pl. 12 integrifolia, Rhus. 7, 10, 28, 20; pl. 12 Introduction. ...-. 1 J Juglandac@®@..________________._.------- 4, 6, 7, 10, 20 Juglandales..__________________._-------- -- 4,7, 20 Juglans... . 6, 20 stellata... (Rhysocaryon) ... .______.___________- JTUMDETU® . . .cc cc californica . mEVD@den$8i8.___________________--= 7, 10, 16; pl. 6 i ° o oe 16 K Kazakhstan flOrA. ... .__________________..---- 6 Kenai flora. .______.------ 6 kernensis, Saliz. ..____---- 27 knowloni, 19, 27 L lacustris, . .. 21 lanceolata, Lariz. __ occidentalis...._.._.. latahensis, Pinus... latifolia, Quercus pseudolyrata . . Lauraceae.__.______-------- leaf, indetermined__________------------- 31; pl. 12 lewisi, PhiladelPhUs.____________________------ 23 lindgreni, 4, 17, 18; pl. 1 Page N5 linguaefolia, SAbima......_.__._..______.__.__.~--- 16 5, 6, 9, 12 Liriodendrom......___._.- 4, 9 Live oak-spruce-cedar 9 local fauna, Cedar Mountain.. z 12 Fish Lake Valley..__________._------------ 12 Stewart Spring. . 1, 12 Lyonothammus.._______.._____...- 6, 7, 8, 12, 25, 26 . . .. no- 26 26 parvifolius....__......- 7,9, 25, 26; pls. 10, 11 M macrophyUM@, 15 macrophyUum, Acer ..... 3, 4, 5, 6, 13, 24, 29, 30; pl. 5 Madro-Tertiary flora. .____________----- 6 Madro-Tertiary 12 magna, Picea... 4, 5, 7, 9, 10, 16; pls 1, 6 magnifica shastensis, Abies. . ..___.....-- 14 5 5, 8, 12, 28 e> 23 o i eee 5 repens. .._... 23 reticulata - . ._ major, Juglans - 4, 7, 9, 28; pls. 4, 9 - 7, 9, 10, 20; pl. 8 Mascall fAUN&. . 12 masoni, - Arctostaphylos. -____.----.-- 7, 10, $1; pl. 11 19 mawbyi, Astronium..... .. - 7, 10, 29; pl. 12 Menispermaceae.... .- 4, 6 menziesi, 31 merridmi, AGT 20 Quercus. ...___.._..---- -- 22 mertensiana, TSU@.._____________________---- 7 MeLSEQUOIQ . .. e-- 4, 25 gly 4 4 Middlegate flOrA...._______________----------- 8, 13 Minutifolia, ACAT 29 Mio-Pliocene floras. 1 mohavensis, Lyonothammus. . . ...- ___ 26 Monocotyledones.......__.-------- _- 4, 7, 16 monticola, Pinus... 4, 5, 15; pl. 1 monticolen8i8, PIMUS-..... -. 15 Mulholland flora. .. 12 Myrica lanceolata. _ 18, 19 23 myricaefolius, Cercocarpus.. 25 myrsingefOli@, 22 -n- 7, 80 N Nanmipus tehOnensi8__________._._______~------- 12 Neogene... .__--- 8 Neogene floras....__..__----------- 9, 12 Neroly flOr@. . __________----------- 12 mervosa, Mahonia. 5 Nevada fIOPAS . . . co- --- 12 mevadensis, Arctostaphy108..._____......-------- 31 --- 7, 10, 16; pl. 6 Philadelphus. .. - 7, 23; pl. 9 ZEURODQL ___. __ 23 mewberryi, 4, 5, 12, 22; pl. 3 mootkatensis, Chamaecyparzs 1, 4, 7, 8, 9, 14, 15; pl. 6 0 Oakdale 12 obtusiloba, Quercus pseudolyrata..........----- 22 occidentalis, Lariz________________------ - 7, 14; pl. 6 MELASEQUOI . ._ oo --- 4 Page occurrence, geologic...________________________ N1 Odostemonm hollicki. ... ________________________ 23 simplex. 23 oklahomensis, Sapindus.._____________________ 30 Oligocene flora......_...__. - 5, 6, 9 oregonensis, Glyptostrobus. ___________ 16 oregomiana, Myrica...._.._____________________ 23 4,5, 8, 28; pl. 3 oregonianum, Acer 29 P Paleocene flora. 6 PAIMSL 1 cscs ccc ccc ccc ls 6 parvifolius, Lyonothammus.... .. 