A 576459
russell
A PARTIAL REPOLT
ON
THE GEOLOGY OF WESTERN TEXAS
CONSISTING OF
A GENERAL GEOLOGICAL REPORT
AND
of Geosical Observations along the Routes Traveled by the Expe-
between. *Indianola, Texas, and the Valley of the Mimbres,
during the Years 1855 and 1856, with an
Appendix giving a Detailed Report on the
Geology of Grayson County.
BY PROF. GEO. G. SHUMARD
ASSISTANT STATE GEOLOGIST OF TEXAS.
AUSTIN:
TATE PRINTING OFFICE
1886

ARTES
LIBRARY
1837
SCIENTIA
VERITAS
OF THE
UNIVERSITY OF MICHIGAN
G PLONIŠU) UNUNT
TUEBOR
SI-QUÆRIS-PENINSULAM AMŒNAM”
CIRCUMSPICE
الم
Science Library
QE
167
AIS
1886



I. C. Russelly
ARTIAL 22
ON
REPORT
THE GEOLOGY OF WESTERN TEXAS
Texas. Geological and agricultural survey,
CONSISTING OF
A GENERAL GEOLOGICAL REPORT
AND
A. Journal of Geological Observations along the Routes Traveled by the Expe-
dition between Indianola, Texas, and the Valley of the Mimbres,
New Mexico, during the Years 1855 and 1856; with an
Appendix giving a Detailed Report on the
Geology of Grayson County.
BY PROF. GEO. G. SHUMARD,
ASSISTANT STATE GEOLOGIST OF TEXAS.
AUSTIN:
STATE PRINTING OFFICE,
1886.
.:
Rec
4-37
INTRODUCTION.
The papers here given to the public consist, first, of "A Journal
of Geological Observations along the routes traveled by the Expedition
between Indianola, on the Gulf of Mexico, and the Valley of the Mim-
bres, New Mexico," in 1855 and '56; secondly, "A General Geological
Report" thereon; and, thirdly, an Appendix embodying a detailed
report on the Geology of Grayson County. They are from the
hitherto unpublished manuscripts of Prof. George G. Shumard, who
was Assistant State Geologist at that time to Prof. B. F. Shumard,
the Chief of the Geological Survey which had been authorized and
ordered by the State, but which was never completed in consequence
of the breaking out of the war between the States.
These papers were probably intended as notes, or rather as the
basis for more careful and elaborate official reports to the Chief Ex-
ecutive of the State, and the Legislature. Although they cover com-
paratively a very small portion of our Imperial State, they contain a
great deal of scientific and what may be called "field note" informa-
tion of the highest practical importance, not only to Western Texas,
the Prairies and the Great Plains, to which they chiefly refer, but
also to the entire State. No friend of Texas can read these some-
what crude but sensible documents without experiencing a feeling
of deep regret that they were not officially printed and published to
the world when first prepared, for it is apparent that the facts and
information, scientific and practical, that they so clearly bring to view,
would have been of inestimable service to a generation then in its
prime, but now passing away; the knowledge contained in them would
have then led to a development of both the mineral and agricultural
wealth of the State, which has been retarded for years. For example,
on the second page of the accompanying "General Geological Report
on Western Texas, the reader encounters the following brief but ex-
pressive paragraph:
66
"}
Many of the soils encountered upon the Plains are found to possess
iv
INTRODUCTION.
in an eminent degree all the necessary elements of nutrition for plants;
and if this region were accompanied with the requisite meteorological con-
ditions, it would possess a character for fertility unsurpassed by any
portion of the North American Continent."
Now, how are these indispensable "meteorological conditions" to
be obtained? The progress and developments made on both sides of
the Atlantic during the past and present century, in the science of
Forestry in connection with Meteorology, have shown that there is
but one very plain and easy way, and that is by covering one-fourth
to one-third of the Plains' surface with forests. Every section of 640
acres on the Plains and Prairies of Texas should have upon it from
150 to 200 acres of well-timbered woodland. Procure the seed or
scions of the right kinds of growths, suited to the soil and climate,
such as Catalpa speciosa (the most durable of all known growths and
best suited for railroad cross-ties), China Aster, Hickory, Maple, Black
Locust, Walnut, Chestnut; White, Post, and Live Oak; Ash, Bois
d'Arc, etc., etc., and respectable forests could be grown in 30 years
or less time; and enough of the same from the necessary thinning out,
beginning the fourth or fifth year, could be sold in the meantime to
pay all expenses. Experience in Germany and other parts of Europe
proves this, and it proves, too, that by or before the end of 30 years
the desired "meteorological conditions" may become such all over the
Plains and Prairie country and adjacent regions, that destructive
summer drouths and devastating freshets would be reduced to the
minimum; countless perennial fountains would bubble up from the
generous bosom of Mother Earth, and all of these streams great and
small would run reasonably full the year round; and much of the
Texas prairie country, the "black hog-wallow lands," for example,
already productive enough, even under present "drouthy" conditions,
to make them equal the best lands in Eastern States, would, with
the increased and equalized rainfall sure to follow foresting and re-
foresting, become unsurpassed in fertility.
Of course, farmers on the Plains or Prairies of the West, or those
having lands there that they may wish to colonize, ought to begin
by boring Artesian wells for immediate purposes. These would also
assist materially in bringing about the desired change in meteoro-
INTRODUCTION.
V
logical conditions; in restoring and equalizing the rainfall; and, in the
meantime, judging by what has happened in some other States, might
be utilized, to some extent, for irrigating purposes.
Unquestionably, much of the future greatness of Texas will de-
pend upon the success of her people, in producing, by comprehensive
management and concerted action, "the requisite meteorological con-
ditions" referred to by Prof. G. G. Shumard, over all that region of
the State lying West of the 98th Meridian of West longitude. Pro-
duce those conditions over all that immense territory of prairie and
plain, lake, river, and mountain, stretching from Austin, Palo Pinto,
and Wichita to the Rio Grande, and, as a matter of course, it
will have a healthy and beneficial effect on every other part of the
State.
In consideration of the importance of the subject to the whole people
of Texas, I take the liberty of publishing an Abstract of a Geological
Report made by Prof. B. F. Shumard, State Geologist, and by him
submitted to the Legislature at its Eighth Session. This Abstract
gives a brief, but very comprehensive and compendious statement
of the progress of the Geological Survey of the State up to August
1st, 1860. It embodies a great many important facts in reference to
the agricultural and mineral wealth of Texas-especially the latter-
which are as yet but little known to the public at large. When
it is remembered that this Report was never officially published by
the State, or if it was, that like the journals and other documents
of the Legislature to which it was submitted, were burned in the
fire which destroyed the Capitol, thus leaving no copy extant--
nothing, except this Abstract which is copied from the "Texas
Almanac" for 1861--it will be admitted that it is in the line of
the public good to reprint it now. (See Appendix.)
In the Abstract of Prof. Shumard's Report, it will be seen that
as early as 1860 he, as State Geologist, had ascertained that in ad-
dition to incalculable quantities of Lignite, Texas also possessed
enough Coal of superior quality to supply the demands of her
people for centuries to come. Further, it may be stated, that a lack
of information as to the existence of valuable and even immense
deposits of such Minerals as Copper, Lead, Silver, etc., widely pre-
vi
INTRODUCTION.
vails, which are clearly if not fully reported upon in the accom-
panying papers.
Dr. George Gettz Shumard, whose geological survey of a portion
of the State of Texas is now for the first time published, was a
graduate of the Medical School of Louisville, where he combined
the study of Geology with that of Medicine.
In the year 1850 a Military Expedition was organized by the War
Department to explore the sources of the Red River of Louisiana.
Captain R. B. Marcy was appointed to command, with Capt. G. B.
McClellan as assistant, and the following year another Expedition was
organized to explore the sources of the Brazos and the Big Wichita
Rivers of Texas. In both of these Expeditions Dr. Shumard served
in the double capacity of Surgeon and Geologist. One of the most
important objects of these Expeditions was to gain a better knowledge
of the geology of the country adjacent to these rivers, and the
selection of Dr. Shumard as Geologist was a high recognition of
his eminent ability.
On the termination of the surveys, complete and exhaustive reports
showing the results of the Expeditions were made by the General
Government.
In March, 1852, another Expedition was ordered by the War
Department, "To make an examination of the Red River of Louisiana,
and the country bordering upon it." This was also under command
of Capt. R. B. Marcy and Geo. B. McClellan, Dr. Shumard again
accompanying them as Geologist, Paleontologist, as well as Surgeon
of the Expedition. In 1853 a report of this survey was published
by the War Department. A large collection of fossils and other
specimens, collected by Dr. Shumard on this Expedition, were
forwarded, with his notes, to Edward Hitchcock, then president of
Amherst College, for his examination, and the result was a joint
report published in 1853 of "The Expedition of 1852," a work
comprising several volumes.
In the year 1855, Dr. Shumard was appointed Geologist and
Surgeon to the Expedition ordered by the War Department, under
command of Capt. John Pope, of the Corps of Topographical
Engineers of the United States Army, who was directed to explore a
INTRODUCTION.
vii
large portion of the plains of Texas and New Mexico, with the pur-
pose of testing "in those distant regions the practicability of ob-
taining water by means of Artesian wells."
To ascertain the practicability of building the Southern Pacific Rail
Road was also an especial object of this Expedition.
Dr. Shumard was engaged in this work about three years, when in
1858 his brother, Dr. B. F. Shumard, President of the Academy of
Science, St. Louis, was appointed State Geologist of Texas, and he
Assistant Geologist.
The surveys for which the above appointments were made were
carried on with vigor for more than two years, until the war between
the States coming on they were discontinued, and Dr. Shumard left
the State, arriving at Cincinnati, Ohio, on the 5th of April, 1861,
and on the 8th of the same month was appointed Surgeon General
of the State of Ohio.
During his connection with the Geological Department of Texas
Dr. Shumard, from time to time, made various reports which are well
known. Scientists will remember his discovery of an American
substitute for gum arabic.
Dr. Shumard's public career, as a geologist, closed with his leaving
Texas. He, however, in private, continued his studies, and con-
tributed largely, by correspondence, to various scientific societies, of
which the following are the most prominent: The Geological Society
of London and of France, the Imperial Geological Society of Vienna,
the Geological Society of Hermstadt, and the Academies of Science
of Philadelphia, California, Cincinnati, New Orleans, and others of
repute.
H. P. BEE,
Commissioner of Insurance, Statistics, and History.
AUSTIN, August 20, 1886.
ERRATA.
Frontispiece, third column, for "Lower Siliceous," read Lower Silurian.
Page 13, first line, for "subforsiformis," read subfusiformis.
Page 13, tenth line, for "lævinsculd," read læviuscula.
Page 13, fourteenth line, for "apuorcus "read æquorcus.
Page 22, last line, for "unheaved," read upheaved.
Page 28, twenty-seventh line, for "Hemitite," read Hematite.
Page 28, third line from bottom, for "tatiniferous," read titaniferous.
1
गया
or-
QUATERNARY.
500
DriftLoess.
60
.

PALEOZOIC PERIOD.
CARBONIFEROUS SYSTEM.
SECONDARY PERIOD.
TERTIARY.
CRETACEOUS SYSTEM.
Upper Cretaceous
or
Calcareous Group.
Lower Cretaceous
or
Marly Clay Group.
Upper Carboniferous
or
Coal Measures.
Lower Carboniferous
or
Mountain Limestone
SILU-
RIAN.
Lower Siliceous.
300
3000
3000
1100
55
2500
50
25
S
PART FIRST.
GENERAL GEOLOGICAL REPORT.
BY GEO. G. SHUMARD.
CHAPTER I.
The region of country the geology of which forms the subject of the
present report lays to the west and southwest of the State of Arkansas, and
is comprised principally within the limits of the 29th and 35th degrees of
latitude and the 94th and 108th degrees of longitude. It extends, on the
one hand, from a line drawn from Indianola, on the Gulf of Mexico, by way
of San Antonio de Bexar, Fort Inge, and Fort Clark, to Fort Davis, north
to within a short distance of the Canadian River; and, on the other hand,
from the western borders of the State of Arkansas and the district imme-
diately south as far west as the Mimbres Mountains, situated sixty miles
west of the Rio Grande.
Confined as my observations have been merely to detached portions of
the region here indicated, and often compelled to conduct examinations
hastily, I cannot hope to do more than present a general outline of its lead-
ing geological features. I shall, however, avail myself freely of notes
taken during my former expeditions to the sources of the Brazos, Big and
Little Wichita, and Red Rivers, and also refer to the observations of such
other explorers as have had opportunities of visiting portions of the same
field that I have not been able to examine myself.
The accompanying vertical section [Frontispiece] is intended to represent
approximately the general character, thickness, and relative order of the dif
ferent stratified formations encountered by myself in the district under
consideration. It has been compiled from more than two hundred local
sections taken in the course of my explorations in the Expedition under
your charge and during former expeditions under Capt. R. B. Marcy. I
trust it will be found as correct as could be expected from the necessarily
rapid manner in which many of the examinations were conducted.
The first and second columns of the section contain the numbers and
names of the several Geological Systems; the third, the subdivisions of the
Systems into Formations; the fourth, their estimated thickness; the fifth, the
colors employed to represent them; and the sixth, their general lithological
character.
2
GEOLOGICAL REPORT.
It will be seen that all the stratified rocks of this region may be referred
to five of the principal systems of geologists, as follows: Quaternary, Ter.
tiary, Cretaceous, Carboniferous, and Lower Silurian. Each of these will
now be described separately
QUATERNARY DEPOSITS.
The Quaternary System comprises all the deposits of later date than the
Tertiary, and in descending order includes: 1st, Alluvium; 2d, Bluff For-
mation or Loess; and, 3d, Drift or Boulder Formation.
Their aggregate
thickness in the district under consideration has been estimated approxi-
mately at about six hundred feet.
ALLUVIUM.
This formation comprises: 1st, Soils; 2d, Sand and Pebbles; 3d, Clays;
4th, Stalactites; and, 5th, Calcareous Tufa.
SOILS.
When we consider the extent of surface and variable geological compo-
sition of this district, it is not surprising that we should find within its
limits a great variety of soils. These, it is well known, derive their char-
acter mainly from the mineralogical composition of the underlying strata;
and in proportion as these abound in materials favorable or unfavorable for
the nutrition of plants, will the soil, other things being equal, be productive
or unproductive.
Many of the soils encountered upon the Plains are found to possess in an
eminent degree all the necessary elements of nutrition for plants, and if this
region were accompanied with the requisite meteorological conditions it
would possess a character for fertility unsurpassed by any portion of the
North American continent.
Marly Clay Soil.-The most extensive and under favoring circumstances
the most productive variety of soil is that derived from the Marly Clay
Formation, which is spread over thousands of square miles of surface. It
is for the most part of a deep red or brown color, and contains silica, car-
bonate and sulphate of lime, allumina, magnesia, and oxide of iron, in vari-
able proportions. Could any means be adopted for transporting it to market.
it would be highly valuable as a manure. Along the streams and in other
moist situations it is generally thickly covered with vegetation.
Gypsum Soils. Gypsum enters largely into the composition of many of
the soils of the Plains, and often in such quantities as to constitute their
most abundant ingredient. These soils are sometimes white, but more fre-
quently of a light grey, bluish, or red color. They are usually very light,
GEOLOGICAL REPORT.
3
and may generally be easily recognized, even at a distance, by the deeper
color of the grass growing upon them. These soils are also remarkably
well adapted as fertilizers, for which purpose they will doubtless hereafter
be extensively employed.
Calcareous Soils.—The soils overlying the limestone of the Upper Creta-
ceous group usually contain a very large proportion of carbonate of lime,
which, indeed, is sometimes present to such a degree as to render the land
entirely unproductive. When mixed, however, as is usually the case, with
a fair proportion of other ingredients, a highly productive marl is formed.
Soils of the Paleozoic Period. Although generally less favorably consti-
tuted than any of the preceding, many of the soils derived from the de-
composition of the Paleozoic rocks are, owing to the more favorable
meteorological conditions of the regions in which they occur, far more pro-
ductive. These do not present a great deal of difference in general miner-
alogical composition, but vary considerably in the amount of vegetable
matter they contain. They consist chiefly of lime and silica in different
proportions, with an admixture of alumina, iron, and vegetable matter.
Soils of Igneous Rocks.-Few of the soils derived directly from the igneous.
rocks have been found of much value. They are generally loose, of a deep
red or brown color, and are composed mainly of quartz and felspar in
coarse and fine particles. When they contain small quantities of clay, lime,
or gypsum, as is sometimes the case along the streams, they become highly
productive and are clothed with rich vegetation.
PEBBLES.
Water-worn pebbles are of frequent occurrence in the beds of the differ-
ent streams of Texas and New Mexico. They are derived mainly from the
Boulder Formation and older rocks, and exhibit almost every variety of
composition. In the beds of the Upper Brazos, Big Witchita, and Red
Rivers, they are sometimes accumulated to the depth of four or five feet.
Various metallic ores, as copper, iron, and manganese, have been found
in connection with these deposits. In Otter Creek, a small affluent of Red
River, having its source in the Witchita Mountains, two small specimens.
of bluish-yellow quartz, containing gold in small quantities, were found.
SAND.
To the Alluvial Period we must refer those accumulations of loose sand
which occur in the beds of nearly all the streams of Texas, New Mexico,
and the adjacent Indian Territories, and which are also occasionally met
with in situations remote from existing water-courses. The latter sometimes
cover many square miles of surface, and appear to be continually shifting
their position. Examples of these shifting sands are to be met with near
4
GEOLOGICAL REPORT.
the headwaters of Red River, in the "Sand Hills" of the Llano Estacado,
and immediately west of the southern extremity of the Guadalupe Moun-
tains.
In the beds of the larger streams of Texas, accumulations of sand occur
many feet in thickness. These often absorb a large quantity of water; and
hence it not unfrequently happens, particularly near the sources of these
water-courses, that while the beds appear perfectly dry at the surface, by
digging down a few feet plentiful supplies of water may be obtained.
CLAYS.
Clays, derived principally from the destruction of the cretaceous strata,
are frequently met with along many of the streams. They are usually of
a deep red color, and contain lime and gypsum in variable proportions.
Many of the principal rivers of Texas, as the Canadian, Red, Colorado,
Witchita, Brazos, and Pecos, either have their sources in or flow for a part
of their course through the marly clays of the Cretaceous System. These
clays mingling with the water impart to the streams their highly character-
istic red hue, and are thus transported hundreds of miles. During freshets
these materials are deposited in the form of fine sediment upon the adjacent
lowlands, and to this circumstance is due the surprising fertility of many
of the valleys bordering the lower portions of the streams of Texas.
STALACTITES AND STALAGMITES
Are abundant in various portions of Texas and the adjacent Territories
In the caverns of the Sacramento Mountains specimens of rare beauty
occur. They are generally composed of carbonate of lime, and most fre-
quently occur in districts where the Paleozoic rocks prevail.
CALCAREOUS TUFA.
In a single locality, viz., in the vicinity of San Antonio, Texas, I have
found a deposit of calcareous tufa. It is here light, porous, and chalky, and
contains impressions of leaves and stems of recent plants. The rock is suffi-
ciently firm to be employed as a building stone.
BLUFF OR LOESS FORMATION.
The formation to which the term "Bluff" has been applied by Prof.
Swallow, State Geologist of Missouri, and which, in the United States, is
usually regarded as the equivalent of the Loess of the Rhine, we have re-
cognized at a number of localities in Texas. As in the State of Missouri
and other portions of the West, it is here found reposing upon the Boulder
GEOLOGICAL REPORT.
5
Formation, and usually consists of thick beds of indurated ash colored loam,
containing more or less calcareous matter and abounding in existing species
of terrestial and fluviatile shells.
Near Preston, on Red River, a good section of this formation is exposed
in a range of vertical bluffs, which extend up and down the river for the
distance of several miles. It is here seen resting directly upon soft bluish
sandstone of the Cretaceous Period. Fossils are very abund-
ant in this locality, and usually they are in a good state of pre-
servation. They belong chiefly to the genera Lymnea. Physa,
Planorbis, Pupa, Helix, and Helicina, and many of the species
are identical with those occurring in the loam of New Har-
mony. Indiana, and elsewhere in the Mississippi Valley, which
Sir Charles Lyell, during his visit to the United States, regarded
as being the equivalent of the Loess of the Rhine.
The following is a section [No. II.] of the Loess Bluffs near
Preston, on Red River. The entire thickness of the formation
in this vicinity is about twenty-five feet.
Sixty miles west of Preston, on a small stream known as the
Elm Fork of Trinity River, the Bluff Formation is also exposed.
It here reposes upon coarse drift, which rests upon Cretaceous
Limestone. Its thickness as exhibited here is about thirty feet.
It is occasionally highly discolored with oxide of iron, but
otherwise does not differ lithologically from that on Red River,
and it abounds in the same fossils. Seventy miles farther south-
west, on another small branch of Trinity River, is a formation
agreeing in lithological appearance with the Bluff, presenting a
thickness of more than sixty feet. No fossils, however, were
detected in this deposit.
On Loess Creek, a small tributary of the North Branch of
Red River, this formation is again well exposed. It here ex-
hibits a thickness of from thirty to forty feet, and is crowded
with fossils of the same species of terrestial and fluviatile shells
as characterize the formation farther east.
Although there are deposits which very closely resemble the
Bluff Formation at several points along the route from Indianola
to El Paso, I have not as yet been able to recognize it with cer-
tainty south of the 33d parallel of latitude.

