REEL CONTENTS 42. Olmsted, J. W. / [The litology of the Sze-Chuan mesozoic red beds of China.] 1925. 43. O'Neill, Frank E. / The application of the Anticlinal theory of oil and gas to prospecting. 1920. 44. Packard, Earl Leroy / Faunal studies in the Cretaceous of the Santa Ana mountains of southern California. 1915. 45. Rae, Colin Campbell / Structural relations of the Coalinga oil fields and probable origin of oil. 1912. 46. Ream, Ruth / Report of geology and mining in northeastern part of the Chico quadrangle. 1939. 47. Rose, R. L. / Geology of a part of the Santa Rosa quadrangle. [19447] 48. Sampson, J. A. / A geological study of the Leona Heights Pyrites deposits. 1910. | 49. Shafer, James Fulton / Flotation on minerals. 1915. 50. Shay, D. C. / Geology of a portion of the Tesla quadrangle, Alameda County, California. 1935. 51. Sheffield, E. S. / A cross-section of the Oakland hills. 1904. 52. Shenon P.J. / A petrographic description of the igneous rocks of the Cisco Buttes area Placer County, California... 1922. UC BERKELEY MASTER NEGATIVE - STORAGE NUMBER 03-67.42 (National version of master negative storage number: CU SN03067.42) MICROFILMED 2003 UNIVERSITY OF CALIFORNIA AT BERKELEY LIBRARY PHOTOGRAPHIC SERVICE REPRODUCTION AVAILABLE THROUGH INTERLIBRARY LOAN OFFICE MAIN LIBRARY UNIVERSITY OF CALIFORNIA BERKELEY, CA 94720-6000 COPYRIGHT The copyright law of the United States (Title 17, United States Code) governs the making of photocopies or other reproductions of copyrighted materials including foreign works under certain conditions. In addition, the United States extends protection to foreign works by means of various international conventions, bilateral agreements, and proclamations. Under certain conditions specified in the law, libraries and archives are authorized to furnish a photocopy or other reproduction. One of these specified conditions is that the photocopy or reproduction is not to be "used for any purpose other than private study, scholarship, or research." If a user makes a request for, or later uses, a photocopy or reproduction for purposes in excess of “fair use," that user may be liable for copyright infringement. University of California at Berkeley reserves the right to refuse to accept a copying order if, in its judgment, fulfilment of the order would involve violation of copyright law. Olmsted. J. W. [The litology of the Sze- Chuan mesozoic red beds of China] 1925 BIBLIOGRAPHIC RECORD TARGET University of California at Berkeley Library Master negative storage number: 03-67.42 (national version of the master negative storage number: CU SN03067.42) GLADIS NUMBER: 184785367B FORMAT : BK AD:991006/FZB LEVEL:b BLT:am DCF:a CCSC:d MOD: FL:7 UD:030604 /MAP CP:cau L:eng INT: GPC: BIO: PIC: CON: ARCV: PC:s PD:1925/ REP: A FSl: ILC: IT1:1 040 CUScCU 090 SbDISS.OLMSTED.GEOL 1925 100 1 Olmsted, J. W. 245 14 [The litology of the Sze-Chuan mesozoic red beds of China.] 260 Scl1925. 300 [1i1, 55 p. :$bcol. maps ;$c29 cm. 500 Includes index. 502 Thesis (B.S. in Geology) --University of California, Berkeley, April, 1925. 610 20 University of California, Berkeley.S$bDept. of Geology and Geophysics$xDissertations. 690 0 Dissertations, AcademicS$xUCBS$SxGeology$y1921-1930 Microfilmed by University of California Library Photographic Service, Berkeley, CA LIST OF IRREGULARITIES, MAJOR DEFECTS, AND MISSING MATERIAL The text is annotated in pencil, filmed as is. FILMED AND PROCESSED BY LIBRARY PHOTOGRAPHIC SERVICE, UNIVERSITY OF CALIFORNIA, BERKELEY, 94720 DATE: 7/03 REDUCTION: 10 X PM-1 3%"x4” PHOTOGRAPHIC MICROCOPY TARGET NBS 1010a ANSI/ISO #2 EQUIVALENT Il 10 Bie Ix — az [32 = =I | EAN ll | | © = " ow = l= 3 es A leu wiv eft 3t tt oft, |6, |8 [2 lo, ls lb 6 [2 |E THES IS To the Department of Geology, Professor G. D. Louderback, Bacon Hall, : University of California, Berkeley, California. Dear Sir: The following thesis based on the results of a petrographic study of a suite of sediments from the Sze-Chuan Mesozoic Red Beds of China is submitted in fulfillment of the requirement for the A.B. degree in the Department of Geology, College of Letters and Science. Respectfully yours, April, 1925. INTRODUCTION INDEX Location and description of the section The problem stated The scope and phases of the study CHARACTER OF THE ROCKS Features of the Features of the Features of the Features of the Common features sandstones shales limestones conglomerates of the various rock types DEDUCTIONS FROM CHARACTERS OF ROCKS Lithologic variations in the series Origin and history of the deposits Significant features of the iron content CONCLUSION Summary of results Additional comment Map of China PLATES Page 1-6 8 =~ 17 11 12 14 17 - 30 17 19 30 33 Opposite 1 Sketch Map of Area of Section Section of Series (with specimen numbers) " 2a E Br ie, AFT TS ITSIKA RZ @ Pe.ton ill t200 > 5, All. a To o Fuorin Deg ® IX ~ 0 2 = WM, + : WE ome) 7) afl 1g Pe tuna FN ‘ ys ny , 2 gars yy; . Kassim tou o i % * "i, “Sow-sing Ng to S09R05, 130° 140° ~ iy a 4 T Noor & eS 22 oh OF $ ; TARTARY BE RUN TE “rl : A 4 ip D & 34 PZ, i hg 3 ; b No ¢ Reeussiyn LY ) & 2s Ruymg: I & D Q N 3 S585 olga Bay YS sac Noto Bay C. Aniva Ih sQ KH OTSEK EN hs 7 A OF \ AR Iw b Manitoo 5 wi WW? 7 RIGETSY’ _ ‘k Ao Wi B chun Cape Povorotaol Kumi 2 r 4 ig, N 0 “opt 2p 1 : 2 or 2 Tsui wh 15 n Qi), 0) wigan 0 faMgy WT; § S.. s.( “ / 0 dit ZHE GREAT hh S Car Pe $ TNE ne ME 2g ap 2 ~ Kil = n (Mateimaye) o No Te \ NY NS G) Nh Kululi6ioges RY hhon o S11 RN (15 « Pilutal i © Sours Za 4 fC Duat F I Mg / A NX Sang? tirosdilo achi-nohe 0. t = = BA OR 0. OS 2S “ oi . 2 : uk-chidn Kuro So i r\woRIVOSHI 40° = NE = 5: ung-pin| Zr & m &. Ham-heung S or g-ping SO em go f 4 7 Fi R 0 8 E 3 & Thiing-chow " /La a ay Enfju’( BROUGHTON BAY C. Kuwaga I i KD Tiensin Fs 4 CIUEIWBOFOR GULF OF KOREA J/Otsuchi i } i fab A 0 Kin-chow{c. bs $ pS AWS pi a iP Conn 4 / - ¢ Group i «= _C, Duroc uZvwa Ja £ ous un Vangel fs” : \ $e ida S THEN GULF OF, aNiar KORES,, A ZaHokya T. PAN-LIONG xe a Lipset Spd ane I S PE-CHI-LI| (Rus) vangju ey 2 a B “ oN i, j Thsaag) '"M1A0-TAO Is, ohh net GSAT UME yang va nagata i it SW AV wa - AA ™ ’, ing hl) / . 3 > Leng-chow oF Chand 3- 0 E31 Kan, Ri Any, - h% 7 dic 5S 8 ifor nng-tcheng oe O° SE ou 3 A oe fo a Ning af R6 Wen-ten e OTichhp = N “3 in-thsin hu-th ol Sie = e Chins. a Si NAN ing eds an ERR) § Q n; Eiko f , “Sining ax TU £57 K moyng or mie od 2h U i ’ of, AINE NG 7 tos J 3 Riv pr vi} fimo 2S 20d SN , a , a Kis Pind ELL OW emg oa a Mo ly Ma TOE 18: 2, Vi chow. ag “2 Chang v; Chin-ja 8 0 B Cox O= § MTS; 7 Kiing> chang Zr SN S Tun 25 } V ' 4 oly) 2 agOya N Cm. BN, Sv 9 BUA, Tunglo | fPoo, (in 2 Rive “Thsso-chow xf , Z A Vaio 4 oplofo ; PN R ¥% Yrs sin-chow : o-na; ; ao-chowd, ¢ Yp-cuow L . ° Supehh EO EA) @ Osmaa-wo-1zv I, QR S181 TL '_Fusy-siang Ser \ Shen KHATSFENG <% Kui-te on itr - Tone, 0 tw l| (VRiEs 1) ~~ A fg Ileal » . Siu chow © J Phet IM as aja © ga “Gr ©, 0 Myvaxe L . “i on WW Say es Sp 1 an We) 0) LTR Su’ hv Nw ren Ha amie o Gre the a > , Pr SS \ K Kat ) 3 AN 3 3 (RN ual <0 Se » Lg SOR RANK i o \ % : woh es Varo, Ti a Ww Hin iss IN 3 ~) Bri: ae. igre Hong, 1) QueLPART I LOY ) °d > \Hacuwo L 'R, Sm le, wg OMros: Hi To eS { raw ;® 2 NS To by Lo, oy i WY NJ iS. oS gl i - ® iy Qing: Kiang Yun yang me] Ju-ning o / sae +7 SFun “yang y 0 3 <¢ 20 a4 / ; oe ] chow i = g au, Ho P “= Huai Yisp %2 Shou Yang gow Th Kr # Goro ¥ Awoea L. o 7s 2 iC Dg ed ~~) nFiign an & Tchuo ,” w Me = NANKI Te . AYONNAISE i 2 20 |, Pow ning 7 © Paff{by/ a ‘Fang, 2 v NEI : chang OHrrer-sua L } % Fa P \o ES ZR hv : Thai-ping Tsune-miNG I, Kosut i FOL. on BEAN Sr Pan “Ral eal 2 0 LATIN ps 2 > - -, = anghai rs (TAN INe.T ne i I Foon Que ng-men ns | Li-tang JE 2 \Kioong,, 8 XInEh Y { chan, ing-chow pin He 2 ang-chow Bay . tan, ; Yao o 1A -nan o = WR ~ 8 Bm, CHUSAN I s | 30 i § oong-Kin Pei or} Man-chuiy” TR wl o 0. e|Nagano IL. iE a N gang Feoo | SV Q ou x PIA * dghwa- I ‘o . 3 A ow Foo-Chogfsh g aad Sie 3 LG on 37, ng Ce eo : ing\Y® ung-nin, wi Lng-ning o¥ aenihow or, ¢ \ Chenyuan® O-Sunt @ & oo 4 = i (aie pinay Ng Malabon R, TC Tambokori 121° Cpe fgan olo ’ ” Tuyoon? ) ‘Li. oi i . oe “ ° = 2 4 Cs 7 o _BindW z Tung-chuati QUE! YANG on he? : 2 . rau Yio asiNG , oAu-shun Toyah ONS WANS ING . Poouo x Tn , ¢ 8, & ng © caY (YUN Nan’, a es INRA oe ' 4 QUEISLIN ? ® 5 BN gan Sol} elung o® UNSNING Tien-chi Lake ! Aes $ bol? also Tw Hoel © 4 - + i Vo. Rigo, 4 = )2 SSenpms JE 0 1-PEI atulia \: mol LY N Shoo Oy yey 3) 72 A Con {ind Banka 9 Xa ow oCHENG Uh Y Tex 2 bin io 720K, 7c ag-chung YLVIA TT +e El - SHIGAKI T-méng sS Salty 4 NV » 8, Sing-jien® i (Chokedny Buh Us gin ms ns as Shibngan h : Choy 5. . FORMOSA. AN _ oSe- Sia “% ¢ Pékiang’ Ze) anau / or Hee (5, Lo-ting » > Khiz Pelam od ° ¢ ST 44 J Maca EQ sind 4% Hoax on eng. in-Kian - G Shp © Ki wah 5 39 Snino-Cuvsy 1. BR.) South Cape B wD i. BAO Gore. Cow i oY Havung [NANPANG L. BASIEE CHANNEL rt mate Ts," Ofvang Chou Bay S. Jose Pt. gry on, th di Ligh Nav L.(Fr.) oBASHEE JsLANDS x i Pt. R&% GUL NAN STRAIT p= : Al | Baran ISLANDS @ , se 4h NC Ni Ninh NieumiNcare L Coe Head 2% : DORRRGIIOR I yond QUE-ph er an-Noa NG-CHOW NNEL HE GS an Rha: ang ey : . TON -KING J =0 fete oy wu dmmrchonesne wil rm BABUYAN. TV] DA oh. ™ I indiman . mac i oF Urieus 0 | > i Ng fs, \ ) The Lithology of the Sze-Chuan Mesozoic Red Beds of China N———. ” { Ale xandravel] o FF EN : |B ie | A Comparative Study of Selected Specimens from a Section in the Tsin- Ling-Shan District. TN w NN 2 FL | Nu AE) Td... € | LOCATION AND DESCRIPTION OF THE SECTION I, 7 Gali mig my il Chors ® \ Il WW, a ] The main body of Mesozoic (Jurassic?) sediments as Thy ; N J A observed by the Louderback Expedition of 1915* lies in iD Cael 23 SRR the northwestern portion of the province of Sze-Chuan, A carajah TI Td (7 . 3 sha NG TRS Z RK ri tle dK Hels m 4 i ! We » oMarag ger J . ANT RE" S : TI asia, 8 Si \ posh goin rr extending into the adjoining provinces of Shensi on the 3 - asi | : ra afhametabid : o Zito | north and Honan and Hupeh (Hoope) on the west. Since oh Hiss Sl) i ) {Xs Cc na A \ a in B\2 F n ZZ5\ £ \ \ gal neeyah r { 28 Souch Blak o \ &° ? this great area is one of folded rocks, the Mesozoic nuh se strata do not outerop without interruption but a rep- etition of the beds is observed. Probably the best section of the red beds of the Sze-Chuan series occurs in the little corner of the province of that name where the adjoining provinces of Kansuh and Shensi come to- gether with Sze-Chuan. (See map preceeding) It is from this area along the Pai-shui-ho and Kia-ling-Kiang rivers from the town of Mei-pa-ko to Mien Chow through Chao-hwa-hsien that the specimens studied were collected by the members of the Louderback party. (See sketch ve [1 ase " * em | G.D. Louderback, Professor of Geology in the Univer- =, | Bity of California, in charge of a two year geologic expedition in China, 1914-16. Ie) ; 4 7 2, . ty, * | Xr map and section on pages = :. *) ¥ o 5 \ BamvEoN dn AJf GharbI\K avast SERCEN Dy MAP OF RKIEY 1x ASTAS (ASIA MINOR) ry eo - “sang SZEL -CHUAN 2 g 7ze- tung - Asien - e X , “X1059-. - - , ~~ xse0 ’ *, a Wes -chren- gr - SKETCH [MAP SHOWING GENERAL AREA OF SECTION -— = foules of Forty (Nammbers are for specimens studied ) x Fin? of collection of. Specimen ro. (2) According to the calculations of Morse*, the total thickness of the continental deposits there exposed is plus or minus 15,000! On the north the Sze-Chuan Series appears to lie with apparent conformity on the Hsu-chia-ho Limestone (Permian?). In general the members of the series have a more or less N.W. to S.E. strike and dip to the south at angles varying from 30 degrees near the base to 1-2 degrees near the top of the formation with an average dip of 10-15 degrees. The series, says Morse, "falls naturally into five divisions, viz. (1) The Coal Measures, (2) Basal Red Bed Conglomerates, (3) Lower Red Beds, (4) Mauerklippe Conglomerates, and, (5) Upper Red Beds." An inspection of the section, which follows, will show that the rocks studied were chosen from all portions of the series and represent a fair sequence across the strike. It was impossible to accurately determine the exact position occupied in the section by each specimen and the positions indicated are relative rather than exact. Since the deposits comprise almost every type and intermediate phase of sedimentary rock commonly found, the specimens used were selected at ran- dom, care being taken however to include the various types present. Thus the suite included shales, sand- stones, limestones and conglomerates of varying degrees of purity, consolidation, color etc. The principal * R.R. Morse, Asst. Professor of Geology in the Uni- versity of California and a member of the Louderback party. SW 3 ! 