7,9, 25, 26; pls. 10, 11 paucidentata, Platanus... .. 12 paucidentatus, Cercocarpus-...._._____________. 25 Payette 10 payettensis, 19 elviga, 7, 9, 10, 18, 19; pl. 8 27 ramosissimtm. 2 22222222222222222200000000 27 vaccimifolium. ... 7, 10, 27; pl. 10 5,12, 13 Philadelphus.... .... ___.. 23 bendirei. ...... 23 2 222222222222 cocci cscs csc nes 23 mevadensig...2 7, 23; pl. 9 PhyUites 20 Piceal 4,5, 7, 8, 9, 10, 14 breweriana. . 1,7, 8, 9, 10, 14, 15; pl. 6 14 4, 5,7, 9, 10, 15; pls. 1, 6 14 Pinaceae... PIMS ccc ccc 15 latahensis.....___._. - 15 15 4,5, 15; pl. 1 ... 15 ponderosa... ---- 4,5, 7, 9, 10, 15; pls. 1, 6 quinifolia . 15 15 15 Platanaceae. l 4, 24 Platanuis2222222222222222222222000000002 1, 5, 6, 10, 24 4,5, 12, 24; pl. 4 12, 13, 24 12 plictremuloides, Populus... 17,18 2 16 ponderosa, Pinus....._______. 4,5, 7,9, 10, 15; pls. 1, 6 Populus 5, 6, 7, 8, 10, 16, 18 alezanderi~. 18 bonatti. ..... 18 booneana..... 18 -- 17 cedrusensig.... .._ 7, 10, 16, 17; pls. 7, 8 emersoni.. . 18 eotremuloides .. 18 grandidentata. ... 18 17 4, 17, 18; pl. 1 plictremuloides. tremuloides..__.________________ 7, 9, 10, 17; pl. 8 7, 9, 10, 18; pl. 8 voyana... .. 17 washoensis.. 22 7, 9, 18; pl. 7 SD ooo onn noc ncs ncn ccc ciel ls 7. 18; pl. 7 preglabra, Aesculus. . 12 preintegrifolia, Rhus-.... .._ __ 29 INDEX Page 2222200222020 222 cc N7, 28 COU ccc 2 conn ccc cns ccc scn concen 24 harneyensige 2 .2222222222222222220000. 1. 28 SD concn noone nnn nnn nc ccie enol. 7, 28; pl. 10 pseudolyrata, Quercus. -- 4, 5, 12, 13, 29; pl. 3 acutiloba, Quercus... - 22 latifolia, Quercus... 22 obtusiloba, 22 PSEUdOSUG@L L .L .c 15 Pterocarya... .... cedrusensis......___________..___._ 10, 21, 22; pl. 9 chrysolepis..... 1, 4, 5, 7, 8, 9, 10, 21, 22; pls. 2, 9 ...... ..... convera.........._. defleritoba.......... duriuscula.. ...... (Erythrobalamus) . JUD - 222222222222 ccc cscs hanmmibali............ merramilllllllllllll myrsinaefolia. pseudolyrata................ 4, 5, 12, 13, 22; pl. 3 pseudotyrata acutiloba. ..... .. 22 pseudolyrata latifolia. . .. . - 22 pseudolyrata obtusiloba.................... 22 4, 5, 13, 2%; pl. 2 UPSHMQLL 2220000000000 cc ccc ccc cscs e> 22 quinifolia, Pimus 1 15 R ramosissimum, Peraphylum....._...._._____. 27 4,7, 28 relata, Alnus -- - 4, 20; pl. 1 relatus, Almus. - 20 PhyUites L - 20 remains, indetermined floral ................. 31 Remington Hill 12 repens, Mahonia.... : reticulata, Clematis. 23 4,7, 9, 23; pls. 4, 9 Rhamnaceae. 7, 80 7, 80 Rhododendron 12 ) - 10, 28 bendireil 20 integrifolia... 7, 10, 28, 20; pl. 12 20 Rhysocaryon ...... 10 Juglans...._ ...... 6 Ribe. 23 23 22222222 ccc cscs cscs cess 28 webbi. -- 7,9, 23; pl. 9 ollo cscs ccs cess ccc ees 7,12, 23; pl. 9 Ricardo flOFA. .L 12 7, 28 alvordemgig. 28 miocenica. .. 28 clo ccc ccc ccc ccc ccs cence ccc ees 28; pl. 10 ROSAC@R@L L222 6,4, 7, 24 4,7, 28 rubra, 3 Ruby Valley 6 S Sabina linguaefolia. L.... 16 Salicaceae. . 1. 6, 4,7, 16 1 000. 4,7, 16 N35 Page -... N5,7,8, 18 _________ 19 kernensig. . 27 19, 27 I@MCeOlaba L2 19 payettensis.. 19 ..... 7, 9, 10, 18, 19; pl. 8 27 HTUERE@M@L L1 2 2222222222222 222 19 VACCHMAJOUGL L cowl l ccc llc cocci cnn neon s 27 Sapindaceag....