No. II.
Section of Bluffs on Red River, Texas.
Fut=soit
Formation or Lord
Sandston
On the Rio Frio and Nueces sections of indurated calcareous loam, sixty
to seventy feet thick, are exposed, resting on a deposit of water-worn frag-
ments of hard limestone. (Vide Journal.) We are inclined to refer this
loam to the age of the Bluff, and should this opinion be found correct, it
would give to this formation a geographical range in Texas of not less
than four hundred miles.
6
GEOLOGICAL REPORT.
DRIFT OR BOULDER FORMATION.
During my journey to the sources of Red River, in company with Capt.
R. B. Marcy's Expedition, heavy deposits of loose materials, consisting of
quartz, greenstone, granite, porphyry, and water-worn shells of the Cretace-
ous Group, were frequently encountered, resting upon the stratified rocks of
the Secondary Period. As the materials forming these deposits were
totally different from the rocks occurring in situ anywhere in the neighbor-
hood, and apparently had been transported from a distance, we ventured in
our notes on the general geology of that region to refer them to the age of
the Drift or Boulder Formation.* Since then we have examined deposits
of a similar character in other parts of Texas, and have not only had that
opinion fully confirmed, but have succeeded in tracing them south and west
over a very large district of country.
The Boulder Formation of the region we are noticing varies considerably
in character and thickness. In some places it is composed almost entirely
of pebbles and small boulders of eruptive and metamorphic rocks, while in
others it consists altogether of angular or rounded fragments of Paleozoic
and Cretaceous rocks. In Southern Texas it is almost exclusively made up
of limestone, sandstone, and silicious nodules, but as we travel north the
deposit consists mainly of eruptive and metamorphic rocks. The formation.
in various parts of the district is often cemented into a conglomerate by
means of calcareous or ferruginous matter. As a general rule it is much
thicker and coarser as we travel westward. In Western Texas and New
Mexico it sometimes attains a thickness of several hundred feet, and con-
tains blocks of sedimentary and eruptive rocks two or three feet in diameter.
Near the headwaters of Red River the Boulder Formation occurs in
gently rounded hills from a hundred to a hundred and fifty feet in height.
It is here composed of well-rounded pebbles and small boulders of igneous
and metamorphic rocks, with occasional beds of coarse silicious sand inter-
stratified, and often contains water-worn fossil shells of the Cretaceous Era,
and fragments of silicified monocotyledonous and dicotyledonous wood,
weighing occasionally several hundred pounds. Specimens of this fossil
wood were submitted to Prof. Hitchcock, who pronounces it to be analogous
to that obtained from the Tertiary Deposits of Antigua and the desert near
Cairo in Egypt.*
This formation may be also traced from near the sources of Red River,
almost continuously, but greatly diminished in thickness, as far east as the
mouth of Cache Creek, and even east of that point. Farther south, on the
Big Witchita and Upper Brazos Rivers, it is again met with, but here is
constituted mainly of water-worn fragments of Cretaceous Limestone, re-
* Red River of Louisiana, by Capt. R. B. Marcy.
GEOLOGICAL REPORT.
7
plete with characteristic fossils of that formation, and for the most part
firmly cemented with a calcareous paste. Its average thickness here we
have estimated at about fifty feet.
In Eastern Texas, Dr. F. Roemer encountered thick beds of loose sand
and silex, which he refers to the Diluvial Period. These, he states, form a
broad belt of "bad land," extending from north to south across a very con-
siderable portion of the State.
This belt was crossed by the Expedition under your charge on the route
from Indianola to San Antonio de Bexar, and was found extending in that
direction from the Guadalupe River, in the vicinity of Victoria, W. N. W.
to a point a few miles beyond Yorktown, occasionally interrupted, how-
ever, by several broad districts of fertile country. (Vide Journal.) Over
this district it consists chiefly of coarse silicious sand, with pebbles and small
boulders of silex and other rocks disseminated through it, the whole repos-
ing on the Cretaceous marls and clays.
Between San Antonio and the Guadalupe Mountains, deposits apparently
of the same geological age are of frequent occurrence. At several points
west of the Rio Pecos they present a thickness of more than a hundred feet,
and are to be traced almost uninterruptedly from near the Horsehead Cross-
ing of that stream to the Guadalupe Mountains, a distance of nearly a hun-
dred and fifty miles.
Source. As has already been remarked, these deposits become thicker
and the materials coarser in proportion as we travel from east to west.
There can, therefore, hardly be a doubt as to the direction whence they
were derived. Indeed in several instances, we have succeeded in tracing
them for hundreds of miles to their original beds. Thus heavy accumula-
tions of rolled fragments of white limestone and sandstone, agreeing pre-
cisely in lithological and paleontological characters with the Upper Carbo-
niferous limestone and sandstone of the Guadalupe Mountains, are found
overlying the clays and sandstones of the Cretaceous System far to the east
of that range, and no deposits of the same kind have been encountered west
of it. (Vide Journal.)
Accumulations of rolled fragments of red porphyry and granite, present-
ing the same character as those of the Witchita Mountains, and which, as
far as our own observations extend, are peculiar to that range, occur many
miles to the eastward, but at no point west of these mountains have we suc-
ceeded in detecting any traces of them.
We have thus far spoken of the Boulder Formation only as it occurs east
of the Rocky Mountains. We have, however, strong evidence of its exis-
tence much farther west. To the same geological period we would refer
those extensive accumulations of loose materials which constitute the basins
between the Guadalupe and Mimbres mountains. They consist chiefly of
sands, clays, and coarse gravel, which have evidently been derived from the
rocks, both stratified and unstratified, of the neighboring mountains. In
8
GEOLOGICAL REPORT.
some of these valleys their thickness cannot fall far short of four or five hun-
dred feet. At the Artesian Well, a few miles west of Fort Fillmore, they were
penetrated to the depth of two hundred and fifty-eight feet without reach-
ing their base, and a little farther north, at the San Diego Mountain, vertical
sections are exposed to the height of near five hundred feet.
on the Jornada del Muerto.)
(Vide Report
Economic Uses.-Should it ever become necessary to construct macada- .
mized roads over any portion of the region in which the boulder formation
occurs, it would furnish excellent materials for that purpose. The lime.
stone boulders would also form a good quicklime, and the sand would be
well adapted for mortar.
TERTIARY SYSTEM.
We have been able to detect strata of the Tertiary Period only in two
localities throughout the entire district under examination, and even in
these the formation is developed upon comparatively an insignificant scale,
extending over very limited areas, and attaining a vertical thickness of
merely a few feet. Both localities where we have recognized it are in
Southern Texas. One is situated thirty-five miles southeast of San Antonio,
and was crossed by the Expedition on the 9th and 10th of April, 1855.
(Vide Journal.) The Tertiary Strata present here a thickness of about
twenty feet, and reposc unconformably partly upon the sandstones and grits
of the Coal Measures and partly upon the marls of the Cretaceous System.
The rock is a dirty ferruginous limestone of a deep yellow color, and varies
much in compactness, some of the layers being quite soft and crumbling,
and others hard and breaking with an uneven fracture. It contains fossils
in great abundance; but they are usually casts, and so badly preserved as
not to permit us to determine accurately their specific characters. They
belong mostly to the genera Tellina, Arcu, Infundibulum, Fusus, and Nutica.
The next locality at which Tertiary Strata were observed is on Leon
Creek, a few miles west of San Antonio. Here it consists of light gray.
earthy limestone, which is scattered at several points over the surface.
Although we have not seen Tertiary Strata in other localities than those
just mentioned, there is reason to believe that they are of extensive occur-
rence in Eastern and Northeastern Texas. Dr. F. Roemer mentions the
occurrence of this formation on the Brazos River near the town of Caldwell,
and also in the vicinity of Nacogdoches. Assuming this last point as the
extreme northeastern limit, it would give to this formation in Texas a north-
east and southwest range of about three hundred miles. Nevertheless, as
extensive as are these limits, we are of opinion that they include only a
portion of the Tertiary area of this region, and that more extended research
will develop its existence as far south as the Rio Grande.
GEOLOGICAL REPORT.
9
CHAPTER II.
SECONDARY PERIOD.
CRETACEOUS SYSTEM.
The next formation that we meet, in descending order, in the district
under consideration, is the Cretaceous System, which, on account of its
great development upon the Western Plains, is far more important than
any we have described. The strata of this system here exhibit the enor-
mous thickness of three thousand six hundred feet, and occupy an area
of many thousand square miles. With some local exceptions, they cover
nearly the whole of the rectangular space included between the 29th and
39th degrees of latitude and the 99th and 105th degrees of longitude, ex-
tending southeast into the States of Louisiana, Mississippi, and Alabama,
and north into the Territories of Kansas and Nebraska.
In the southern part of the district we have traced them almost con-
tinuously from near Victoria on the Guadalupe River in a course nearly
W. N. W. to within a few miles of the southern extremity of the Guada-
lupe Mountains, and thence southward along the base of the Limpea Moun-
tains. Farther north we have encountered them at Fort Towson, Fort
Washita, Preston, the Cross Timbers of Texas, and throughout the entire
country watered by the Big and Little Witchita, and the upper portions of
the Trinity, Brazos, and Red Rivers. Along the Canadian River they have
been met with by Mr. Marcon,* and north of that stream by Maj. Emory,
Lieut. Simpson, Lieut. Abert, Capt. Stansbury, and other explorers.
In the Horse Mountains, and at several other points west of the Guada-
lupe Mountains, the Cretaceous rocks have likewise been encountered, but we
have met with no proofs of the existence of deposits of this age in any portion
of the region explored by ourself west of the Rio Grande.
North of this,
however, along the 35th parallel of latitude, they have been observed by Mr.
Jules Marcon, and from the explorations of others we have abundant evi-
dence of their existence in detached basins as far west as the Pacific coast. Dr.
John Evans, U. S. Geologist, has recognized well marked Cretaceous strata
at a number of points in Oregon and as far west as Vancouvers Island.
The Cretaceous Formation of our district may be separated by well
marked lithological characters into two principal groups, viz.:
1. Upper Cretaceous or Calcareous Group.
2. Lower Cretaceous or Marly Clay Group.
*These rocks have been described by Mr. Jules Marcon as belonging mostly to the Trias-
sic and Jurassic Systems, but evidence of their Cretaceous age will be presented farther on.
10
GEOLOGICAL REPORT.
1. UPPER CRETACEOUS OR CALCAREOUS GROUP.
LITHOLOGICAL CHARACTER.
This division of the Cretaceous System consists chiefly of limestone and
sandstone, of which the former is much the most abundant and varies much
in character. It presents every degree of compactness, from soft chalk to
hard subcrystalline limestone. It is, however, generally compact, of a dull
earthy appearance, and varies in color from pure white through shades of
light gray, yellow, blue, and brown. In many localities it contains a good
deal of silex, or sometimes passes into pure silicious sandstone; in others it
exhibits a more or less argillaceous character, though beds of clay are rarely
observed in it.
The strata are sometimes cherty, and often, especially in the southern ex-
tension of the formation, they are crowded with light gray, blue, and dark
nodules of flint from one to six inches in diameter. These are sometimes
arranged in nearly parallel bands, but more frequently scattered promiscu-
ously through the strata, now and then occurring so abundantly as to form.
a kind of conglomerate. As we travel north, the Cretaceous strata assume
a much more arenaceous character, so that near the headwaters of Red
River they are composed almost exclusively of silicious sandstone. But
generally the sandstone alternates with the limestone in bands of from
twenty to one hundred feet in thickness. It is usually highly ferruginous,
and often contains spherical concretions of iron. Its color varies from light
gray to deep red and brown. In some localities it is quite hard, durable,
and possesses all the requisites of a good building material, but it is often
soft and yields readily to the action of the weather.
RANGE, EXTENT, AND THICKNESS.
This division of the Cretaceous System has heretofore been regarded as
occupying a comparatively limited portion of the region under considera-
tion. From our own observations, however, taken in connexion with those
of other explorers, we are convinced that its real importance in this respect.
has been greatly underrated, and that instead of being confined merely to
isolated and distant points, it really constitutes the prevailing formation.
over a very large portion of the Plains.
Commencing in the southeast, these rocks occur at a number of points
along the route traveled by your Expedition between Victoria and San
Antonio. They do not, however, present here a vertical thickness of more
than twenty or thirty feet, and are confined to limited areas.
In the vicinity of San Antonio the Upper Cretaceous strata occur in
GEOLOGICAL REPORT.
11
gently-rounded hills and bold escarpments about two hundred feet in height,
but as we travel westward from this place they increase rapidly in thickness,
and at the San Pedro or Devils River, as well as at other points, they show
a vertical development of upwards of a thousand feet, and constitute the
prevailing surface formation until we arrive within a few miles of the Horse-
head Crossing of the Rio Pecos. West of this point they are observed at
frequent intervals as far as the sources of Delaware Creek, twenty-one miles
east of the Guadalupe Mountains, and in this vicinity exhibit a thickness of
five or six hundred feet. (Vide Journal.) Farther south their development.
is equally well marked along the base of the Limpea Mountains, as well as
at several intermediate points.
On our return route from the Rio Pecos by way of Fort McKavett, Fort
Mason, and Fredericksburg, they are the prevailing rocks as far as San
Antonio, being interrupted occasionally by igneous protrusions, upheaved
strata of the Paleozoic Period, and bands of red marls of the Lower Cretace-
ous Group. At several localities along this route the thickness of the Upper
Cretaceous strata was estimated at about eleven hundred feet.
North of this route we find these rocks also well developed. From Fort
Towson to Fort Washita, and thence in a southwest direction, they are
traced almost uninterruptedly as far as the Upper Cross Timbers of Texas.
In the vicinity of Fort Washita, and at several localities between that point
and the Cross Timbers, they exhibit a vertical thickness of three or four
hundred feet, though in this part of the district their usually observed
thickness is from one to two hundred feet.
Along the Big and Little Witchita Rivers these rocks form abrupt and
gently-rounded hills from four to five hundred feet high. On the Upper
Brazos River they occur in elevated plateaus, and near the head of that
stream appear in nearly perpendicular escarpments six or seven hundred
feet high, forming here those high table lands that stretch away for many
miles to the north, south, and west.
Again, these rocks are equally well developed in the region watered by
the Upper Red River. Near the source of the Ke-che-ah-que-ho-no, or main
branch of Red River, they exhibit a thickness of about six hundred feet,
and form the bold escarpments which there characterize the eastern borders
of the Llano Estacado.
Finally, other observers have shown the existence of the rocks of this
division of the Cretaceous System along the Canadian River, and at a num-
ber of points north of that stream.
LOCAL DIFFERENCES.
In the vicinity of Fort Washita the Upper Cretaceous Limestone is usu-
ally hard, fine textured, and sometimes more or less crystalline. Its color
varies from light gray to blue, yellow, and brown, and not unfrequently it
is pure white.
12
GEOLOGICAL REPORT.
Near the town of Preston, and at a number of localities between that
place and the Upper Cross Timbers of Texas, it is soft, highly argillaceous,
and crumbles rapidly on exposure to the weather.
On the Big and Little Witchita and Upper Brazos Rivers, it is hard, thin
bedded, and of a dull light gray color, while along the Upper Red River it
becomes more or less arenaceous, often passing into pure sandstone, which
not unfrequently contains numerous nodular concretions of iron.
Farther south, along the route traveled by our Expedition between Vic-
toria and San Antonio, and at various points west of the first crossing of
the Rio Pecos, it is dull white, soft, and resembles pulverized chalk. At
San Antonio, Fort Inge, and Fort Clarke, it is white or light gray, earthy
in texture, and quite soft when first taken from the quarry, but possesses
the valuable property of hardening upon being exposed for a short time to
the action of the weather.
On the Rio Seco it is a dull white, soft, and cannot be distinguished from
chalk. On the Arroyo Pedro it is of a light fawn color, compact, and breaks
with a conchoidal fracture.
At several localities between San Antonio and San Pedro or Devils River
it is a buff, compact calcareo-magnesian limestone. Between the San Pedro
and Pecos Rivers it is sometimes hard, ferruginous, and contains a great
abundance of flints, while in other localities it is more or less arenaceous,
and at times passes into a pure sandstone.
Near the mouth of Delaware Creek it is a hard limestone, full of small,
rounded cavities, and of a light cream color; but towards the sources of
that stream the strata are thin bedded, of a light gray color, and appear to
be undergoing rapid disintegration. South of this stream they are both
compact, and porous and sometimes crystalline.
PALEONTOLOGY.
Many of the organic remains such as collected by your Expedition from
the upper division of the Cretaceous System have been described by Dr.
Ferd. Roemer in his excellent and finely illustrated work on the Cretaceous
Strata of Texas. We are able, however, to considerably augment the list
by the addition of a number of new and interesting forms, which have been
placed in the hands of a paleontologist for examination and description.
We will, therefore, at present merely enumerate some of those species which
have been found most characteristic of the mass.
The following species have been found to range from the top to the base
of the formation: Gryphia Pitcheri (Morton), Exogyra arietinu (Roemer),
Janira Texana (Roemer sp.), Janira quadricostata (Sowerby), and Terebratula
Wacoensis (Roemer).
In the upper part of the formation we find most commonly the follow-
ing, and as far as our observations extend they are peculiar to it: Ceratites
GEOLOGICAL REPORT.
13
(Ammonites) Pedernalis (Roemer sp.), Pterodonta subforsiformis (B. F. Shu-
mard), Pleurotomaria crotaloides (Morton), Scalaria vertebroides? (Morton sp.),
Natica (Globiconcha) tumida (B. F. Shumard), Natica elevata (B. F. Shumard),
Monopleura Texana (Roemer), Lima Wacoensis (Roemer). Ostrea crenulimargo
(Roemer), Ostrea carinata (Lamarck), Panopaa Texana (B. F. Shumard), and
Astrocania Guadalupe (Roemer).
In the inferior strata the most characteristic forms are: Ammonites vesper-
tinus (Morton), Ammonites Popeanus (B. F. Shumard), Turrilites Brazoensis
(Roemer), Baculites asper (Morton), Exogyra costata (Say), Exogyra arietina
(Roemer), Exogyra lævinsculd (Roemer), Ostrea vesicularis (Lamarck), Gryph-
œa Pitcheri (Morton), Pecten (sp. undt.), Janira quadricostata (Sowerby), In-
oceramus Cripsii (Mantell), Inocerumus mytiloides (Mantell), Inoceramus (sp.
undt.), Pholadomya elegantula (D'Orb), Cardium elegantulum (Roemer), Cas-
sidulus apuoreus (Roemer), Terebratula Choctawensis (B. F. Shumard), Nerinea
Texana (Roemer), and Trigonia (nor. sp.).
It will be seen from the above list of species that with some few excep-
tions the fossils of the superior and inferior portions of the Upper Creta-
ceous strata of Texas and New Mexico are quite distinct. Nevertheless, as
we cannot draw a well marked horizon by lithological characters, we have
thought proper to make no separation of the strata.
PHYSICAL FEATURES.
This formation more than any other of the Plains is characterized by lofty
and rough precipices and deep and fearful canyons. The elevated plateaus,
which sometimes attain an altitude of seven or eight hundred feet, and often
are seen stretching across extensive districts of country, present everywhere
rough and precipitous cliffs, with sometimes nearly vertical faces, showing,
almost at a single glance the entire thickness of the formation.
Section No. III, taken from near the headwaters of the Ke-che-ah-que-ho-no,
or main fork of Red River, presents a remarkable example of the kind. Here
the elevated plateau known as the Llano Estacado terminates abruptly in a
line of escarpments from six to eight hundred feet in height. These are
for the most part nearly vertical, and extend north and south for a distance
of over thirty miles. From their bases there is a descent of about four
hundred feet by a succession of abrupt terraces of gypsum, red marly clay,
and sandstone, so that we have here in a single locality an exposure of
eleven hundred feet of Cretaceous strata.
Section No. IV was taken from near the sources of the main branch of
the Brazos River, and exhibits another marked example of the kind. The
table land of which this escarpment forms the abrupt boundary has an ele-
vation above the bed of the river of about eight hundred feet, and presents
a smooth and nearly flat surface on the top, covered with short yellow moss-
like grass and a scattering growth of Mezquite trees. These cliffs are
GRALIA
AND YELLOW
No. m.
Section of Bluffs on Ke-Che-Ah-Que-Ho-No or Main Branch of Red River.
DRIF
SANDSTONE WITH THEN SEAMS OF LIMESTONE ENTERSTRATIFIED
RÈ DI MARLY¹CLÂY¬WÌTH
M`S OF
DSTONE
GYPSUM AND SANDSTONE INTE'R STRATIFIED.
家
​No. IV.
Section of Bluff near the head waters of the Brazos River, Texas.
PPER CRETA
MARLY GLA WIT
ŞUM ASAND SI N
ON
FC
700 FL


GEOLOGICAL REPORT.
15
nearly vertical, and form a continuous line thirty or forty miles in length,
and throughout nearly the whole of this distance the edges of the limestone
strata are finely exhibited, resting on the red marly clay and its intercalated
sandstones. The lower plains extending cast of this line of cliffs, say for
fifty or sixty miles, are marked with small plateaus and truncated conical
hills of the same strata as compose the main table land, with which doubtless
they were at one time continuous.
The cliffs near the Rio Pecos, known as the "Castie Mountains," and
the succession of abrupt terraces encountered on the route of the Expedi-
tion between San Antonio and the San Pedro River, and described in the
Journal of this report, afford other examples similar to those presented by
Sections III and IV. The "Castle Mountains," which are over sixty miles
in length, are nothing more than the precipitous borders of an elevated
plateau, which stretches thence in an easterly and southeasterly direction
for many miles.
Canyons.—Another very important characteristic of this formation is its
numerous and remarkable canyons. The most extensive of these with
which we are acquainted are those of the San Pedro and Red Rivers. Both
of these, as well as others so frequently met with in this region, have been
hollowed out of the solid strata of the table lands by the erosive action of
water so as to exhibit on either side abrupt and often perpendicular walls
seven or eight hundred feet high.
The Canyon of San Pedro River is about sixty-five miles long, and varies
from a few hundred yards to several miles in width. The walls of this
immense chasm are often deeply fissured, and composed of variously colored
limestone in nearly horizontal beds. The river, which winds its way
through the canyon, is now comparatively a very insignificant stream,
usually not exceeding fifteen or twenty yards in width, with a depth of
three or four feet.
The canyon in which the Ke-che-ah-que-ho-no, or main trunk of Red River,
takes its rise, has been already graphically described by Capt. Marcy. It
is scarcely less extensive than the Devils River Canyon, being about sixty
miles in length. On either side are nearly vertical walls of limestone, sand-
stone, gypsum, and red marly clay, from five to eight hundred feet high.
The strata are in nearly horizontal beds, often traversed by deep fissures,
and the main chasm is intersected at various points by tributary canyons,
some of them several miles long. This gigantic canyon has been produced
by the erosive action of the river, which winds through its entire length.
and finally emerges into the open plain, whence it flows for many miles
along the base of the escarpment which forms a portion of the eastern
boundary of the Llano Estacado.
Other canyons scarcely less extensive are described in the Journal of this
*Report on Red River of Louisiana.
16
GEOLOGICAL REPORT.
report. These are often exceedingly rugged, and though generally very
tortuous, all of them appear to have a general east and west direction; hence
they would afford no very serious obstacle to the construction of a railroad
to the Pacific.
Denudation.—Besides its numerous escarpments and canyons there are
other phenomena in the region we are considering showing the great extent
to which the strata of this formation have been removed by denuding
agencies. There can be no doubt that the Upper Cretaceous strata at one
period occupied almost the entire space included between the western bor-
ders of the settlements and the Rocky Mountains. Some of the facts upon
which this opinion is based are given in detail in the accompanying Jour-
nal, and others equally conclusive are abundantly exhibited along the Colo-
rado, Big Witchita, Upper Brazos, and Red Rivers, and at many points
north of these streams. The isolated, truncated, conical hills we have so
frequently encountered, and which are described by travelers as constituting.
one of the most characteristic features of a very considerable portion of the
Plains, are nothing more than the remains of a once continuous plateau that
has gradually been removed by erosion. These are often six or seven hun-
dred feet high, and in many instances almost wholly composed of nearly
horizontal strata of the Upper Cretaceous Group. They are often widely
separated from each other, and as already instanced on the Brazos River,
sometimes fifty or sixty miles distant from the table lands which they once
formed a part. Sections . . . . and . . . . of the Journal exhibit the char-
acter of some of these hills.
..
Disturbance.—As will have been gathered from the foregoing remarks,
the Upper Cretaceous formation exhibits generally but little evidence of
violent disturbance in the district we are noticing. The strata are usually
spread out in smooth parallel layers, which usually conform to the general
slope of the country. The only localities in which we have observed them
violently dislocated or contorted are in the southern extension of the for-
mation; as along the base of the Limpea Mountains; near the mouth of Dela-
ware Creek; a few miles west of Castroville; on the San Saba and Frio
Rivers; and in the vicinity of Forts Inge, Clarke, and Mason. Of these the
most important is that near the Limpea Mountains, where the strata are seen
contorted, fractured, and inclined against eruptive rocks at angles of from
30 to 50 degrees. The next in point of importance are the disturbed dis-
tricts of Fort Mason and the San Saba River, which appear to occupy ex-
tensive areas. These are elsewhere described in this report.
GEOLOGICAL REPORT.
17
ECONOMICAL GEOLOGY.
BUILDING MATERIALS.
Many of the beds of the Upper Cretaceous Group afford excellent mate-
rials for construction, for which purpose they are already largely employed
in the settled portions of Texas. They are usually very easily wrought,
and often combine firmness, beauty, and great durability; hence they are
exceedingly valuable for the construction of public works. Some of the
most useful varieties have been indicated in the Journal. The rock quar-
ried near San Antonio, Fort Inge, and Fort Clarke, is, on account of its
beauty and property of acquiring hardness upon exposure to the atmosphere,
peculiarly valuable.
Quicklime. By burning, an excellent quality of quicklime for mortar can
almost always be obtained from the limestone of this formation.
ROAD MATERIALS.
For the construction of macadamized roads upon the Plains this forma-
tion will furnish materials in great abundance. In making selections the
hard cherty varieties of limestone should always be preferred when they
can be readily obtained.
USEFUL MINERALS.
Chalk. This important article exists in great abundance on the Rio Seco,
and is also believed to occur in the neighborhood of Fort Clarke. It is
generally much less pure than the foreign article, but may be made to
answer many of the purposes for which the latter is employed.
Lithographic Limestone of very fair quality occurs on the Arroyo Pedro.
Some examples obtained from that locality are hard, compact, and suscept-
ible of a very good polish, but contain minute veins and crystals of calcite,
which would interfere very materially with the usefulness of the rock for
lithographic purposes. Others, however, are perfectly homogeneous in
texture, possess a light uniform color, and present all the requisites of a
good lithographic stone.
Calcareous Marl. This valuable fertilizer occurs in the greatest abund-
ance throughout almost the entire region occupied by the Upper Cretaceous.
strata. In many instances it is composed of nearly pure carbonate of lime,
existing sometimes in beds thirty or forty feet in thickness. Could means
be devised for transporting it to market, it would prove of inestimable
value.
}
18
GEOLOGICAL REPORT.
METALLIC ORES.
The only ores of this formation of sufficient importance to require notice
are those of iron. This metal is disseminated through the different layers,
principally in the form of oxides and the bisulphuret or iron pyrites.
Oxides of Iron.-The coloring matter of most of the limestones and sand-
stones is due to the oxides of iron, which also exist in the form of spherical
concretions, which are sometimes so abundant as to impart to the rock a
highly mottled appearance. Brown Hematite of very fair quality is found
in beds of considerable thickness in connexion with these rocks along the
Upper Brazos River.
Bisulphuret of Iron (Iron Pyrites), in cylindrical and globular masses, often
studded with beautiful crystals, are of frequent occurrence in the limestone.
AGRICULTURAL CHARACTER.
..d
By far the largest portion of the rich agricultural district of Texas is
comprised within the limits of this formation. Whenever favorably situ-
ated for natural irrigation the soil derived from these rocks is usually
highly productive and well adapted for the growth of the great staples,
corn, cotton, wheat, tobacco, and almost every product suited to the climate.
But as we have already spoken of this subject in detail in connexion with
the quaternary deposits and in the Journal, it is unnecessary to pursue it
any farther at present.
SPRINGS.
Although not generally so abundant as we might be led to suppose from
the character of the rocks, springs are nevertheless of frequent occurrence
in various portions of the region occupied by this formation. Indeed in
some instances they furnish almost the only supply of water over districts
of country hundreds of miles in extent. They are sometimes unusually
large, and generally much more abundant near the base than towards the
summit of the formation. The springs in the vicinity of San Antonio and
Fort Washita issue from near the junction of the limestone with the under-
lying marly clay, and afford streams of considerable magnitude. The San
Antonio, Guadalupe, Frio, Seco, Medina, San Pedro, Concho, San Saba,
False Washita, Brazos, and Red Rivers all originate from springs that gush
from the Upper Cretaceous strata.
Subterranean Rivers are known to occur in connexion with these rocks in
several parts of Texas. The most remarkable one known to us was dis-
covered near the northern base of the Limpea Mountains by Mr. Thomp-
son, a member of your Expedition. This stream emerges from a triangular
GEOLOGICAL REPORT.
19
opening in the strata, and after flowing about a hundred yards through a
basin-shaped depression in the prairie, again disappears beneath massive
strata of limestone. Near the point of emergence it is about fifty feet wide,
ten feet deep, and flows with a rapid current, but contracts somewhat in
width a little lower down. It abounds in fish of the same species as are
usually found in the streams of Texas.
20
GEOLOGICAL REPORT.
CHAPTER III.
2. LOWER CRETACEOUS OR MARLY CLAY GROUP.
LITHOLOGICAL CHARACTER.
The inferior division of the Cretaceous System is composed chiefly of
marly clay, sandstone, and gypsum. The clay and sandstone occur in alter-
nating beds of variable thickness, and constitute the chief mass of the for-
mation; the gypsum usually occurs towards the top, and is either found
upon the surface or interstratified with the clay in nearly horizontal bands.
·
The Marly Clay varies considerably in lithological character, and, as the
name implies, it is composed mainly of clay and carbonate of lime com-
bined in different proportions, with which there is frequently a large admix-
ture of sand and gypsum. The prevailing color is a deep venetian red,
often elegantly variegated with various shades of blue, brown, and yellow.
It is for the most part highly indurated, and sometimes exhibits a schistose
structure not unlike the shales of the Coal Measures. In some localities,
particularly towards the western boundary, it abounds in small rounded
pebbles of granite, porphyry, quartz, and other eruptive rocks. Near the
upper part the layers are often beautifully reticulated with gypsum.
The Sandstone passes from a fine-grained variety to coarse gritstone, and
its colors are dark purple, red, brown, yellow, gray, and white. In many
instances it is thickly marked with small circular light yellow and green-
ish spots, which are distributed through all the beds. The layers are often
finely laminated, and sometimes contain rounded pebbles of eruptive rocks.
and nodular concretions of iron. The sandstone often contains a good deal
of calcareous matter, and sometimes passes gradually into limestone. Usu-
ally it is quite soft, being in many instances but little more than slightly
coherent sand, which crumbles more or less rapidly when exposed to the
weather.
The Gypsum is mostly white, amorphous, and occurs in layers, sometimes
of enormous thickness. This rock will be more particularly described
under the head of useful minerals.
EXTENT AND THICKNESS.
The Marly Clay Group attains a vertical development of several thousand
feet, and as far as our observations have extended, forms, with a few local
exceptions, the prevailing formation of all that portion of the Plains east of
the Rocky Mountains not included within the limits of the superior division
of the Cretaceous Group. It is exposed at various points subordinate to
GEOLOGICAL REPORT.
21
+
the last, and is well ascertained to occur as far east as Fort Washita, in the
Chickasaw Territory.
Beginning in the southern part of the district under notice, we find this
formation well developed along the route traveled by your Expedition be-
tween Victoria and San Antonio, Texas, where it is frequently exposed in
natural sections from fifty to a hundred feet high. Near San Antonio it
has been artificially excavated in one place to the depth of a hundred and
ten and in another to a hundred and fifty feet without reaching the base.
Immediately west of this it disappears beneath the rocks of the Upper Cre-
taceous Group, and does not again show itself in that direction, save at a
few isolated points, until we arrive at the abrupt escarpments known as the
"Castle Mountains," near the base of which it is seen reposing in nearly
horizontal layers (vide Journal), thence westward it forms, with the excep-
tions pointed out in the preceding chapter, the only rocks to be seen until
we approach the sources of Delaware Creek, where it is succeeded by the
Paleozoic rocks.
West of the Guadalupe Mountains we again observe the Marly Clay
Group, but here it is developed upon a very limited scale, being only a few
feet in thickness, and confined to a strip of country not exceeding fifteen or
twenty miles in width. West of this we have not been able to recognize
positively its existence over any portion of the region explored by ourselves,
but from the examinations of others it is highly probable that it appears in
detached basins over a large portion of the region comprising the Western
or Pacific Slope of our continent.
Farther north we have ascertained its existence at Fort Washita, at
several points between there and the Upper Cross Timbers of Texas, and
throughout the greater portion of the region watered by the Big and Little
Witchita, Upper Brazos, and Red Rivers, and still farther north it has been
encountered by Capt. Marcy, Lieut. Simpson, Mr. Marcon, Col. Long, and
numerous other explorers.
Thickness.—As deep natural sections are very rarely observed in this for-
mation, we can merely estimate its thickness approximately. As already
stated, it has been artificially excavated in the vicinity of San Antonio to
the depth of a hundred and fifty feet without reaching the base. Near
Fort Washita it is exposed in natural sections sixty or seventy feet high.
At the first Artesian Well, located upon the Llano Estacado, about four-
teen miles east of the Rio Pecos, the Marly Clay formation was penetrated
to the depth of six hundred and forty-one feet, and at the second one,
located a few miles farther south, the borings were carried to the depth of
eight hundred and fifty-eight feet, and in neither instance was the base of
the formation reached. On the Big and Little Witchita and Brazos Rivers
it forms bluffs from two to five hundred feet high, while along the Upper
Red River its general thickness, estimated after an examination of numer-
ous sections, cannot be less than two thousand five hundred feet. This is
22
GEOLOGICAL REPORT.
the thickness which we have accordingly given it in the general vertical
section; nevertheless it is proper to state that at no point on Red River
were we able to see the base of the formation, so that even this enormous
thickness may prove to be an underestimate.
PHYSICAL FEATURES.
The principal distinguishing features of the district occupied by this for-
mation are a gently undulating surface, low ridges often with precipitous.
sides, and abrupt truncated conical hills. The surface of the country is usu-
ally of a deep red color, and the hills and ridges, being composed chiefly of
clay and sandstone in alternating and nearly horizontal bands, exhibit a re-
markably striated appearance. Owing to the general softness of the strata
composing this formation, the beds of the principal rivers are generally
broad and deeply sunk below the general level of the country, and the clay
mixing with their waters in the form of sediment tinges them their charac-
teristic red hue.
This division of the Cretaceous System, like the preceding, exhibits evi-
dence of denudation on a grand scale. The different hills and ridges, which
form such a striking feature in the otherwise monotonous scenery, are the
remains of once continuous strata which have been gradually eroded.
Many of these hills are four or five hundred feet high. They are, as
already remarked, usually isolated and rise abruptly from the surface of
the prairie in the form of truncated cones, their summits being usually
smooth, flat, and covered with short grass. The accompanying section
(No. V) exhibits the geological character of these hills as they occur along
the Big Witchita River.
In addition to the above phenomena, there are others of a less general
character that serve occasionally to relieve the dull uniformity of the region
occupied by this formation. The sandstone and clay, being of unequal
hardness, weather unevenly, and the former is sometimes seen projecting in
a series of shelves several feet from the face of the bluffs. At other points
we observe detached layers of sandstone ten or fifteen feet in diameter sup-
ported several feet from the ground on slender pedestals of clay, as exhib-
ited in the following section [No. VI] taken from near the source of the
Little Witchita River.
Caverns and deep pits are of frequent occurrence in the gypsum, the
former sometimes extending many feet. The pits are usually quite smooth
and funnel-shaped.
Dip. These strata exhibit little evidence of violent disturbance, and are
usually found dipping at very slight angles E. S. E. In a few instances
they are undulated and unheaved, but these are mere local exceptions.