33 3 RB EE 33 a ~ * 33 83 3 3 ° 2.0% 33% 3 3 22x 1g at 3 2? 3 X EL, op x X XX x x TN CoA . A X x LH — ‘o bo ‘a : Te gor ily eS ear 5 Er asi Te 7. pe A fA oe 7 ool, Zs ye mr A Pd Te T gp = il ; ” 2 %2 pr CRIS ir < oo 0° © . eT = - = ~~ = wo -~e i CSA Ir mr W 7 4 LZ Hsu ~chia 2. ne 4 Upper X ar Beds pMouerklppe Cong. Lower Red Beds J Coal Measures (Permian) . Lower RK. 8. C org Mesozoic Coperdurassic)) Generalized Seclion of Sze-Chuan Series Sho wing RKelafive Locafion of Specimens Stuciéd 8 Their Numbers intent was to study the lithology of the "red bed" members of the series, three specimens from the Coal Measures horizon being included merely for purposes of comparison. It was hoped that results of the inves- tigation might throw some furthur light on the problem of the red beds, and at the same time add in the separa- tion of the series into its component parts as well as indicating the source and types of rocks from which these members were derived. THE PROBLEM STATED The great thicknesses of red bed deposits found the world over have long been the source of much confu- sion to geologists. Great horizons of these beds of Permian and Mesozoic age are found in England, Europe, Asia, America, South Africa and elsewhere; and these of course are of quite widely varying ages. Perhaps all these deposits are not of continental origin, although the majority are so considered. In practically every instance fossils are conspicuously absent, only a very few fresh and brackish water forms being found. The beds are commonly a bright deep red color, remarkably uniform in the sandstones, the shales varying from red to chocolate with intervening colors of green and maroon, all typically bright. Generally the ‘color is due to a thin coating of iron oxide on the component grains, there being but little interstitial coloring matter. The frequent occurrence of green sands and shales, and irregular green patches seems due to local reduction (4) processes. In addition, the materials are commonly well sorted mechanically, while occasionally beds of rock salt, gypsum, and anhydrite are carried. Such are the more characteristic features of the red beds. A moments consideration will show that the fore- going characters are rather difficult to reconcile with a simple continental origin. The great extent, vary- ing age, good sorting and stratification, angularity, occasional marine shells, frequently good chemical sorting are typical; to tie these in with a continental origin is difficult. It is only possible to conclude that the beds may be either marine or continental, probably / ;* 2 i yy > y YY 5 A) b HT QRRear 70 ngs wie - i bo) A Ce rho 1 $70 ui go I chiefly the latter. In this case the presence phases ~~ were developed under arid conditions, thus reconciling the small fauna and the anhydrous character of the iron content (hematite predominant). To account for the great amount of iron, ascertain the conditions of dep- osition and reconcile the conflieting evidence, --- such is the "problem of the red beds". Already much effort has been directed to this study, and in the fol- lowing pages the deductions from the study of the Chinese series will be compared with the leading views and possibilities at present held by most geologists.* *References: C.W. Tomlinson: The Origin of Red Beds. Jour. Geology, vol. 24, pp. 163-179, 238-253. J.W. Beede: Origin of Sediments and Coloring Matter of the Red Beds of Oklahoma. Science N.S., 40:312-3; Aug. 28,1914. (5) THE SCOPE AND PHASES OF THIS STUDY To aid in a mature and thorough consideration of the problem presented by the Chinese Red Beds by others more qualified to do such work, it was thought desirable in this preliminary and somewhat elementary study to attempt to obtain certain definite information, viz. (1) Lithologic variations in the upper and lower series and conglomerates, together with any evidences of trans- itional changes in the character of the constituents; (2) All information obtainable bearing on the origin and history of the deposits, including, (a) Conditions of preparation, transportation, deposition, (b) The rock types represented, (c) Subsequent history, (d) Origin, condition and relations of the iron content. To make sash data and deductions possible, certain information was required. In making the study, the results of which are here presented, the most instructive information was obtained by a detailed microscopic study of the thin sections of about fifteen specimens. The hand specimen was inspec- ted in each case and in addition the features of fifteen or twenty additional specimens were observed with the hand lens. A few analyses of the total iron content of various rocks was made; the distinction of ferrous and ferric iron in relation to the green color noted; and in most all cases the nature and relative amount of the ce- menting material was noted by dissolving out the calcite in cold hydrochloric acid. (6) As will be seen by an inspection of the reports on the individual samples in the Appendix attached, certain definite observations were made in each case, the infor- mation falling andr three main heads, viz. (1) Struc- tural features; (2) Character of the grains; (3) Min- eral composition and relations. From these data and the knowledge of the location in the section of the various specimens (see page 3%) it was possible to arrive at certain conclusions along the lines previously indicated. In the following pages various characters of the suite as a whole will be presented, their significance noted, and the information obtained presented in the general order already outlined. CHARACTER OF THE ROCKS 1. Peatures of the Sandstones Structurally the sandstones from the Red Bed series possess several points in common. Usually massive, these rocks are fairly well to very well indurated with a good degree of consolidation and a cementation which is always calcareous. As a rule the cementing material constitutes about 20% of the rock and shows abundant lamellan twinning, thought by some to indicate that the rocks have been under pressure. The type of specimen #1034 is probably quite typical as regards cementation, #1032 in which calcite is plus or minus 35% representing an extreme case and a transition toward the class of sandy limestones. The calcite is commonly as well crys- tallized as its interstitial character permits. The (7) poposity of the sandstones is commonly slight while the chemical sorting is typically "fairly good" as in #1034 or #1059, reaching the extreme "good" sorting in #1067. In no case observed is the chemical sorting poor. Mech- anically the sands are fairly well sorted, being slightly silty as a rule. The typical case is shown by nos. 1059 and 1067, nos. 1034 and 1036 representing extremes on either side. No doubt all degrees of chemical and mechanical sorting may be found in the section, but in those sands observed, the sorting of both types may be classed as "fairly good". Chiefly arenaceous, the sandstones are secondarily calcareous and to a lesser de- gree typically ferrgginous in varying amounts. The gA¥ins of which the sands are composed vary from one sixteenth to one mm. in size ("very fine"to "very coarse”) the typical grain being imm. ("medium"). In- evitably pebbles of larger size and silt particles of a smaller size occur in many of these rocks. The most common relationship is sand > silt > 10% or a "silty sandstone”, nus the clay matrix averages 10-15%. In all but one of the specimens studied the majority of the component grains are of marked angularity varying to sub- angular with very rarely a well rounded grain. No. 1034 represents a type in which sub-angular grains pre- dominate; but in the other specimens distinctly angular fragments are most abundant. Mineralogically the group of sandstones represents a rather constant composition, there being variations -in- (8) in the relative amounts present rather than in the kind of minerals. Quartz is of course abundant, being pres- ent chiefly as angular fragments often showing minute linfes of inclusions, while in every specimen a few grains show by their extinction the result of strain effects. In no. 1032 quartz is predominant. Again quartzite and some chen fragments are usually present --- sometimes in abundance. Oftentimes these show flecks of iron oxide. Again others which show the mottled extinction are so marked with chloritic patches outlining the grains that it is difficult to be sure they really are quart- gite. One possibility is that many of these grains represent chloritic shale or sandstone fragments, some of them approaching a "cement quartzite" in character. In addition it is possible that a very few of the grains of this type may be fragments of badly altered volcanic rocks. Certainly there is a distinet difference in many of the grains which superficially appear to be ordinary quartzite. In #1059 what appears to be al- most a predominance of gach material is observed, while in #1034 much is inoluded with the nearly predominant quartzite. Just what the significance of these grains is I have not been able to determine. The abundance of calcite in the sandstones has al- ready been noted. In additiog it should be added that at times, occasional Flastic fragments of this mineral are observed. Only in the sandy limestonessuch as #1032 can these §lastic grains be found in noteworthy numbers. The grains are so fine that the character of the limestones from which they are derived is difficult to ascertain, a fair crystallinity commonly being sug- gested. Thus while preponderantly secondary in the sense of being interstitial, calcite does infrequently occur as Plastic grains in the sandstones as well as in the other groups of rocks. Among the more minor mineral constituents, the following are almost always present, viz., altered flakes of a{éotite, mscovite, magnetite, zigoon and occasionally chlorite, while very rarely grains of anatase, garnet, and possibly spinel are observed. Bi- otite is the only ferromagnesian observed and it prob- ably does not reach 1% in amount. Only in one or two of the specimens (see #1032) are fresh feldspar fragments observed and they are very rare, even then. Commonly there are abundant grains of what appears to be turbid and badly altered feldspars. Alteration to both kaolin and sericite is noted, the former being most abundant. A few of these may be shale or clay fragments. The grains are too far altered to allow any observation of their original properties, but the form and character appears quite reliable evidence. Qccasionally an index less than 1.54 is suggested and in #1059 the assumption of an interstitial character by some of the kaolin ma- terial is noted. The amount of feldspar present prob- ably does not exceed 10% in any one case. The variation in the iron content of the sands is well indicated by the variation in color, this ranging (10) from gray or buff to brick red. In the lighter colored rocks the amount of iron oxide is small --- principally limonite derived from the alteration of constituent minerals as in #1067. Occasionally a minor amount of hematite may be present as in #1059. In these rocks showing a marked red color the iron content is large, and from analysis of a sandy limestone and two shales probably varies from 2-6% (see #1030, 1031, 1054). The analyses were made by grinding portions of the spec- imens to powder, dissolving out calcite with cold di- lute hydrochloric acid (HCL) and then removing any other carbonates with warm HCL. By boiling vigorously with strong HCL all the ferruginous material was removed and the residue left clean and white. By diluting the solute and adding ammonia, the iron hydroxide precipita- ted and probably some aluminum hydroxide in addition. The precipitate was then filtered out, dessicated and Walghed: Just how much error resulted from the presence of AIR9% is difficult to say, but it is probable that the results are a little high. The iron oxide is in the form of hematite and present almost entirely as fine coatings or pellicles on various mineral grains, chiefly on quarts. It does have an inter- stitial character although no doubt it is present in the matrix material. While the specimens of sands from the Coal Measures division are light colored and two of the three are but poorly consolidated, they differ but little from the Red Bed sands in their major features. In #949 quarts is (11) predominant and only an occasional quartzite grain is geen. Calcite is about 30% and the common minor min- erals are present with a fresh feldspar or two and a notable amount of secondary limonite. In nos. 947 and 948 which where only examined megascopically there appears to be an abundance of mica and an absence of calcite which is not noted in the samples from the Red Bed series. 