___._______________________. 4, 7, 80 Sapindales.. - 4, 7, 28 .____ .cc 12, 80 oklahomensis ...... 30 SD e coon oc 7, 10, 80; pl. 12 savagei, Schimus._____________________. 7, 28; pl. 12 Saxifragaceae. ._.. Schinus... @racilipes. . ._ 28 7, 28; pl. 12 scudderi, Amelanchier..______.________________ 24 scopulina, Sorbus... 28 Securidaca_...._.___________________ 6 seed, indetermined coniferous..-..-_._______. pl. 6 sempervirens, Sequoia. ..._____________________ 3 septilobatum, Acer... 29 Sequoia . ._.... - 4, 25 sempervirens. ... - 3 Sequoiadendron. .... 8 shastensis, Abies magnifica...________________. 14 simplex, Odostemon...______________________.__ 23 simulata, Quercus. -- 4, 5, 13, 22; pl. 2 sonomensis, Picea. .___________________________ 14 somorensis, Populus... 16, 17 ... . ___ ___ 9 ... c cll ll llc 5, 7, 28 5, 28; pl. 5 speciosa, 22 SDPUOB..22 2222 8 stellata, Juglans major . 20 Stewart Spring...... 12 Stewart Spring dicotyledons. 14 Stewart Spring fauna.___.____________________ 12 Stewart Spring flora._.______________..__- 3, 7, 8, 12 composition Of..___._____________________ 7 floristic relationships of..___.._____.____.. 9 Stewart Spring local fauna L222 1, 12 Stinking Water flora.....___________________._ 5, 10 subserrata, Amelanchier._______________. 4, 24; pl. 5 subwashoensis, Populus.._____________________ 18 Succor Creek flora.... 10 succorensis, Saliz....._. 27 Systematics. . 13 T Table Mountain flora.........________________ 12 Taxodiaceae.._______________________ 4, 16 Tehachapi flora.....__________________________ 1,12 tehonensis, Nammipus...__.__________________. 12 Tertiary floras.._____________ 3 Puget flora. .._______________ 6 Tetracentrom_._..____________ 6 tetrafolia, 15 thor, BERU. . 4, 20; pl. 1 Thorn Creek flora. ____ 5,10 Thuja dimorpha......_______.__ __ 15 tonkinensis, Carya...._______. - 20 Tracheophyta....___________________________. 4,7 tremuloides, Populus.._____.________ 7,9, 10, 17; pl. 8 traini, Arbutus. .~... 4, 5, 7, 9, 12, 31; pls. 5, 12 trichocarpa, Populus... __-- 7, 9,10, 18; pl. 8 Trout Creek flora....._____________________._.- 8 truckeana, 19 N36 Page truncatum, Astronium. ...____________________ N29 Teuga.-.__________- 15 heterophyUMa...___________________.. 7,9, 15; pl. 6 METIEMSI@MG. . .. . 7 U Ulmaceae.....__...--- o i oe 1, 5, 6, 12, 22 C@LfOPMIC® L . . . 12 newberryi. . . - 4,5, 6, 12, 22; pl. 3 speciosa... .. 22 SDP c one- 5 INDEX Page UmbeUlularia califormica......_.._____________- N3 Upper Cedarville flora_..._______________....-- 8, 10 ursina, Quercus.________. - 22 Urticales...______________. - 4,22 utahensis, Juniperus. ._.... - 16 Utili8, 30 v vaccimifolia, Salix... 27 vaccinifolium, Peraphyllum........ ... 7,10, 27; pl. 10 ETA, 13 Page verdiana, Arctostaphy108._...__________________ N31 voyama, Populus. 17 w washoensis, Populus...________________ 7,9, 18; pl. 7 webbi, Ribes..._____.._ 7, 9, 23; pl. 9 wheeleri, PIMUS. . . 15 Z 1, 5, 6, 12, 28 densis. .. - 23 4, 5, 8, 23; pl. 3 U.S. GOVERNMENT PRINTING OFFICE : 1964 O - 695-377 PLATES 1-12 FigurE 1, 4 2, 9. 3, 5. 