No. V.
Section of Hills on the Big Witchita River.
Red Marly Clay. 2.
Saccharoid Gypsum. 3. Finely Laminated Sandstone.
No. VI.
Section of Lower Cretaceous Strata near Little Witchita River.
I. Indurated Red Marly Clay. 2. Thinly Laminated Quartzose Sandstone.
24
GEOLOGICAL REPORT.
ORIGIN.
The materials composing the larger portion of the Marly Clay formation
have been deposited in the bottom of the ocean in the condition of fine
sediment, which appears to have been derived chiefly from the destruction
of the granites and porphyries that we find towards the western slope of
our continent. These are generally of a deep red color, and their disinte-
gration produces materials similar to those constituting the larger part of
the Marly Clay formation. The great thickness and extent of this group,
covering, as it does, many thousands of square miles, seems to preclude the
idea of its having been derived from the destruction of the rocks of the
Plains east of the Rocky Mountains, since granites and porphyries that
would produce such a deposit are there of uncommon occurrence. More-
over, we find in the marly clay and sandstone, pebbles identical in composi-
tion and appearance with the granites and porphyries that form the eruptive
ranges towards the western side of the Continent. These pebbles also in-
crease in size and number as we advance in that direction, and the forma-
tion itself is greatly increased in thickness. At Fort Washita it is probably
not more than a hundred feet thick, while farther westward it is estimated
to be not less than twenty-five hundred feet thick.
PALEONTOLOGY.
This formation has been described by Mr. Marcon as belonging partly to
the Jurassic and partly to the Triassic Systems. Under the Jurassic he in-
cludes a large proportion of the strata described in the preceding chapter,
while the Triassic is made to occupy, with a few local exceptions, not only
all that portion of the Plains east of the Rocky Mountains not included
within the limits of his Jurassic, but also a very extensive area in other
parts of the United States.
The data for these conclusions appear to have been derived mainly from
the region along the Canadian River, explored by Lieut. Whipple's party,
of which Mr. Marcon was a member. Our observations on the geology of
the Upper Red River country have also been brought forward in support
of these views. Inasmuch, however, as we cannot agree with this geologist
in his opinions respecting the parallelism of these strata, we shall proceed to
consider a portion of the evidence that has led us to refer the Marly Clay
formation of this and other portions of the Plains to the Cretaceous Period.
In the first place we would premise, that with the exception of the gyp-
sum, which is confined to the superior part of the mass, we have not been
able to detect any permanent characters that will warrant us in separating
the Marly Clay formation into distinct groups. Nearly all the main fea-
tures mentioned by Mr. Marcon as characterizing the divisions proposed by
GEOLOGICAL REPORT.
25
him, we have found to occur indiscriminately throughout the entire thick-
ness of the formation.
While engaged in the exploration of Upper Red River under Capt. R. B.
Marcy, fossil shells, principally Gryphæa Pitcheri, and fragments of silicified
monocotyledonous and dicotyledonous fossil wood, were, upon several occa-
sions, observed in the upper part of the Marly Clay formation; but as these
appeared to be worn by attrition, and were also abundantly distributed
through the overlying Quaternary drift, little attention was at that time
paid to them. During the same journey we also found in the clay, consid-
erably below the surface, a fossil coral, which Prof. Hitchcock refers to the
genus Scyphia, and which he regards as being closely allied to species that
are characteristic of the Cretaceous rocks in other parts of the world.
Subsequently, while exploring near the sources of the Brazos and Big
and Little Witchita Rivers, we again found the same shells in the Marly
Clay formation, many feet below the top, associated with Ostrea and other
forms that we have since detected in the Upper Cretaceous limestone
farther southward.
The fossil wood mentioned by Mr. Marcon as occurring so abundantly.
along the Canadian, and which, we presume, is the same as we have ob-
tained on Red River, only a few miles farther south, cannot be relied upon
as evidence of the Triassic age of the Marly Clay formation, since fossil
wood occurs abundantly in the Cretaceous rocks of Texas, as will be seen
by referring to the Journal of this report, where it is mentioned that speci-
mens were encountered at frequent intervals along our route from Indianola
to El Paso. On the Frio and Nueces Rivers fragments of the trunks of
trees, some of them several feet in length and weighing over five hundred
pounds, were observed. After a careful comparison of some of these speci-
mens with those obtained from the Brazos and Red River country, we are
unable to detect any difference whatever. Fossil wood is also mentioned
by Roemer and other explorers as occurring abundantly in the Cretaceous
strata of Texas. The evidence derivable from fossil wood is therefore alto-
gether in favor of the Cretaceous age of the Marly Clay formation of the
Canadian and Red Rivers.
At Fort Washita the layers of the inferior part of the Cretaceous Group
contain Ammonites, chiefly A. vespertinus, in a good state of preservation.
These are confined principally to the clay, the included layers of sandstone
being almost entirely destitute of organic remains.
The shell figured by Mr. Marcon as Ostrea Marshii, and regarded by him as
characteristic of the American Jurassic, we have found in the Upper Lime-
stone of Fort Washita, in the same beds with Gryphaa Pitcheri, Hemiaster
elegans, Holaster simplex, and Ammonites vespertinus. This shell was described
under the name of Ostrea subovata, by Dr. B. F. Shumard, in Capt. Marcy's
Report of the Red River of Louisiana (p. 205, pl. 5, fig. 2), who regards it
as being quite distinct from O. Marshii, though it is doubtless a closely allied
26
GEOLOGICAL REPORT.
species. At the same locality we have found in the clay and overlying lime-
stone examples of Gryphæa, which present no specific differences from those
figured by Mr. Marcon as G. dilatata (G. Tucumcari), which this author
considers peculiar to the so-called American Jurassic. These difficulties
can hardly be reconciled unless we refer the upper rocks of Fort Washita,
with their rich array of well-marked cretaceous fossils, also to the Jurassic.
That the clays and sandstones of Fort Washita are really of the same
geological age as those farther west, can, we think, hardly admit of a doubt.
They are found reposing beneath the same limestone and rest immediately.
upon the Coal Measures, while their lithological characters are very similar,
the only difference being in the color of the clay, which, at Fort Washita,
is blue instead of red; but, as will be seen by referring to the Journal, this
color also prevails to some extent towards the south and southwest.
Near San Antonio de Bexar well marked specimens of Exogyra costata
and Inoceramus crispii, both of them highly characteristic fossils of the Cre-
taceous formation of Texas and various other portions of the United States,
were obtained from near the bottom of the well, which was sunk in the
marly clay to the depth of a hundred and fifty feet. (Vide Journal.) Speci-
mens of Exogyra costata were also abundantly met with in the same forma-
tion a few miles west of San Antonio.
With the exception of that at Fort Washita, the best locality for fossils
of the Marly Clay occurs near the Rio Pecos, and is mentioned in the notes
of May 17, 1855. (Vide Journal.) Here the Marly Clay is well exposed,
subordinate to thick strata of limestone, and is crowded with Gryphæa,
identical with those figured by Mr. Marcon as Gryphæa Pitcheri, and which
is admitted by him to be a cretaceous species. The same shell is well
known to occur at many localities in the upper limestone of the Cretaceous
Group throughout Texas.
In looking over the journals of other explorers we find still farther
confirmation of the cretaceous age of this formation. Specimens of Ino-
ceramus, and other fossils considered characteristic of the Cretaceous for-
mation, were obtained by Lieut. Abert from near the Raton Pass, latitude
70 degrees 41 minutes, longitude 104 degrees 07 minutes, and at Pablozon,
on the Rio Puerco. From the published notes of that officer we judge that
one, and probably both, of these localities occur in the Marly Clay forma-
tion. Well marked specimens of Inoceramus of the Cretaceous System
have also been obtained by Wislizenus and Lieut. Simpson along the valley
of the Canadian River, only a short distance from Pyramid Mount, where
the Gryphoa Tucumcari and Ostrea Marshii, mentioned by Mr. Marcon, were
obtained. On the False Washita, near the Canadian River, Gryphæa Pit-
cheri has been observed in great abundance in the vicinity of extensive
gypsum deposits. Cretaceous fossils were also procured by yourself from
the vicinity of the Sulphur Springs of the Colorado. These last, however,
as well as those procured by you from the neighborhood of the Sand Hills
GEOLOGICAL REPORT.
27
of the Llano Estacado, may have been obtained from the rocks of the Up-
per Cretaceous Group.
Finally, among the host of fossils obtained from the Secondary Strata of
Texas, New Mexico, and the adjacent Indian Territory, we are not aware.
that a single one has been found that is positively identical with either Tri-
assic or Jurassic species of Europe. The Ostrea subovata (O. Marshii, Mar-
con) and Gryphaa Tucumcarii, mentioned by Mr. Marcon as occurring along
the Canadian, were probably obtained from the Upper Cretaceous, as they
occupy this position in other parts of this region.
The mere lithological character of these strata, so much relied upon by
that author, cannot be taken as evidence of their being the equivalents of
the Triassic and Jurassic Systems of Europe, though it is true they some-
what resemble the latter in mineralogical composition; but from the same
kind of evidence we might, with equal propriety, regard them as being
parallel with the Permian of Russia, the Tertiary of Auvergne, or the Car-
boniferous of Nova Scotia.
ECONOMICAL GEOLOGY.
BUILDING MATERIALS.
As a general rule the rocks of this formation possess very little firmness
or durability, and are, therefore, but poorly adapted for building purposes.
or works of internal improvement. In some localities, however, the sand-
stone is moderately firm and resisting, and might, in the absence of better.
materials, be used for construction.
GYPSUM.
This mineral, on account of its economical value and enormous develop-
ment upon the Plains, is of far more importance than any rocks we have
considered. The Gypsum Field of the West, the great extent of which
was published in 1852, shortly after the return to the States of the Red
River Expedition, is believed to be the largest in the world, and will here-
after prove an inexhaustible source of wealth to the State of Texas and
adjacent Territories.
The exact limits of the gypsum cannot at present be very accurately
determined. It is well known to occur in great abundance at several points
north of the Arkansas River, and on that stream it is mentioned by Col.
Long and others. Thence southward it has been traced through the
regions watered by the Canadian,* Red, Big and Little Witchita, Brazos,
and Pecos Rivers to within a few miles of the northern base of the Limpea
* Reports of Capt. R. B. Marcy, Lieut. Simpson, and Mr. Marcon.
28
GEOLOGICAL REPORT.
Mountains, with an average width east of the Rocky Mountains of perhaps.
not less than two hundred and fifty miles.
West of the Rio Grande gypsum is also met with in great abundance,
and towards the south we have abundant evidence that it extends through
various portions of Mexico. As already remarked, it occurs chiefly towards.
the summit of the Marly Clay formation, and is found either upon the sur-
face or interstratified with the clay in successive and nearly horizontal
layers of variable thickness. It usually occurs amorphous and pure white,
more or less granular, and sometimes its texture is subcrystalline, resem-
bling loaf sugar. Not unfrequently it passes into selenite, fibrous gypsum,
or compact alabaster. In some localities it is much discolored with oxide
of iron, in others it is variegated with various shades of green and blue by
oxides and carbonates of copper. Between the beds the clay is often
thickly reticulated with thin veins of selenite and fibrous gypsum.
The thickness of the different beds is sometimes enormous. On Red
River they vary from a few inches to twenty-five or thirty feet. On Dela-
ware Creek, a few miles below its source, bluffs of pure white gypsum are
exposed to the thickness of about sixty feet, while between the Big Witch-
ita and Brazos Rivers hills composed entirely of gypsum were encoun-
tered, whose heights were estimated by myself, as well as by several others
of the party, at about seven hundred feet.
METALLIC ORES.
nese.
We have detected in this formation ores of Iron, Copper, and Manga-
Of these the most abundantly distributed are those of iron, which,
in the form of oxides, furnish the principal portion of the coloring matter
in the clays and sandstones.
Brown Iron Ore (Brown Hemitite) occurs in workable quantities in several
localities along the Big Witchita River. It sometimes contains a large
admixture of clay. In the form of Yellow Ocher, it is often used by the
Indians as a paint.
Bisulphuret of Iron (Iron Pyrites) occurs in small crystals and spheroidal
masses, occasionally disseminated through the clay. The spheroidal form
is often beautifully studded with minute shining crystals, and when broken.
usually exhibits a fibrous radiated structure.
Ferruginous Sands of remarkable purity occur in great abundance on
Cache Creek, an affluent of Red River. Specimens which we collected
from this locality were submitted to Prof. C. U. Shephard for examination,
and found to be composed of about equal proportions of tatiniferous and
magnetic oxide of iron.* These sands have doubtless been derived from
the Witchita Mountains.
*Marcy's Report of Red River of Louisiana.
GEOLOGICAL REPORT.
29
Chloride of Copper (Marcylite). Specimens of a dark colored compact
mineral, very closely resembling black oxide of copper, were collected by
myself from the Marly Clay formation on Red River, not far from the
Witchita Mountains. Prof. Shephard, to whom they were submitted for
examination, has pronounced them to belong to a new ore of copper, which
he has named Marcylite, in honor of my friend Capt. R. B. Marcy. The
following is the result of his analysis of the ore:
Copper
Oxygen and Chlorine.
Water
54.30
36.20
9.50
100.00
with traces of silica.
This ore, if obtained in sufficient quantity, would, on account of its rich-
ness, prove highly valuable. Only a few small specimens of it, however,
were met with.
Oxides and Carbonates of Copper.—Small rounded masses of oxide and
carbonate of copper of remarkable purity were observed abundantly distri
buted upon the surface near the sources of the Big Witchita and Brazos
Rivers. We were unable to trace them to their source. Specimens of
impure oxide and carbonate of copper have also been found in connec-
tion with the gypsum near the sources of the North Branch of Red
River.
Several other varieties of copper ore have been met with in this forma-
tion along the Brazos and Red Rivers, but on account of their great im-
purity they do not possess much value.
Manganese.-Impure ores of this metal have been met with in two locali-
ties- one on the Witchita River, near its source, and the other on Copper
Creek, an affluent of Red River. Specimens from the latter were exam‍
ined by Prof. Shephard, and found to consist of Manganese in the state
of binoxide with a very large percentage of silica and some peroxide
of iron.
SALT (CHLORIDE OF SODIUM).
The only deposits of this character met with by myself occur in the
southern part of the district, and are described in the Journal. From the
observations of other explorers, however, I am inclined to believe that this
valuable substance is of extensive occurrence in the country north of Red
River. Mr. Marcon mentions thick deposits of rock salt in the Marly Clay
formation along the Canadian, and it is known to occur in the greatest
abundance N. W. of Fort Gibson, near the great bend of the Arkansas
River.
30
GEOLOGICAL REPORT.
SPRINGS.
One of the principal difficulties experienced by travelers upon that por-
tion of the Plains embraced within the limits of the Marly Clay formation,
is the great scarcity of water. This arises principally from three causes:
first, the great deficiency in the annual amount of rain; second, the imper-
meable character of the clay, which allows most of the water that falls to be
conducted off, either by surface drainage or by evaporation; and, third, the
general absence of extensive faults or breaks in the strata, from which
cause the water, after having once entered them, is often made to flow long
distances through subterranean channels before finding an outlet.
Most of the springs examined by ourselves in this formation issue from
near the top of the strata, and are consequently not of a very permanent
character, usually drying up soon after the close of the rainy seasons. In
some few instances, however, they were found to issue from much greater
depths beneath the surface, and then they are larger and yield a more con-
stant supply of water. Wherever the gypsum prevails the water usually
possesses a nauseous and bitter taste. This appears to be owing mainly to
the presence of salts of lime, magnesia, and soda. It is while flowing
through the gypsum formation of the Plains that the waters of many of the
larger rivers of Texas, such as the Red, Brazos, and Witchita, acquire their
bitter taste.
GEOLOGICAL REPORT.
31
CHAPTER IV.
PALEOZOIC PERIOD.
Lying unconformably beneath the rocks of the Cretaceous System, we
have an assemblage of strata belonging to the Paleozoic Period, and com-
posed, for the most part, of hard gray, blue, and white limestone; heavy
bedded quartzose sandstone, conglomerate; millstone grit, and dark shales.
Collectively they exhibit a thickness of between six and seven thousand
feet, and are observed cropping out extensively both upon the eastern and
western side of the Plains. On the east they are well exposed along the
western borders of Iowa,* Missouri, and Arkansas, and through various por-
tions of the adjacent Indian Territories, and are observed extending south-
ward through Texas as far as Fort McIntosh, on the Rio Grande. West of
these they constitute the great floor or trough upon which are deposited the
newer formations of the Plains, and after disappearing beneath the latter,
are not again met with, save at a few isolated points, until we approach
within one or two hundred miles of the western borders of the Atlantic
slope, where they rise majestically to the height of several thousand feet in
lofty mountain ranges.
Near the western line of Arkansas they exhibit a vertical development of
near four thousand feet, and constitute a large portion of the Ozark Range.
Thence, with the exception of a granitic protrusion about twenty miles in
width and the area covered by the Cretaceous deposits of Fort Washita and
the Cross Timbers already mentioned, they are traced continuously west and
southwest to Fort Gibson, Fort Belknap, and the Clear Fork of the Brazos.
On the western side of the Plains they constitute the floors of several of
the principal valleys. They also form the Guadalupe, Sacramento, Robledo,
Fra Cristoval, and a large portion of the Organ and Horse Mountains.
North of the district examined by myself, the Paleozoic rocks have been fre-
quently encountered by others. Mr. Marcon mentions their occurrence in
the mountains near Albuquerque. Lieut. Simpson met with them in lati-
tude 36 degrees 12 minutes, longitude 108 degrees 52 minutes; Lieut.
Abert, in latitude 37 degrees 15 minutes, longitude 104 degrees 35 minutes;
while still farther north they have been recognized by Emory, Fremont,
Parker, Stansburry, and other explorers.
CARBONIFEROUS SYSTEM.
The rocks of the Carboniferous System are separated by their lithological
and paleontological characters into two distinct and well defined divisions:
*Owns' Report.
32
GEOLOGICAL REPORT.
1.
2.
Coal Measures, or Upper Carboniferous.
Mountain Limestone, or Lower Carboniferous.
1. COAL MEASURES.
LITHOLOGICAL CHARACTER.
The Coal Measures consist principally of limestone, sandstone, conglom-
erate, millstone grit, and shale. The limestone and sandstone exist in about
equal proportions, and these constitute the chief part of the formation.
The Limestone is usually compact, subcrystalline, and occurs in strata of
very variable thickness. Sometimes the layers are massive and many feet
in thickness, but more frequently they are thin-bedded, and in some locali-
ties laminated or even foliated. The prevailing colors are light gray, blue,
and brown. Occasionally they are dark gray and black, or, as in the Gua-
dalupe Mountains, almost pure white. Veins of quartz sometimes traverse
the strata from top to bottom, and in their western extension they are not
unfrequently highly metamorphosed. In some localities they pass into
nearly pure calcite, and in others they contain a great deal of chert.
The Sandstone is both massive and thin-bedded, and, in general lithologi-
cal character, corresponds very closely with that of the Coal Measures of
Illinois, Indiana, and Kentucky. It is both coarse and fine grained, more
or less ferruginous, and exhibits every variety of hardness. Many of its
layers are highly micaceous, and the rock often contains disseminated
nodules of brown and black iron ore. In color it presents various shades
of gray, yellow, brown, and black. The surface of the different layers are
often beautifully ripple-marked. This rock sometimes passes into millstone
grit and conglomerate, and, like the limestone, is not unfrequently traversed
from top to bottom by tortuous veins of quartz.
The Millstone Grit generally occurs in thin layers, situated usually near
the base of the sandstone, into which it passes by almost insensible grada-
tions. It consists mostly of coarse quartz grains firmly cemented with
silicious matter.
The Conglomerate of the Coal Measures has been observed only in Eastern
Texas and the Choctaw Territory, where it sometimes presents a thickness
of more than a hundred feet. The prevailing color is red, and it is com-
posed altogether of well rounded pebbles of eruptive rocks, cemented with
silicious and ferruginous paste.
The Shale occurs interstratified with the sandstone in beds of from a few
inches to over a hundred feet in thickness. It is usually soft and of deep
blue and black colors, and contains thin bands of black ferruginous lime-
stone and sandstone interstratified. Wherever stone coal abounds it is
highly bituminous. Selenite and iron pyrites are of frequent occurrence
in it.
GEOLOGICAL REPORT.
33
As a general rule the rocks of this group are harder and more crystalline
in texture on the western than the eastern side of the Plains. In the former
region they are also more calcareous in their composition.
EXTENT AND THICKNESS.
Commencing towards the east we find the rocks of the Upper Carbonifer-
ous Group well exhibited in the western portions of Iowa, Missouri, and
Arkansas, through various portions of the Cherokee, Choctaw, and Chicka-
saw Territories, and in Eastern and Southeastern Texas. Near the western
line of Arkansas they exhibit a vertical development of about two thousand
feet, forming here the Ozark Mountains. Thence they are traced almost
continuously to Fort Gibson and Fort Washita, being interrupted in the
last mentioned direction at two points only, one by a narrow strip of coun-
try occupied by strata of older date, and the other by the granitic protrusion
already mentioned. At Fort Washita they disappear beneath the Cretace-
ous strata, but are exposed by denudation at several points between this
point and the Upper Cross Timbers of Texas.
Directly west of the Cross Timbers the rocks of the Coal Measures are
again met with, and thence extend uninterruptedly as far as the Clear Fork
of the Brazos River, or about fifty miles west of Fort Belknap, where they
appear in gently-rounded hills and ridges, and exhibit, by their exposed
edges, a thickness of upwards of two thousand feet. A few miles west of
this they disappear beneath the Cretaceous strata of the Plains, and are not
again encountered in that direction until we approach the eastern base of
the Rocky Mountains.
Farther south they are known to occur on both sides of the Rio Brazos
for the distance of nearly a hundred miles; on the San Saba River, between
Forts Mason and McKavett; and also near Fort McIntosh, on the Rio
Grande.
Along the route traveled by your Expedition between Victoria and San
Antonio heavy beds of coarse quartzose sandstone and conglomerate, agree-
ing lithologically in all respects with those of the Coal Measures farther
north, were encountered. (Vide Journal.) These rest unconformably be-
neath the strata of the Cretaceous System, and are known to contain in
several localities beds of iron ore. They have been traced, as I am in-
formed, many miles both north and south of the point where they were en-
countered by myself, and fifty miles south of San Antonio, on a stream
known as the San Miguel River, contain workable seams of bituminous coal.
Considering these, therefore, as also belonging to the upper division of the
Carboniferous System, they would seem to indicate for the rocks of this
group a continuous line of outcrop from Fort Belknap south as far as Fort
McIntosh.
34
GEOLOGICAL REPORT.
Towards the west these rocks exhibit a vertical development of about three
thousand feet, and are observed cropping out extensively on both sides of
the Rio Grande. Near the sources of Delaware Creek they are seen to
emerge from beneath the Lower Cretaceous strata of the Plains, and soon
after attain, in the Guadalupe Mountains, an elevation of about three thou-
sand feet Immediately west of this they are partially concealed by strata
of the Cretaceous Period, but at the distance of fifteen or twenty miles again
appear, and thence westward constitute, with the exception of a few igneous.
protrusions hereafter to be described, the only rocks met with until we ar
rive at the western base of the Sacramento Mountains, where they are inter-
rupted by an igneous valley (Valley of the Salt Lakes) from thirty to forty
miles in width. Upon the northern side of this valley they are again well
exposed in the mountains on both sides of the Jornado del Muerto, as well
as at several points between the Rio Grande and Membres Valley.
North of Dona Ana I have succeeded in tracing these rocks continuously
throughout the entire length of the region known as the Jornado del Muerto.
I have also ascertained their existence at several points between the north-
ern extremity of that plain and Albuquerque. Near Albuquerque they were
encountered by Mr. Marcon; Lieut. Simpson met with them in latitude 36
degrees 12 minutes, longitude 108 degrees 52 minutes; Lieut. Abert in lati-
tude 37 degrees 15 minutes, longitude 104 degrees 35 minutes; while still
farther north they are mentioned as occurring along the different routes ex-
plored by Emory, Fremont, Parker, and Stansbury. Their north and south
range upon this portion of the continent is therefore coextensive with that
of the same group upon the eastern side of the Plains.
In the mountains forming the eastern boundary of the Jornado del Mu-
erto the exposed edges of these strata show a thickness of over two thousand
feet. Near the southern extremity of the Sacramento Mountains they are
exposed vertically to the thickness of about eight hundred feet. At the
Sierra Alto the thickness of their upheaved edges was estimated approxi-
mately at about two thousand five hundred feet; while still farther east,
along the western face of the Guadalupe Mountains, they are exhibited in a
single vertical section to the thickness of near three thousand feet.
LOCAL DIFFERENCES.
In the State of Arkansas the rocks of this group consist of coarse and fine
grained quartzose sandstone, with intercalations of thin bedded, dark colored,
compact limestone and bituminous shale. The sandstone greatly predom-
inates over the limestone, and is mostly hard, ferruginous, and often easily
separated into smooth flat layers. The layers are often highly ripple-inarked.
At Fort Belknap the sandstone is in many places soft and highly fissile.
Its position is there seen to be below that of the limestone. The latter is
hard and highly crystalline, and occurs in layers both massive and thin
GEOLOGICAL REPORT.
35
bedded. Conglomerate in beds nearly a hundred feet thick occur in this
neighborhood. The same rock is also found fifty or sixty miles farther east.
On the Clear Fork of the Brazos River the calcareous rocks also occupy
a superior position, and in general thickness, at least as far as the layers in
that vicinity are exposed, greatly exceed that of the sandstone. They are
mostly compact, thin bedded, and of a light gray color. The sandstone is
coarse grained, of moderate hardness, and occurs in massive layers.
Between Victoria and San Antonio the rocks of this group consist mostly
of coarse ferruginous sandstone, grits, and conglomerate. The sandstone
varies greatly in hardness, and is often of a deep red or brown color. On
the San Saba it is granulate and gray.
In the Guadalupe Mountains the calcareous beds are exposed to the thick-
ress of about fifteen hundred feet, and are found occupying positions both
above and below the sandstone. The upper beds are mostly white, massive,
and highly crystalline, often passing into calcareous spar, while those towards
the base are thin bedded, compact, and of a dark blue or black color. The
sandstone is both coarse and fine grained, of different degrees of hardness,
and usually of a light yellow color. Near its base it is interstratified with
thick bands of dark colored shale.
In proportion as we travel west of the Guadalupe Mountains the sandstone
appears to gradually thin out, while the limestone becomes proportionably
developed. In the upheaval around the Sierra Alto the former is still found
occupying a middle position, but does not there exceed in thickness four or
five hundred feet. In that locality the limestone, except where in contact
with the igneous rocks, is hard, highly crystalline, and of light blue and gray
colors.
In the mountains upon the eastern side of the Jornado del Muerto the
limestone is both thick and thin bedded, and varies in color from light gray
to blue and black. When struck with the hammer it often emits a sulphur-
ous odor. The exposed layers of sandstone do not there exceed in thickness
one or two hundred feet. In the mountains upon the western side of that
plain, however, it is exposed to the thickness of five or six hundred feet. In
this locality it is coarse grained, passing into millstone grit, and contains
thick seams of soft dark colored shale.
PHYSICAL CHARACTER.
In general physical character the rocks of the Coal Measures differ in a
remarkable manner from those of the Cretaceous System. Wherever they
occur they exhibit strong evidences of subterraneous disturbance as well as
of subsequent denudation, and therefore usually impart to the country at
rough and broken character, accompanied with great variety and pictur-
esque beauty of scenery. Upon the eastern side of the Plains they are seen
rising in abrupt or gently sloping ridges to the height of one or two thou-
36
GEOLOGICAL REPORT.
sand feet, with broad, undulating valleys intervening; while towards the
west they constitute, as already intimated, some of the loftiest summits of
the Rocky Mountains.
From the general character of their dislocations the causes producing them
would seem to have operated in a much more sudden and violent manner
towards the east than towards the west. In the Ozark range of mountains
the strata are often seen violently twisted as well as fractured, and dipping
in different directions at high angles, while the ridges of greatest elevation
pursue a very irregular course, often approaching or blending with each
other, and are interrupted at frequent intervals by broad and deep valleys.
Towards the west, on the contrary, tho mountains exhibit a remarkable
uniformity in general character, and are grouped together in nearly parallel
ranges, while the lines of dislocation are exceedingly well defined, and are
traced continuously north and south over areas hundreds of miles in extent.
The uplifted layers, too, are usually found dipping uniformly, and often at
comparatively moderate angles either towards the cast or the west, and are,
at least as far as my own observations have extended, much less marked by
local flexures or violent contortions than upon the eastern side of the Plains.
The causes producing the dislocations in this direction would appear, there-
fore, to have operated in a much more gradual and uniform manner than
towards the east, and to have extended at the same period north and south
over extensive districts of country.
The great extent to which the rocks of this formation have yielded to
denudation is well exhibited in the Guadalupe Mountains near their south-
ern extremity. The materials derived from these mountains are, as already
remarked, spread over the Plains towards the cast for the distance of a hun-
dred and fifty miles, and fully attest by their abundance the great amount
of solid strata thus removed. Farther west the evidences of extensive den-
udation are equally well exhibited. In some of the canyons of the Organ
Mountains beds many feet in thickness appear to have yielded in this man-
ner, the materials derived from these sources being found profusely scattered ·
over the adjacent valleys, sometimes twenty or thirty miles from their orig
inal position.
ECONOMICAL GEOLOGY.
MATERIALS FOR CONSTRUCTION.
Wherever these rocks occur there can be no want of excellent building
From their great hardness and durability they are exceedingly
well adapted for large public edifices, as well as for roads, bridges, and
other works of internal improvement. Should the contemplated railroad
from the Mississippi Valloy to the Pacific Ocean, therefore, ever be con-
structed, they would furnish over a large portion of the route the very
best of rich materials for that purpose.
GEOLOGICAL REPORT.
37
By burning, an excellent quality of quicklime for mortar can almost
always be obtained from the limestone. Some of the dark varieties of
limestone would also furnish good hydraulic cement.
COAL.
Among the useful minerals hitherto discovered in this formation, de-
cidedly the most important, as well as the most extensively distributed, is
coal. This valuable substance, so inseparably connected with the pros-
perity of many of the States of the Union, occurs in the greatest abundance
throughout various portions of Arkansas, Texas, and the adjacent Chero-
kee, Choctaw, and Chickasaw Territories. In the State of Arkansas the
coal seams, so far as yet ascertained, are from a few inches to eight or ten
feet thick, and are seen reposing successively one above another, with their
intervening shales, sandstones, and grits, in a manner very similar to those
of Missouri, Illinois, and Kentucky. They occupy by far the greater por-
tion of the western half of that State, and are observed cropping out ex-
tensively along the Arkansas River between Little Rock and Fort Smith, as
well as much farther south. Near Fort Smith several seams of this mineral
have been discovered; one of them, eight feet in thickness, has been success-
fully worked for several years past, and is capable of yielding annually
thousands of tons of the very best quality of fuel. The coal obtained from
the neighborhood is light, highly bituminous, possesses an uneven fracture,
and burns with a brisk flame, leaving but little residue and no cinder. In
the direction of Little Rock it assumes more the character of cannel coal.
From Fort Smith coal deposits are traced, by means of numerous out-
crops, to within a few miles of Fort Gibson, in the Cherokee Nation, and in
a southwesterly direction as far as Fort Belknap, in Texas; thence south-
ward they are found to occur on both sides of the Brazos River for the dis-
tance of seventy or eighty miles; also on the San Miguel River, fifty miles
south of San Antonio, and near Fort McIntosh, on the Rio Grande.
Localities for Coal.
In treating of the different localities in Texas and the adjacent Indian
Territories in which workable seams of coal have been discovered, I shall
confine myself chiefly to such ones as are most important within the limits
of the region explored by myself. It is important, however, to bear in
mind that this region composes only a portion of the vast coal district of
the southwest, and that nearly all the discoveries of coal hitherto made
within its borders are purely accidental, as no systematic effort has over
been made for the development of this branch of its mineral wealth.
Bituminous coal of very fair quality has been ascertained to exist in
several localities between Fort Smith and Fort Gibson, in the Cherokee
38
GEOLOGICAL REPORT.
Nation. The scams, however, are for the most part poorly exposed, and
appear to have been but little worked. Their thickness, therefore, can not
be very accurately determined. The coal is both underlaid and overlaid by
thick beds of black bituminous shale, containing iron pyrites and thin bands
of black ferruginous limestone. In the neighboring sandstones sigillaria
and calamites have been discovered in the greatest abundance. The im-
pressions of the leaves of coal vegetables are also found in the shale.
In two localities on the Pateau River, one eight and the other about four-
teen miles southwest of Fort Smith, seams from three to six feet in thick
ness have been discovered. The coal is light, brittle, breaking with an un-
even fracture, and highly bituminous. It contains but little sulphur or other
impurities, and burns with a clear, bright flame, leaving but little ashes and
few cinders. The associated shales are over sixty feet in thickness, and con-
tain thin bands of laminated sandstone and nodules of ironstone, the whole
being overlaid by thin bedded quartzose sandstone, containing calamites.
and other fossils, and often thickly ripple-marked.
On Bayou Zeal, a small tributary of the Pateau River, two seams, one six
inches and the other about six feet in thickness, are exposed. The coal is of
excellent quality, and very closely resembles that in the neighborhood of
Fort Smith. Neither of these seams have been much worked.
At the Narrows, on the Fort Washita road, a few miles west of the last
mentioned locality, a seam one foot in thickness is exposed near the bottom
of a deep ravine. The coal is hard, compact, and burns with a brisk flame.
The associated shale is only three or four feet in thickness, and is underlaid
by coarse quartzose sandstone and grit. This seam appears to occupy a
position much lower in the series than those last described. The coal is also
of inferior quality, and in some places contains much slate.
On Gaines Creek, a tributary of the Canadian River, bituminous coal is
found cropping out in several places. The coal is represented to be of very
good quality. Thickness of seams unknown. Coal is also found on Coal
Creek, a small tributary of the last.
Near the Fort Washita road, six miles west of Gaines Creek, a seam
eighteen inches in thickness is found cropping out from beneath heavy bed-
ded quartzose sandstone. The coal has been employed by the blacksmiths
in the neighborhood, who pronounce it of excellent quality. Six miles
farther west another exposure of coal occurs. The seams vary in thickness
from eighteen inches to two feet. The coal is heavy, compact, and breaks
with a square fracture.
Near the Fort Washita road, about eight miles west of the residence of
Mr. Blackburne, I am informed by that gentleman, a seam of bituminous
coal over ten feet in thickness has been discovered. The coal is represented
to be light, brittle, and of excellent quality, and is overlaid by shale and
thin bedded quartzose sandstone. Near this locality occurs an extensive
GEOLOGICAL
39
REPORT.
exposure of heavy bedded, light gray, cherty limestone, containing goniatites.
and encranite stems in great abundance.
Twelve miles cast of Boggy Depot, in the Chickasaw Nation, a seam from
one to two feet in thickness has been discovered. Quality of coal unknown.
At a point about twenty miles north of Boggy Depot several seams are
found cropping out. They vary in thickness, as I am informed, from two
to seven feet, and present at the side of a hill in such a manner as to be
very easily worked. The coal is bituminous, and represented by those who
have tried it to be of good quality. No specimens from this locality have
been examined by myself.
Between Fort Washita and the Cross Timbers of Texas the Coal Measures
are, as already remarked, generally concealed by strata of the Cretaceous
System. They have been, however, exposed at a number of localities by
denudation, and at three points workable seams of coal have been dis-
covered.
The first of these localities occur about eight miles east of Preston, on
Red River. Here the coal is exposed near the bed of a small creek, and
exhibits a thickness of several feet. I am informed by Mr. Tyson, who
discovered this coal, that it is of excellent quality.
The second locality is about twelve miles, and the third, near the resi-
dence of Mr. McCarty, about thirty-five miles west of Preston. The coal
from both of these localities is, as I am informed, of very fair quality, and
well adapted for manufacturing purposes.
Bituminous coal has been discovered near Gainesville, Texas.
and character unknown.
Thickness
In the vicinity of Fort Belknap coal is found cropping out extensively in
no less than four distinct localities. The seams-of which there are several―
usually present in such a manner as to be very easily worked, and from
their great thickness are capable of affording with comparatively little labor
an inexhaustible supply of excellent mineral fuel.
This coal is likewise bituminous, but differs somewhat in character from
that occurring farther east. When first taken from the seam it is usually
hard, compact, and of a pitch-like luster, soiling the fingers but very little,
and breaks with a smooth square fracture, but upon exposure to the weather
becomes soft, of an iron rust color, and separates into very thin laminæ.
When heated it softens and swells a great deal, and burns with a reddish
flame and much smoke, leaving a good deal of ashes and cinders. The
seams sometimes contain nodules and thin bands of black limestone and
bisulphuret of iron (Iron Pyrites). These can, however, be very readily
distinguished and separated from the coal in the mines, and need, therefore,
interfere but very slightly with its value.
Section No. VI is taken, about one mile north of the Fort, from the side
of a deep ravine, which extends into the high bluffs forming at this point
the eastern boundary of the valley of the Rio Brazos, and exhibits an ex-
40
GEOLOGICAL REPORT.
posure about two hundred feet in length, of coal, shale, and sandstone. The
coal occupies the base of the section, and presents a thickness above the bed
of the ravine of about ten feet. How far it extends downward is not
known, as no artificial excavations have been made below the bed of the
ravine, but from the fact of coal being also exposed in the floor of the
ravine, which is quite uneven, it is presumable that it extends downward
several feet.
The seam contains nodules and thin bands of black ferruginous limestone
and bisulphuret of iron. These are sometimes crowded with fossils, prin-
cipally of the following species: Pleurotomaria carbonaria, P. ornata, Myalina
subquadrata, etc.
The overlying shale and sandstone are in places also highly fossiliferous.
The former is about five feet in thickness, and contains selenite and nodules
and thin seams of ironstone. The sandstone is soft, thinly laminated, the
laminæ being about one-twentieth of an inch in thickness and of a light color.
In the other localities in this vicinity the seams are of uniform thickness,
but do not differ in general character from those above described.
Large specimens of bituminous coal were obtained from the bed of the
Brazos River, ten miles southeast of the Fort. Two miles south of this a
thin seam of the same mineral has been discovered.
On the Brazos River, seventy miles below Fort Belknap, as I am informed
by Major Neighbors, coal crops out extensively. It is represented as bitu-
minous and of good quality. Coal is also reported to occur at several points
between this and San Antonio. I have been unable to obtain specimens
from any of these localities.
As already remarked, coal has been discovered on the San Miguel River,
fifty miles south of San Antonio. From this locality it has been hauled to
San Antonio, and there employed by the blacksmiths, who pronounce it of
moderately fair quality. By a gentleman engaged in working the seams I
have been furnished with the following section of this locality:
1.
Soft bluish-black bituminous shale.
2. Black bituminous coal, 2 feet thick.
Bituminous coal, 18 inches thick.
3.
Shale of the same character as above.
4.
5.
6.
Shale.
Bituminous coal, 20 inches thick.
These are both underlaid and overlaid by quartzose sandstone.
The coal on the Rio Grande* is reported, by several army officers stationed
in that vicinity, to occur in beds of great thickness, and will no doubt here-
after prove of inestimable value. It is bituminous, and is found associated
with shales, sandstones, and grits, the same as in other portions of Texas.
*The Coal Deposits on the Rio Grande were published in the "Report to the Rio Grande
Land Company" as early as the year 1834.
GEOLOGICAL REPORT.
41
On the Nueces River, ten miles west of Fort Inge, a seam of bituminous
coal several feet in thickness has been discovered. The coal has been em-
ployed by the blacksmiths at the Fort, and found to be of good quality. This
deposit is probably cretaceous.
No mineral coal has heretofore been discovered in any portion of the re-
gion examined by myself west of the Guadalupe Mountains. From the gen-
eral character of the strata, however, I feel satisfied that more thorough
explorations in that direction will succeed in developing the existence of
this mineral over a very large extent of territory. Strong evidences of the
existence of coal were discovered by myself in several localities in Western
Texas and New Mexico.
METALLIC ORES.
Iron is found abundantly distributed through the rocks of the Coal Meas-
ures in various portions of Arkansas and the adjacent Indian Territories;
also in Eastern Texas. Among the different ores of that metal hitherto
discovered in this region, the most abundant are the Brown Hematite, Mag-
netic Oxide, and Bisulphuret, or Iron Pyrites.
Copper, in the form of black oxide and sulphuret, or Copper Pyrites, has
been discovered in abundance in the Chickasaw Nation and in several locali-
ties in Western Arkansas.
Lead, in the form of sulphuret, or common galena, occurs abundantly in
Western Arkansas. It has also been found in the Choctaw and Cherokee
Territories.
The ores of other metals have been discovered in connection with these
rocks in Western Arkansas and the neighboring Indian Territories, but in-
asmuch as they do not occur near any of the proposed railroad routes, it has
not been thought advisable to mention them.
SPRINGS.
The region occupied by this formation is usually much better watered
than that of the Cretaceous System. This, towards the west, is owing
mainly to the greater elevation of the exposed edges of the strata, by which
means they are made to receive a much larger proportion of rain than
usually falls upon the Plains, while the rocks themselves are generally of
such a nature as to absorb water readily, which, following the general dip
of the strata, may gush out anywhere at lower levels in the form of springs;
hence they are abundantly met with near the base of many of the moun-
tains of Western Texas and New Mexico, while upon the Plains to the cast
but little water is found. In the region bordering the castern side of the
Plains, the rocks of this group being still more favorably situated with re-
gard to atmospheric moisture, the surface is abundantly enlivened with
springs and brooks, and there is no deficiency of good water.
42
GEOLOGICAL REPORT.
CHAPTER V.
2. MOUNTAIN LIMESTONE, OR LOWER CARBONIFEROUS.
ness.
The Mountain Limestone, or Inferior Carboniferous Group, rests immedi-
ately beneath the Coal Measures, and is composed principally of limestone,
quartzose sandstone, and argillaceous shale. Of these the limestone greatly
predominates, constituting fully five-sixths of the entire mass of the forma-
tion, and is traversed by the sandstone and shale in layers of variable thick-
It occurs both massive and thin bedded, the layers being in some
localities over a hundred feet in thickness, while in others they do not
exceed in this respect a few inches. It is usually hard and highly crystal-
lino, and sometimes contains irregular masses of pure cale-spar. Осса-
sionally it is homogeneous in texture, and breaks with a smooth conchoidal
fracture. The predominating colors of this rock are light gray and blue,
from which they pass into brown and black. In a few instances it is white.
In some localities the seams are largely intermixed with chert, and are
occasionally, more especially towards the west, traversed by veins of quartz,
calc and fluor spar.
The Sandstone varies considerably in character. Most generally, however,
it is hard, and composed of coarse quartzose grains. In some places it is
soft, highly ferruginous, and rapidly disintegrating Its prevailing colors
are light gray and yellow, from which it often graduates into red and
brown. Occasionally it is white and saccharoidal. The different beds very
seldom exceed a hundred and fifty or two hundred feet in thickness, and
are usually well defined, there being an abrupt transition from the sand-
stone into the limestone.
The Shale sometimes occurs in seams seventy or eighty feet in thickness.
It is mostly soft, of a dark blue or black color, and contains thin seams of
dark limestone. In places it is highly ferruginous, and is often interspersed
with nodules of brown iron ore. As in the preceding group, these rocks
aro generally harder and more crystalline towards the west than towards
the east. In the former situation they are also sometimes found in a highly
metamorphosed condition, and often emit a sulphurous odor when struck.
with a hammer.
EXTENT AND THICKNESS.
Commencing towards the east, we find the rocks of this group well
developed near the western borders of Arkansas, where they exhibit by
their exposed edges a general thickness (estimated approximately) of about
two thousand feet. In Washington county, in that State, they form the
1
GEOLOGICAL
43
REPORT.
Boston and several others of the loftier summits of the Ozark range of
mountains, and there constitute a portion of the principal axis or line of
greatest elevation between the Illinois and White Rivers. Immediately
west and southwest of this they disappear beneath the arenaceous beds of
the Coal Measures, but afterwards reappear at several points in the Chero-
kee and Choctaw Territories. In the latter Territory, about 100 miles
southwest of Fort Smith, they are well exposed in a low ridge, which extends
irregularly across the country for many miles in a southeasterly direction.
Beyond this they are again seen to dip beneath the rocks of the Upper Car-
boniferous Group, and are no more met with in that direction during the
remainder of the distance to Fort Belknap and the Clear Fork of the Brazos
River.
On the San Saba River, at a point about midway between Fort Mason
and Fort McKavett, the rocks of this group are seen cropping out exten-
sively from beneath thick strata of the Cretaceous Period. At this locality
the thickness of their exposed edges was estimated by myself at about two
thousand five hundred feet. (Vide Journal.) The same outcrop is described
by Roemer, who succeeded in tracing, it many miles east of the point (on
the San Antonio road) where it was encountered by myself.
Towards the west, strata belonging to this division of the Carboniferous
System has been met with in the Organ and Fra Cristoval Mountains. In
the Organ Mountains their exposed edges are exhibited in some places to
the thickness of about three thousand feet. Commencing about twenty
miles north of El Paso, they are traced in low hills and ridges along the
western base of the igneous protrusions, of which these mountains are there
mainly composed, to a point nearly due east of Fort Fillmore. Here they
suddenly attain an elevation of about three thousand feet, but immediately
afterwards descend, and thence northward appear at a few points only along
the western base of the mountains until we arrive in the neighborhood of
the San Augustine Pass, about fifteen miles east of Dona Ana, where they
are exposed to the thickness of seven or eight hundred feet. A little north
of this they again attain an elevation of several thousand feet, and from
that point constitute, with the exception of the overlying Coal Measures
already mentioned and an interrupted chain of igneous hills, the entire mass
of the Organ Mountains as far north as the northern extremity of the Jornado
del Muerto. Upon the western side of this plain they are again met with in
the Fra Cristoval Mountain. In this mountain the thickness of their ex-
posed edges was estimated approximately at about two thousand feet.
On both sides of the Plains north of the region examined by myself the
rocks of this group have been abundantly encountered by other explorers.
Towards the cast they are mentioned by D. D. Owen as occurring along the
western borders of lowa and Missouri; while in the opposite direction they
have been encountered by Mr. Marcon near Albuquerque, and by others at
various points in the Rocky Mountains much farther north.
44
GEOLOGICAL REPORT.
LOCAL DIFFERENCES.
In the western portion of Arkansas the calcareous rocks of this group
occur mostly in massive beds of great purity. Their color varies from light
gray to blue and brown. They are usually highly crystalline, and sometimes
contain irregular masses of calc-spar. Occasionally they are homogeneous
in texture, breaking with a smooth conchoidal fracture, and of a bright
fawn color.
In the Choctaw Territory, a hundred miles southeast of Fort Smith, the
limestone is hard, compact, and of a light blue or drab color. It is there
largely intermixed with chert, and as far as exposed contains no layers of
sandstone.
On the Upper San Saba River it is thin bedded, of a dull gray color, and
more or less granular. The sandstone is hard, coarse grained, and highly
ferruginous, sometimes passing into silicious iron ore, and in color varies
from deep brown to red and black. In places it is highly metamorphosed.
In the Organ Mountains the limestone is hard, highly crystalline, and oc-
curs in layers of variable thickness, being in some places massive and in
others thinly laminated. Its prevailing color is blue, from which it passes
into various shades of gray, brown, and black. The sandstone is both
coarse and fine grained, and usually of a light yellow color. These rocks
are here traversed by tortuous veins of quartz, calc and fluor spar, and
often exhibit a highly metamorphosed appearance.
In the Fra Cristoval Mountain these rocks do not differ in general char-
acter from what is observed in the Organ Mountains.
PHYSICAL CHIARACTER.
Like that of the preceding group, the country occupied by the Lower
Carboniferous rocks exhibits strong evidence of subterraneous disturbance,
as well as of subsequent denudation, and is characterized by a rough and
broken surface, lofty mountains, rugged precipices, and great variety and
beauty of scenery. Wherever favorably situated with regard to climate, as
in Western Arkansas, it is well supplied by innumerable springs with the
best of water, covered with highly productive soil, and it well affords every
inducement for the agriculturist.
ECONOMICAL GEOLOGY.
MATERIALS FOR CONSTRUCTION.
These rocks furnish excellent building materials. The limestone and
sandstone are both hard and durable, and are, therefore, well adapted for
GEOLOGICAL REPORT.
45
edifices, both of a public and private character. For bridges, roads, and
other works of internal improvement they likewise furnish the most ap-
proved materials. By burning, a good quicklime for mortar can almost
always be obtained.
METALLIC ORES.
Of the different metallic ores occurring in this formation, the most im-
portant are those of silver, lead, and iron.
Silver, associated with sulphur and lead in the form of argentiferous
galena, is found along the western base of the Organ Mountains, in New
Mexico. The ore is there exposed at the surface in veins, all of which are
contiguous to eruptive rocks, and occur, at least as far as my own exami-
nations have extended, in thin bedded, hard, compact, dark blue and black
crystalline limestone. The veins are all nearly vertical, and preserve a
highly tortuous course, their direction being in some places north and south,
and in others inclined towards the east and west. Their thickness, includ-
ing matrix and all, varies from five to ten feet. The ore is often mixed
with a small percentage of iron and titanium, and sometimes contains traces
of copper and other metals. When pure it yields from four to six ounces
of silver to the hundred pounds. Associated with it as a matrix we have
calc and fluor spar. Of these two the former greatly predominates, and is
for the most part highly discolored with black and red oxide of iron, while
the fluor spar occurs mostly in semi-transparent masses, and is of a beauti-
ful green color.
About fifteen miles east of Dona Ana two of these veins are well exhi-
bited. One is situated near the base of the exposed limestone, which is
here strongly upheaved, dipping towards the west at an angle of about 80
degrees, and the other near its summit. The first is about eight fect in
thickness, and has at one point been partially worked by means of a shaft
sunk to the depth of ten feet. The metalliferous portion occupies fully one-
third of the entire thickness of the vein, and occurs in such a manner as to
be very easily separated from the gangue. This vein, at the point examined
by myself, has a W. N. W. bearing, and is traced, as I am informed, for
the distance of several hundred yards on both sides of the shaft. From
some cause or other it has not been worked for several years past, although,
from the character and thickness of the ore, it would doubtless, if properly
managed, prove highly profitable. The second vein is about ten feet in
thickness, and is at present worked by Mr. Stephenson, who has sunk a
shaft in it to the depth of near thirty feet. The ore occurs in a solid sheet
from eighteen inches to two feet in thickness, and is also very easily sepa-
rated from the gangue. After its extraction it is conveyed upon the backs
of mules to the place of smelting, a distance of about sixteen miles, and in
spite of the great disadvantages attending its present mode of working, the
46
GEOLOGICAL REPORT.
silver being only partially separated from the lead, and the latter, for want
of a market, thrown aside as refuse, yields, as I am informed, a very hand-
some profit. The direction of this vein is nearly north and south.
The position of these two veins, as well as the character of the neighbor-
ing rocks, are shown in the accompanying Section No.
About one mile north of Mr. Stephenson's mine, near the San Augustine
Pass, several other veins are exposed at the surface. None of them, how-
ever, appear to have been much worked, although, from the character and
thickness of the ore, they could no doubt be made highly profitable.
Silver is also found in connection with lead in Arkansas. It there, like-
wise, occurs in the vicinity of eruptive rocks.
Lead.-Besides the argentiferous galena above mentioned, lead has been
found in several localities in Washington county, Arkansas. It there oc-
curs mostly in the form of sulphuret. Specimens of this ore from that re-
gion were tested by myself, and found to yield near eighty per cent of lead.
The same metal has been found in connection with the Mountain Limestone
in the Cherokee Territory.
Iron, in the form of oxide, is very generally distributed throughout the
rocks of this formation, and furnishes the principal portion of their coloring.
matter. This metal has been found in workable quantities in several por-
tions of Western Arkansas and the adjacent Indian Territories.
LOWER SILURIAN SYSTEM.
Strata belonging to the Devonian and Upper Silurian Periods have not
been encountered by myself in any portion of the region under consider-
ation. Others, however, unequivocally Lower Silurian in their character,
have been met with along the western base of the El Paso Mountains, a few
miles north of Fort Bliss. These rocks are there found resting in imme-
diate contact with eruptive rocks, and consist of upheaved and highly con-
torted strata of hard, compact, light gray and blue crystalline limestone.
They are exposed only at intervals; in some places exhibit a thickness of
about three hundred feet, and are traced in a northerly direction for the
distance of ten or eleven miles. Near their junction with the igneous rocks
they are highly metamorphosed, and exhibit no traces of organic remains,
but at a little distance are crowded with well preserved fossils, among which
I have succeeded in recognizing the following well known species: Orthis
testudinaria, etc.
At several points along the western base of the Organ Mountains farther
north, strata of the same lithological character were observed cropping out
from beneath the fossiliferous beds of the Lower Carboniferous Group. No
fossils, however, were detected in any of them.
GEOLOGICAL REPORT.
47
CHAPTER VI.
ERUPTIVE ROCKS.
Most of the eruptive rocks encountered by myself in Texas and New
Mexico are described in detail in the Journal and accompanying report
upon the Jornado del Muerto. I shall, therefore, in this place only notice
those of the Limpea Mountains, and such others as were examined during
my former trip to the sources of Red River. The general distribution of
this class of rocks in the region under consideration will be more particu-
larly noticed when I come to speak of mountain ranges.
Eruptive Rocks of the Limpea Mountains.-These, as far as examined by
myself, consist mostly of claystone and feldspar porphyries and dark col-
ored basalt. The porphyries are hard, compact, and of purple, red, brown,
and gray colors. Their crystals are usually well defined, and consist for the
most part of labradorite, quartz, and feldspar. Those composed of labra-
dorite are by far the most abundant, and usually exhibit in great perfection
the characteristic change of colors of that mineral. The basalt is only ob-
served near the northern base of the mountains. In some places it is hard
and very compact, while in others it is soft or more or less vesicular, some-
times passing into vesicular lava. All these rocks appear to be yielding.
rapidly to the weather, and are traversed in almost every direction by deep
fissures or canyons, some of which are many miles in length. Externally
they are of reddish brown and black colors, and not unfrequently their
weathered surfaces present a highly glazed or polished appearance.
Eruptive Rocks of the Witchita Mountains.-The rocks of the Witchita
Mountains consist of hard, compact granite and porphyry, with occasional
veins of greenstone, hornblende, and cellular and compact quartz. The
granite is far more abundant than the porphyry, and composes the great
mass of the formation. It is usually fine textured, of a deep red color, and
contains a great predominance of feldspar and a deficiency of mica, the lat-
ter mineral being in many instances almost entirely absent. Not unfre-
quently the rock passes into nearly pure feldspar. Externally it is of deep
brown, yellow, or red colors, and owing to the great number of joints and
master joints by which it is traversed, presents somewhat of a cuboidal
structure.
The porphyry is confined almost exclusively to the eastern extremity of
the mountains, where it is exhibited in gently rounded hills and ridges from
three to five hundred feet high. It is also of a deep red color, but is usually
much softer than the granite. Its crystals are mostly small and composed
of flesh-colored feldspar. The veins of greenstone, hornblende, and quartz are
sometimes many feet in width, and traverse the mountains in almost every
48
GEOLOGICAL REPORT.
direction. Those of quartz are apparently much more abundant in the por-
phyry than in the granite. Near Cache Creek several of them are seen
traversing the mountains from top to bottom. The quartz in that situation.
is highly ferruginous, often exhibiting distinct crystals of bisulphuret of
iron, and contains small irregular cavities partially filled with liquid nap-
tha. In Otter Creek, a small affluent of Red River, having its sources in
these mountains, two specimens of bluish yellow quartz, each containing a
small particle of gold, were found. Black ferruginous sand has also been
discovered in great abundance in several of the streams flowing from these
mountains.
Igneous Protrusion near Fort Washita.-This protrusion has been traced in
a northeasterly and southwesterly direction for the distance of about thirty
miles, with an average width of about six miles. It consists altogether of
coarse porphyritic granite and quartzose rock. The granite is mostly hard,
of a reddish color, and contains distinct crystals of foldspar of the flesh col-
ored variety. It is traversed by the quartz in thick veins, which are in
some localities quite numerous. This rock is mostly white and very com-
pact. In a few places it is highly discolored with oxide of iron.
MOUNTAIN RANGES.
Eight different ranges of mountains have been examined by myself in
Texas and New Mexico. Of these four are composed entirely of eruptive
rocks, one partly of eruptive and partly of sedimentary rocks, and three alto-
gether of sedimentary rocks. Those composed entirely of eruptive rocks.
are the Witchita, Limpea, IIucco, and Membres Mountains. The Organ
Mountains consist partly of sedimentary and partly of eruptive rocks, while
those altogether sedimentary in their composition are the Guadalupe, the
Sacramento, and the Horse Mountains, the last including the Fra Cristoval
and Robledo Mountains, both of which are but detached portions of the same
range. Although differing remarkably in their general composition, these
different ranges possess certain features in common which at once serve to
distinguish them from any of the mountains occurring east of the Plains.
With the exception of the Witchita range they all have a general north and
south bearing, and the parallelism of the lines of eruption or of upheaval are
usually exceedingly well marked, the different chains being sometimes traced
continuously for hundreds of miles, with the same general curves, and with
broad, smooth intervening valleys, open only at their northern and southern.
extremities. Owing to the great thickness of the quaternary deposits of
western Texas and New Mexico, the minor inequalities of the surface of the
country are generally obliterated, so that the mountains are usually seen
rising abruptly from smooth level or gently ascending plains, while for the
same reason many of the igneous protrusions of these regions appear com-
pletely isolated that would otherwise be exhibited in continuous chains, their
lower portions being covered by these deposits.
GEOLOGICAL REPORT.
49
The mountains composed entirely of sedimentary strata are remarkable
for their great general uniformity of character. They occur mostly in con-
tinuous ranges, each one of which exhibits usually but a single slope, which
is either towards the east or the west, being abruptly terminated in the oppo-
site directions by bold vertical or nearly vertical escarpments, some of which,
as for instance those forming the western faces of the Guadalupe and Sacra-
mento Mountains, are nearly three thousand feet in height.
Inasmuch as the ranges composed altogether of sedimentary rocks are
fully discussed in the Journal and report upon the Jornado del Muerto, be-
sides being several times referred to in the chapters upon the Carboniferous
System, I shall for the present confine myself entirely to such as are com-
posed wholly or partially of eruptive rocks.
WITCHITA MOUNTAINS.
With the exception of those occurring near the eastern extremity of the
range, these mountains present a nearly uniform appearance and structure.
Composed mostly of fine granite, they rise abruptly from a smooth and
nearly level plain, and attain at their highest points an elevation of about
nine hundred feet. Many of them are completely isolated, and of an irreg-
ular conical shape, while others are grouped together in clusters of eight or
ten, and are more or less rounded. At a distance they appear to be smooth,
but upon a nearer approach their surfaces are found to be quite rough, and
present very much the appearance of loose rocks thrown confusedly together.
This range is about seventy miles in length, and varies in width from five
to fifteen miles. Its general bearing, as determined by Capt. R. B. Marcy,
is about south 60 W.
At the base of these mountains the Marly Clay Formation (Lower Cre-
taceous) is exhibited in nearly horizontal layers, and presents generally but
little evidence of disturbance, while the clays and sandstones have been
found in several localities to contain inbedded fragments of rocks in all re-
spects similar to those of the mountains. The period of eruption of these.
mountains must, therefore, date anterior to that of the deposition of the
Lower Cretaceous Strata of the Plains.
LIMPEA MOUNTAINS.
The Limpea range has been only partially examined by myself. As
already remarked, it is composed mostly of dark colored porphyry and ba-
salt, and is evidently much more recent in origin than the range last consid-
ered, its protrusions occurring after the deposition of the limestone of the
Upper Cretaceous group, which is found strongly upheaved against its north-
ern base. These mountains exhibit at their highest points an elevation of
about one thousand feet above the level of the surrounding country, and as
50
GEOLOGICAL REPORT.
far as examined by myself present everywhere a dark and exceedingly rug-
ged appearance. In some instances they are completely isolated, and are seen
rising in the form of truncated cones; in others their summits are sharp and
jagged, and from their peculiar shape are sometimes compared not very in-
aptly to a bishop's mitre. Most frequently, however, they are grouped to-
gether in short detached ranges, most of which appear to have a general
north and south bearing, and are usually marked on all sides by abrupt and
in many instances nearly vertical walls, which sometimes exhibit a slightly
columnar appearance.
HUECO MOUNTAINS.
Under the name of Hueco Mountains are included all igneous protrusions
encountered by the Expedition between the sounthern extremities of the Gua-
dalupe and Sacramento Mountains as well as those described in the Journal as
occurring farther north along the western base of the Sacramento Mountains.
This range consists altogether of isolated peaks, the highest of which, the
Sierra Alto, is about fifteen hundred feet above the level of the surrounding
plain. Towards the south they are generally much more elevated than at
the north, and pursue a very irregular course, their general direction being
there pretty nearly W. S. W. Near the Sierra Hueco, however, they are
seen to bend abruptly towards the north, and are afterwards traced in low
hills and ridges for a considerable distance along the western base of the
Sacramento Mountains. As far as examined they are, with a single excep-
tion (viz., Sierra de los Alamos), composed entirely of fine compact granite,
containing a much larger percentage of feldspar than usual, and a deficiency
of mica. Around the base of several of them the limestone and sandstone
of the Coal Measures are found metamorphosed and strongly upheaved.
The protrusion of these mountains must, therefore, have occurred after the
close of the Carboniferous Period.
MIMBRES MOUNTAINS.
The Mimbres Mountains form a nearly continuous range, whose general
bearing is pretty nearly north and south. As far as examined they appear
to attain their greatest elevation at the Picache de los Mimbres, a sharp
conical peak situated near their southern extremity, from which point there
is a gradual descent towards the north. At the "Picache," the only por-
tion of the range visited by myself, the principal rock was found to be a
hard and very compact porphyritic granite, which composed the main axis,
with porphyry, quartz, vesicular amygdaloid, and chalcedonic rocks on either
side. No sedimentary rocks were anywhere observed in the neighborhood.
I am, therefore, unable to form an opinion with regard to the relative age
of these mountains,
GEOLOGICAL REPORT.
51
ORGAN MOUNTAINS.
This range, as already remarked, is composed partly of eruptive and
partly of sedimentary rocks. The eruptive rocks consist mostly of hard,
compact, red and gray porphyritic granite and red porphyry. Those towards.
the south are seen rising in sharp jagged peaks to the height of near three
thousand feet, and with some local exceptions constitute all that portion of
the range lying between El Paso and the San Augustine Pass. Immediately
north of this pass the eruptive rocks are seen to descend rapidly, and at
the distance of a few miles farther north are exhibited only in low detached
hills, their place in the mountains becoming occupied by upheaved strata of
the Carboniferous System, which last soon attain an elevation of about three
thousand feet, and thence northward constitute the principal portion of the
Organ range until we arrive at the northern extremity of the Jornado del
Muerto, beyond which point my examinations have not extended.
Wherever the sedimentary strata prevail the mountains exhibit but a single
slope, which is uniformly towards the west, being abruptly terminated in
the opposite direction by lofty escarpments, many of which are nearly verti-
cal. So far as ascertained, the most recent strata elevated by these moun-
tains are those of the Coal Measures. The period of eruption and of upheaval
must, therefore, have occurred subsequent to the deposition of these strata.
VOLCANIC RANGE.
Besides the mountains above described, a volcanic range of much more re-
cent origin has been traced for several hundred miles along the Rio Grande.
The general direction of this range appears to be pretty nearly north and
south. I have myself encountered it at several points between El Paso and
the Fra Cristoval Mountain. By Mr. Marcon and others it is mentioned as
occurring as far north as Albuquerque and Santa Fe, while Mr. Thompson,
a member of our own party, informs me that he has traced it in a southerly
direction to the Laguna Patos, nearly a hundred miles south of El Paso.
The range, as far as examined by myself, is formed altogether of isolated
conical hills, which vary in height from three to six hundred feet, and are
composed entirely of dark greenish compact basalt and vesicular lava. From
each of these cones streams of dark colored vesicular lava, varying in width
from a fourth to one or two miles, and from thirty to seventy feet in thick-
ness, are seen to have issued. Several of these cones and lava streams are
described in detail in the Journal and report upon the Jornado del Muerto.
The lava appears to have undergone but little alteration since the period of
eruption, its upper surface being black, highly vesicular, and totally devoid
of vegetation, and from the fact of its being usually found resting above the
drift is evidently of more recent origin than the latter.
OF
CH