2. Peatures of the Shales Among the three specimens of shales examined, the only structural variation is in the degree of induration, this ranging from fair to good, the consolidation being fairly compact. Lamination varies from quite distinct and fine to coarse and hardly notable. As in the case of the sandstones, calcite is the cementing material and is abundant, occasional clastic grains being noted. The amount of cement varies directly with the degree of induration and is more variable than in the sands ex- amined. As before, chemical sorting is quite good, while mechanical sorting varies from fairly good to good. (See #10320, 1035, 1054.) The porosity of the shales is very slight and the general type is argillaceous --- subordinately arenaceous, calopreous, and ferraginous. The character of the grains is much like the sand- stones, The size typically ranges from one sixteenth to less than one two hundred,fifty sixths mm. ("very fine" grains to "silt particles"). As before, the grains are principally quite angular. In addition the gilts are not clean but are commonly sandy, the type relationship (12) being silt > sand > 10%. The mineral composition of the shales as far as determinable shows no marked variation from that of the sandstones. In specimen #1030 quartz is predominant while magnetite, biotite, muse oxite and chlorite are noted. A very few unaltered grains of a plagioclase feldspar (possibly oligoclase --- extinction angle 0 degrees) are present, the main feldspar content being the typical turbid grains. These grains are spoken of as "frequent". No gircon is observed, and no quartzite. The clay ma- trix is abundant and composes probably 50% of the rock. The iron content is large, at least 6%, the analyzed value of 8.57% probably including some A1B50, The primary character of the hematite is clearly indicated and will be discussed when the general problem of the ired con- tent is considered. Other specimens examined seem to be very similar, a larger content of micas being the most noteworthy difference. All shales examined had colors of red or chooglate brown. 3. Features of the Limestones The limestones examined are very well indurated and cemented; massive in hand specimens; cemented by calcite which here, in distinotion to the previous rock types is. notably present as primary clastic grains. They vary from well sorted chemically and mechanically (#1046) to fairly well sorted chemically and fairly sorted mech- anically (#1066). Porosity is of course very slight, while the general type is calcareous and arenaceous. (13) mn In close correspondence to the shales and sandstones the sand grains of the limestones are principally angu- lar, the only exception being found in #1051 where the larger grains of the small sand content are sub-angular. The size of the grains is principally "very fine" to "Pine" or one sixteenth to one eigth mm. Typically these rocks show calcite > sand = 20%, they being de- | trital limestones, and therefore sandy. The mineral composition of the limestones varies so slightly from that of the sandstones as to require almost no comment. Quartz is the most abundant miner- al after calcite, with certain amounts a quartzite, tur- bid feldspars, magnetite, biotite, muscovite and a very few possible volcanic fragments, and occasional grains of ‘giroon, anatase and in one instance what appears to be epidote. In #1031 a few slightly altered grains of plagioclase are noted. The color of the specimens is principally a gray brown, the content of iron (chief- ly hematite) being low except in the red-brown #1031 where it approaches 4%. The iron oxide again appears pri- mary. In regard to the calcite, it should be mentioned that primary grains are clearly present. Most of the specimens show a fair state of grystallization and lamell6n twinning is abundant. The rocks, with the exception of #1051, are characterized by the absence of organic structures. In the latter, sbout three frag- ments which clearly indicate an organic character (fresh water organisms?) may be observed. (14) 4, Features of the Conglomerates Like their brother rocks in the Sze-~-Chuan Red Beds, the conglomerates, very well indurated, with calcite the cementing material, are quite well sorted chemically. However, massive in character and only very slightly porous, they are inevitably only poorly sorted mechani- cally. The cementing material is very abundant in these rocks in which limestone pebbles predominate (#1068,1069), dropping to 10-15% in #1060 where shale pebbles are most abgndant. » Apart from the fact that the material is chiefly sub-angular, the structural relations of the pebbles have little significance. The size of the latter varies con- siderably, the largest seen approaching 3 inches. Except in #1060, no application of grade relations can be made, the material all being calcareous. For #1060 the rela- tion is gravel > sand 10%. The composition of the conglomerates examined varies quite markedly. In specimens #1068 and #1069, lime- stone pebbles of all sorts and colors, largely organic, greatly predominate. Shale and quartzite pebbles are rere while occasionally finer grains of turbid feldspars, magnetite,biotite and a small amount of hematite are present. These rocks are from the "Lower Red Bed Conglomerates". A series of pebbles (nos. 1037-1044 incl.) from the middle part of the Mauerklippe division shows a predominance of quartzite fragments with some limestones of varying colors and one shale pebble. The ratio appears to be about 4:3:1. Specimen #1060 from near the top of the Upper Red Bed series is composed principally of shale and kaolinized feldspar pebbles and grains, while quartz and quartzite, possible vol- SaBL rock fragments, magnetite, chlorite, biotite, anatase, gireon and a small hematite content are found in the ground mass. It is difficult to be sure of the significance of these differences, since Morse states that phases of the lower conglomerates show many quart- zite pebbles at times. 5. Common Features of the Various Rock Types Prom the description of the different rock types, the following would appear to be the chief structural fea- tures held in common: l. Induration - usually quite good 2. Cementation - always by calcite 3. Sorting a. Chemical - usually quite good b. Mechanical - " fairly " 4, Porosity - slight The significant characters of the grains would then ap- pear to be: l. Angularity - grains chiefly angular 2. Grade relations - not pure - rock types are transitional, sands being silty, shales sandy etc. 3. Mineral composition - quite constant for major- ity of rocks, variation being in amounts present rather than in kinds of grains. The minerals the suite as a whole it should now be possible to proceed (16) and rock fragments commonly observed may be classed thus (in their average abundance): “Abundant Frequent Occasional Rare Very Rare Quartz Hematite Magnetite Zircon Garnet Calcite Turbid, Biotite Fresh Epidote Quartzite foldaonis Limonite feldspars Muscovite Anatase Chlorite Tourmaline Possible Vol- canic rock fragments Chert 4. The calcite as it ocours is always abundantly twinned, indicating pressure, except in those clastic grains previously mentioned. Furthurmore the abundant cementing material is present under quite uniform con- ditions in all the rocks examined, the porosity of the rocks being very slight. The logical inference is that the calcite all came in at the same time. Later con- siderations bearing on the conditions of deposition strongly suggest that this deposition was concurrent with the deposition wf the clastic grains. Thus the calcite is probably secondary only in the sense of being inter- stitial. The preceding discussion has briefly outlined the chief characteristics of each type of rock studied, to- gether with its most noteworthy features. From the des- cription given and the general common characteristics of to the next principal task --- the deductions to be made from the various features of the rocks themselves. DEDUCTIONS FROM CHARACTER OF ROCKS 1. Lithologic Variations in the Series The evidence presented by a comparison of the min- eral composition of these specimens from the Lower Red Bed Series (nos. 1029, 1030, 1031, 1032, 1033, 1034, 1036, 1036) furnishes no intimation of a lithologic variation in the series. The components of all the specimens are so much the same that no distinctive variation is apparent. The relative abundance of quartz, quartzite and chloritic sedimentary rock fragments varies quite widely in some of the specimens, but in’ no regular or progressive way. [For & furthur idea of the composition, see the reports on the specimens in Appendix A. Only in #1034 do quartzite and the chlor- itic shale and sandstone fragments approach a predomin- ance. In the other specimens quartz is usually the predominant primary mineral. An inspection of specimens from the Upper Red Bed Series (nos. 1046, 1051, 1054, 1059, 1066, 1067) sheds little light 4n possible variations in composition within this series. Here again the most notable dif- ference is in the relative abundance cf quartz, quart- zite, and chloritic shale and sandstone fragments. Quartz is generally the most prominent of the three, as in #1046, but quarzite and even the chloritic fragments are nearly on a par in some of the later rocks ,as in #1067. In #1059 the latter peculiar fragments appear to be predominant. The abundance of these chloritic sediments of an prgillaceous type does appear a little more marked toward the upper part of the series, although it grades down beyond #10659. (See Appendix A.) While a slight variation of a possible transitional character is suggested, it is not very clear cut or distinctive. Compared with evidences of lithologic variations of the two conglomerates lying below, however, this evidence is quite marked. Since the number of specimens from the Lower Red Bed Conglomerates was small and those from the Mauer- klippe series consisted only of the pebbles, a compar- ison is difficult. In those specimens from the Lower Conglomerates, limestone pebbles of many kinds, mostly of organic origin, greatly predominate as previously mentioned. However, the report of Morse indicates that this is a phasal rather than a constant general character. In the Mauerklippe pebbles (all from one place) quartzite, limestone and shale are observed in about the ratio 4:3:1. To draw any logical inference from this rather scanty evidence seems impossible and the examination of a much larger number of specimens would be required to establish any variation in the composition of the two series. The minerals of the matrix material of specimen #1068 and in the sandstone #1073 (Lower Conglomerate) are very similar to the minerals of rocks of the Lower Red Bed Series, quartz being very abundant in #1073. Prom the preceding comment on the composition of the various members of the Sze=-Chuan Series, sufficient (19) evidence is not forthcoming to indicate a transitional lithologic variation in the series. The components are very much the same in all the specimens and a gradual change in composition does not seem to occur. However, one noteworthy fact is that an examination of the reports of Appendix A. does seem to indicate that the relative abundance of the chloritic shale and quartzite fragments is notably greater in the Upper Red Bed Series. Great- est in amount in specimen #1059, these fragments are abundant in the succeeding rocks of the series. Just what significance this fact may have is difficult to say from the limited scope of this work. In addition, the iron content appears to grade off from the middle of the upper series, being relatively abundant through the lower series, but dropping to a rather low figure to- ward the upper limit of the section. This may be the result of the specimens chosen and not be a general char- acteristic. 