13 14 PLATE 1 [All figures natural size] . Pinus ponderosa Douglass. (p. N15). Hypotypes USN M 42017. Pinus monticola Douglass. (p. N15). Hypotypes USNM 42016 (fig. 2,) UCMP (fig. 9). Picea magna MacGinitie. (p. N15). Hypotypes USN M 42026-42028. . Cyperacites sp. (p. N16). USNM 41976. Carya bendirei (Lesquereux) Chaney and Axelrod. (p. N20). Hypotype USN M 41943. . Glyptostrobus sp. (p. N16). USN M 41933, 41934. . Abtes concolor Lindley. (p. N14). Hypotypes USNM 42025. . Populus lindgrent Knowlton. (p. N17). Hypotype USN M 41947. . Alnus relata (Knowlton) Brown. (p. N20). Hypotype USNM 41969. . Betula thor Knowlton. (p. N21). Hypotype USN M 41971. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 1 FINGERROCK FLORA PLATE 2 [All figures natural size] FigurEs 1-10, 14. Quercus chrysolepisLiebmann. (p. N21). Hypotypes USN M 41887-41897. 11-13. Quercus simulata Knowlton. (p. N22). Hypotypes USN M 41938-41940. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 2 l/~ l‘," . FINGERROCK FLORA PLATE 3 [Al figures natural size] Figur® 1. Quercus pseudolyrata Lesquereux. (p. N22). Hypotype USNM 41905. 2, 3, 5. Zelkova oregoniana (Knowlton) Brown. (p. N23). Hypotypes USNM 41944-41946. 4,6. Ulmus newberryi Knowlton. (p. N22). Hypotypes USNM 41942 (fig. 6), UCMP 8642 (fig. 4). GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 3 FINGERROCK FLORA PLATE 4 [All figures natural size] Figur®Es 1, 2, 4. Platanus bendirei (Lesquereux) Wolfe. (p. N24). Hypotypes USNM 41941 (fig. 2), UCMP 8648, 8649 (figs. 1, 4). The margin of the specimen in fig. 1 is broken and hence simulates P. paucidentata. 3. Mahonia reticulata (MacGinitie) Brown, (p. N23). Hypotype USN M 41953. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 4 FINGERROCK FLORA FicurRE 1. 2. 3. 4-6. 7. 8, 9. PLATE 5 [All figures natural size] Amelanchier subserrata Smith. (p. N24). Hypotypes USNM 41954. Cercocarpus antiquus Lesquereux. (p. N24). Hypotype USNM 41912. Sorbus harneyensis Axelrod. (p. N28). Hypotype USNM 41977. Acer macrophyllum Pursh. (p. N29). Hypotypes USNM 41956, 41957, UCMP 8660. Acer bolanderi Lesquereux. (p. N29). Hypotype USNM 41955. Arbutus train? MacGinitie. (p. N31). Hypotypes USNM 41928, 41929. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 5 FINGERROCK FLORA FicurEs 1-3, 6, 10, 11. 4, 5, 8, 9, 13, 14, 19. 7, 12, 17, 18, 22. 15, 16, 20, 21, 24. 23, 28, 29. 25. 26. 27, 30, 31, 34-37. 32, 33. PLATE 6 [All figures natural size] Abies concolor Lindley. (p. N14). Hypotypes USNM 42032-42037. Picea breweriana; S. Watson. (p. N14). Hypotypes USNM 42042-42048. Picea magna MacGinitie. (p. N15). Hypotypes USNM 42049-42053. Tsuga heterophylla Sargent. (p. N15). Hypotypes USN M 42053-42057. Larix occidentalis Nuttall. (p. N14). Hypotypes USNM 42040, 42041 (figs. 23, 29), UCMP 8604 (fig. 28). Indetermined coniferous seed. USNM 42058. Juniperus nevadensis Axelrod. (p. N16). Hypotype UCMP 8612. Chamaecyparis nootkatensis (Lambert) Spach. (p. N15). Hypotypes USNM 42020, 42021 (figs. 27, 30), 42022- 42024 (figs. 34, 36, 37), UCMP 8613, 8614 (figs. 31, 35). Pinus ponderosa Douglas. (p. N15). Hypotypes USNM 42038, 42039. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 6 STEWART SPRING FLORA FicURE 1. 