UPPER FOSSILIFEROUS BAND
NORTH
LOWER FOSSILIFEROUS BAND
GEOLOGICAL SECTION OF THE ESCARPMENTS NEAR THE RIO PECOS KNOWN AS THE CASTLE MOUNTAINS.
Upper Cretaceous Limestone.
2.
Lower Cretaceous or Marly Clay Group.
GAST&CO ST. LOUIS & NY.
SOUTH,
PART SECOND.
JOURNAL OF GEOLOGICAL OBSERVATIONS
ALONG THE ROUTES TRAVELED BY THE EXPEDITION
BETWEEN INDIANOLA, TEXAS, AND THE VALLEY OF THE MIMBRES, NEW MEXICO.
BY GEO. G. SHUMARD.
CHAPTER I.
FROM INDIANOLA TO SAN ANTONIO DE BEXAR.
As the scientific division of the Expedition was fully organized previous
to our leaving Indianola, it was thought advisable to commence the geo-
logical investigations at that point.
The country in the vicinity of Indianola is for the most part flat, and
but little elevated above the adjacent bay of Matagorda. It is traversed
in different directions by long, narrow lagoons, whose depths vary from a
few inches to fifty feet. These are apparently diminishing in size, while
the dry beds of others, often containing thick accumulations of Ostrea and
other marine shells of existing species, and the low, flat character of the
surface generally, proclaim this region to have been but recently recovered
from the domain of the Ocean.
The Geological Formation here consists of alluvial deposits of tough calca-
reous clay, of light blue and red colors, and fine yellow calcareo-silicious
sand. The sand is a more recent deposit than the clay, and is arranged
chiefly along the coast in nearly parallel ridges, from five to twenty feet in
height, thus constituting a kind of natural levee. As these ridges coincide
with the various indentations of the coast, and are largely composed of
finely comminuted shells, they are doubtless the result of the conjoint ac-
tion of the waves and wind; the former throwing the materials up, the
latter transporting them inland.
We left Indianola on the 4th of April, the general direction to be pur-
sued from this point to San Antonio de Bexar being nearly northwest.
During the first day's march we traveled over gently undulating prairie,
composed of alluvial deposits of tenacious clay and dark silicious sand; the
54
JOURNAL OF GEOLOGICAL OBSERVATIONS.
former assuming a variety of colors-black, brown, red, blue, and light
yellow, and containing small white particles of carbonate of lime. The
darker varieties of clay greatly predominate over the others, and are al-
ways observed nearest the surface. The sand is only occasionally seen,
and does not attain any considerable thickness. It is for the most part
coarse, highly ferruginous, and contains pebbles of metamorphic rocks
scattered through it, and is sometimes loosely cemented with ferruginous.
and calcareous matter.
The surface is often characterized by numerous small ridges, from two
to three feet high, familiarly known as "Hog Wallows."
Soil a deep vegetable mould, highly productive; sub-soil generally calca-
reo-argillaceous, sometimes arenaceous.
Distance traveled, 25 miles.
April 5.-For the first fifteen miles we continued to travel over deposits
of the same character as noted yesterday. Afterward the formation be-
came much more arenaceous, consisting chiefly of coarse yellow quartzose
sand, with pebbles and small boulders of silicious rocks disseminated
through it. Surface gently undulating, and covered, as far as Victoria,
with dark, rich, arable soil
At Victoria we crossed the Guadalupe River, which is here about fifty
feet wide, flowing between high bluff banks. Here I saw, for the first time
since leaving Indianola, strata of older date than those of the Quaternary
Period. They consist of laminated layers of soft, crumbling, reddish
quartzose sandstone, with rounded silicious pebbles embedded, which are
sometimes so abundant as to form a conglomerate. These strata appear
only at a few points, forming ledges from four to five feet high, with a dip
of 10 degrees southeast. They are surmounted by twenty-five feet of ash-
colored loam, containing here and there small angular fragments of com-
pact gray limestone.
I have been informed that about four miles south of this place extensive
beds of soft gray limestone occur, that yield a good quality of quicklime,
for which purpose they are extensively employed in the neighborhood. I
was not, however, able to procure specimens of the rock for examination.
Distance, 16 miles.
April 6.—The prevailing formation encountered to-day was coarse red-
dish sand and sandy clay of the Quaternary Period, in places abounding
with pebbles and small boulders of dark silicious rocks. Commingled
with these also occur silicified fossil dicotyledonous wood, resembling in
all respects specimens I obtained from deposits of the same geological age
near the headwaters of the Brazos, Big Wichita and Red Rivers of Texas.
The fossil wood, as well as the pebbles and boulders, have doubtless been
mainly derived from the destruction of Cretaceous strata.