0f a marked transitional variation then, we find no evidence ;but of a distinct variation in the abundance of certain components we do find a good sugges- tion. 2. The Origin and History of the Deposits Rather than attempt in the limited space available to present a number of varying and rather outworn the- ories relating to the probable origin of red beds, it would seem best to present the views which are now most commonly accepted. In the article by Tomlinson pre- viously referred to, an excellent summary of red bed origin is presented. Briefly outlined, the main points (20) are as follows, viz. (1) Types of sediments probably most important in series of red beds are: stream depos- its, sub-marine fluviatile deposits, and playa deposits. Lack of continuity of single types of sedimentation over large areas, imperfect assortment as a rule, and presence of ripple marks, cross bedding etc. are basis for this deduction and indication of dominance of flu- viatile type, (2) Presence of feldspars, micas and lime- stone fragments is evidence of dominance of mechanical over chemical weathering --- a condition best developed by arid regions and high relief, (3) Perruginous mater- ial transported chiefly as a mechanical sediment as shown by rounded pellicles on angular grains and ab- sence of notable interstitial material; (4) Colors appear due to a combination of lithologic, topographic, and climatic conditions in regions of denudation and deposit- ion not since reproduced on so large a scale. Morse points out the difficulties introduced by the occasional presence of marine shells, good sorting (particularly chemical) and shows that red beds may be either continental or marine. The character of good chemical sorting is difficult to tie up with an arid climate. As possibilities to account for the origin of the beds, he suggests the following: (1) Accumulation of lategite slowly may, through diastrophic movements, be transported to a more arid region and deposited in ad- jacent continental basins; (2) With accumulation as above and rejuvenation of erosion together with change to arid climate, rapid marine deposition would give marine facies (21) of beds. These suggestions are based on the characters previously mentioned and’ others common to red beds the world over. To return to the possible conditions of accumulation and preparation of the rock material of the Sze-Chuan se- ries, first let us consider the possible types of rocks eroded. Prom the composition of the various rocks as previously described,it is apparent that limestone and quartzites (both true quartzites and thechloritic cement quartzites or sandstones) must have furnished a large part of the rock material derived from the region of denud- ation. In addition, of the mineral components,altered feldspars and biotite, muscovite, magnetite, zircon, tourmaline as well as the possible volcanic rock frag- ments would tend to indicate that igneous rocks, both gran- itic and volcanic furnished their share of the materials composing the Red Bed Series. The abundance of quartz and clay matrix, and the occurence of the chloritic sand- stones and shale fragments are evidence for the erosion of sediments. Of metamorphic rocks, apparently only ‘ me Sr quartzites were abundant ae no minerals peculiar to metamorphic rocks of other types appear to occur. Por older rocks found in place resembling some of the fragments observed in the Sze-Chuan series, the fol- lowing specimens in the collection of Prof. Louderback are mentioned. Limestones Quartzites #144 #143 (22) Limestones Qquartzites #147 #407 297 450 319 456 902 500 1074 578 1080 613 10856 1103 (Those underlined show the most marked resemblances). In the attempt to establish the relative region from which the above specimens were obtained, the maps avail- able only furnished the location of some certain few. However, the maps together with some regional cross sec- tions did show the great thicknesses of limestone in the Permian, Silurian, Devonian and all the Paleozoic horizons. The Paleozoic rocks of the region are essen- tially limestone with minor quartzites, and it is from these rocks that the very abundant calcite and limestone fragments of the Sze-Chuan Red Bed series must have been derived. Purthurmore it was found that the great quart- zite and chloritic shale horizons occur in the Pre-Cam- brian rocks. If these were the principal source of the quartzite in the Red Beds, then this must indicate very deep erosion and a cutting down beyond the Paleozoic strata --- a process requiring great lengths of time. Specifically some of the occurrences of older rocks found in place which resemble rock material of the Red Beds are: #297 - limestone - Pre-Cambrian - unclassified. (23) Between King-tze-kwan and Sen-kwen-misu in the N.W. part of the quadrangle very near the intersection of Shensi, Hupei and Honan provinces. #407 - quartzite - Pre-Cambrian - unclassified. In N.W. area near Yun-hsi on boundary of Shensi and Hupei provinces. | $450,456 ,464 - quartzite and limestone - middle | Paleozoic. In N.W. portion of area very near Shih-yao- | tze in Shensi just east and north of Yun-hsi. #902 - limestone - Paleozoic - unclassified. In central vart of quadrangle south of Kwan-chuan-pu. #1074 - limestone - Permian. Very near east central boundary of quadrangle one mile north of Siao-pa and northeast of Mien-chow. #1080, 1085, 1103 - limestone - Permian. In same | general locality as $1074 but due north of Mien-chow. While the foregoing list is not extensive it will serve to indicate that the source of the Red Bed material was apparently in the limestones, quartzites and other rocks of Paleozoic and Pre-Cambrian ages. The evidence of the conditions under which the mater- ial composing our Red Bed Feries accumulated is not ex- tensive. From the angularity of the material and the commonly fairly good sorting, (both chemical and mechanical, ) it would appear that the larger part of the detritus did not accumulate under arid conditions or in a region of high relief. If it had, the chemical weathering would be very poor, a condition which is not realized. In arid regions or those of high altitude, mechanical weathering (24) greatly predominates and conseguently the rock debris awaiting transportation is angular and unsorted chemically, and sediments of the arkosic type result. Since the section ropuries by Morse shows arkosic beds occasionally in the lower series, these becoming more abundant toward the top it is possible that a gradual change in the conditions of accumulation took place. In dealing with a series of such great areal extent and rather remarkable thicknesses,it is extremely diffi- cult to be specific as regards the probable conditions of accumulation and deposition. Rather it is necessary to outline certain general possibilities only. With this in view it is possible that a major part of the red ved material may have been derived from the deep decay of limestone, quartzite and igneous material in a region of low relief. This would produce what is termed lat- erite or residual ferruginous soils (the end products of weathering) in which iron oxides would be very abun- dant. The deposits of residual iron ore Sree developed from limestone as in the Appalachian region )suggest that some of the iron content may have had its origin in this way. Of course, in the lateritic material would be inclu- ded much quartz, quartzite and chert. Again, regions of high relief adjacent might contribute phases of the ma- terial in which mechanical weathering would predominate. Thus,from the great extent of the series ,it is highly probable that the conditions of preparation and accumu- lation of material were somewhat variable over the large area involved. The very great thickness of the (25) series makes it difficult to accept the common view that a humid climate prevailed at the time of preparation of the material, deposition taking place under arid con- ditions. Under just what climatic conditions preparation did take place is an enigma, but in the main, these con- ditions were probably the same for both preparation and deposition. Just what instituted the beginning of the deposition of the Sze-Chuan Series of deposits is a problem that is beyond the scope of this work. Suffice it to say that orogenic movements possible of an epeiregenio character caused a re juvanation of erosion in the regions in which the material for the deposits had accumulated. That any climatic changes accompanied is a mere conjecture, but such a change, possible of a gradual character, to an arid condition appears possibly. As was mentioned in - the view of Tomlinson, stream deposits are the most abun- dant in a red bed series. The material which was now being eroded must have been transported by streams at a fair degree of grade and for a short distance only. Such a conclusion is all that can follow from the marked angularity in the grains of the specimens studied. The transportaion must in the main have been (1) by stream action; (2) for a relative short distance only; (3) rather rapid in character. Since rapid accumulation and transportaion tend to reduce the degree of chemical sort- ing, the merely fair chemical weathering of the Red Bed material may have resulted from a rapid accumulation and transportation, the climatic conditions perhaps favoring - (26) more thorough decay. From the work that has been done in this study, it is possible to speculate but little as to the conditions under which the rocks of the Sze-Chuan gories were depos- ited. Because of a 16k of evidence to the contrary it is only possible to accept the common view and conclude that most of the material was deposited in a great inland basin where sediments of the types of stream deposits end playa deposits and submarine fluviatile deposits were developed, the deposition being principally continental. No definite marine facies of the series have been ob- served. That the deposition fin the main took place under arid conditions seems likely Zeon THE TFIGATPEL consid- erations: (1) the iron content was probably hematite at the time of deposition (see below for a more detailed consideration); and (2) the series is predominantly red in color. Other things being equal, more red deposits will be developed in an arid than in a humid climate. Furthur conjecture than the foregoing relative to the origin of the Sze-Chuan Red Beds is hardly justifiable. Since the probabilities as to climatic conditions have been mentioned, no separate consideration of that factor is needed here. In reality the study of the suite of rocks has given but little information except of a very general character which bears directly on the problem of the origin of this great series. In concluding the discussion of this division of the problem undertaken, it is necessary merely to state that evidence as to the history of the Sze-Chuan Series since deposition is chiefly negative in character. (27) The common occurrence of lamelldh twinning in the calcite which cements the rocks probably indicates the sub jec- tion of the series to a certain amount of pressure, not enough, however, to produce strain effects in the quartz. Furthurmore, since the iron content appears to be largely hematite and this not in an arid region, it is highly probable that the iron oxides present have undergone little change since deposition. Finally, in all this discussion, of deposition which has preceded, no evidence has been forthooming which definitely conflicts with those views of red bed origin commonly held by geologists. 