2. 3. 4, 5, 8. 6, 7. PLATE 7 Poacites sp. (p. N16). USNM 41973, X 1. Cyperacites sp. (p. N16). USNM 41972, X %. Populus sp. (p. N18). USNM 41937, X 2. Populus cedrusensis Wolfe. (p. N16). Holotype USNM 41876 (fig. 8); paratypes USNM 41877, 41878 (figs. 4, 5), X 1. Populus washoensis Brown. (p. N18). Hypotypes, USNM 41885, 41886. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 7 STEWART SPRING FLORA FreurEs 1, 2, 8. 3, 11, 12. 4. PLATE 8 [All figures natural size} Saliz pelviga Wolfe. (p. N18). Hypotypes USNM 41958, 41959 (figs. 1, 8), UCMP 8625 (fig. 2). Populus trichocarpa Torrey and Gray. (p. N18). Hypotypes USNM 41882-41884. Populus cedrusensis Wolfe. (p. N16). Paratype USNM 41879. Populus tremuloides Michaux. (p. N17). Hypotypes USNM 41880, 41881 (figs. 5, 6), UCMP 8620 (fig. 7). . Juglans major Torrey. (p. N20). Hypotypes USNM 41960-41961. PLATE 8 PROFESSIONAL PAPER 454-N GEOLOGICAL SURVEY STEWART SPRING FLORA FigurRE 1. 2, 3, 5-7, 12, 16. 4. 8-10. 11. 13, 14, 17, 18. 15. PLATE 9 [All figures natural size] Betula sp. (p. N21). USNM 42008. Quercus chrysolepis Liebmann. (p. N21). Hypotypes USNM 41898, 41903, 41904, 41899-41902. Philadelphus nevadensis Condit. (p. N23). Hypotype USNM 41907. Mahonia reticulata (MacGinitie) Brown. (p. N23). Hypotypes USNM 41951, 41952 (figs. 9, 10), UCMP 8644 (fig. 8). Ribes (Grossularia) sp. (p. N23). UCMP. Ribes webbi Wolfe. (p. N21). Holotype, USNM 41908 (fig. 13); Paratypes USNM 41909-41911 (figs. 14, 17, 18). Quercus cedrusensis Wolfe. Holotype USNM 41968. PLATE 9 PROFESSIONAL PAPER 454-N GEOLOGICAL SURVEY STEWART SPRING FLORA FiGurREs 1, 14, 15. 10, 16-19. 11, 13. PLATE 10 Lyonothamnus parvifolius (Axelrod) Wolfe. (p. N26). Hypotypes USNM 41917, 41918 (figs. 1, 14), UCMP 8653 (fig. 15) X1. . Cercocarpus antiquus Lesquereux. (p. N24). Hypotypes USNM 41913, 41914, X 1. . Peraphyllum vaccinifolia (Knowlton) Wolfe. (p. N27). Hypotypes USNM 41965-41967, X 1. . Rosa sp. (p. N28). USNM 41924, % 1. . Holodiscus fryi Wolfe. (p. N26). Holotype USNM 41915 (fig. 8); paratype USNM 41916 (fig. 12), X 1. . Amelanchier cusicki Fernald. (p. N24). Hypotype USNM 42009, X 1. Indetermined inflorescences. (p. N31). USNM 42029, 42013-42015, 42030, X 2. Prunus sp. (p. N28). USNM 41949, 41950. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N _ PLATE 10 L7. 16 19 STEWART SPRING FLORA PLATE 11 [All figures natural size] FicurEs 1, 3-6. Lyonothamnmus parvifolius (Axelrod) Wolfe. (p. N26). Hypotypes USNM 41920-41923 (figs. 1, 3, 4, 6), UCMP 8654 (fig. 5). 2. Arctostaphylos masoni Wolfe. (p. N31). Holotype USNM 42000. GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N PLATE 11 STEWART SPRING FLORA FiGur® 1. 2. 6, 8, 9. 10. 