Section of Strata on Guadalupe River, Taken April 5, 1855.
Subs
Ash coloud Loam containing figments of compact
ay limestone
Section of Strata, April 7, 1855.
2
براتان
in
(-.
I.
Soft Limestone.
2. Red and Blue Marly Clay.
3. Thinly Laminated Sandstone.
Section of Strata near the Salt Lakes, April 8, 1855.
I.
Pulverulent Limestone.
2. Indurated Blue and Yellow Marly Clay. 3. Laminated Sandstone.
56
JOURNAL OF GEOLOGICAL OBSERVATIONS.
The newer deposits entirely conceal those of older date until we reach
Rice Creek, where we found a low exposure of soft ferruginous sandstone,
similar to that observed on the Guadalupe River at Victoria. Soil poor,
sandy, supporting a sparse growth of stunted oak.
Distance, 3 miles.
Τ
April 7.—For the first two hours our route led over gently undulating
land, with a sterile, reddish, sandy soil, bearing sometimes a scattered.
growth of scrub oaks. This district, as well as that passed over yesterday,
may be regarded as totally unfit for agricultual purposes, as the soil con-
tains but few elements of nutrition, and the sub-soil is loose and poorly
adapted for the retention of moisture.
At the distance of four miles we reached thick beds of red and blue
marly clay, which continued to be largely developed during the remainder
of the day's journey These strata I have no hesitation in referring to
the Cretaceous Group. The clay is hard, tenacious, and contains thin and
nearly horizontal seams of thinly laminated, fine grained, silicious sand-
stone, of light reddish and pink colors. This sandstone differs in character
from any hitherto encountered. In many places the surface was found
whitened with pulverulent carbonate of lime, exhibiting often a thickness
of six or seven feet, and resting on the clay and sandstone, as shown in the
accompanying section.
On striking this formation a marked change in the character of the
country is at once observed. The soil becomes much more productive, and
supports a luxuriant vegetation; in fact, we now find a desirable agricul
tural district, destined at no very distant period to become thickly inhab-
ited.
Distance, 12 miles.
April 8.-Soon after leaving camp, we again struck heavy deposits of
red sand and boulder formation, with its accompanying sterile soil, which.
continued for several miles, and was then succeeded by the Cretaceous
marls, clays, and sandstones, overlaid by white pulverulent limestone, the
whole being precisely similar in lithological character to that encountered.
yesterday. The limestone appears only near the surface, and is much
thinner than that before noticed, nowhere exhibiting a thickness of more
than a few inches, and appearing only at intervals. I was unable to detect
any fossils either in it or the underlaying marls, which latter were often
exhibited in ravines and bluffs to the height of fifty or sixty feet.
The country is gently rolling, and where the cretaceous deposits approach
the surface the soil is often several feet thick. Timber mostly post oak
and mezquite.
At Yorktown I saw a number of blocks of coarse grained red sandstone,
said to have been procured from an extensive quarry situated about three
JOURNAL OF GEOLOGICAL OBSERVATIONS.
57
miles south of that point. The specimens of this rock examined were
compact, and contain a large percentage of iron in the state of protoxide,
which renders it unfit for building purposes. I was also informed that in
the same neighborhood occur heavy beds of hard gray sub-crystalline lime-
stone, well adapted for burning into lime. I could not obtain specimens
of the rock, and was unable to determine its geological position.
After leaving Yorktown the land assumes an arenaceous character, the
soil being in many places composed almost entirely of coarse red and
black silicious sand, supporting here and there a sparse growth of stunted
oak and mezquite trees. Occasionally, however, where the soft chalky
limestone forms the surface rock, the soil is quite productive, and covered
with rank vegetation.
Late in the day we reached a watering place known as the
"Salt
Lakes "
Near this point, on the banks of a small stream, is exhibited a
section of about thirty feet of alternations of indurated blue and yellow
marly clay and coarse grained sandstone, surmounted with six feet of soft
pulverulent limestone. The sandstone is soft, ferruginous, and disin.
tegrates readily on exposure to the weather. The layers are from a few
inches to a couple of feet in thickness. The character of the bluffs as
seen here is shown in the accompanying section.
Distance traveled, 12 miles.
April 9.-During the early part of our day's journey no material change
was observed in the character of the geological formation, the strata main-
taining nearly a horizontal position. The cretaceous beds were frequently
well exposed, sometimes presenting sections of more than a hundred feet.
I could not discover any traces of organic remains in any of these beds,
although diligent search was made for them at various points. Soil usu-
ally of good quality, and bearing groves of mezquite. Sub-soil calcareo-
argillaceous, sometimes arenaceous.
In a small ravine, about twelve miles distant from our last camp, we
found an exposure of about twenty feet of quartzose ferruginous sand-
stone, in beds from three to four feet thick. This rock differs in a marked
manner from any we have hitherto encountered, and resembles lithologic-
ally the sandstone of the Coal Measures that I have seen at Fort Belknap
and other points in Texas.
It is coarse-grained, and often passes into a kind of millstone grit. Its
color varies from deep red to ferruginous brown, and the beds dip at an
angle of 10 degrees northeast.
This sandstone continues to be largely developed for several miles, and
often exhibits local flexures and other evidences of disturbance. In a few
places the rock is of a light bluisn color, composed of fine grains, and
would doubtless furnish a good building material.
Towards evening we came to an exposure of about twenty feet of yellow,
58
JOURNAL OF GEOLOGICAL OBSERVATIONS.
argillaceous, porous limestone of the Tertiary Period. This rock reposes
partly upon the sandstone last described, and partly upon Cretaceous strata,
and contains imperfect fossils of the genera Tellina, Arca, and Infundibulum.
The layers dip about two degrees east southeast.
Soil, during the latter portion of the day's march, a productive vegetable
loam.
Distance, 20 miles.
April 10.-Three miles from the last camp we came to another exposure
of yellow argillaceous limestone of the Tertiary Period, containing fossils
of the same character of those of yesterday. These strata constitute the
prevailing surface formation for several miles, and nowhere exhibit a thick-
ness of more than fifteen or twenty feet.
The rock yields readily to the action of the weather, and consequently
would not be well adapted for building purposes.
The white pulverulent limestone, marls, and sandstones of the Cretaceous
System underlay the limestone just described, the whole resting unconform-
ably upon coarse sandstone, which sometimes exhibits a thickness of forty
feet, and is usually coarse-grained and more highly ferruginous than that
observed yesterday.
About one o'clock we arrived at Cibolo Creek, a fine stream of clear
water, which at this point flows between high bluff banks, and has an
average width of about forty feet. Here the sandstone is well exposed, ex-
hibiting a thickness of near sixty feet above the bed of the creek. In this
vicinity several large fragments of excellent iron ore were picked up. In fact
strong indications of this metal were frequently observed during the day.
Shortly after crossing the stream we encountered heavy beds of millstone
grit and coarse conglomerate. These strata continued to be largely devel-
oped during the remainder of our day's march, presenting frequent indica-
tions of local disturbance, and a general inclination of about fifteen degrees
northwest. The conglomerate is of various degrees of hardness, and con-
sists of metamorphic rocks, cemented sometimes with a silicious and some-
times with a ferruginous paste.
The surface of the country passed over during the day was more or less
broken and hilly, and often covered to the depth of several feet with dark,
rich, vegetable soil. Sub-soil calcareo-argillaceous, occasionally arenaceous.
Distance, 17 miles.
April 11.-Our road during the day was over a broken, hilly country.
For the first few miles no change was observed in the character of the for-
mation. The conglomerate was constantly exposed, occasionally exhibiting
a thickness of forty feet. The sandstone and gritstone were also largely
developed. In one instance a well was sunk to the depth of sixty feet,
wholly through these beds.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
59
At the distance of about fourteen miles these rocks were succeeded by
heavy beds of blue marly clay and hard and soft chalky limestone, which
continued to be largely exhibited during the remainder of the distance to
San Antonio.
Iron ore was again frequently met with to-day, and specimens of brown
hematite of excellent quality were collected. The indications were such as
to lead to the belief that this important metal exists here in considerable
quantity.
The surface of the country for the first fourteen miles was thickly cov-
ered with loose pebbles and small boulders, derived principally from the
destruction of the conglomerate. But as we approached San Antonio the
soil became quite fertile and often clothed with luxuriant vegetation. Soil
and sub-soil calcareo-argillaceous.
Distance, 20 miles.
SAN ANTONIO DE BEXAR.
While the expedition was detained several days in San Antonio, I em-
ployed my time in the examination of the geological structure of the
country in that vicinity.
The Cretaceous System is here well developed, and consists for the most
part of nearly horizontal strata of light gray limestone; thin bedded, fine-
grained, and compact sandstone; and indurated marly clay. These beds
correspond in geological position and, with the exception of the limestone,
lithologically with the strata occurring between this place and Victoria,
which we have already described.
The limestone, which constitutes the upper part of the Cretaceous Sys-
tem around San Antonio, has been extensively worn away by denudation.
In some places it is very thin or entirely wanting; in others it forms grace-
fully rounded hills with gentle slopes; and at others again presents precip-
itously in bold and rugged escarpments. This last character is well exhib-
ited near a small creek, known as the Salado, eight miles northeast of the
city, where a range of gently sloping hills terminate abruptly to the south-
west in a long line of bold and nearly vertical cliffs, over a hundred feet in
height.
This rock varies considerably in character, and exhibits almost every de-
gree of hardness. When first taken from the quarry it is often quite soft,
white, or of a light gray color, and can hardly be distinguished from chalk;
but after exposure to the atmosphere it soon hardens to form a most useful
and durable building material, for which purpose it is largely employed in
San Antonio. When first quarried it is easily cut with a knife, or common
hand saw, into convenient sized blocks, which are exposed for a few days
to the weather, and are then fit for use. While in the city I was shown a
number of old buildings constructed of this material; one of them a church,
60
JOURNAL OF GEOLOGICAL OBSERVATIONS.
supposed to be a hundred and fifty years old, has suffered comparatively
little from decay, and is still used as a place of public worship. Near its
upper portion the rock is often filled with dark nodules of flint, sometimes
arranged in nearly parallel bands, varying from a few inches to a foot in
thickness, but more frequently they are scattered promiscuously through
the layers, and often so numerously as to form coarse conglomerate.
Many of the layers are highly fossiliferous; indeed, some of them are
almost wholly composed of Ostrea (Exogyra) læviuscula. The fossils are
usually in a good state of preservation and may be readily detached from
the matrix. The most common species are Ostrea læviuscula, Ostrea Pit-
cheri, Inoceramus Crispii, Cardium elegantulum, and Ammonites.
A second variety of limestone, somewhat extensively quarried about one
mile east of San Antonio, corresponds lithologically with the soft limestone
so frequently encountered on our route from Victoria, and although some-
what largely employed in the neighborhood as a building material, pos-
sesses but little durability and will yield readily to the weather. It is so
soft that it crumbles readily between the fingers, and resembles the softer
varieties of chalk.
Still another kind, occurring however much less abundantly than either
of the above, is a hard compact variety. It was only observed in detached
fragments, strewn over the surface. I was unable to find the beds from
which it was derived.
In one place a local deposit of soft porous limestone was observed,
which, from its containing impressions of the stems and leaves of cedar
trees and other existing plants, is evidently of very recent origin.
The following section will explain more fully the relative position, and as
far as could be ascertained the thickness of the different strata composing
the formation as observed in this vicinity:
No. 1. Flint nodules and rolled fragments of limestone. Thickness, 15 feet.
No. 2. Soft and hard white chalky limestone, containing flints and nu-
merous fossils. Thickness, 200 feet.
No. 3. Soft chalky limestone. Thickness, 25 feet.
No. 4. Indurated blue and yellow marly clay, with thin bands of sand-
stone interstratified, and a thin seam of selenite. Thickness, 150 feet.
The bed (No. 4) of this section has been artificially excavated to the depth
mentioned without reaching the base of the formation.
I have received from a gentleman residing in San Antonio specimens of
Exogyra costata and Inoceramus Crispii, which were procured from the clay
at the bottom of this well.
JOURNAL OF GEOLOGICAL OBSERVATIONS. 61
CHAPTER II.
FROM SAN ANTONIO DE BEXAR TO FORT CLARK.
April 16.-After leaving San Antonio, we traveled over a level and
highly fertile prairie, thickly strewn in places with coarse angular frag-
ments of white and grayish white limestone, often crowded with the same
fossils as found in the vicinity of San Antonio. At the distance of four
miles we encountered thick beds of indurated blue marly clay, which con-
tinued to be frequently exhibited until we arrived near Leon Creek, where
it disappeared beneath the limestone, and was not again met with during
the day. The suface now became undulating, more or less broken, and in
places thickly covered with coarse silicious nodules, many of them encrusted
with a white coating of carbonate of lime, which sometimes acted as a ce-
menting material to form them into a coarse conglomerate. When broken
they exhibited various shades of blue and brown, not unfrequently crossed by
parallel lines. They have been derived from the disintegration of the adja-
cent limestone, in which they were often found embedded in great numbers.
At the crossing of Leon Creek a good section is exposed of nearly hori
zontal layers of white pulverulent limestone, with nodules of flint, and
fine-grained greenish calcareo-silicious sandstone. The limestone is super-
imposed upon the sandstone, and is itself surmounted by about ten feet of
partially consolidated detritus of coarse angular and rounded fragments of
compact bluish-gray limestone, containing an abundance of water-worn
fossils of the following species: Exogyra costata, E. arietina, and Pecten
quadricostata. From the general appearance of the fossils they evidently
could not have been transported far.
Near this locality occurs a low exposure of soft light-gray earthy lime-
stone, containing fossils evidently of the Tertiary Era. This rock is only
visible at a few points, resting directly on the Cretaceous Limestone. The
larger part of the formation appears to have been removed by denudation.
The soil, during the day's march, was thick and very productive. Sub-
soil mostly calcareo-argillaceous.
Distance, 12 miles.
April 17-A half mile from our last camp we reached a gently sloping
prairie, thickly studded with small hillocks and ridges, varying from a few
inches to several feet in height. These are of frequent occurrence through-
out various portions of Texas and the adjacent Indian Territories, and are
everywhere known by the name of “ Hog Wallows." Wherever they occur
they impart to the face of the country a peculiar waved appearance, and are
generally supposed to indicate a rich soil.
62
JOURNAL OF GEOLOGICAL OBSERVATIONS.
As we progressed the surface became more rolling, and often thickly
coated with fragments of limestone of the same character as that met with
yesterday. This deposit is sometimes accumulated to the depth of ten or
twelve feet, and not unfrequently is loosely cemented with calcareous
matter. Two miles to the east of our road and about six miles from the
last camp, there occurs an extensive exposure of hard gray sub.crystalline
limestone and thin bedded quartzose sandstone, the whole presenting a dip.
E. S. E. of about 2 degrees. These rocks are hard and durable, and afford
excellent building materials, for which purpose they are already somewhat
extensively employed in the neighborhood.
After traveling eight miles the country became still more hilly and broken,
and at the same time the strata presented more or less evidence of local
disturbance, but did not differ lithologically or paleontologically from the
beds already noted. The pulverulent limestone still continues to be fre-
quently seen, often exhibiting a thickness of fifteen or twenty feet. About
ten o'clock we came to a small stream of clear water, along the margin of
which is an exposure of about ten feet of yellow and reddish silicious lime-
stone, containing rounded masses of flint, and compact gray limestone,
replete with organic remains, chiefly, however, Exogyra costata. In places
the rock is highly discolored with oxide of iron, and is undergoing rapid
disintegration. The general dip is about 2 degrees to the west.
Shortly after leaving the creek we entered an extensive and nearly flat
prairie, of but little geological interest. It extends to the Medina River,
which is about seventy-five feet wide, and flows over a bed of solid lime-
stone. The water is clear and strongly impregnated with carbonate of
lime. Its temperature was found to be 77 degrees F. On either side of
the stream are high bluffs, one of which exhibits a vertical section of thick-
bedded yellow, brown, and white limestone, with alternating bands of soft
blue shale, surmounted with, loose detritus derived from the destruction of
these beds. The whole cliff is replete with fossils, but owing to the soft-
ness of the rock they are very poorly preserved. The most abundant forms
are, Ostrea vesicularis, Pholadomya (allied to P. elegantula D'Orb.) and Tri-
gonia and Pecten of undetermined species. The accompanying section shows
the strata at this locality.
The soil, during the greater portion of the day's march, was a deep and
highly productive vegetable loam; sub-soil calcareo-argillaceous.
Distance, 16½ miles.
April 18.-Shortly after crossing Medina River we ascended by a gradual
slope to the base of an extensive range of limestone bluffs from one to two
hundred feet in height, which stretch irregularly across the country in a
northwesterly and southeasterly direction as far as vision extends. They
constitute the beginning of a series of abrupt ascents leading to the ele-
vated table land of the Llano Estacado. As well as I was able to determine,
JOURNAL OF GEOLOGICAL OBSERVATIONS.
63
they are composed of nearly horizontal layers of white and light grayish
limestone, with nodules of flint embedded. Reaching the summit of these,
we found ourselves upon a broad and gently sloping plain, over which we
traveled several hours. Its surface is often thickly strewn with rounded
masses of flint and angular fragments of limestone, the latter sometimes
passing into a hard light drab-colored variety, which, from its firm texture
and uniformity of composition, is well adapted for lithographic purposes.
It breaks with a smooth conchoidal fracture, and is susceptible of a good
polish.
After traveling ten miles we arrived at a range of hills with gentle
slopes and varying from two to three hundred feet in elevation. Their
general bearing is northeast. The cretaceous strata are here strongly up-
heaved, as well as fractured, dipping on either side of the line of strike at
angles varying from 40 to 50 degrees. The rock is of a light gray or
yellow color, hard, and sub-crystalline, and abounds in fossils; but as the
matrix is extremely hard, they are obtained with difficulty. I found here
undescribed fossils of the genera Arcu, Cardium, and Buccinum, also frag-
ments of a crustacean of the genus Callianassa, very similar to C. Danai,
recently described by Messrs. Hall and Meek.
Four miles beyond this place brought us to a small stream of clear water,
where the cretaceous strata were again well exposed in nearly horizontal
layers, containing fossils of the same character as those last mentioned.
Soil and sub-soil the same as seen yesterday.
Distance, 13 miles.
April 19.—Our march to-day was over an elevated and highly fertile flat
prairie, of but little geological interest. In the evening we encamped near
the valley of the Rio Seco, which is here about a half mile wide, and
bounded on the west by a range of high bluffs of nearly horizontal strata
of white chalk, with flints embedded, resting on blue marly clay, the whole
overlaid by about twenty feet of drift. The chalk presents a thickness of
about twenty-five feet, and, although less pure, resembles in chemical com-
position and external character the foreign commercial article. This will
doubtless prove of considerable economical importance. The embedded
flints are from one to six inches in diameter, and are scattered promiscuously
through the mass. They are more or less rounded, and in color vary from
light brown to deep blue and black. Fossil remains were detected in
several of them.
The underlying clay exhibits a thickness of over a hundred feet, and is
the same lithologically as that seen at San Antonio. Its upper portion is
banded with numerous thin seams of fine grained yellow and gray argilla-
ceous limestone, often foliated, and containing minute scales of mica.
These strata crumble readily on exposure to the weather. The dip is about
1 degree E. S. E.