3. Significant Features of the Iron Content To discuss the abundant iron oxides which character- ize the Sze-Chuan series, the first question which arises is, what was the source of the great amount of iron in- volved? In answer to this, reference can only to be made to the preceding section in which it was brought out that the most likely source was in the widespread development of large amounts of laterite, ferruginous soils and even residual iron ores in which abundant iron oxides of a probable hefiatitic character were developed. Furthur than this, nothing can be stated. Conceding the development of the needed amounts of ferruginous matter, the next question to arise is, how was this material transported? Was it carried as a pasty mass or was it carried as coatings or pellicles on other grains? To this query, evidence of a more direct character is available,and this appears to favor the latter method. In studying the thin sections of (28) those specimens in which the iron content was great enough to give a distinet coloration to the rock, these points were noted: (1) The red iron oxide, apparently hematite, compo- sing the great bulk of the ferruginous content occurs chiefly as coatings or pellicles covering grains of quartz or quartzite, principally the former. In addition a certain amount occurs as £1ecks and patches on these and other grains, not all the coatings being perfectly developed. (This may result from the grind- ing of the section). In no sense is the iron oxide notably interstitial in character, (#1020, 1031, 1032, 1034.) (2) It is often noted that very sharply angular grains of quartz will be enclosed by a pellicle of hematite with sub-angular outlines sr—the—grain-enelesed (#1030, 1032) (3) Sometimes the hematite appears to have impregnated altered grains of previous rock material. (4) The tron oxide is always previous to the intersti- tial cementing calcite and lies between this and the grains of quartz and other minerals even when the oxide is of a psuedo-interstitial character. Prom these observations, it is difficult to conceive of the major portion of iron oxides present being transported in any other way than as coatings on other mineral grains. Since it is not of an interstitial character in the rocks, it could not seemingly have been transported as a pasty mass which would almost inevitably (29) take on an interstitial character relative to the other grains. This much does appear rather definite. And in answering He Second query as to transportation of the iron, that which logically follows relative to the mode of deposition of the iron oxides has been really answered. a Apparently then, the deposition of the iron oxides of the Sze-Chuan Fories was contemporaneous with that of the other mineral and rock fragments present and took place as a mechanical process. In no sense was the i conten) iron present of a secondary character, but having been carried in largely as coatings on mineral grains or independently it was decidedly primary in character. How it first became attached to these grains is conjectural, a8 is the relative amount deposited independently. The final point which arises concerns the condition of the same famous iron oxides since their deposition. On this point direct information cannot be brought to bear but it would seem most likely that no extensive changes in the degree of hydration or in the relative amounts of ferrous and ferric iron have taken place since deposition. Even though now lying in a region far from arid, the predominant oxide appears to be hematite. Likewise the patches of green colored matter,or the green spots caused by local reduction to the ferrous state, (cf. analysis in report or specimen #1034, appendix.) have probably not changed to any marked degree since dep- osition. The conditioning factor in this was probably the original distribution of organic (carbonaceous) (20) material in the sediments, this locally causing the re- duction to the ferrous state producing the green patches in the shales. A fair idea of the range of the amount of iron present is given in the analyses in the reports on specimens #1030, 1031 and 1054. These values are probably high because of the precipitation of Bowe plutiits with the iron hydroxides. From 2/-8% by weight Pe£9% in those rocks of a marked red color would doubtless be a good average range. Having presented the chief features of the iron oxides oF the specimens studied, it remains to enquire if the resulting deductions differ from views previously expressed. However, as with the question of the dep- osition of the rocks, the evidence noted, although in this case more abundant, seems to. agree very well with the views presented by Tomlinson in his excellent ar- ticle previously referred to. As his work is a good summary of those views which appear to be the best found- ed, any comparison with other theories is hardly nec- essary. Generalizations are usually easy to make, but the definite knowledge which can be brought to bear on the varied problems of the red beds is very limited and after all it is knowledge and not conjecture which de- serves the most consideration. CONCLUSION In the preceding pages the attempt has been made to give a fair idea of the character, conditions and most noteworthy features as observed by a study of the selec- (31) ted suite of specimens from the Sze-Chuan Mesozoic Red Beds, In addition much that is merely conjectural and probable in regard to the origin and history of the deposits has been considered. In doing this, the hypoth- eses have been of a general character, the desire being to present definite information first, and then state the general theoretical possibilities which appear most prob- able. That the task undertaken may be briefly summar- ized it would now be well to outline the most important conclusions derived from the study. As stated in the introduction certain information as definite as possible in character was desired. The data resulting has not been as abundant or as definite as had been hoped,but the conclusions and theoretical considerations previously discussed can now be outlined in the order in which they were consideredr (1) Lithologic variations in the series. No variations noted within the rocks of the five divisions of the series and no transitional change in lithology across the series. Presence of quartzite and chloritic shale and sandstone fragments more char- acteristic of rocks of Upper Red Bed series. This change not transitional. Dropping off of iron content toward top of series suggested. Rocks of Coal Measures divi- sion quite like those of Red Bed Series except for absence of hematite and greater content of mica. (2) Probable conditions of accumulation, transpor- tation and deposition of rocks. Material probably accumulated under variable (32) conditions of weathering, large part having undergone thorough chemical weathering in a region of low relief and humid? climate, result being production of great amounts of laterite and ferruginous soils. Regions of high relief contributed material in which mechanical weathering was predominant. The inauguration of Red Bed sedimentation must have been closely related to topographic and possibly climatic changes resulting from grogenic changes. A rejuvenation of erosion and a change to or continuation of arid conditions, possibly gradual in character resulted. The accumulated material was swept away and likely underwent transportation chief- ly of a rapid and short character. The deposits were then laid down under conditions chiefly continental in character in some great inland basin. Stream deposits, submarine fluviatile deposits and playa deposits resulted in which the former were probably most abundant. (3) Conclusions on source and nature of iron content. The source of the iron content was probably in the deep decay of the rock material weathered to laterite, ferruginous soils and residual iron ores. The material largely hematite, was probably transported both indepen- dantly and (abundantly as coatings on grains, as a mech- anical sediment. The deposition was simultaneous with that of the constituent minerals of the rocks and the iron oxides do not have an interstitial character. The oxides are not secondary and always occur between the mineral grains and the -seeendary cementing calcite. The degree of hydration and the amounts of ferrous and ferric iron have probably remained quite constant since | deposition. The iron content for colored rocks appears | to vary from 3 - 6%. | | In brief, the foregoing is a fair summary of the | results brought out by this study. The details have previously been discussed and considered at some length, | while in the appendix attached complete reports on all the specimens examined may be found. Finally, it may be well to quote Tomlinson's conclusions on the origin of red beds and leave the problem as it is, still in the very early stages of its solution. "The inauguration = . and cessation of red bed sedimentation seem closely con- APPENDIX A ( nected with climatic and topographic changes involved in | the orogenic history of the continent. The colors are due to a combination of lithologic, typographic and cli- Reports on Rock Specimens Bxauined. matic factors in the regions of denudation and those of deposition which have not since been reproduced over so great an area." To the future remains the solution of this riddle. * : Thesis Je We Olmsted INDEX ( Page Coal Measures Division 1-8 Specimen: Field No. 947. Field Designation: Sandstone. = # 947 1 & 4 948 3 Locality: Station # 1252.30. £ 949 5 Study: Hand specimen only. Lowe Red Bed Conglomerates 8 - 15 l. Structural Features. # 1068 8 1-Epiclastic. # 1069 i 2-Massive. ~~ #1073 13 3eInduration - faire. Lower Red Bed Series | 15 - 36 ae Consolidation - fairly friable. £ 1029 15 | be Cementation - chiefly by a limanitic # 1030 17 material - possibly partially kaolin. ; # 1031 21 | | 4-Parosity - moderate. | ( # 1032 25 | 5-Sorting. | # 1033 28 | a. Chem = good. | # 1034 28 | be Mech.= good. | # 1036 32 11. General types # 1036 | 33 : l-Arenaceous . | Mauerklippe Conglomerates 111. Character of grains | # 1037 - 1044, inclusive 36 - 38 | l-Size range - fine to medium Upper Red Bed Series 38 ~ 55 2-Sandm 80%. # 1046 38 3-Angularity - sub angular in main to distinctly | ~ £ 1051) } > 7 41 | angular. # 1054 44 4-Composition # 1059 | 46 : a. Quartz - very abundant and predominant | | # 1060 49 Sub angular fine and medium grains. | # 1066 52 | b. Kaolinized feldspars - appear abundant | 1 = 1067 04 2e #947 (con) ce Muscovite - very abundant.as flakes and patches. de Magnetite - fairly abundant. Sub angular fine and med. Black grains. ee Yellow iron oxides - fairly abundant. Very likely a combination of kaolin and limanite which appears to act as cement- ing material. A little red oxide. fe. Other rosigtant numerals present appar- ently some zifcon, titanite and biotite (altered) IVe Name. Fine to medium sandstone. ? Color: Slightly yellowish (See #948) Se Specimen: Field No. 948. Field Designation: Sandstone. Locality: Station #1252.30. Study: Hand specimen le Structural Features. l-Epiclastice 2-Massive. 3=Induration - poor a. Consolidation = fairly loose and friable be Cementation - Calcite - small amt. 4-Parosity - moderate. 5« Sorting. ae Chemical - appears good. be Mechanical = fairly good. II. General Type. le. Arenaceouse. IIT. Character of grains. . le Size range = Chiefly medium to occasional worse or fine grains. 2. Grade ratio: Sand> silt = 5-10%. 3e Angularity - Sub angular to angular. 4. Composition. ae Quartz - predominant. Sub angular to angular med. grains. be Muscomite - very abundant. ce Magnetite - abundant. Sub angular black grains. IV. 2. de Turbid feldspars - fairly frequent Presence strangly suggested - not definite ee Iron oxides - frequent - chiefly limonite possibly some hematite. More or less interstitial. fo Accessories - appear to have gixcon, titanite and possibly anat@se present, together with bigotite. color - buff. Name - Medium sandstone. (See #947) Se Specimen: Field No. 949. Field Designation: Sandstone. Locality: Station #125255. Study: Hand specimen and thin section. I. Structural Features. l-Epiclastice. 2-Massive = (from hand specimen evidence) 3=-Induration - very good. Qe Gensolldation - hard and compact. be. Cementation. Chiefly cemented by secondary calcite very abundant and may approximate 30% of rock masse. Limonite may act as subor- dinate cementing material. 4-Porosity - slight. S=Sorting. aes Mechanical = quite good. be Chemical - quite good. ITI. General type. l=-Arenaceous in main. Subordinately argillaceous and calcareous. ITI. Character of Grains. l-3ize range - fine to medium sandstone grains from 1/8 = 1/4 mm. in general. 2-Grade ratios and class terms. Sand> silt> 10% Thus "silty sand." S=Angularity - in general grains are quite angular Ge (#949 Cont.) IV. though numerous sub angular grains are present as well as an occassional well rounded grain. Ratio of angular / sub angular is 3:1 or 2:1 at least. Composition. 1-Quartz = approximately 40%. The predominant individual mineral present. Angular to sub angular in character, many uneven fragments suggesting a previous interstitial character as in igneous rocks. Grains fine to medium in size (1/8 - 1/4 mm.) Some few grains show strain effects. 2=Feldspar = frequent. Inferred from marked occurrence of turbid grains in which sericitization and kaolinization are - very marked. One unaltered fragment showing marked microemecline cross hatching observed. Wo unaltered &athoclase feldspar distinguished. Grains subeangular in main varying to angular; size medium to fine. 8. Volcanic rocks fragments - altered grains suggested. 3=Calcite 30%. Very abundant secondary material = chiefly of an interstitial cementing character but with same well developed jShombohedrins . Shows Samellan twinning. (#949 cont) 4 | B. ( 4- Biotite = trace. Badly altered and defamed Specimen: Field No. 1088. fragments - bent etc. but still showing cleavage ; Field designation: Conglomerate. and some of characters. Chiefly as flakes and | Locality: Station 1483.10. irregular fragments. Study: Hand specimen and thin section S5=Magnetite = trace. l. Structural Features. Zosoue black mineral showing metallic luster. l-Epiclastic. Sub angular and medium to fine in grain. | 3-Massive. 