11-14. PLATE 12 [All figures natural size] Sapindus sp. (p. N30). USNM 41920. Rhus integrifolia Liebmann. (p. N28). Hypotypes USNM 42011. Colubrina sp. (p. N30). USNM 41927. . Garrya azelrodi Wolfe. (p. N19). Holotype USNM 41935. . Indetermined leaf. (p. N31). USNM 42012. Elaeagnus cedrusensis Wolfe. (p. N30). Holotype USNM 41962 (fig. 9), paratypes USNM 41963, 41964 (figs. 6, 8). Astronium mawbyi Wolfe. (p. N29). Holotype USNM 41948. Schinus savagei Wolfe. (p. N28). Holotype USNM 41926. Arbutus traint MacGinitie. (p. N31). Hypotypes USNM 41930-41932 (figs. 12-14), UCMP 8667 (fig. 11). GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-N - PLATE 12 STEWART SPRING FLORA rre Relationship of Precambrian Quartzite-Schist Sequence Along Coal Creek to Idaho Springs Formation Front Range, Colorado GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-0 Prepared partly on behalf of the U.S. Atomic Energy Commission Relationship of Precambrian Quartzite-Schist Sequence Along Coal Creek to Idaho Springs Formation Front Range, Colorado By JOHN D. WELLS, DOUGLAS M. SHERIDAN, end ARDEN L. ALBEE SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY S6EOLOGICAL SURVEY PROFESSIONAL PAPER i4s4-0 Prepared partly on éefia/f of the U.S. Atomic Emergy Commission UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page | Metamorphic grade-Continued Page i s" lo ne us lies Al ct areca a Boe TX - O1 Metasedimentary, etc.-Continued introduction c_ crouse _ of 1 Schist layers in 09 Location Lic icc .to 2 Calcium silicate rocks with schist in quartzite... 11 Fieldwork and acknowledgments__________________ 2 Igneous . _c LLQ a 1201 11 Geope ol ..} . _.l8 00cm lil ct 2 Boulder Creek Granite and the quartz monzo- Geologic setting.... 20. .l L. uc... 2 .. .oo neenee dee emia s Llc ale cake 11 Feneral geology .=. ..:... LL. 2 Boulder Creek Granite .________________ 12 Nomenclature of Precambrian rocks_______________ 4 Quarts c...} ? 12 Distribution and stratigraphy of the metasedimentary and Hornblende diorite and hornblendite. __ 13 imetavoleanic(?) tooks. 20000. 4 Pegmatite and 1°" _ 13 Metamorphic grade:. -: 5 Cataclastic rocks.. 14 Metasedimentary and metavolcanic(?) rocks ___. 5 Augen ae Sete soave o 14 Microcline - quartz - plagioclase - biotite gneiss Cataclastic loll cul ltr cones 14 (microcline gneiss). 51 Structural-geology --->. uce leo., 14 Mornblende enclss: ._.: 6 Structural 41.00 - 0 uC 14 Microcline - quartz - plagioclase - biotite gneiss Three periods of deformation _-_ 15 and hornblende gneiss (microcline gneiss and Orientation of 2 16 hornblende gneiss) 6 Metamorphism related to structural and igneous Mica schishs ___ su lucius selec ruc, 6 Mistory S22: ol. Aste elan renta alee ie 21 Biotite-quartz-plagioclase gneiss and mica schist Conclusion. nine acd 22 (biotite gneiss and mica schist) .____________ * |/ Hiterature ca last 22 Quartzite: 2 cull resell c illo coca rara ayo T I ..J... t eil Poa ot al al 25 ILLUSTRATIONS Page Prats 1. Geologic map of the Coal Creek area. In pocket FicurE 1. Index maps of the Coal Creek area, Eldorado Springs, Ralston Buttes, and Blackhawk quadrangles.__________ 03 2. Photomicrograph showing staurolite surrounded by 9 3. Photomicrographs showing folded alinements in andalusite and 10 4» Triangular diagram of Boulder: Creek Granite: :: c: ":l scl. oo luc co rC f 12 o Ariangular diagram of the quarts :l. Ill} tn lel yeu 13 6 specimen Allein lone lal lice l a ic iui l 3a 28.222 15 map showing location of sectors.. -t cot l.f ctr A If OuT _ 17 $x Contour of lineations. "-! "