DODO
Section of Strata on Medina River, April 17, 1855.
1. Detritus. 2. Cretaceous Limestone. 3. Blue Shale.
پرندژ
I.
Sub-soil.
2. Diluvium.
000
Section of Bluffs on Rio Seco, April 19, 1855.
་་ དའརཧ
アヘ
​13^
20 ft.
60 ft.
3. White Chalk with Flints. +. Marly Blue Clay with thin seams of Limestone Interstratified.
Geological Section on Rio Frio, April 21, 1855.
No. 1. Quaternary or Bluff Formation.
2. Drift.
3. Cretaceous Limestone. 4. Basalt.
L

JOURNAL OF GEOLOGICAL OBSERVATIONS.
65
The accompanying section, taken about one mile from our evening camp,
indicates more clearly the character and position of the strata composing
these bluffs.
Distance traveled, 15 miles.
April 20.-Shortly after crossing the Rio Seco we ascended the bluffs
above described. These were observed stretching somewhat irregularly
north and south for many miles. They constitute the second of the series
of terraces leading to the elevated plateau of the Llano Estacado.
The Rio Seco at the point of crossing is of moderate depth, and possesses
a wide, clayey bed. The water is clear and calcareous. Temperature 79
degrees F.
We next traveled for several hours over a gently sloping and very fertile
mezquite prairie, upon the surface of which the Cretaceous Limestone and
detritus were often exhibited. The detritus is in places firmly cemented with
calcareous paste, and appears more angular and coarser than that noticed
yesterday. Its thickress is from ten to forty feet, and it contains occasion-
ally fragments of soft yellow sandstone. We are evidently approaching
the source of this deposit.
At the distance of eight miles we came to a small creek, whose banks
exposed about ten feet of soft porous limestone, containing flints and an
abundance of organic remains, chiefly of the following species: Exogyra
arietina, Nucula (undt. sp.), Baculites asper, and Cassidulus aequoreus. The
two last are especially interesting, as they likewise characterize the Ferru-
ginous Sand Formation of the Cretaceous Group of Prairie Bluff, Alabama.
After crossing this stream the surface of the country becomes much
more hilly and broken, and in many places contains small springs and rivu-
lets of clear water. Indeed, in this respect we have as yet experienced no
deficiency whatever; for with a few exceptions the entire country between
this point and San Antonio is well watered by springs; and where these do
not occur, excellent water may almost always be obtained by means of wells,
which need seldom or ever be excavated to any great depth.
A travel of four miles farther brought us to the Rio Sabinal, a sluggish
stream, with a wide, gravelly bed. Here the Cretaceous Limestone, the
same as last mentioned, is again exposed in nearly vertical bluffs, in some
places over fifty feet high.
Soil mostly dark and highly productive; sub-soil calcareo-argillaceous.
Distance, 12 miles.
April 21.-Leaving the Rio Sabinal we traveled over a highly undulating
and rocky prairie, underlaid by the same rocks as noted yesterday. About
ten miles north of our road occurs a range of rugged conical hills, appa-
rently from two to three hundred feet high. These rise abruptly from a
basin-shaped depression in the prairie, and in general outline differ in a
66
JOURNAL OF GEOLOGICAL OBSERVATIONS.
marked manner from any hitherto encountered, from which I am led to the
belief that the rocks composing them belong to the eruptive class.
At the distance of ten miles we reached a series of abrupt rocky steps,
extending across the country in a direction nearly north and south, and
varying in height from twenty to one hundred feet. All of them are
composed of hard light-colored limestone of the Cretaceous Period.
Ascending these we traveled for several hours over a gently rolling plain,
covered in many places with dark rich soil. The formations here present.
evidence of disturbance, being inclined at high angles, but they have under-
gone little or no alteration in texture, and are crowded with fossils, chiefly
Inoceramus mytiloides and I. Crispii.
As we progressed the surface of the country became much more uneven,
and here and there divided by deep ravines, whose sides often exposed ver-
tical sections of limestone many feet in thickness.
Late in the day we arrived at the Rio Frio, a beautiful, clear stream,
about one hundred feet wide, with a rocky bed. Here projects abruptly
from the water's edge a long line of vertical cliffs, from a hundred to a
hundred and fifty feet in height, and exhibiting about midway the exposure.
an outburst of dark green basalt, with crystals of chrysolite disseminated
through it. On either side of the eruptive mass the sedimentary strata
are strongly upheaved, contorted, and metamorphosed, as exhibited in the
accompanying section.
The basalt near its base possesses an imperfect columnar structure, and
is intersected in various directions with veins of calcite. At the distance
of half a mile on either side of the eruptive rocks, the Cretaceous strata,
though much contorted and upheaved, have undergone but little metamor.
phic change. They contain Inoceramus mytiloides, Inoceramus Crispii, and an
undescribed species of Ammonite.
Fragments of silicified fossil wood occur in great abundance in the bed
of the Rio Frio. One of the specimens examined is about seven feet long
by eighteen inches in diameter, and from its size and perfect preservation,
the bark being nearly entire, it could not have been transported far. All
the specimens examined have the structure of dicotyledonous wood, and re-
semble closely some examples I collected near the head of Red River.
The water of the Rio Frio contains a good deal of calcareous matter;
temperature 70 degrees F.
Soil and sub-soil observed during the day the same as on yesterday.
Distance, 13 miles.
April 22.—Crossing the stream we ascended by several benches to an
elevated rolling prairie, with a dark rich carbonaceous soil, and exhibiting
frequent outcrops of white and light-gray Cretaceous Limestone. The
strata are frequently folded, fractured, and in some places highly metamor-
phosed.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
67
After traveling eight miles we arrived at Fort Inge, where occurs another
outburst of dark colored basalt, rising above the general surface to the
height of two hundred and fifty-five feet, from a sub-quadrangular base
about five hundred yards long and two hundred yards broad. On either
side the sedimentary strata are upheaved and highly metamorphosed. This
protrusion is of the same composition and in all other respects similar to
that examined yesterday. At the distance of about ten miles in a north-
westerly direction other hills are seen, which, from their dark color and
close general resemblance to the one last described, are undoubtedly of sim-
ilar composition.
From Fort Inge to the crossing of Nueces River, a distance of about
eight miles, our road was over continuous beds of white chalky limestone
and detritus, the former existing in nearly horizontal beds and containing
characteristic Cretaceous fossils. At several localities near our road this
formation was exposed in canyons and ravines to the height of more than
a hundred feet. It is identical in appearance with that observed in the
vicinity of San Antonio, and presents a slight general dip E. S. E.
The soil of this part of our day's journey was rich and supported a luxu-
riant growth of vegetation. Timber mostly mezquite and oak.
The river Nueces at the crossing is about one hundred yards wide, and
flows over a flat bed of hard gray limestone. The water, as usual, con-
tains a great deal of lime. In the bed of the stream I observed large frag-
ments of silicified fossil wood, the largest of which was four feet long,
twenty inches wide, and would weigh not less than five hundred pounds.
I was informed that near this point occurs a seam of bituminous coal,
but was not able to visit the locality or obtain specimens of it.
Distance, 15 miles.
April 23.-A short distance beyond the Nueces River we came to a suc-
cession of low abrupt benches, composed of limestone of the same character
as before noted, and on ascending these found ourselves upon a broad and
fertile prairie, whose surface was traversed by long parallel ridges, of vari-
able height, extending in a northeasterly and southwesterly direction.
These ridges were found to correspond with the flexures of the strata,
which are here strongly disturbed. The limestone is about double the
hardness of chalk, and contains flints and Cretaceous fossils.
In many
places the ground is thickly strewn with small angular fragments of red
and black iron ore.
As we progressed the Cretaceous formation was found to exhibit fre-
quent flexures, and finally assumed a decided metamorphosed character,
being converted into sub-crystalline gray and deep purple limestone, very
hard and compact in its texture. This area of disturbance extends about
ten miles east and west, but no eruptive rocks were observed during the
day.
68
JOURNAL OF GEOLOGICAL OBSERVATIONS.
At Turkey Creek unaltered Cretaceous strata are again well seen, dip-
ping gently E. S. E. Fossils chiefly of the following species are there
abundant: Ostrea vesicularis, Inoceramus Crispii, Janira Texana, Turrilites
(new sp.) and Ammonites (new sp.).
April 24.—During the earlier portion of our day's travel horizontal beds
of white and light grayish chalky limestone were of constant occurrence.
Eight miles from the last encampment the strata again presented evidence
of disturbance, and after traveling a short distance farther they were found
reposing at an angle of about sixty degrees on a mass of dark basalt, very
similar to that encountered upon the Rio Frio and at Fort Inge. This out-
burst is about a mile wide, and its bearing is northeast and southwest. At
its western edge the Cretaceous Limestone is again observed, inclined at an
angle of about sixty degrees in a direction opposite to that on the east, and
thence it continues to be seen at frequent intervals, often in undulated beds,
until we arrive at Fort Clark, where it is again nearly horizontal.
The surface of the country during the latter portion of the day's march
was somewhat broken. Small angular fragments of iron ore, the same as
noticed yesterday, were again observed frequently strewn over the ground.
Soil and sub-soil the same as before.
Distance, 16 miles.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
69
CHAPTER III.
FROM FORT CLARK TO THE LOWER EMIGRANT CROSSING OF THE RIO PECOS.
April 26.-Shortly after leaving Fort Clark I observed several miles
north of our road a number of conical hills, very rugged in their outlines,
and bearing a close resemblance to the hills of basalt before encountered.
They doubtless have the same geological structure.
During the day we continued to travel over white and grayish white
limestone in thick beds, occasionally more or less folded.
This rock agrees
lithologically as well as paleontologically with the building stone of San
Antonio, and is now employed in the construction of the government
buildings at Fort Clark, for which purpose its softness and the ease with
which it is wrought, together with its property of acquiring hardness on
exposure, renders it exceedingly valuable. In ravines at several points I
saw exposures of this rock from eighty to a hundred feet thick.
The surface of the country traversed to-day was gently rolling, and often
thickly covered with fragments of limestone, among which loose masses of
brown iron ore were frequently observed.
Soil dark, calcareous, and highly productive.
Distance, 9 miles.
April 27.—No change in the character of the strata was observed during
the first few miles of this day's travel. The general surface of the country
is flat, although frequently traversed by ravines, in which the Cretaceous
rocks are well exhibited. From some of these ravines specimens of Am-
monites vespertinus, Inoceramus Crispii, and other cretaceous fossils, were ob-
tained.
In about ten miles we again encountered heavy deposits of fragments of
Cretaceous Limestone, often firmly cemented with calcareous matter, and
agreeing in every respect with that encountered east of the Rio Frio. The
country at the same time was quite uneven, and intersected in every
direction by rocky canyons, from thirty to forty feet in depth, and which
have been excavated by running water.
About eleven o'clock we reached the Arroyo Pedro, a clear stream of
excellent water, with a broad, flat, rocky bed. Here is an exposure, up-
wards of a mile in length, of cream colored, compact, brittle, fine textured
limestone, breaking with a conchoidal and splintery fracture. Many of the
layers are susceptible of a good polish, and some present all the characters
of an excellent lithographic limestone. The beds exhibit a thickness of
about fifty feet, and their geological position is above the white chalky
limestone. No fossils were detected in any part of the mass.
70 JOURNAL OF GEOLOGICAL OBSERVATIONS.
Fragments of iron ore were again observed strewn over the surface at a
number of points to-day.
Soil and sub-soil the same as before.
Distance, 144 miles.
April 28.-For the first eight miles after leaving the Arroyo Pedro our
road led over a gently rolling mezquite prairie, with fragments of lime-
stone scattered over the surface, and possessing a dark, rich soil. Beyond
this the country became more hilly and broken, and often cut up by deep
canyons, with sides formed of precipitous walls of limestone. This lime-
stone is of various degrees of hardness, sometimes very compact, and
emitting a ringing sound when struck with the hammer, and at other times
so soft that it may be crushed readily between the fingers. The width of
the canyons varies from fifty to eighty feet.
About eight o'clock A. M. we attained an elevated part of the road,
whence we had an excellent view of the broad and fertile valley of the Rio
Grande, estimated to be about eight miles distant; and beyond this, say
twenty or thirty miles, a range of mountains was dimly visible.
After traveling for several hours over a hilly and rather broken country,
we reached a group of isolated, truncated, conical hills of limestone, three
hundred feet high, and beyond these encountered a succession of abrupt
terraces of Cretaceous Limestone, varying from one hundred to two hun-
dred and fifty feet in height. These form the eastern border of an elevated
table land that stretches irregularly for many miles in a northwesterly and
southerly direction. We here struck the San Pedro, or "Devil's River," a
broad stream of clear water, which winds its way through a deep and rug-
ged canyon.
This remarkable canyon is upwards of a hundred yards wide
at the entrance, and presents on either side nearly vertical walls of white,
gray, and yellow limestone, in nearly horizontal beds. The layers vary
greatly in compactness, some of them being soft like chalk, and others
extremely hard. This difference in the character of the beds causes them
to weather unequally, giving to the sides of the canyon a remarkably pic-
turesque appearance. As we advance the walls increase in altitude, and
at one mile from the entrance they rise to nearly four hundred feet above
the bed of the river. In some places large caverns, with arched ceilings,
have been scooped out of the rock, while in others isolated sharp pointed
columns are seen standing at various distances from the sides of the canyon.
On reaching, after some difficulty, the summit of the table land, we had
an extensive view of the adjacent country, which exhibits evidences of de-
nudation on a large scale. The surface is everywhere traversed by rocky
canyons, some of them many yards in width; here rude, conical, flat-topped
hills of limestone project abruptly to the height of two or three hundred
feet; there extend long ranges of lofty cliffs, or gently sloping ridges,
sometimes close together, at other times miles apart; while in the distance
JOURNAL OF GEOLOGICAL OBSERVATIONS.
71
long lines of bold and rugged escarpments mark the borders of a still more
elevated country than that upon which we were standing.
The thickness of the Cretaceous Limestone at our evening camp, as deter-
mined by observations with the barometer, is about six hundred feet.
The strata here are replete with characteristic Cretaceous fossils. They
are, however, confined chiefly to two rather broad bands, one situated near
the bed of the river, and the other toward the summit of the cliffs. In
the lower band we recognize the following forms: Exogyra arietina; Ja-
nira Texana; Janira quadricostata; Cardium Sancti-Saba; Ostrea vesicularis ;
Terebratula Wacoensis; Turrilites Brazoensis; and Turbo, Holectypus, Tocaster,
and plants of undetermined species.
In the upper band the fossils are quite distinct from those of the lower
band, and all of them appear to be of undescribed species. They belong
to the following genera: Conus, Nerinca, Pleurotomaria, Turritella, Lima,
and Cyprina.
The soil, during the latter portion of the day's march, was generally bar-
ren, and the surface of the country rocky.
Distance, 19 miles.
April 29.-Shortly after leaving camp we ascended from the canyon of
Devil's River to an elevated rocky district, over which we continued to
travel during the remainder of the day's march. The surface is here stud-
ded with ridges and abrupt conical hills, from two to four hundred feet
high, and often situated several miles apart. The geological formation
does not differ materially from that observed yesterday. The strata are
often crowded with fossils, the same as above enumerated, confined to dis-
tinct bands, which form but a very inconsiderable portion of the mass, the
intermediate beds being almost entirely destitute of organic remains. Our
road was in many places thickly strewn with small angular fragments of
dark oxide of iron, and at a single point I saw a thin seam of selenite.
The soil, for the first twelve miles, was barren, and composed mostly of
disintegrated limestone. Afterward it was dark, calcareo-argillaceous, and
moderately fertile.
Distance, 15 miles.
April 30.--For the first few miles we passed over a barren and slightly
undulating prairie, covered with coarse angular detritus, and studded with
ridges and small conical hills, similar to those encountered yesterday. We
then ascended by a gentle slope to a more elevated region, and shortly
afterward entered a deep valley, bounded on either side by rugged hills of
thin bedded limestone from four to five hundred feet high. The sides of
this valley were at first widely separated, but they converged rapidly as
we again approached the canyon of Devil's River, near which they were
only a couple of hundred yards apart.


GOOFE
+
Section of Cretaceous Limestone, April 28, 1855.
COSSFELI
EROUS
BAND
LOWER FOSSILIFEROUS BAND:
Section of Hills of Cretaceous Limestone, May 5, 1855.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
73
The canyon here was about five hundred feet deep and a hundred yards
wide. The rocks composing its sides have in general the same lithological
character as those near the entrance. There are, however, some differences
worthy of mention. Some of the layers are nearly pure white, and re-
semble chalk, and others near the top contain nodules of flint, with fossils
and hematite, the former sometimes so abundant as to constitute a very
large proportion of the beds.
The thickness of the Cretaceous strata, as determined by barometrical
observations and sections taken to-day, cannot fall far short of a thousand
feet. The fossils collected are identical with those obtained in the lower
band at the mouth of the canyon.
Devil's River, as seen to day, is an insignificant stream, having an aver-
age width of only about fifteen yards, and not exceeding two or three feet
in depth.
The soil, during the day's march, was of the most unproductive charac-
ter, consisting of little else than disintegrated limestone.
Distance, 20 miles.
May 1-During the entire day we continued to wind our way through
the canyon of Devil's River, which was found to vary in width from a few
hundred feet to three miles. Its floor is rough and uneven, but here and
there covered with rich soil, bearing a luxuriant growth of grass.
On
either side of our road nothing was to be seen but abrupt conical hills and
bare cliffs, which shoot upward to the height of five or six hundred feet,
and mark, by their flat summits, the level of the table land above. They are
everywhere composed of limestone of the same character as before noted,
except near their summits, where occurs a hard grayish band, crowded
with well preserved fossils, chiefly of the genus Arca.
The strata are frequently deeply excavated and fissured in such a manner
as to require but a short stretch of the imagination to convert them into
ruined temples and castles, or long lines of fortification. From the summit.
of the cliffs the eye encounters naught but a vast rolling surface, covered
with loose fragments of limestone and coarse bunch grass, and intersected
in various directions with deep and frightful rocky canyons, some of which
appeared to be even more extensive than the canyon of Devil's River.
Distance, 14 miles.
May 2.-Our way continues through the canyon of Devil's River. No
change in the character of the geological formation. Some of the beds con-
tain fossils in the greatest profusion. The most characteristic forms are
Janira Texana; Lima Wacoensis; Gryphaa Pitcheri; Cardium multistriatum ;
Globichoncha elevata; Scalaria vertebroides; and Scalaria, Natica, and Pleurolo-
maria of undetermined species. These fossils are chiefly confined to two
bands, one near the base, and the other toward the summit of the cliffs.
74
JOURNAL OF GEOLOGICAL OBSERVATIONS.
The intervening beds, about five hundred feet in thickness, are very mea-
gre in organic remains, and as far as my observations extend contain only
a single species of corel (Astrocania Guadalupe Roemer).
The part of the canyon through which we traveled to-day is from a half
to three miles in width. It is often intersected by lateral canyons, some of
them several hundred yards in length.
Soil and sub-soil the same as previously noted.
Distance, 73 miles.
May 5.-Near our last night's camp we saw a number of small shallow
lakes of fresh water, derived from springs in the vicinity. The soil near
these lakes is rich, and would produce well.
After winding for several hours amid rough hills and cliffs of Cretaceous
Limestone, we finally reached the head of the canyon, and from thence as-
cended by an easy slope to the high table land, over which we traveled
during the remainder of the day.
This table land, which corresponds in altitude to the summits of the
cliffs, is somewhat undulating, and its surface overspread with a thick
deposit of coarse angular fragments of light colored limestone. Here and
there it is studded with isolated, truncated, conical hills, from one hundred
and fifty to two hundred feet high, composed of nearly horizontal layers of
Cretaceous Limestone. These hills are often isolated, and many miles
apart, and serve as monuments to indicate the existence in former times of
an elevated plateau, which has been almost entirely removed by denuda-
tion.
The strata of these hills contain many fossils of the same kind as those
collected from the canyon of Devil's River.
Soil, for the first nine miles, calcareo-argillaceous, and moderately fertile,
but afterward barren.
Distance, 16½ miles.
May 6.-Shortly after leaving camp our road descended into a broad
uneven canyon, two hundred feet deep, bounded on either side by ranges of
rugged cliffs, and sharp conical hills, the former often fissured, and ap-
parently crumbling rapidly under the influence of the weather.
In places
the limestone is highly ferruginous, and contains small nodules of black
oxide of iron, and flints. The layers vary in color from dull white to dark
brown and black, and are of different degrees of hardness, sometimes be-
ing quite soft, earthy, and resembling chalk, and at other times hard, crys-
talline, and resonant under the hammer.
Fossils were again observed in great profusion to-day. Besides many of
the species last enumerated, I found Ammonites vespertinus, Panopaa Texana,
Monopleura Texana, and Ostrea carinata, of which the two first are quite
characteristic of the Cretaceous beds of Fort Washita.
JOURNAL OF GEOLOGICAL OBSERVATIONS. 75
Soil moderately fertile; sub-soil calcareo-argillaceous.
Distance, 12 miles.
May 8.-For the first six miles to-day we continued our way through the
canyon, the walls of which were often deeply fissured, and sometimes pre-
sented a remarkable castellated appearance. We then ascended by a
gradual slope to the upland, which we again found covered with coarse
angular fragments of limestone. The strata wherever observed still pre-
serves a slight inclination E. S. E.; but in general character do not differ
from what has already been described.
After traveling about three miles farther we entered another deep canyon,
through which we journeyed the remainder of the day. Its depth is from
three to four hundred feet, and on both sides are presented sharp conical
hills, and abrupt walls with deep fissures, and cleft by small lateral canyons.
The rocks are in many places highly fossiliferous, and afforded some inter-
esting specimens.
Late in the day we reached "Howard's Springs," a small stream of clear
water, formed by the union of a number of springs which gush from be-
neath the limestone. The water is highly calcareous, and its temperature
71 degrees F.
The soil, as observed during the day, is variable in character; in some
places deep, calcareo-argillaceous, and moderately fertile, and in others
barren, and composed almost entirely of disintegrated limestone.
Distance, 16 miles.
May 9.-Leaving Howard's Springs we continued to wind our way
through the canyon, which varied from a few hundred yards to several miles
in width, exhibiting an uneven floor, and in many places a moderately
fertile soil.
About eight miles from the springs we again reached the summit of the
table land, over which we traveled the remainder of the day.
As before, the surface of the table land or plateau is here covered with
coarse fragments of limestone, and is traversed by immense rocky canyons,
some of them many miles in length. This feature, together with the almost
entire absence of soil, imparts to the face of the country a remarkably
sterile and forbidding aspect.
Distance, 15 miles.
May 10.-After a travel of about seven miles we entered another canyon,
similar in all respects to the last. The strata of this canyon presents a slight
dip E. S. E., and assumes a variety of colors-white, gray, yellow, brown,
red, and black. In some places they are highly ferruginous, and contain
nodules of flint in great abundance; at several points thin seams of selenite
were observed traversing the limestone.
76 JOURNAL OF GEOLOGICAL OBSERVATIONS.
The principal fossils seen to-day are Arcopagia Texana, Gryphaa Pitcheri,
Janira quadricostata, Cardium multistriatum, Ammonites acuto-carinatus, and
Pterodonta (Eulima) subfusiformis.
Late in the day we came to Live Oak Creek, a beautiful stream of clear
water, flowing over a rough, rocky bed. The temperature of this stream
was found to be 70 degrees F.
The soil, during the greater portion of the day's march, was barren, being
composed principally of disintegrated limestone; but in the vicinity of
Live Oak Creek it is moderately fertile, and supports a sparse growth of
oak trees.
Distance, 11 miles.
May 11.-Beyond Live Oak Creek our route lay over a broken, rocky
region, characterized on all sides by rough hills and cliffs of thin-bedded
Cretaceous Limestone, some of which attain a height of more than five hun-
dred feet.
As we progressed through the canyon it widened rapidly, and finally
opened into the broad valley of the Rio Pecos, which here pursues a tor-
tuous course between rough hills and picturesque cliffs from four to six
hundred feet high.
The water of this stream is of a deep red color, and contains some
muriate of sodium. Its average width is about seventy-five feet. Tem-
perature 70 degrees F.
The valley possesses a red clayey soil, which appears to be moderately
fertile.
Near the bed of the river I observed a layer, a few feet thick, of coarse
breccia, made up of fragments of limestone, loosely cemented with a calca-
reo-ferruginous paste.
Distance, 74 miles.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
7777
CHAPTER IV.
FROM THE LOWER EMIGRANT CROSSING OF THE RIO PECOS TO THE MOUTH
OF DELAWARE CREEK.
May 12.-The greater portion of this day was spent in exploring the hills
and cliffs in the vicinity of our camp on the Rio Pecos. The thickness of
the Cretaceous Limestone here was estimated at not less than a thousand
feet. In its lithological character it varies considerably from that previ-
ously encountered, consisting for the most part of hard, compact rock, often
crystalline, and usually of a light bluish color. The greater portion of the
mass is almost entirely destitute of organic remains, but near the summit
of the highest hills I discovered a band of soft earthy limestone, of a
bright yellow color, highly charged with elegantly preserved fossils, which
have been determined by my brother, Dr. B. F. Shumard, to belong chiefly
to the following species: Ammonites acuto-carinatus (Shum.), Ceratites (Am-
monites) Pedernalis (Roem. sp.), Pterodonta subfusiformis (Shum.), Scalaria
vertebroides? (Mart. sp.), Natica (Globiconcha) tumida (Shum.), Arcopagia Tex-
ana (Roem.), Panopœa Texana (Shum.), Janira quadricostata (Sow. sp.), Exo-
gyra Texana (Roem.), Gryphaa Pitcheri (Mort.), Homomya alta (Roem.),
Curdium multistriatum (Shum.), Holectypus planatus? (Roem.), and Toxaster
Texanus (Roem.). In addition to these we found a number of species not
yet described.
Ev-
After leaving the Pecos crossing we wound our way amid rough hills
and cliffs of the same geological constitution as those just described.
erywhere we found a barren soil, composed almost entirely of pulverized
limestone.
Distance, 5 miles.
May 13.-During the entire day we traveled through the valley of the
Rio Pecos. For the first six miles the rocks do not differ in general ap-
pearance from those observed yesterday. Beyond this the hills assume a
more regular outline and the cliffs are less rugged in their aspect. The
former are generally smooth, of a conical form with truncated apices. At
first they are closely aggregated, but as we progress they become widely
separated by smooth and gently undulating prairie. Their height is from
five to eight hundred feet, and they present every indication of having once
formed a portion of the elevated table land, now several miles distant, and
from which they have been separated by denudation. The different strata
composing them are found to agree in every particular with those compo-
sing the table land. Near the summits of the highest of them the strata
are very prolific in well preserved organic remains. The following are the
78
JOURNAL OF GEOLOGICAL OBSERVATIONS.
prevailing forms: Ammonites vespertinus, Ammonites Marcyana, Pterodonta
subfusiformis, Terebratula Wacoensis, Janira Texana, Lima Wacoensis, Cardium
Sancti-Sabæ, Trigonia (undt.), Gryphoa Pitcheri, and Hemiaster elegans. With
these I also found examples of Gryphea which are not to be distinguished
from those figured by Mr. Marcon under the names of G. Marshii and G.
Tucumcarii.
Near the base of one of the hills I observed layers of soft, thin-bedded,
quartzose sandstone, about twenty feet in thickness. This rock is fine
grained, of a light yellow color, and is conformable with the limestone.
Thin seams of white gypsum and selenite were observed to occur at several
points.
The surface of the valley is for the most part thickly strewn with coarse
angular fragments of limestone, which are not unfrequently firmly cemented
into calcareous breccia. Near the base of some of the hills this breccia
often presents a thickness of twenty or thirty feet, and is of such extreme
hardness as to be broken only with great difficulty.
Soil and sub-soil highly calcareous and barren.
Distance, 13 miles.
May 14.-Continued our way through the valley of the Pecos, encounter-
ing the same character of hills and cliffs as seen yesterday. The hills are
often separated by wide intervals, and vary much in altitude, the highest of
them being from six to eight hundred feet above the level of the Pecos.
The cliffs are often deeply excavated, and at a distance present the appear-
ance of a succession of hills. From their summits the table land may be
seen stretching away for many miles, its surface everywhere broken and
divided by rude rocky canyons.
The Cretaceous Limestone as observed to-day was found to vary consider-
ably in texture at different points. In some places it was soft, earthy, and
of a light yellow color; in other places hard, compact, and more or less crys-
talline. Owing to their unequal hardness the different beds weather in such
a manner as to leave horizontal bands projecting sometimes several feet,
which in the distance give to the cliffs the semblance of lines of fortifications.
The yellow fossiliferous band, above mentioned, was again met with
during the day, but organic remains are much more sparingly distributed.
In a few places beds of coarse yellowish and reddish quartzose sandstone
were interstratified with the inferior layers of limestone in beds from ten
to thirty feet in thickness.
The Rio Pecos as observed during the day presented an average width
of about seventy-five feet, and flows over a hard rocky bed, with low bluff
banks of red loam on either side. The water is highly charged with red
sediment and impregnated with common salt.
Soil moderately fertile.
Distance, 11 miles.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
79
May 15.-In its general appearance and geological structure the region
of country traversed to-day differs but little from that of yesterday. In
places the strata were found to be more or less arenaceous, and every.
where appear to be undergoing rapid disintegration.
The width of the valley of the Rio Pecos is from five to ten miles, the
surface dotted over with truncated conical hills, occasionally grouped to-
gether in small clusters, but generally separated by intervals of five or six
miles. Usually they are much smaller than those encountered yesterday,
and everywhere present a strikingly uniform character.
The surface of the country still continues to be often thickly covered
with coarse angular fragments of fossiliferous Cretaceous Limestone, occa-
sionally cemented with great firmness by calcareous matter.
Soil thin and moderately fertile. Sub-soil calcareo-argillaceous.
Distance, 9 miles.
May 16. Still continue to travel through the valley of the Pecos, which
is observed to increase gradually in width, but otherwise does not differ
from the portion traveled through yesterday. Geological formation the
same as before. The line of cliffs on either side of the valley exhibits an
altitude of from six to eight hundred feet, and presents a less rugged out-
line than those seen yesterday. Fossils are abundant, but, as before, con-
fined chiefly to two principal bands, one near the summit and the other
near the base of the cliffs. With many of the species above enumerated,
I collected examples of Trigonia crenulata, Lima Wacoensis, and Janira
Texana.
The course of this part of the Rio Pecos is remarkably tortuous, and its
average width about eighty feet. The banks are low and composed of red
clay. Small lakes of clear water were met with at a number of points,
which upon being tested proved to be strongly impregnated with salt, and
the surface of the ground in their immediate vicinity is often whitened
with saline efflorescences.
At our evening camp the valley of the Pecos presented a width of
nearly twenty miles. Its surface is rough and broken, but sustains a good soil.
Distance, 16 miles.
May 17.-Continued our course through the valley of the Rio Pecos,
which is still characterized on either side by abrupt cliffs, but they are now
often widely separated, and do not anywhere exceed four or five hundred
feet in height. In places they are deeply fissured, and sometimes large de-
tached portions of the table land are to be seen standing out several miles
from the parent mass.
The strata present a slight but uniform dip to the E. S. E., and every-
where appear to be rapidly yielding to the influence of the weather. In
•
800 ft.
Section of Hills of Cretaceous Limestone. May 13, 1855.
810 ft.
Table La
Subli Lanil