6=Quartzite pebbles =~ trace. 3-Induration - very good. p Sub angular and angular pebbles of quartzite a. Consolidation - hand and compact and " Stony" material which show granular character between b. Cementation - Calcite. crossed nicols. Secondary interstitial material from pri- 7-Limonite « very notables ary limestone pebbles. ( Apparently secondary from altering magnetite, 4.Porosity - rather slight. biotite etc. although some may have been carried a. Chemical - good. in by solution. Certain grains appear to have E b. Mechanical - poor. whatg approximates a pellide or covering of lim- II. General type. onite but this is questionable. Material is most l-Calcareous. abundant as a sort of secondary "halo" about M III. Character of Grains. altering grains of other minerals.pay serve as a 1-81 -Size range. subordinate cementing material. Fine grains to pebbles. IV. Name: Fine to medi dsto: x i : um sandstone - calcageous and 2-Grade ratio - no application - rock almost ent- slightly silty. irely limestone pebbles and calcite. 6olor: bark gray wiih black csvie 3-Angularity - sub angular to well rounded. . 4-Composition. a. Limestone pebbles - greatly predominant. Pebbles of black, gray, brown, white and red L. 8., (#1068 Con's) h. Wany of which show clearly an organic origin. Rounded organic structures some much like foraminifera are common in pebbles in thin section. Some fairly warse grained but fine grained pebbles predominate. Some of pebbles appéaria-ldttle silty. Some show strictly crystalline character without any indication of organic character while in others this latter is very marked. Shale pebbles - rare. One pinkish pebble noted which appears to have been flattened and sheared out. Quartz ite pebbles - very rare. Turbid feldepars - occasional. Fine sub angular grains occur in ground mass. Calcite - very abundant - as almost entire ground mass - commonly quite crystalline and showing marked lamellar twinning. Iron oasides - limonite and hemgtite - occas- ional. Coatings of hematite and outlining by limonite observed. Not abundant and chiefly hematite. Reddish colors of L. S. pebbles are seen to be due to presence of hematite. Magnetite - rare. Fine grains in gd. mass and in some L. S. pebbles. Biolite - rare. Badly altered flakes. IV. (#1068 Con't) Rock quite. metamorphaeed (recrystallized) Name - Limestone pebble conglomerate. Color: Pinkish cast in main. 11. Specimen: Field No. 1069. Field designation: Conglomerate. Locality: Station #370.30. Study: Hand specimen. I. Structural Features. l1-Epiclastic. 3-Very maseive. 3-Induration - extremely good. a. Consolidation - very hard and compact. b. Cementation - Calcite - very abundant. 4-Porosity - very slight. 5-Sorting. a. Chemical - good. b. Mechanical - poor. II. General Type. 1-Calgareous. III. Character of grains. 1-Size range - Fine graine to large pebbles. 3- Grade ratio — Cannot apply. At least 90% of rock is some form of calcite. 3- Angularity - Chiefly sub angular to well rounded 4-Compesitian. a. Limestone pebbles - greatly predominant. Wide range of colores and grain as in #1068. b. Shale pebbles - rare. c. Iron oxides - some present. Reddish color of many L. S. pebbles is evidence. (#1069 Con't.) IV. d. Magnetite - rare. Very fine black grains. Limestone pebble conglomerate. 13. 13. Specimen: Field No. 1073. Field Designation: Looality: S. 300 E. of Station 1513.18. Study: Hand specimen and thin section. I. Structural Features. l- Epiclastic. 3-Massive. 3-Induration - good. a. Consolidation - hard and compact. b- Cementation - Calcite - abundant secondary. interstitial. 4~-Poroesity - slight. 5-Sorting. a. Chemical - fairly good. b. Mechan ical - fal rly good. II. General Type. l+8ize range - Very fine to fine. 3-Grade ratio - Sand> calcite>silt = 15%. 3-Angularity - Chiefly distinctly angular to sub angular. 4-Composition. a. Quartz - very abundant (predominant mineral) Angular very fine and fine grains. Some show inclusions and some strain effects noted. b. Calcite - as noted above under cementation. c. Turbid feldspars - frequent. ( Sub angular fine grains all kaolinized and some appear slightly impregnated with calcite. (#1073 Con't.) 14. Somewhat interstitial character of some grains ‘amy be due shearing. d. Magnetite - occasional - Fine sub angular grains and some which appear possibly of secondary origin. e. Iron oxides - amount amall - Yellow iron oxide observed but appears to be chiefly secondary. No significant features observed. f. Zigcon - occasional. Fine sub angular grains noted. g. Beotite - occasional - Only elightly alter- ed. h. Chlorite - frequent. Clear green grains showing pleochroiem, sign, cleav. and all other characters. IV. Name: Fine calcgneous sandstone (silty). Color: Gray. 15. (#1029 Con't.) 18. Specimen: Field No 1039 c. Biotite - fairly abundant. Field Designation: None. Locality: Station # 1333.81 (C) Does not appear badly altered. d. Magnetite - fairly abundant. e. Iron oxides - rare. Traces of Limonite. Study + Hand specimen. I. Structural Features. f. Titanite - frequent. 1-Epiclastic. Yellowish brown and pinkish grains. r 3-Distinctly fissile - cleaving in layers of about g. Accessories — Appear to have zipcon and ’ ssibl anatgse resent 3 inch. Gives step like appearance when breaks po y ose Pp . JV. Name - Fine sandstone. out. 3-Induzation - good. But? colored. a. Consolidation - firm. b. Cementation - Calcite. Moderate amt. cf ( secondary cement ing material. 4-Poroesity - slight. 5-8orting. a. Chemical. b. Mechanical - gcod. II. General type. l-Arenaceous. III. Character of grains. l-8ize range - chiefly fine. 3- Grade ratios - Sand >80% 3-Angularity - sub angular. 4-Composition. a. Quartz - very abundant. Sub angular fine grains. b. Musconite - abundant. Flakes and plates. (#1030 con't.) Im, Field No. 1030. 3-Angularity - chiefly quite angular; less notably Field Designationt sub angular. Locality: Station #1339.03. 4-Composition. Study: Hand specimen and thin section. a. Quartz - predominant as a primary mineral. I. Structural Features. Grains chiefly fine and angular. Some l-Epiclastic. grains show strain effects. 3- Coarsely laminated. b. Calcite - abundant and in aggregate proba- 3-Indurat ion - good. bly predominant. Apparently present almost a. Consolidation - hard and compact. entirely as formless interstitial cementing b. Cementation - chdéefly calogneous. Calcite material. Shows twinning and cleavage occas- very abundant as cementing material.evid- ionally. Slight veining noticed in hand ently of secondary origin. Obviously in- specimen. terstitial in character. Limonitic or c. Magnetite - frequent as fine angular to sub hematitic iron oxide present may play a angular grains - some quite fresh and others subsidiary part as cementing material. in varying stages of alteration to iron oxides 4-Porosity - elight. d. Biotite - frequent as badly altered platee and 5-8orting. flakes still showing traces of pleochroism a. Chemical - quite good. and other characters. Fine in size and sub b. Mechanical - good. angular. Ae II. General type. e. Simonitic and Hematitic Iron oxides (Chiefly l-Argillaceous, arenaceous, calcafeous and ferru- latter) Shale is chocolate brown color with a ginous. reddish cast from abundant hemgtite- appar- ITI Character of Grains. ently quite uniformly distributed. Looks 1-Size range - "very fine" with an occasional fine chiefly primary and calcite seems to have (1/16 - 1/8 mm.) come in after iron oxides. Present as grains 3-Grade ratios and class terms - Probably eilt > of hematite and as coatings about grains - sand >10% - or "silty sand". some quite distinct; also as alteration from (#1030 con't) Analysis: Wt. Sample 3 4.177 g. a h. i. 19. biotite, magnetite etc. Where pellicle of iron oxide is distinct appears that grinding action has rounded the outer coating of iron oxide. Thie is not marked in many cases. Some grains appear to be of previous rock material very thoroughly altered and even impregnated with iron oxide. Iron seems too abundant and lacks interstitial characters to indicate that it is secondary. Iron is previous to calcite définitely as always lies between primary grains and cal- cite. This does not of course make iron necessarily primary. Wt. Fe_O % Fep03 (some 41,0) 8.57% 0.358g. Muscovite - trace. To’ fine to be definitely distinguished but appears to be present as fine flakes. Very high mottled int. tints. Chlorite - trace - apparently secondary after biotite. Turbid feldepars - frequent. Plagioclase Feldspar - rare. a very few unaltered grains showing albite twinning - low relief and other props. noted. From extinction angle (around 0° ) may be (#1030 con't.) IV. Name ¢ Color: 20. oligoclase. j. Volcanic rock fragments? - possibility: k. suggested by a few badly altered grains which appear to carry some microlitjes - possibly of feldspar. Tourmaline - very rare. Very fine sandy shale - calcorieous. Chocolate brown with reddish cast. al. Specimen: Field No. 1031 Field Designation: Sandy Limestone. Locality: Station #1339.08. Study: Hand specimen and thin section. I. Structural Features. ’ l-Epiclastic. 3-Massive in hand specimen - probably stratified in aggregate. 3-Induration - very good. a. Consolidation - compact and firm. Quite hard. b. Cementation - Calcite 1s cementing mat- erial and probably most abundant consti- tuent of rock. Calcite is present clearly as primary grains in rock and solution and reprecipitation of this original material has probably been responsible for secondary cementation of the original rock. 4-Porosity - very slight - pore spaces fine and irregular. 5-8orting. a. Chemical - fairly good. b. Mechanical - fairly good but some variation in size of grains. II. General Type. l1-Calcareous and arenaceous. III. Character of grains. (#1031 Con't.) 33. 1-83z@& range - very fine to fine ( 1/16mm. - 1/8 mm.) 3-Class terms - cannot apply here. 3-Angularity - Chiefly quite angular with occasional sub angular grains and a very few well rounded. 4-Composition. a. Calcite - probably approximately equal in amt. to quartz. Present both as primary grains and as secondary interstitial cem- enting material. Sometimes find primary grain surrounded by secondary ring of differ- ent optical orientation so that two parts extinguish differently. Chiefly fine in grain and sub angular or angular in form. Shows lamellar twinning. b. Quartz - with calcite the predominant miner- als. Approx. = calcite in amt. Present as angular grains, varying to sub angular and even will rounded, from very fine to fine in size. Some grains show strain effects. c. Biotite - abundant as flakes and fragments only slightly altered in most cases. Some fragments badly altered. Fragments sub angular or very irregular and chiefly fine (1/8 - 1/16 mm.) in size. Both brown and green. d. Iron oxides - hematite and limonite in main. Iron not greatly abundant and probably heme’ “e is in excess (at least as original material) (#1031 Con't.) Analysis: #1031. Wt. Sample 3.933g & -’ 33. Some pellicles of hematite on qtz. noted - apparently primary and previous to deposition also. Probably other iron of more inter- stitial character is primary in main - tho some appears to be derived from alteration of primary minerals. Interstial iron pre- vious to calcite even where does not form complete coating. Surprising how much color is given by small amt. of iron. Notepitted qtz. filled with little flecks of hematite. Turbid Feldspars - frequent. Cannot be sure of nature in thin section, but appear to be badly kaolinized feldspars. Feaing are angular to sub-angular and generally elonga- ted, suggesting feldspar form. Magnetite - scarde. Occasional opaque black sub angular fine grains. Some altering to lower oxides on margins. Zipcon - occasional. Sub-angular grains of fine size. Quartz ite or Chet grains - frequent. Sub angular grains of fine and very fins grained crystalline quartzitic rocks. Chlorite - occasional. Flakes and patches noted. Anatgse — rare Chm (-); Chz (4) not definite Sub angular C>Q (Wag )d-a=.00) but very probable. (#1031 Con't.) 24. x. Plag iodose feldspare - rare altered grains still showing trace of albite twinning ex- tinction near 00°. IV. Name. Fine sandy limestone (sand 50% + ) or Very calcameous sandstone. (Former probably most appropriate) Color: Reddish gray brown (slight red cast) Study 1. II. III. 35. Specimen: Field No. 1033. Field Designation: Sample #IA. Locality: v Vo A? AL Hand specimen $6 thin section. Structural Features. l-Epiclastic. 3-Massive in hand specimen. 