Section of Strata, May 17.
WERFOSE SILVAFE-ROU
ད.༤ད ༽ - ༽
ご
​1-1-4
I. Cretaceous Limestone.
2.
BAN
Red and Blue Marly Clay, with Fossils.
Section of Strata, May 21.
12.
ایران
چه ایران
I. Cretaceous Limestone.
~༔
~༔ -དཀ?
2.
Marly Clay with Seams of Sandstone interstratified. 3. Diluvium.
سے آئے

JOURNAL OF GEOLOGICAL OBSERVATIONS.
81
the lower fossiliferous band I collected the following fossils: Ammonites
vespertinus, Scalaria vertebroides?, Turritella sp. ?, Gryphaa Pilcheri, Ostrea
crenulimargo, Janira Texana, Lima Wacoensis, Trigonia crenulata?, Terebratula
Wacoensis, and Pygaster, Fusus, Opis, and Cardium of undescribed species.
Toward the latter portion of the day we found nearly horizontal layers
of red and blue indurated marly clay beneath the limestone. This clay
agrees lithologically in all respects, save in color, with that observed in the
vicinity of San Antonio, and is in several places crowded with an angulated
variety of Gryphia Pitcheri.
The valley as observed during the day varies from twenty to twenty five
miles in width, and the surface is in many places rough and broken.
Soil marly and fertile; sub-soil calcareo-argillaceous, in a few places are-
naceous.
Distance, 15 miles.
May 18.—After traveling a few miles from our camp of last evening, the
valley through which we have been passing for so many days widens rap-
idly, and soon terminates in a broad, open, and gently undulating plain.
Here the Cretaceous Limestone, while still preserving a nearly horizontal
position, terminates abruptly to the west and northwest in bold, rugged
precipices, from four to six hundred feet in height.* These are to be
traced, stretching somewhat irregularly north and southwest, as far as vision
extends, marking the edges of the table land and serving to indicate the great
extent to which the strata of this region have been removed by denudation.
The surface now assumes a deep red color, and is everywhere marked by
small hills and ridges of indurated red marly clay, which are for the most
part gently rounded and from ton to forty feet high. The summits of the
highest of them are thinly capped with nearly horizontal layers of Creta-
ceous Limestone, generally soft, of light grayish and yellowish colors, and
with imperfect fossils of the same character as those of the cliffs.
The Rio Pecos as observed during the day has a width varying from
sixty to eighty feet, and still continues to flow between low bluff banks of
red clay. The water is highly charged with deep red sediment, and still
contains a small percentage of saline matter. On either side of the stream
there extends a chain of small, shallow, saline lakes, and the adjacent
ground is often covered with an efflorescence of chloride of sodium, usually
about a fourth of an inch in thickness.
Soil moderately fertile; sub-soil calcareo-argillaceous, occasionally aren-
aceous.
Distance, 16 miles.
*These cliffs are laid down on some of the maps as the "Castlo Mountains." It is hardly
necossary to stato that no mountains occur in this portion of Texas, the so-called Castle
Mountains being nothing more than the abrupt borders of the Table Land.
82
JOURNAL OF GEOLOGICAL OBSERVATIONS.
May 19.-Our way still leads over rolling and gently ascending prairie,
its surface often whitened with saline efflorescences, and presenting here and
there small patches of Cretaceous Limestone and detritus. The former is
usually soft, white or of a light grayish color, and resembles very closely
the pulverulent limestone observed in the vicinity of San Antonio. From
the harder varieties a few imperfect characteristic cretaceous fossils were
obtained. The prevailing formation consists for the most part of indurated
red and blue marly clay, with intercalations of soft yellow and pinkish
fine grained quartzose sandstone. The sandstone does not anywhere exceed
two or three feet in thickness. It is usually thinly laminated, and traverses
the clay in nearly horizontal bands. During the day sections of sixty or
eighty feet of these strata were exposed, and near the base of one of them
the sandstone was found to contain small rounded pebbles of eruptive rocks.
The Pecos still pursues a tortuous course, and lakes of highly saline water
abound in its vicinity. The ground is also frequently coated with white
saline efflorescences. Soil marly, in some places arenaceous; sub-soil cal-
careo-argillaceous and argillo-arenaceous.
Distance, 16 miles.
May 20.-In general appearance and structure the country traversed to-
day differs but slightly from that of yesterday. As we advance the soft
pulverulent limestone is better developed, and presents often a thickness of
ten or fifteen feet. Its stratigraphical position is immediately over the
marly clay.
At the distance of twelve miles we arrived at the rapids of the Pecos.
Here the water descends impetuously for a distance of about twenty feet
over coarse quartzose sandstone and conglomerate. The total amount of
fall is about ten feet. On either side are high bluff banks of red marly
clay, coarse quartzose sandstone, and pulverulent limestone, in nearly hori-
zontal strata. The sandstone is soft, friable, and of red and gray colors.
Near the base it passes into a conglomerate of well rounded pebbles of
quartz, red porphyry, granite, and other varieties of eruptive rocks.
Soil and sub-soil the same as before.
Distance, 21½ miles.
May 21.-General formation the same as before. After a travel of
three miles, over a nearly flat and moderately fertile district, we arrived
at a range of low hills, composed of red and blue clay, sandstone, and con-
glomerate, surmounted by about ten feet of hard grayish limestone, the
latter containing a few imperfect fossils, of which the most common species
is Janira quadricostata. Dip 2 degrees E. S. E. These hills constitute the
remains of a once continuous plain, the borders of which, by denuding
agencies, have been made to recede, gradually, many miles to the east,
JOURNAL OF GEOLOGICAL OBSERVATIONS.
83
where, as we have already seen, they are abruptly defined by lofty and
nearly vertical precipices.
As we progressed the surface became much more uneven, and sometimes
covered with coarse drift deposits, consisting of quartz, jasper, chalcedony,
and granite, often loosely cemented with calcareo-ferruginous paste, and
with an average thickness of about three feet.
The red clay formation was seen in several places exposed to the height
of nearly a hundred feet. South of our road, and at a distance of perhaps
sixty miles, are seen the bold rugged chain of the Limpea Mountains,
whose lofty peaks and sharp outline denote, even at this distance, their ig-
neous character.
During our day's travel the pulverulent limestone frequently presented
itself on the surface, but nowhere exceeded five or six feet in thickness.
The accompanying section, taken from a deep depression in the prairie,
shows the character of the strata observed during the day.
Soil and sub-soil calcareous and calcareo-argillaceous.
Distance, 12 miles.
May 22. For the first few miles after leaving camp we traveled over
nearly flat prairie, underlaid by indurated red and blue marly clay, elevated
but a few feet above the bed of the Pecos River; surface of the country
for the most part barren, and frequently whitened with saline efflorescences.
About two miles north of our road, on the opposite side of the river,
extends a range of clay bluffs, of a deep red color, containing small shining
particles of selenite, and between these and the river are a number of
small lakes of salt water. As we advance the surface becomes more or less
undulating, and occasionally thickly strewn with coarse transported materi-
als, composed almost entirely of rounded masses of hard light gray and white
crystalline limestone, differing lithologically from any hitherto met with.
These rocks contain fossils which may be unhesitatingly referred to the
Paleozoic Period, and to the upper division of the Carboniferous System.
Among other examples collected were Productus splendens (Norw. & Prat.),
P. semireticulatus (Mart.), Fusulina (sp. ?), Chonetes Smithi (Norw. & Prat.),
Spirifer plano-convexa (B. F. Shum.), S. lineatus (Martin), Rhynchonella several
undescribed species, and numerous stems of Encrinites.
These materials are often firmly cemented with calcareous matter, and
their thickness is upwards of twenty feet.
At the distance of six miles we came to a small elevation in the prairie,
on the summit of which occurs a thin layer of hard grayish Cretaceous
Limestone, from which I obtained a few imperfect specimens of Ostrea.
This rock agrees lithologically, as well as paleontologically, with that of the
cliffs to the east. It continued to appear at intervals during the remainder
of our day's march, but was only observed near the summits of the highest
hills, and nowhere exceeded two or three feet in thickness.
84
JOURNAL OF GEOLOGICAL OBSERVATIONS.
Soft pulverulent limestone and sandstone were also again frequently
met with during the day. In some places the limestone exhibited a thick-
ness of fifteen or twenty feet. Its position seems to be directly beneath.
the hard limestone.
In several localities sections of eighty or a hundred feet of red and
blue marly clay were exposed, with bands of finely laminated quartzose
sandstone interstratified, and occasionally the upper beds were parted by
thin seams of white saccharoid gypsum.
Late in the day we arrived at a small stream of clear water, highly
charged with muriate of sodium. In its immediate vicinity the land is.
boggy, and occasionally thickly coated with salt, and emits an odor of sul-
phuretted hydrogen.
Salt lakes were also observed at frequent intervals along the Pecos
River.
The accompanying section exhibits the character and relative position of
the strata as observed to-day.
Distance, 151 miles.
May 23.-Alternating beds of red and blue marly clay, with intercala-
tions of soft silicious sandstone, continued to be largely exhibited during
the entire day's march, sometimes presenting sections of more than a hun-
dred feet. Occasionally horizontal bands of white gypsum and selenite
occur towards the upper part of the sections. The former is of various
degrees of hardness, and in places passes almost insensibly into soft pul-
verulent limestone, which latter appears to be altogether confined to the
surface, and nowhere exceeds two or three feet in thickness.
At ten miles we reached a range of low hills and ridges of hard Qua-
ternary conglomerate, which prevailed the remainder of the distance to
camp. This conglomerate is from thirty to forty feet thick, and consists,
as on yesterday, of coarse rounded masses of hard crystalline limestone,
firmly cemented with calcareous matter. Near the base of the deposit are
several seams, from one to three feet thick, of coarse yellow sandstone,
with metamorphic pebbles disseminated through it. Many of the limestone
masses are almost entirely composed of organic remains belonging to the
upper division of the Carboniferous System. The examples collected were
mostly of the same species as those of yesterday.
Soil and sub-soil calcareo-argillaceous, in some places arenaceous.
Distance, 17 miles.
May 24.-Red and blue clay, with alternating bands of sandstone and
gypsum, surmounted with conglomerate, were everywhere visible on our
route to-day. The clay formation occasionally presents sections of more
than two hundred feet. The conglomerate forms hills and ridges, with
gentle ascents, from fifty to sixty feet high. The materials of which it is

Section of Strata on Rio Pecos, May 22, 1855.
=121-1
1. Drift and Quaternary Conglomerate.
4. Marly Clay.
2. Hard and Soft Limestone.
5. Quartzose Sandstone.
3. Saccharoid Gypsum.
86
JOURNAL OF GEOLOGICAL OBSERVATIONS.
composed are somewhat coarser and more angular than those before no-
ticed. The surface in many places still appears whitened with saline
efflorescences, and on either side of the river small salt lakes are of fre-
quent occurrence.
About eleven o'clock we reached a succession of hills and bluffs, from
forty to sixty feet high, composed almost entirely of greenish gray and
white gypsum and selenite. The greenish gray variety greatly predomi-
nates over the white and crystalline varieties, and differs somewhat in
character from any previously encountered. It is hard, fissile, possesses a
shining silken lustre, and contains a large admixture of sand. Between the
different layers occurs a yellow calcareous earth, doubtless derived from
the disintegration of the white pulverulent limestone, seams of which occur
with the gypsum.
The entire thickness of the gypsum deposit in this
vicinity I estimate at about sixty feet.
Soil and sub-soil calcareo-argillaceous, in some places arenaceous, and
in others it contains a large quantity of gypsum.
Distance, 14 miles.
May 25.-After leaving the gypsum bluffs we traveled over smooth and
gently undulating prairie, often whitened with gypsum and soft powdery
limestone. At the distance of six miles from the last encampment we
again came to heavy beds of conglomerate, composed, as before, chiefly of
limestone, and with an average thickness of about forty feet. In general
it is much coarser than any previously observed, and contains blocks from
eight to ten inches in diameter. Fossils of the same character as before
noted were again detected in it in great numbers. This rock prevailed
largely during the remainder of our day's march, everywhere imparting a
rough and broken aspect to the country.
Along the Rio Pecos vertical sections of clay and sandstone were fre-
quently exposed. The former has now assumed a uniform red color, and
contains a great deal of gypsum, while the sandstone becoming much
thicker and coarser. The dip is uniformly about 2 degrees E. S. E. These
rocks constitute the bed of the river, which, owing to their unequal hard-
ness, is often disturbed by rapids, while the clay mingling with the water
imparts to it its characteristic deep red color and a slightly gypseous but
not very disagreeable taste.
About twelve o'clock we arrived at a range of high bluffs of red clay
and gypsum, overlaid by about forty or forty-five feet of conglomerate, and
at the foot of them meanders a small creek of clear strongly saline water.
The soil here is also covered with salt, and emits an odor of sulphuretted
hydrogen gas.
Soil and sub-soil for the first eight miles calcareo-argillaceous; afterward
arenaceous.
Distance, 11 miles.
JOURNAL OF GEOLOGICAL OBSERVATIONS. 87
May 26.-During the greater portion of this day's march our road was
over a succession of gently rounded hills and ridges, from fifty to one
hundred feet high, composed almost entirely of conglomerate. The thick-
ness of this deposit increases rapidly as we advance, and the materials com-
posing it are continually growing coarser. Some of the masses are over a
foot in diameter, and, as before, consist almost entirely of fragments of
hard white and gray crystalline limestone. Fossils of the same character
as before were collected from it.
The red clay, soft earthy limestone, gypsum, and sandstone were also
largely developed along our route to-day-but they were best exposed
along the river, presenting there vertical sections often fifty or sixty feet
thick. The sandstone is usually soft, deep red or purple, and often marked
with small circular spots of light green and yellow.
A few miles before we reached our permanent camp near the mouth of
Delaware Creek, we again struck hard Cretaceous Limestone, which in-
creased rapidly in thickness and continued to show itself at short intervals
during the remainder of our day's journey.
Soil and sub-soil sandy, calcareous, and calcareo-argillaceous.
Distance, 12 miles.
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
CHAPTER V.
FROM THE MOUTH OF DELAWARE CREEK TO THE FOOT OF THE GUADALUPE PASS.
As the Expedition remained for several months encamped near the mouth.
of Delaware Creek, a favorable opportunity was afforded for examining
minutely the geological structure of that vicinity and the Llano Estacado.
The latter is to be seen from our camp, stretching for an indefinite distance
eastward, in the forin of an elevated and gently undulating plateau, thinly
covered with short grass, and presenting generally but little variety of sur-
face. It is abruptly terminated on the west by the Pecos River, which
flows in a tortuous course, with an average width of about eighty feet,
amid low hills and bluffs of conglomerate and limestone. Beyond the
Pecos the country assumes a more broken and hilly appearance, and at the
distance of sixty miles rise the lofty summits of the Guadalupe Mountains,
of which the highest points had been observed long before we arrived at
the mouth of Delaware Creek.
All the rocks of this vicinity, save the limestone noticed on our last
day's journey, were found to differ somewhat in general character from
those already described. The limestone here attains a thickness of over a
hundred feet, exhibiting itself chiefly in the form of flattened conical hills.
and rough cliffs, sometimes with vertical faces, and in places rising above
the creek or river bed to the height of fifty or sixty feet. The rock is
usually hard, of a light cream color, earthy texture, and contains numerous
spheroidal cavities, from a fourth to a half an inch in diameter, which are
sometimes partially filled with loose ferruginous earth. In one locality the
exposed edges of the strata were covered with an incrustation of salt a
fourth of an inch thick. This limestone forms the bed of the Pecos River,
and here gives rise to a succession of rapids. Fourteen miles to the east the
same limestone becomes much softer, lighter colored, and resembles impure
chalk, but does not there exceed in thickness thirteen or fourteen feet. Fossils
are exceedingly rare in it. In a few instances I obtained imperfect speci-
mens of Exogyra [?] Pitcheri and Janira quadricostata. Underneath the lime-
stone we have the gypsum, clay, and sandstone, which are often well exposed
in this vicinity. The gypsum is frequently found in connexion with white
soft carbonate of lime, and presents an average thickness of about twenty-
five feet. From the Artesian Wells, situated one fourteen and the other
eight miles east of the Rio Pecos, vertical sections of the clay and sand-
stone were obtained to the depth of eight hundred and fifty-eight feet.
The clay is usually highly indurated, and contains more or less of an ad-
mixture of lime. In color it varies from nearly white to blue, brown, and
vermilion. The intercalated layers of sandstone are generally softer than
OF
ICH
GEOLOGICAL SECTION WEST BANK OF RIO PECOS NEAR THE MOUTH OF DELAWARE CREEK.

2
I. Cretaceous Limestone.
2. Gypsum.
3. Alluvium.
4. Quaternary Conglomerate.
GEOLOGICAL SECTION EAST BANK OF RIO PECOS TEN MILES E. S. E. OF THE MOUTH OF DELAWARE CREEK.