3-Induration - good. a. Consolidation -~ hard and compact. b. Cementation - col@areous. Colcite as interstitial material 1s cement- ing substance and quite abundant. Some grains of cglcite suggest primary character Probably +35% amount. 4-Porosity - very slight. 5-8orting. a. Chemical. b. Mechanical - fair. General type. 1-Chiefly arenaceous; to lesser degree calcgneous. and ferruginous. Character of Grains. 1-Size range - very fine to medium - fine grains greatly predominant. 3-Grade ratios - Sand®eilt = 10%. 3-Angularity - Very angular to sub angular. Angular grains predominant. 4-Composition. (#1033 Con't.) 36. a. Quartz - Very abundant + 35%. As very fine to medium grains - chiefly angular, some show strain effects. b. Caloite + 35%. - As abundant interstitial cementing material. Apparently practically all secondary. No primary grains noted. Shows famellar twinning. c. Iron oxides - Abundant. Chiefly the red oxide - hematite. As pellicles, crusts and patches on qtz. grains chiefly. Always pre- vious to calcite, if secondary, but relation to quartz - even where pellicle only part- ially or very slightly encloses grain strong- ly suggests primary nature. Yellow oxide present appears chiefly to come from alter- ation of primary minerals such as biotite and magnetite. Note color marked for amount of iron present. Not all qtz. carries hem- atite on surface or boundaries. Probably pellicles quite complete in many cases be- fore grinding of slide. Hematite not evenly distributed - but more in certain portions of slide. No separate grains noted. d. Turbid feldspars - quite abundant. Greatly altered to kaolin with suggestion of semicite in some cases. Determination not definite but appearance with turbid appearance due (#1032 con't.) ge ( ZB. i. 37. to opaque. kaolin and form of some grains strongly suggest altered feldspars. Sub angular and fine in size. Biotite - very frequent. As sub angular flakes and plates — generally quite badly altered to iron oxides. Usually fine in grain and generally brown in color. Magnetite - frequent. Black opaque angular to sub angular grains - commonly altering to hydrous iron oxides on margins or in some cases quite badly altered. Muscofite - occasional flakes. Zicon - rare. Sub angular grains. Quartzite or chert pebbles - occasional angular and subangular pebbles of recrystall- ized quartzitic material showing crystall- ine character under crossed nickols. Rock fragments - occasional. Fragments, which under crossed nicols show crystalline character and some very fine grains of opaque minerals. Cannot make out character. Some suggest impure quartzite.- or a few may be altered volcanic rocks. Feldspars - rare - a very few grains whigh still show albite twinning. Extinction angle small. ar IV. Name - Fine Calcgrieous Sandstone. Color: Reddish brown. 28. Specimen: Field No. 1033. Field No. Sample #1 B Study: Hand Specimen =- very similar to #1031 and #1046 in main features. Noteworthy differences: le. Less calcapeous and yet an impure L.S. Intermediate between #1031 and #1046 and a calcapeous S.S. such as #1032 or #1034. 2+ Not quite as well sorted mechanically. 3. Not as marked an even conchoidal fracture. 4, Have some notable elongated and circular segre- gations of what appears to be chiefly hematite. Color: Reddish graye. Name: Very sandyL.S. or very calcageous SeSe Clearly an intermed, type. Specimen: Field No. 1034. Field Designation: Pebbly Sandstone. Locality: Station #1354.94 Study: Hand specimen and thin section. I. Structural Features: 1. Epiclastic. 2+. Massive in hand specimen. 3s Induration - fairly good A. Consolication - fairly hard and compact. Slightly friable in places. Induration: slightly uneven. B. Cementation - calcite + 20% 29. B. (Continued) Secondary calcite filling interstices serves to cement grains together. 4. Porosity - very slight. Se Sorting A. Chémical - fairly good Be. Mechanical = poore II General type. le Arenaceous chiefly. Notably calcafeous and ferruginous alsoe III. Character of grains le. 2e Se 4. Coarse sand grain to very fine sand grain -- large proportion of grains probably "fine" Grade ratios -~ do not well apply. Contains both silt and gravel in addition to sand. Might term sand> silt) gravel. Silt) 10%, gravel 5%.C an ferm p cbbly silty sand Angularity - ¥esy GCenerete-term-"pebbly silty sands Angular to Rounded. Sub-angular grains predominant. Composition. a. Quartzite -- predominant + 35% Very abundant I to rounded fragments of veidystallized and cemented quartzitic material. Presence very noticeable under crossed nicols by mosaic pattern given by varying extinction peeitions of grains. Iron stains along lines between grains often indicate granular nature in ordinary light. Often stained on surface by hematite. Grains chief- ly fine to occasionally medium and coarse. Many of aoe be Ce de fe 30s (Quartzite Continued) grains are chloritic and may be chloritic shales or sandstones. Quartz - abundant. angular to sub-angular grains of quartz chiefly fine -- rarely medium in size. Notable strain effects. Turbid feldspar -- abundant. Sub-angular fine grains of what is apparently feld- spar turbid from alteration to ovale kgolin and some sericite. Occasionally get suggestion of index <1l.54 on some of these grains. No trace of twinn- ing or cleavage could be found. Elongated form of some grains suggests feldspar habit. Calcite + 20% -- secondary cementing material only. Shows Bameliar twinning. Biotite =~ occasional Badly altered flakes of brown mica. Some flakes appear altered to chlorite. Chlorite «=~ fairly rare | Patches of green slightly pleochrfic mineral show=- ing micacEous cleavage and apparently secondary after biotite. Muscovite -- occasional. Flakes and grains of fine size. Iron oxides =-- hematite and limonite fairly abun=- dant. Hematite chiefly as coatings on quartzite graims. Limonite merely scattered. Strong sug- Sl. ( h. Iron oxides - continued gestion of green character of ferrous iron in some places on thin section. Hand specimen shows very marked patches of green in a red mat- rix where ferric iron has been reduced to ferrous. Some small patches are round as if might be formed around a small carbonaceous nucleus of some sorte. Note depth of color from small amount of iron. Analysis: Fe ++ Pet tt (Tet is present in green patches Yes Yes but only in small amount apparently. ) i. Magnetite -- fairly rare. ( Fine sub-angular grains not algered on margins. Joe Zifcon -- trace -- too small to make definite. ke. Volcanic rock fragments -- very rare. One or two of grains which resemble quartzite may be badly alt. volcanic or igneous rocks showing microlites. IV. Name: Pebbly silty sandstone =-- calcaneouse Color: Brownish red with green patches. Specimens Field Noe 1035s Field Designation: Sandy shale. Locality: Station #1556546 Studys Hend specimens ~ Ie Structural features. 1. Epiclastics 2. Massive =--only very poorly -lamineted- 32 Specimen: Field No. 1035 Field Designations Sandy shale. Locality: Station #1355.48 Study: Hand specimen. le. Structural Features: le. Eplclastic. 2. Massive = only very poorly laminated. 3¢ Induration - fair. A. Consolidation - fairly firm and compact. Be Cementation - calcite =- considerable secondary cementing material. 4. Sorting. A. Chemical - appears good. Be Mochaniosd - fairly good. 5. Porosity - slight. 11. General type. l. Chiefly alS11200008 Secondarily arenaceous, ferruginous and calcageous. 111 Character of grains. 1. Size range: From silt particle™ to "very fine sand.” 2. Silt > sand 10%. 3. Angularity - sub-angular for fine grains - while silt particles appear fairly angular. 4. Composition. A.Quartz - predominant B.Kaolin - abundant C.Muscavite - abundant D. Iron oxides - abundant. Hematite appears to be present largely as coatings on quartz. E. Magnetite - frequent. 1V Name: Sandy calcageous shale. Color: Dull earthy reddish brown. Notes Lamination bywery fine red layers. Uneven distribution of red coloring matter. Green spots = usually of coarser texture and of all sizes. Polish taken by red clay lumps which are uncolored on inside. Specimens: Field No. 1036. Field Designation: Locality: Station #1356.28 Study: Hand specimen and thin section. le Structural Features: l. Epiclastic. 2. Massive in hand specimen - very slight fissile tendency in places. 3e¢ Induration - quite good. A. Consolidation - firm and fairly compact. Slightly friable. B. Cementation - Calcite = 20%. As secondary cementing material. Cemented somewhat by kaolin. 4. Porosity - slight but notable. Spaces very irregular but slightly larger than is common « Se Sorting. 2 5. (Continued) A. Chemical - quite good. Bes Mechanical - good. 11 General type: l. Arenaceous and calcapeous. 111 .Character of grains: le Chiefly "fine" - some "very fine" or smaller. 2¢ Sand» calcite> silt= + 5% 3+ Angularity - quite angular to sub-angular. 4. Composition A. Quartz - + 25% Angular and sub-angular fine grains showing some strain effects and inclusions. Bs Calcite - + 20% - secondary cementing material as noted. Shows lamellar twinn- ing. C. Quartzite - fairly abundant. Sub-angular grains of recrystallized quartzite material. Some appears fairly impure. D. Piotite - fairly abundant. Usually badly altered. 2. Fuscorite - rare. Flakes and plates. F. Magnetite - occasional. Rather unaltered to altered sub-angular and even very irregular fine grains. Note outline such — ~~ 2 as this gh Secondary. 111. (Continued) Ge. Iron Oxides - hematite and limonite. Very small amounts - both present as alteration products from biotite and magnetite with occasional Srusts of hematite on quartz and quartzite grains. Compared to other slides is very little present and coloration of rock is very slight - merely a suggestion. He Turbid feldspars - abundant. Sub-angular grains of what appears to be feldspar very badly altered to kaolin and showing no trace of cleavage or twine ing. I. Zircim - occasional. Sub-angular grains. J. Garnet or spinel - frequent. Isotrgpic grains of high index - iso- metric but not difinitely distinguish- able. Properties check best with garnet (almandine) Very small. Ke. Anatase - trace L. Cassliterite - trace Me. Volcanic rock fragments - very rare r lV Name =~ Fine calcapeous sandstone. Color: Buff-Gray 36 Specimeng: Field Nos. 1037 - 1044 incl. Locality: Station 1367.60 Field Designation: Pebbles from Conglomerate. Study:: Hand specimens. A, #1037 Fine sandy shale - calcajyieous - Sub-angular Color: Reddish pink. Secondary veinings of calcite. Streaks and patches of deeper red hematitic material noteworthy. Rock is not homogeneous and carries large fragments of earlier limestone. Shaly material in one seems to be a hard coating on L.S. oy consider a shaly L.S. B. #1039 Quartzite Pebbles - Sub-angular, Fine grained - fairly pure and dense. One is very fine grained and black from impurities. Others gray, one of which is frac- tured and shows iron stains along fracture planes. C. #1038 Quartzite Pebbles - Sub-angular Fine grained and almost aphanitic. Veining (fine) of second- ary quartz in one gives best evidence. Appear to be impure quartzites with some hematite which have started on meta- morphism. Get some slight suggestion of presence of micas and a bright blue mineral and ong one fracture a sort of semi-schistose fracture. Seems an impure quartzite a little metamorphosed. #1041 #1044 #1042 #1043 - Sandy Limestone Pebbles -- sub-angular One fine and one medium grained. One 1s reddish from hematite present. Fine Limestone Pebble -- sub-angular. Very hard and dense showing some development of a black mineral which appears secondary. Quartzite -- sub-angular Fine dense quartzite - showing marked brown reddish colors along lines of fracture. A light gray where fresh. Quartzite -- sub-angular Massive dense fine quartzite with what appears to be sort of a good sized vein of rock quartz on one side. Surface of quartzite, Shows many little patches of a soft brown material which appears to be an "iron oxide". Color is grayish brown with a slight reddish cast. Limestone Pebbles -- sub-angular One white and medium grained. Other QsriE grag-broms (carbonacéous?) and fine grained. Some brown iron oxide in latter, Specimen: Field No. Fleld Designation: Locality: Station #1367.42 Study: Hand specimen and thin section. I. Structural Features: a, Epiclastic b. Massive in hand specimen c. Induration -- very good 1, 2. 4. Se II. General type a. Calcajeous and a avenaceous III, Character of grains. a. Chiefly "fine" in size. b. Calcite > sand. ¢. Angularity -- chiefly distinctly angular. Less notably sub-angular., d. Composition: 1. 1046 Hard and compact. Cementation - Calcite + 50% As secondary cementing material, Possibly some primary grains. See under composition. Porosity -- extremely slight. Sorting. (2). Chemical -- good (b)e Mechanical -- good Quartz - + 30% Chiefly distinctly angular fine greins. Some show strain effects. Some gas and liquid in- clusions noted. Some carry coatings of hematite. { #1046 - continued 2. Se Se Calcite - + 50% Chiefly as secondary cementing material showing lamellar twinning. Also as primary grains showing lamellar twinning. Grains angular end fine observed. Rock quite metamorphic in character. Quartzite - abundant | Sub-angular fine grains of recrystallized quartz. Occasionally almost well rounded. Usually carry flakes of hematite on sur- face and often between grains of minute pebbles. Iron oxides -- not abundant. Chiefly as red hematite on grains of quartz and quartzite. Limonite present chiefly as alteration product from bio- tite or less commonly from magnetite. No evidence of secondary hematite. One quartz grain shows hematite pellicle plainly where coating has not been ground away. a hematite quartz showing hematite ground away. Coloration marked for amount 6f iron. Turbid feldspars - frequent. grains apparently of kaolinized feldspar-- sub-angular, Some grains seem somewhat impregnated by calcite. #1046 - continued 6. Blotite - frequent variably altered flakes 7. Magnetite - occasional Sub-angular grains -- somewhat limonitized in some cases. 8. Epidote - rare --- doubtful Only one grain noted whose character could not be made out. Possibly a sec- ondary product. This not likely from condition of other constituents. IV, Name - Fine sandy limestone. Color: Grayish brown (light) » { Specimen: Field No. 1051 Station: #1397.70 Study: Hand specimen. l. Structural features: 1. Epiclastic-massive-unconsolidated-uncemented-loose and friable-very porous. A. Mechanical sorting - fairly good Chemical sorting - good 11. General type - arenaceous. 111 Character of grains l. Medium to fine sand grains and coarse pebbles. 2. Sandy 80% 3¢ Grains - sub-angular in main. 4. Composition A, Quartz + 50% Be. Turbid feldspar - abundant C. Biotite - occasional altered flashes D. Magna¢tite - abundant E. Limonite and Hematite =~ occasional patches F. Accessories - appear to have garnet, titanite, anatase, zimcon, etc. lV. Name =~ pebbly medium sandstone Light color. Note: Hand specimen and thin section are not the same so cannot logically consider whatever evidence either ( one gives unless know which is correctly numbered. » TY ro —— 42 * Specimen: Field No. 1051 Field Designation: Locality. W Study: Thin section. U rr ae Oo Ny [ l, Consolidation - hard and compact V4 I. Structural Features a, Epiclastic b. Massive - apparently 1 c. Induration - very good. 2. Cementation - Calcite Very marked and rock appears to have under- gone recrystallization so actual interstitial character of cementing material is marked. At least 80% rock is calcite. d. Porosity - extremelyslight . e. Sorting l, Chemical - good 2. Mechanical - good II. General type a. Calcazieous III. Character of grains a, Size range - very fine to fine b. Calcite > 80% Ce Angularity - detrital grains chiefly sub-angular -- to angular where very fine. #1051 - continued. d. Composition l. IV, Name ~ Fine calcite + 80% Distinctly crystalline showing marked mosaic pattern and very abundant lamellar twinning. Distinct secondary vein of calcite traverses slide. Principal part of calcite must be primary and recrystallized under pressure. Iron oxides --~ abundant. Hematite occurs around and between small aggregates of very fine grains some of which are probably quartz. Patch like occurence may be due to recrystallization. Magnetite - occasional sub-angular and very fine. Quartz - occasional grains. Sub-angular and fine to angular and very fine. Biotite - occasional Very fine altered flakes and fragments. Organic fragments -- some peculiar rounded /x 2 structures which suggest possibility, redigal arrangement and ~ peculiar extinc- tion strongly suggest this. Chlorite - occasional petches Appears to be a secondary development -- possibly due to metamorphism. crystalline limestone. Specimen: Field No. 1054 Field Designation: Red sandy shale. Locality: Station #1398.62 Study: Hand specimen. I. Structural Features a, Epiclastic b. Quite well laminated (fairly thin) and cracking up very much like a mud, ¢+ Induration - fair l. Consolidation - rather firm 2. Cementation - Calcite - moderate amount of secondary material, d. Porosity - slight e. Sorting l. Chemical - appears good 2. Mechanical - quite good II. General type Primarily Petitaceous. Secondary arenaceous, ferrug- inous and calcafieous. III. Structural features. a. Size range - "silt particle" to "very fine sand". b. Grade ratio -- silt > sand >10% c. Angularity -- smallest particles very fine; others chiefly sub-angular. d. Composition. l, Quartz -- appears predominant. ‘very fine and ‘silt particles of clear glassy material. 054 - continued L #1 | Specimen #1059 d. Composition: ws”, Field Designation: Sandstone 2, Kaolin - appears fairly abundant. Locality: Station #1441.356 3. Muscovite - abundant. Study: Hand specimen and thin section. 4, Hematite - very abundant. I. Structural Features Appears present notably as coatings on Pp Pp | y Eg a. Epiclastic quartz grains. b. Massive - slightly fissile parting Analysis: Wt. Sample Wt. Feo Feo0 | 4.390 ge 0.4808. Ene 3° ce. Induration - fairly good 5. Magnetite - frequent. l. Consolidation - firm and fairly compact - IV, Name: Sandy shale. friable tendency slight. Color: Marked brownish red. 2. Cementation - Calcite + 15% d. Porosity - Interstitial and clearly secondary. Very slight. e. Sorting - l., Chemical -- quite good 2. Mechanical -- fairly good. II. General type a. Arenaceous III. Character of grains a, Size range - "fine" to"coarse" - chiefly medium b. Grade ratio - sand > silt > 10% c. Angularity - Chiefly angular - to sub-angular d. Composition - l. Quartz - abundant, Angular medium and fine grains showing in- clusions and some strain effects. #1059 - continued. r #10569 - continued - IV, Name - silty medium buff sandstone i . d. Composition (Calcaneous) 2. Quartzite - probably predominant Sub-angular and medium grains - some of true quartzite, others of very chloritic recemented sandstones and shales carrying abundant micaceous or chloritic materials now largely altering to limonite. A 3. Turbid feldspars - abundant 7, F Chiefly medium and sub-angular. Some coarse grains noted. Get suggestion of cleavage and twinning on one or two grains but no extinc- tion or figure. Some grains only kaolinized ( others sericitized as well. Note interstitial suggestion. 4. Calcite + 15% - as noted under cementation 5. Magnetite - rare 6. Biotite - occasional very badly altered flakes. 7. Iron oxides - chiefly limonite. Secondary alterations and stains on quartzite, Tidotite, magnetite, etc. Some crusting on quartzite. 8. Zijicon - occasional sub-angular grains. 9. Muscovite - occasional Flakes and plates - somewhat altered 10. Chloritic patches - occasional. Some clearly secondary after biotite with which intergrows. fF Specimen: Field No. 1060 Field Designation - Conglomerate Locality: Study: Hand specimen and thin section. I. Structural Features. a, Epiclastic b. Massive ¢. Induration - Good l. Consolidation - Hard and compact 2. Cementation - Calcite 4 10 - 15% As secondary interstitial material. d. Porosity - slight e. Sorting - [ l. Chemical - quite good 2. Mechanical - poor. II. General type. 8, Pebbly and arenaceous III, Character of grains, a, Size range - "Fine" to "pebble". Pebbles chiefly 6-10 mm, and other grains chiefly "medium" (z-# m.m.) b. Grade ratio - gravel > sand > 10% c. Angularity - Angular to sub-angular d. Composition: l, Shale and Keolinized feldspar pebbles. Predominant - Sub-angular pebbles and grains of kaolin like material which in thin section shows extremely turbid character and minute flecks of quartz and sericite along with yellow 50 #1060 - continued d. Composition 1. (continued) iron stains. Are probably both altered feldspar and shale fragments. Chieéfly pebbles but are numerous "medium" grains in ground.mass. Colored yellow, reddish, brown and gray brown. Shale pebbles probably predominate or may be ‘nearly equal. Shales carry turbid kaolin material. Quartz, muscovite, magnetite, bio- tite, and iron stains. Biotite and magne- tite quite altered. 2. Quartz - abundant. Angular and sub-angular fine and medium grains both in ground mass and in kaolinized pebbles. 3. Quartzite and chert - abundant. Chert is rare. Abundant sub-angular grains of true quartzite and cement quartzite or chlor- itic sandstones and shales which carry consid- erable chlorits and limonite in places. Abun- dant in ground mass. 4. Magnetite - occasional Fine angular and sub-angular grains - chiefly in ground mass. Some altered and secondary. 5. Muscovite - frequent Flakes and plates. 6. Chloritic patches - occasional - largely on volcanic fragments. #1060 - continued d. Composition - continued Te 8e Qe 10 ® 11. Biotite - occasional - altered "fine" flakes and plates in ground mass and pebbles. Some grains unaltered. Iron oxides - limonitic and hematitic stains and crusts and alteration products. Hematite outlines on some quartzite. Calcite - see under Cementation. Anatase - Rare fine grains) Cannot identify ) with any Zircon - Rare fine grains ) certainty. IV. Name - Sandy pebble conglomerate. (Calcaneous with medium ground mass) (Color: mottled yellow brown -- grayish matrix.) 52 Specimen: Field No. 1066 Field Designation: Limestone Locality: Study: Hand specimen and thin section, I. Structural Features. a. Epiclastic b. Massive ce. Induration - very good. l. Consolidation - hard and compact 2. Cementation ~- Calcite d. Sorting l. Chemical - fairly good 2+. Mechanical - fair - some shale pebbles present. e. Porosity - very slight II. General type a. Size range - very fine to fine, b. Grade ratio - Calcite > sand=40% + c. Angularity - Chiefly angular to sub-angular. d. Composition. l. Calcite - predominant. As primary grains and secondery interstitial material, 2. Quartz - very abundant. Angular and sub-angular very fine and fine grains some showing inclusions and strain effects. Se Quartzite - fairly abundant. Sub-angular very fine grains of quartzite #1066 - continued d. Composition - continued 3. Quartzite - continued . material showing character mottled extinction. 4. Turbid feldspars - fairly abundant Sub-angular kaolinized grains. 5. Magnetite - fairly abundant. Angular and sub-angular very fine grains 6. Zincon - fairly abundant Highly refractive sub-anguler very fine grains. 7. Iron oxides - not abundant. Some quartz greins show hematite coatings and limonite stains are present from alt, of magnetite, biotite, etc. 8. Biotite - occasional - some slightly alt. very fine flakes and plates. Other green and brown flakes fresh. | 9. Anatose - rare Very fine green pleochrgic wndaxiel (=) sub~- angular grains. 10. Fourmaline - I'are IV. Neme: Fine pebbly and sandy limestone. Color: Brownish graye. 54 Specimen: Field No. 1067 Field Designation: Sandstone Locality: Mien-Shau Study: Hand specimen and thin section. I. Structural features a. Epiclastic b. Massive c. Induration - very good l. Consolidation - hard and compact 2. Cementation - Calcite 4 25% As secondary interstitial material. d. Porosity - slight e. Sorting l., Chemical - good 2. Mechanical - fairly good II. General type a. Arenaceous and calcapeous III. Character of grains. a. Size range - very fine to medium, Chiefly fine. b. Grade ratio - Sand >calcite = 25§-30% c. Angularity - Angular to sub-angular d. Composition - l, Quartzite - abundant Chiefly fine sub-angular grains. Some show Chloritic matter and are probably chloritic shales. 2. Quartz - abundant Chiefly angular fine grains - some showing lines of inclusions and some strain effects. #1067 - Continued 56 d. Composition - continued Se 4. 5. 6. Te 8e Calcite - Some of material appears primary but great majority is interstitial in character. Twinning noteworthy. Turbid feldspars - very esbundant Sub-angular grains of kaolinized feldsper (Some also appear sericitized). Some grains have appearance of having been squeezed out so as to be almost interstitial, Biotite - frequent. Plates of badly altered biotite. One appears fairly fresh in places. Hematite - slight amount As crustings on occasional quartz and quart- zite. Some limonite present as alteration product on steins, Zipcon - occasional - Sub-anguler grains, Chloritic patches - occasional Chiefly on volcanic rock fragments. IV. Name - Fine calcaneous sandstone Color - graye. END OF TITLE