1.
Alluvium.
2. Quaternary Conglomerate.
3. Marley Clay and Sandstone.
4. Cretaceous Limestone.
5. White Gypsum.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
89
those previously encountered, and constitute by far the greater portion of the
exposed thickness of the formation. The superior beds are often little else
than loosely coherent sand; but at the base of the sections the strata are
much firmer, of a light yellow color, and contain small rounded pebbles of
eruptive rocks.
Besides the strata above described, the superincumbent Quaternary con-
glomerate is also largely developed. Near the junction of the Pecos and
Delaware Creek this formation attains a thickness of near seventy feet, and
appears mostly in the form of gently rounded hills and ridges, some of
which terminate abruptly towards the river. With the exception of being
somewhat coarser, and occasionally traversed by irregular bands of coarse
yellow silicious sandstone, the materials composing it do not differ from
those of the same formation last described. Many of the included masses
are rich in organic remains, and present a considerable variety of species
characteristic of the Carboniferous System, as follows: Productus semi-
reticulatus, P. splendens?, Chonetes Smithi, Camarophoria Schlotheimi?, and
Fusulina.
Commingled with these I found a few imperfect Cretaceous species in
angular fragments of soft yellow limestone, as follows: Arcopagia Texana
Janira quadricostata, Cardium multistriatum, and Gryphaea Pitcheri. From
the general appearance of these fossils they evidently could not have been.
transported far.
Directly south of Delaware Creek the strata are strongly folded and
inclined in different directions at angles varying from twenty to fifty
degrees. The period of disturbance appears to have been anterior to the
deposition of the conglomerate, since the latter is found reposing uncon-
formably in nearly horizontal beds on the ruptured edges of the older
strata.
Section is from a nearly vertical exposure extending along the west
bank of the Rio Pecos from near the mouth of Delaware Creek S. S. E.
for the distance of about a half a mile. Here the limestone is found dip-
ping in opposite directions at angles varying from 20 to 30 degrees, the
upper beds having been ruptured and widely separated, and the entire mass
traversed from top to bottom by fissures ten or twenty feet wide, filled,
chiefly, with small angular fragments of limestone, firmly cemented with
calcareous matter. In one place, near the base of the section, the gypsum
is exposed to the thickness of fifteen feet. It is for the most part white,
amorphous, and resembles more or less loaf sugar.
Section No. was taken from near the east bank of the Rio Pecos, sev-
eral miles below the last. It exhibits a still greater amount of disturbance,
the underlaying clay and sandstone being here well exposed, dipping in dif-
ferent directions at angles of from forty-five degrees to fifty degrees, and
at the same time the ruptured edges of the limestone appear somewhat
altered in texture, being harder, and sometimes fractured into small angular
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
fragments, firmly recemented, so as to give the rock a fragmentary or brec-
ciated appearance. The sandstone is also harder, of dark red and purple
colors, and thickly besprinkled with small green and yellow spots.
The extent of this region of disturbance could not be accurately deter-
mined on account of the leveling effects of the subsequent denudation and
the thickness of the superincumbent deposits of more recent date; but from
the fact that the limestone is observed twelve or fifteen miles both east and
west of the Pecos River, in nearly horizontal strata, and appears merely in
gentle undulations at our second camp a few miles south of the point
where the last mentioned section was seen, it is highly probable that it
does not in any direction exceed fifteen or twenty miles.
On the morning of the 23d of September we started from our camp near
the mouth of Delaware Creek, still pursuing a westward course.
For the first few miles our road wound amid gently rounded hills and
ridges of Quaternary conglomerate or limestone breccia, from thirty to a
hundred feet high, with occasional exposures of Cretaceous Limestone ten
or fifteen feet in thickness. Soil and subsoil calcareo-silicious. As we
proceed the conglomerate gradually thins out, and finally appears only at
intervals, while the limestone is much more largely developed, and forms
short ridges and truncated conical hills, sometimes five or six hundred feet
in height. Occasionally these were isolated and widely separated from each
other, and sometimes grouped together in clusters of eight or ten. In gen-
eral outline and composition they very closely resemble the hills and ridges
previously encountered farther east, thus indicating pretty clearly that they
constitute the remains of a once continuous table land, of whose former ex-
istence and subsequent removal by denudation they are the monuments.
The dip of the strata is pretty uniformly about one degree E. S. E. Near
the summits of some of the highest elevations, hard projecting bands of
brown and light gray limestone occur, but, unlike those forming the sum-
mits of the hills and cliffs farther east, they are exceedingly barren of fossils,
and have yielded after a careful search but a single imperfect specimen of
Mytilus. In conformable beds beneath the limestone we find the red marly
clay, sandstone, and gypsum, exhibited in nearly vertical sections, sixty or
seventy feet in height. The gypsum is in places deeply discolored with
oxide of iron.
The surface of the country during the greater portion of the day's march
was found covered with powdered gypsum and white carbonate of lime,
sometimes ten feet in thickness. Along the valley of Delaware Creek the
soil is moderately fertile, and composed of sand, clay, and lime in variable
proportions. The water of this stream is clear, and possesses a strong taste
of gypsum. Temperature, 71 degrees F.
Distance, 9 miles,
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91
Sept. 24.-For the first few hours our road was over thick beds of marly
clay, gypsum, and limestone The clay varies in color from bright vermil-
ion to deep blue. The gypsum in places presents a thickness of about sixty
feet, and assumes every degree of compactness from the soft pulverulent
variety noticed yesterday to compact bluish-white alabaster. The softer
varieties often pass upwards, insensibly, into soft white carbonate of lime,
sometimes fifteen or twenty feet thick. This is undoubtedly due to the dis-
integration of the gray limestone, which, wherever seen, is found gradually
yielding to the influence of the weather.
As we continue to advance the compact limestone rapidly diminishes in
thickness, and in a distance of six miles disappears entirely, and is replaced
by thick beds of Quaternary conglomerate, or rather breccia, much coarser
than any previously encountered and abounding in a great variety of fossils.
We are evidently approaching the source of this deposit, since the fragments.
are not only larger and more angular, but the formation is increasing rapidly
in thickness. In some places its thickness was estimated at from four to
five hundred feet.
Soil, in some places moderately fertile, in others barren, and composed
principally of soft carbonate of lime and gypsum.
Distance, 15 miles.
Sept. 25.-For the first few miles red and blue clay, gypsum, and pulveru-
lent carbonate of lime were largely exhibited along our route; they then
suddenly disappeared and were not again met with during the remainder of
the day's journey.
At the point where they abruptly terminate strata of the Carboniferous
System show themselves in low hills and ridges. They consist of yellow
quartzose sandstone, surmounted by black, gray, and white limestone, as ex
hibited in the following section:
1. Heavy bedded compact white and light gray limestone.
2. Black thinly laminated limestone.
100 feet.
3.
Dark gray thin bedded crystalline limestone.
50 feet.
4. Yellow quartzose sandstone, with thin seams of black compact limestone
interstratified at its upper portion.
These rocks are unconformable with the Cretaceous strata, though the
dip is still E. S. E.
Owing to the great thickness of the Quaternary deposits the upper white
limestone is not well exposed just at this point, but at other places not far
distant it presents a thickness of several hundred feet. It is usually a
hard crystalline limestone, abounding in fossils identical with those so fre-
quently observed in the conglomerate.
The organic remains of this limestone so far as they have been described
92 JOURNAL OF GEOLOGICAL OBSERVATIONS.
are as follows: Productus semireticulatus (Martin), Productus splendens (Nor-
wood and Pratten), Chonetes Smithi (Norwood & Prat.), and Spirifer plano-
convexa (B. F. Shumard). These species are regarded by geologists of the
Western and Southwestern States as being characteristic of the upper divi-
sion of the Carboniferous System, or Coal Measures.
From the dark gray limestone (No. 3 of the section) the following unde-
scribed fossils were obtained, which, as far as my observations extend, are
peculiar to this portion of the formation: Rhynchonella, Straparollus (two
species), and Phillipsia.
No fossils were observed in the underlying sandstone. This rock is fine
grained, more or less micaceous, and of moderate hardness. Although
sometimes exposed in heavy massive strata, it is for the most part thin
bedded and occasionally finely laminated. It contains near its upper por-
tion bands of dark compact limestone from a few inches to two feet thick.
Denudation.—As we proceeded on our way the country everywhere ex-
hibited the strongest evidence of denudation, being deeply excavated, and
often appearing in detached hills, usually of a conical form, and sometimes
separated from each other by intervals of several hundred yards. The
limestone is now only occasionally observed capping the summits of the
highest elevations, and nowhere presents a thickness of more than one or
two hundred feet. Immediately south of our route the country is much
cut up by deep valleys and rocky ravines; to the north the surface, although
less broken, is nevertheless rough and thickly strewn with coarse angular
fragments of limestone.
By following the windings of the different valleys our road was for the
most part a smooth and gentle ascent, the rate corresponding pretty nearly
with the dip of the strata, thus affording a firm foundation and other con-
ditions highly favorable for the construction of a railroad. The Quaternary
breccia still prevails along our route, with an average thickness of over two
hundred feet, and contains angular blocks of limestone sometimes several
feet in diameter.
Head of Delaware Creek.-About ten o'clock we arrived at the sources of
Delaware Creek. This stream rises in a broad and fertile valley, and is formed
by the united waters of several springs that issue from the base of the con-
glomerate and the upper portion of the sandstone, which constitutes the
floor of the valley. These springs are contiguous to each other, but vary
remarkably in character. When they issue from the conglomerate the
water is clear, slightly calcareous, and possesses an agreeable taste; but
when they flow from the sandstone they are highly impregnated with vari-
ous saline ingredients, have a disagreeable taste, and emit a strong odor of
sulphuretted hydrogen.
The Valley of Delaware Creek at this point is about two hundred and
fifty feet deep, and its width is from a few hundred yards to several miles.
It appears to have been hollowed out of the solid strata by denudation. On
JOURNAL OF GEOLOGICAL OBSERVATIONS.
93
either side are abrupt escarpments and hills of massive and thin bedded
sandstone, surmounted by heavy and finely laminated strata of limestone,
as exhibited in the following section, taken a few hundred yards from our
evening's camp:
1. Heavy bedded gray and white limestone.
2. Finely laminated black limestone.
50 feet.
110 feet.
3. Heavy and thin bedded yellow quartzose sandstone, with thin seams of
dark compact limestone interstratified. 100 feet.
The floor of the valley is generally smooth, but here and there marked
with ridges and abrupt conical hills of sandstone and limestone from one
to two hundred feet high.
Soil calcareous and calcareo-argillaceous, in some places silicious.
Distance, 8 miles.
Sept. 26. During the day we gradually approached by a gentle ascent
the eastern base of the Guadalupe Mountains. Our road, although marked
on both sides with hills and deep valleys, is still smooth, and from the
gentle and uniform dip of the strata capable of affording everywhere a
firm and easy grade for a railroad.
The hills are for the most part gracefully rounded and from one to four
hundred feet high. The valleys to the south are apparently much deeper
than those met with yesterday. The strata seen to-day do not differ in
character from those last described. In places the sandstone is exposed by
denudation to the height of six hundred feet. The overlying limestones.
are confined mostly to the hills, and at some points exhibit a thickness of
nearly four hundred feet. They are filled with fossils of the same character
as those last enumerated.
The strata still present an E. S. E. dip, but with a gradually increasing
angle. No evidence appears of sudden or violent disturbance, but the up-
lifting of the stratra has evidently been the result of causes operating in a
uniform and very gradual manner. The subsequent denudation to which
they have been so largely subjected imparts to this region a rough and
broken aspect. It is only by following the different valleys, most of which
appear to have a general east and west bearing, that a practicable and easy
grade for a railroad may be obtained.
Independence Springs.-Towards evening we arrived at Independence
Springs. From these a small stream of water flows for some hundreds of
yards through a fertile valley, and then is lost amid deep rocky ravines.
The springs, of which there are several, bubble up through nearly circular
openings in the sand-rock that composes the floor of the valley. Each of
these openings is surmounted by a deep and nearly circular basin, from five
to ten feet in diameter, and capable of containing from two to four hundred.
94
JOURNAL OF GEOLOGICAL OBSERVATIONS.
gallons of water. By enlarging these a constant supply of excellent water
can always be obtained here in quantities sufficient to answer the purposes
of a railroad. At one of these openings a pole was sunk to the depth of
fifteen feet without reaching the bottom.
Near this place there are thin seams of dark argillaceous shale interstrat-
ified with the sandstone.
Soil during the day calcareo-argillaceous and moderately fertile.
Distance, 18 miles.
Sept. 27.—From Independence Springs to the eastern base of the Guada-
lupe Mountains, a distance of about six miles, our road led over a gradual
ascent of several hundred feet. For the whole of this distance the dark
thin bedded limestone and subjacent sandstone is well exposed.
As we ap
proach the mountains the inclination of the strata increases, the dip being
about twenty degrees and the direction still E. S. E. At the mountains
they are seen to pass under the massive white limestone, which, as we shall
soon see, is here much better developed than farther east.
To the south, and apparently continuous with the line of upheaval of the
mountains, the ruptured edges of the same strata are to be seen, presenting
to the west rugged and nearly vertical escarpments from fifteen hundred to
two thousand feet high, and extending southward as far as vision reaches.
These cliffs are occasionally capped with light colored limestone, but gener-
ally this rock has been removed by denudation.
The Guadalupe Mountains, near the southern extremity, rise abruptly from
a gently ascending surface, and attain at the highest point an altitude of
nearly three thousand feet above their base and about eight thousand feet
above the level of the ocean. The main axis or line of upheaval trends
somewhat irregularly northeast and southwest. From our point of observa-
tion there is a gradual descent to the northeast, while to the south the range
terminates abruptly in a frightful precipice upwards of two thousand feet
high. Around the base of this precipice our road led by a gradual descent
through a deep canyon composed on both sides of rough and nearly vertical
cliffs. The eastern slope of the mountains is rapid towards the Plains, and
marked by deep and rugged canyons often with nearly vertical sides. One
of these canyons, situated near the southern extremity and known as "The
Pinery," was explored for the distance of about a mile. At some points it
is upwards of a half a mile wide, and bounded on either side by vertical or
abrupt sloping walls of such extreme height that their summits appear often
enveloped in clouds.
It is only, however, when observed from the west that these mountains
can be contemplated in all their grandeur. Here extends an unbroken line
of vertical precipices from two to three thousand feet in height, the faces
of which are of such extreme smoothness as to be accessible only a few
hundred feet above the base. The abrupt faces of these cliffs pursue a
JOURNAL OF GEOLOGICAL OBSERVATIONS.
95
general course parallel with the axis of upheaval of the mountains, which
present the appearance of having been cleft vertically through their centers
and the western halves removed. They attain their greatest elevation
about one mile north of the southern extremity, from which point there is
a gradual descent to the north and south.
Geological Structure.-The Guadalupe Mountains consist of white, gray,
and bluish-black limestone and fine and coarse-grained quartzose sand
stone, the whole appertaining to the upper division of the Carboniferous.
System, or Coal Measures. The white and gray limestone reposes in heavy
beds upon the standstone, and exhibits the enormous thickness of more
than a thousand feet. It is harder than any previously encountered, but
in all other respects it is precisely of the same character as that seen at the
head of Delaware Creek and between that point and the Guadalupe Moun-
tains. It is remarkably rich in organic remains, a large portion of which
are new to science, but others appear to be forms characteristic of the Coal
Measures. Some of the layers of white limestone are composed almost
wholly of remains of Crinoidea. I collected a number of species of fossils
from the beds, as follows: Productus semireticulatus, Productus splendens?,
Productus Boliviensis?, Productus undetermined, Chonetes Smithi (Norw. &
Prat.), Rhynchonella several undetermined species, Spirifer plano-convexa, and
Avicula, Ostrea, Cypricardia, Straparollus, Cyathophyllum, Fenestella, Chatetes,
and Phillipsia of each one or more undescribed species.
With these occurs a slender Fusulina upwards of an inch in length, which
appears to be quite distinct from the Fusulina cylindrica so characteristic of
the Coal Measures of the Missouri River. There is also a brachiopod which
possesses all the external characters of Camarophoria Schlotheimi (Verneuil
sp.) of the Permian System of Russia.
From the dark limestone interposed between the white limestone and
sandstone beds, fossils were collected identical with those occurring in the
beds near the head of Delaware Creek.
The Sandstone is best displayed in the canyon and on the western side of
the mountains. In the latter position it exhibits a thickness (estimated
approximately) of from twelve to fifteen hundred feet. Towards the top
it is soft, and contains fossils of the Coal Measures, frequently in great
abundance, as follows: Spirifer Meusebachanus, Athyris subtilita, Productus
Boliviensis?, Productus new species, Spirifer plano-convexa, Bellerophon Urii?,
and Fusulina. At one point strata upwards of a hundred feet in thickness
are composed almost entirely of the last mentioned fossil. The inferior
layers are generally compact, coarse grained, and micaceous. At the base
are intercalated bands of hard dark argillaceous shale, and beneath these
are thin layers of dark compact limestone, which, at a locality a little north
of the pass, is exposed to the thickness of five hundred feet. Diligent
search was made for fossils in these beds, but no traces of any were detected.
The Pass.-As we wound around the southern extremity of the moun-
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
tains our road led first by a gradual descent over the upturned edges of
the limestone strata, and afterwards the fine and coarse grained sandstone,
shale, and underlying dark colored limestone were successively passed over.
At the point where the line of survey diverges from the emigrant road the
lower sandstone is largely developed, and from the E. S. E. dip and durable
character it is capable of affording not only a firm and easy foundation for
a railroad, but also the very best of materials for construction.
Beyond the foot of the canyon a range of hills from five to eight hundred
feet high presents a precipitous face towards the east, extending irregularly
for several miles in a direction nearly parallel with the mountains. In this
range the dip of the strata is 25 degrees W. N. W., or in a direction con-
trary to that observed in the Guadalupe Mountains. But the rocks are in
all respects similar to those of the mountains, a portion of the western slope
of which they at one time formed, although at present separated by a deep
valley several miles wide. Facing also in an easterly direction and about
fifteen miles to the southwest there occurs an extensive range of rugged
cliffs, from the summits of which the surface slopes gently towards the
west. These cliffs, as well as could be determined at a distance, are from a
thousand to fifteen hundred feet in height. Their bearing is nearly parallel
with the escarpments south of the mountains, which they very closely re-
semble in general appearance, and doubtless have the same geological
composition. Between the ranges is a broad and gently undulating valley,
with its surface often dotted with small saline lakes.
Soil. From Independence Springs to the summit of the Guadalupe Pass
the surface of the country is rocky, but thickly covered in many places with
dark carbonaceous and highly productive soil. Beyond this it is altogether
unfit for cultivation.
Distance, 14 miles.
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97
CHAPTER VI.
FROM THE FOOT OF THE GUADALUPE PASS TO DONNA ANA, NEW MEXICO.
Sept. 29.-After traveling for several hours through the deep valley
above described, and over the same fossiliferous rocks observed yesterday,
we emerged into a broad and gently undulating country, over which we
continued to journey during the remainder of the day. The surface con-
sists chiefly of tenacious red calcareo-argillaceous clay, coarse yellow quartz
sand, and limestone detritus, which is often firmly consolidated by ineans
of calcareous matter, and characterized by fossils different from those found
in the mountains. Its general thickness is about ten feet.
I
Salt Lakes.-About three or four miles south of our road are several
shallow saline lakes, the largest of them being from two to three miles in
circumference. Owing to their pure whiteness they afford a remarkably
pleasing contrast to the otherwise monotonous character of the surface.
have been informed that from these lakes salt may be readily obtained in
almost any quantity, their flat beds after the evaporation of the water being
often incrusted with it to the thickness of several inches.
At the distance of fourteen miles we came to a range of hills of fine yel-
lowish silicious sand. These extend five or six miles southward, with an
average width of about a mile. They are from twenty-five to forty feet
high, and appear to be gradually shifting their position to the north. To
the south they slope gradually towards the plain, but present abruptly in
the opposite direction, where several of them at a recent period have par-
tially covered a number of mezquite bushes so as to leave merely their
tops projecting above the sand.
Soil and sub-soil for the first eighteen miles calcareo-argillaceous and sili-
cious; afterwards highly calcareous and composed almost entirely of disin-
tegrated limestone.
Distance, 24 miles.
Sept. 30.- Gypsum Lakes. A short distance from our last evening's
camp occur several shallow lakes, the largest a half a mile in length and
about three hundred yards broad. The water of these lakes is strongly im-
pregnated with gypsum; and the dry beds of others, situated a little further
off, are thickly covered with small shining particles of selenite.
For the first few miles we traveled over slightly undulating prairie, un-
derlaid by beds of red marly clay and white earthy carbonate of lime, the
latter not unfrequently mixed with soft white gypsum, and presenting at
general thickness of fifteen or twenty feet. We then came to an extensive
outcrop of dark gray sub-crystalline and highly fossiliferous limestone,
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
which continued to exhibit itself more or less frequently during the remain-
der of the day's journey. This rock in a few places contains bands of soft.
ferruginous sandstone, and is marked by fossils of the Coal Measures, as
follows: Bellerophon Montfortianus? (Norwood & Prat.), Orthis umbraculum,
Straparollus catilloides?, and remains of Crinoidea.
Among the loose detritus I observed to-day some small fragments of soft
yellow earthy Cretaceous Limestone, containing Ostrea.
Soil and sub-soil for the first five miles calcareous and calcareo-argilla-
ceous; afterwards more or less silicious.
Distance, 9 miles.
Oct. 1. Massive strata of dark gray sub-crystalline limestone of the
Coal Measures were largely exhibited during the greater portion of this
day's march. The rock in some places presents a thickness of nearly four
hundred feet, and differs from the limestone of yesterday only in being
harder and occasionally more or less cherty. The embedded fossils are
usually finely preserved, and often so thickly crowded as to constitute the
larger part of beds many feet in thickness. The most common species are
Athyris subtilita, Productus semireticulatus, Productus muricatus, and Strapa-
rollus, Pleurotomaria, Bellerophon, and Archæocidaris of undescribed species.
This rock will afford an excellent building material, and, by burning, the
very best of lime.
As we progress the strata are highly contorted and the surface more un-
dulating. The hills are characterized by gentle slopes, and attain a height
of from fifty to one hundred feet. Late in the day we arrived at the
Cornudas Mountain, an isolated mass of eruptive rock, rising almost vert-
ically to the height of six or seven hundred feet, and appearing at a
little distance to be composed of materials thrown confusedly together.
On every side it presents rugged and nearly vertical cliffs, some of them
fissured, and exhibiting near their bases small triangular openings. The
largest of these extends into the mountain nearly a hundred feet, and ter-
minates in a spacious chamber of an irregular elliptical form, and in the
center a pool of pure water. This chamber is lighted from above by means
of a large triangular opening, which at the summit of the mountain termi-
nates in an irregular basin-shaped depression, through which the water of
the chamber is conducted. The pool is at present almost entirely filled
with sand; but by clearing this out a sufficient supply of water might be
obtained for the use of a large number of emigrants and their stock during
the entire year. Besides the main chamber there are several smaller ones,
all of which could very easily be rendered available for supplying water
during the dry season of the year.
The Cornudas Mountain extends about one mile northeast and southwest,
and its width is from a half to three-fourths of a mile. It is composed
entirely of compact light gray albite granite, in which the albite predomi-
JOURNAL OF GEOLOGICAL OBSERVATIONS.
99
nates over the other ingredients. The mica is of a jet black color and exists
in very small particles. This granite is very poorly adapted for building
purposes, as it disintegrates very rapidly.
From the Cornudas the limestone presents a quaquaversal dip at angles
varying from 45 to 50 degrees. Near the point of contact with the eruptive
rocks it is highly metamorphosed and converted into hard cellular rock of
a dusky brown color. Its visible thickness is upwards of five hundred feet,
and at a little distance from the erupted mass the beds are crowded with
fossils, many of them highly characteristic of the Coal Measures.
Soil, during the greater portion of the day, calcareo-silicious.
Distance, 20 miles.
Oct. 2.-After leaving the Cornudas Mountain we continued to travel
over highly undulated strata of limestone of the age of the Coal Measures.
The surface of the country is rolling and diversified with low rocky hills
and ridges. Southwest of our road is an interrupted chain of hills of eruptive
rocks, which, after connecting with the Sierra de los Alamos, stretch across
the country for a number of miles in a southwest course.
Eight miles from the Sierra Cornudas we came to the Sierra de los Alamos,
three rough isolated peaks, the highest of which is about eight hundred feet
above the general level of the adjacent country. These, as has already been
remarked, are southwest of the Sierra Cornudas, from which they differ
somewhat in appearance and mineralogical composition, though they un-
doubtedly form a part of the same system of eruption. The rock consists.
of granite, gneiss, and light greenish porphyry. The granite is hard, compact,
and fine textured, and graduates almost imperceptibly into the gneiss and
porphyry. The latter is usually hard, and contains crystals, sometimes of
quartz and sometimes feldspar. On both sides of the eruptive rocks the
Upper Carboniferous Limestone is slightly metamorphosed and inclined at
angles of from 10 to 30 degrees.
Beyond the Sierra de los Alamos this limestone is largely developed,
and in places crowded with characteristic Carboniferous fossils.
Soil and sub-soil calcareo-silicious.
Distance, 26 miles.
Oct. 3. From the last camp to the Sierra Alto, a distance of about
four miles, our road was still over undulating strata of Upper Carbonifer-
ous Limestone. The surface of the country was also marked with low hills
and ridges, from the rocky sides of some of which fossils were obtained in
the greatest abundance.
SIERRA ALTO.
The Sierra Alto rises majestically from a nearly quadrangular base to

Section of the Sierra Cornudas, Oct. 1, 1855.
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
101
the height of about fifteen hundred feet. It is completely isolated from
the neighboring mountains, and its rugged summit projects considerably
above the highest of them. Its main axis extends nearly east and west for
the distance of about two miles, and its width varies from a fourth to about
three-fourths of a mile. On all sides it is surrounded by hills and ridges,
all of which present abrupt faces toward the mountain, and slope gradually
in an opposite direction.
This mountain is composed of hard granite, of a light gray color, in
which the feldspar predominates over the quartz and mica. The weathered
face of the rock presents sometimes a yellow and sometimes a brown color,
and occasionally exhibits a jointed structure, but more frequently a smooth
and polished appearance. The surrounding hills and ridges consist of
limestone and soft sandstone, which are strongly upheaved, and dip quaqua-
versally at angles of from 5 to 40 degrees. The layers in contact with the
eruptive mass are highly metamorphosed, and of dirty brown and yellow.
colors. As well as could be determined from their exposed edges the
thickness of the limestone and sandstone cannot here fall short of two thou-
sand five hundred feet. As we recede from the mountain the dip of the
strata becomes much less apparent, so that in the distance of a mile it does
not anywhere exceed 5 or 10 degrees.
As the strata exposed at the Pass are some distance removed from the
central axis of eruption they have undergone but slight metamorphic change,
and are often densely crowded with fossils. Among these we recognize
several species which are quite characteristic of the Coal Measures of Mis-
souri, Illinois, and Kentucky, along with others that range downwards to
the base of the Carboniferous System, but most of the species are not yet
described. The list includes Productus costatus, Productus Cora, Tellinomy
protensa?, Allorisma regularis, Bellerophon Urii, Bellerophon several new species,
Straparollus several species, Pleurotomaria, Murchisonia, Natica, and Chemni-
tzia several species. Most of the fossils at this locality were obtained from
the debris at the base of the cliffs.
The rocks in this vicinity would afford the very best of building materi-
als, and particularly the granite, which is of firm texture and admirably
adapted for any work requiring great strength and durability.
SIERRA HUECO.
From the western extremity of the Sierra Alto our road led by a gradual
descent through a broken and hilly region into a broad fertile valley, some-
what semi-circular in its form. This valley to the west and northwest
opens into the "Valley of the Salt Lakes," but in every other direction it
is abruptly terminated by rough hills and cliffs of limestone from five to
eight hundred feet high. Its floor consists entirely of eruptive rocks, whose
sharp and jagged points are seen protruding on either side, and near the
102
JOURNAL OF GEOLOGICAL OBSERVATIONS.
center rises the Hueco Mountain, precipitously, to the height of about six.
hundred feet. The mountain is divided by a broad canyon into two nearly
equal portions, and on all sides are vertical cliffs, often deeply fissured from
top to bottom, affording by their frowning appearance a remarkable con-
contrast with the smooth grassy surface by which they are surrounded.
The rock composing the Sierra Hueco is a fine textured light greenish-
gray granite, which is soft, and crumbles readily on exposure to the
weather. It contains a much larger proportion of feldspar, and less quartz,
than any of the granites we have hitherto encountered. The weathered
edges present ferruginous brown and yellow colors.
"Hueco Tanks."-Owing to its rapid disintegration, the granite is in
places deeply excavated so as to form chambers, some of which serve as
natural reservoirs, or basins, into which,*
*
**
[Here one page of the manuscript is missing.]
**
**
*
Oct. 4. "Valley of the Sull Lakes."-Shortly after leaving the Hueco
Mountain we entered the "Valley of the Salt Lakes," which stretches north
and south several hundred miles. It is bounded on the west by the Organ
and El Paso Mountains, whose sharp and jagged outlines bespeak, even at
this distance, the eruptive character of the rocks composing them. On the
cast the valley is limited by an uninterrupted line of bold abrupt cliffs of
limestone, which to the south are continuous with the bluffs in the vicinity
of the Hueco Mountains, while in the opposite direction they extend for a
distance of forty or fifty miles, and terminate in the Sacramento Mountains,
which rise majestically to an altitude of several thousand feet.
A little west of this line of cliffs, and running parallel with them, is a
chain of sharp ridges and conical hills which connect with the Sierra
Hucco, and possess, as far as examined, the same structure, being composed
of fine textured gray granite. The valley at the point of entrance is about
twenty-five miles wide, and has a smooth, even surface, covered for the
most part with short grass. After entering it our road during the remain-
der of the day was over coarse reddish sand and detritus of eruptive
rocks.
Distance, 16 miles.
Oct. 5.-El Paso Mountains.-After traveling twelve miles farther, over
extensive deposits of sand and detritus, we reached the southern extremity
of the El Paso Mountains, around which our road led by a gradual descent
into the valley of the Rio Grande. These mountains form a continuous
chain about thirty miles in length, extending, as already intimated, in a
north and south direction, and although bearing a different name constitute
merely a detached portion of the Organ range, from which they are sepa-
rated on the north by a smooth valley from a fourth to a half a mile wide.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
103
To the south they terminate abruptly to form "The Pass," beyond which
the lofty summits of the same range are again seen stretching southward
for many miles. Viewed from the east, they rise abruptly from a smooth
and gently ascending plain, attaining at the highest points an elevation of
about two thousand five hundred feet. Their summits are generally sharp
and jagged, and to the north they rise in succession, one above the other,
like the pipes of an organ; hence the name of Organ Mountains, which has
been applied to the entire range.
As will be shown hereafter, they vary considerably in composition. The
southern portion consists of hard granite and porphyry. The granite
greatly predominates over the porphyry, and varies in color from light
gray to deep vermilion. It is sometimes more or less porphyritic, and its
hardness and durability would render it an excellent building material.
The porphyry is confined chiefly to the suminits. Usually it is of a deep
red color, and contains crystals of quartz and sometimes of feldspar. Near
the western base of the mountains fraginents of dark colored scoria were
frequently observed.
Against the western declivity of the mountains the limestone strata are
strongly upheaved, and where it is in immediate contact with the eruptive
rocks, is highly metamorphosed. I was much interested in finding here,
near the base of the exposure, well marked strata of the Inferior Silurian
System, corresponding in age to the Blue Limestone of Cincinnati and the
Hudson River Group of the New York Series. The following fossils were
procured from these beds: Orthis testudinaria (Dalman), Orthis occidentalis
(Hall), Rhynchonella capax (Conrad), Rhynchonella (a species of the Blue
Limestone of Cincinnati), Streptelasma cornicula (Hall), and columns of
Crinoids.
In following the windings of "The Pass" we first descended over thick
deposits of loose and partially consolidated detritus, after which nothing
was encountered but granite and limestone. The surface is generally hilly,
and slopes toward the Rio Grande, which is here of moderate depth and
flows over a rocky bed.
From this point to Dona Ana the course to be pursued by the Expedition
is nearly north.
Distance traveled during the day, 20½ miles.
Oct. 7.-Our route this day was along the valley of the Rio Grande,
which varies greatly in width, and is characterized by dark rich alluvial
soil, bearing a luxuriant vegetation. From the east the surface presents a
gradual slope towards the Rio Grande, and the western border is marked,
for the first few miles above El Paso, by rugged mountains of granite and
porphyry, and afterwards by precipitous bluffs which form the eastern edge.
of an elevated Mesa. I observed again to-day the soil frequently encrusted
with efflorescences of common salt and soda. The river presents an aver-
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
age width of about one hundred yards, the water is moderately deep and
highly charged with fine yellow sediment.
The El Paso Mountains exhibit the same general appearance and minera-
logical composition as described yesterday. The limestone of the Lower
Silurian System is seen strongly upheaved against the western base, until
we reach a point about ten or eleven miles north of the place it was first dis-
covered, where it disappears, and is succeeded by strata of the Carboniferous
System, which are exposed in places to the thickness of about three hundred
feet.
Black ferruginous sand was observed in several localities near the base of
the mountains, and the indications are such as to lead to the belief that this
region may be found rich in valuable metals.
Distance, 16 miles.
Oct. 8.-With the exception of being wider the portion of the valley of
the Rio Grande traveled over to-day does not differ in general appearance
from that of yesterday. The soil continues rich and clothed with luxuriant
vegetation. East of our road the surface of the country ascends gradually
towards the base of the mountains (estimated now to be about ten miles dis-
tant). It is for the most part covered with a thick accumulation of coarse
red sand, with fragments of limestone and eruptive rocks embedded. Be-
tween our road and the mountains there occurs several uneven hillocks of
hard gray porphyry, containing crystals of light gray feldspar. They are
from thirty to sixty feet high.
The mountains for the first fifteen miles present the same character as
before, but after passing the " Puerto del Bracito" they change in appearance
and structure, and consist chiefly of highly inclined strata of dark blue and
gray Carboniferous Limestone, dipping west, and presenting precipitously to
the east. The thickness of the limestone, as shown here by its exposed
edges, is about three thousand feet. In a couple of miles the limestone dis-
appears, and is succeeded by eruptive rocks of the same character as before.*
From Fort Fillmore to Dona Ana, a distance of about fourteen miles, our
road was principally over alluvium and coarse detritus. East of us the sur-
face is rough, much cut up by ravines, and still exhibits a gradual ascent
towards the mountains. At a locality about three miles east of Las Cruces
the Carboniferous Limestone is exposed to the thickness of about six hundred
feet. In places the strata are crowded with encrinite stems and other
fossils.
*For a further description of the rocks of this locality, see notes of March 8th, 1856,
Chapter VIII.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
105
CHAPTER VII.
RECONNOISANCE WEST OF THE RIO GRANDE.
FROM FORT FILLMORE TO THE
VALLEY OF THE MIMBRES, NEW MEXICO.
The reconnoisance of which the following is a report was ordered princi-
pally with a view to the determination of the practicability of obtaining
water by means of Artesian Wells from the elevated and arid region situ-
ated between the Rio Grande and Mimbres Valleys. This has already been
made the subject of a special report, but inasmuch as many of the facts.
collected were omitted in that report as foreign to the subject then under
consideration, and as they may have an important bearing upon the question
of a Pacific Railroad, besides being of general scientific interest, it is thought
advisable to give the results of the exploration in detail.
In this excursion I was accompanied by a topographer and a small escort
of mounted soldiers. We started from our camp near Fort Fillmore on the
morning of the 15th of October, and shortly afterwards forded the Rio
Grande, which is here about one hundred yards wide, of moderate depth,
and flows between low bluff banks of yellow loam. Its bed is composed
principally of quicksand, and the water is highly charged with fine yellow
sediment, but it possesses an agreeable and somewhat alkaline taste.
either side the land is flat and covered with rich soil, bearing a heavy
growth of timber, principally cottonwood.
On
Taking a northwest course we traveled for several hours over thick allu-
vial deposits of fine yellow micaceous sand and sandy clay. The river
valley here is from three to six miles wide, with a gentle slope from the east
to the river, but abruptly terminated in the opposite direction by a range of
bluffs varying from two to four hundred feet in height. These serve to
mark the eastern border of an elevated mesa or table land, and are com-
posed chiefly of coarse red silicious and feldspathic sand, with irregular
seams of clay and fragments of porphyry, basalt, greenstone, and other erup-
tive rocks disseminated through it. Here and there occur hills and low
terraces of fine, light yellow, silicious sand, and the surface is at some points
covered with a saline efflorescence. The soil is deep and usually well
adapted for cultivation. It is capable of yielding corn, wheat, barley, and
other agricultural products in plentiful crops, but owing to the dryness of
the climate requires frequent irrigation. This is in general very readily
accomplished by means of irrigating canals, which traverse the valley in all
directions, and are so arranged as to spread their contents over the surface
whenever required.
As we continued on our route the surface assumed a broken and hilly
aspect. At the distance of ten miles we reached the " Picacho," a sharp
106 JOURNAL OF GEOLOGICAL OBSERVATIONS.
conical peak rising abruptly to the height of eight hundred and fifty feet.
It forms the most elevated part of a broad dyke that extends somewhat
irregularly, with a W. S. W. bearing, from the Dona Ana Mountains, a dis-
tance of about fifteen miles. To the east this protrusion exhibits an aver-
age width of five or six miles, but rises above the surface only at a few
points in the form of low rounded hills and ridges. After having been
partially cut through by the valley of the Rio Grande it is again seen ris-
ing near the eastern base of the Robledo Mountains to the height of several
hundred feet, attaining its greatest elevation at the "Picacho," whence it
again diminishes in height and for a time disappears beneath the detrital
deposits of the mesa.
It is composed principally of dark red and slate colored porphyry, green-
stone, and claystone. The porphyry is soft, yields rapidly to the weather,
and near the "Picacho" is thickly reticulated with veins of fibrous gypsum.
From this point the sedimentary strata dip towards the mesa at an angle of
about 16 degrees, being highly metamorphosed and partially converted into
schist.
Immediately north of the "Picacho" is the Robledo Mountain, presenting
abruptly to the river. It is a bold, rugged escarpment, about one thousand
feet in height, and, as far as examined, consists of hard gray and blue cry-
stalline limestone of the Carboniferous System. Among the species collected
from this locality were Productus costatus, Athyris subtilita, and Pleurotoma-
ria, Chemnitzia, and Straparollus of undescribed species. The strata dip.
southwest at an angle of about 16 degrees.
After leaving the "Picacho" we traveled in a westerly course over a
rough and hilly district, composed for the first mile or so of eruptive rocks.
of the same character as above mentioned; afterwards we encountered light
gray limestone and metamorphosed argillaceous shale. The limestone is fort
the most part hard semi-crystalline, and although occasionally much divided
and upheaved by the protrusion of basaltic dykes, appears to have under-
gone but slight metamorphic change, as it is replete with well preserved
examples of Productus costatus, Athyris subtilita, and other Carboniferous.
fossils. The inclination of the strata is S. S. W. 25 degrees. Their exposed
edges show a thickness of over six hundred feet.
North of our route the country is everywhere rough and mountainous,
but south the eye encounters a smooth grassy surface (mesa), with a gentle
slope towards the river valley, here and there interrupted by low ridges and
abrupt conoidal hills, which are grouped together in clusters of six or eight.
From their general broken outline there can scarcely be a doubt that the
rocks composing them are of the eruptive class.
As we advanced the strata became highly undulated and folded, finally
assuming a marked metamorphosed character, the limestone being altered
in color and texture and devoid of any traces of organic remains.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
107
we
Valley of the "Boundary Station."-Nine miles from the "Picacho'
came to the valley of the "Boundary Station," which is about fifteen miles
wide, and bounded on either side by abrupt escarpments of upheaved sedi-
mentary strata.
This valley extends many miles northward, but to the south is limited
by chains of hills and ridges several hundred feet high. Its floor is com-
posed of eruptive rocks, which are traversed by nearly parallel dykes of
hard red and purple porphyry, basalt, and vesicular amygdaloid. One of
these dykes rises abruptly above the general surface as high as six hundred
feet, forming what is denominated the Boundary Station.
The elevations composing the southern boundary of the valley consist of
eruptive rocks, from which other dykes extend in low but apparently con-
tinuous ridges across the mesa to within a short distance of its southern
boundary, where they connect with the igneous ranges already mentioned.
The surface of the valley is generally smooth, and thickly covered with coarse
reddish feldspar and quartz sand, with chalcedony, agates, and cornelians dis-
seminated through it. I also observed black iron sand in several localities,
and it is not improbable that this district as well as that farther west may
prove to be auriferous.
The abrupt edges of the strata constituting the western boundary of the
valley are terraced, and as they extend northward attain the height of over
a thousand feet; but not having time to examine them I was unable to de-
termine their precise character.
Ascending from the valley of the Boundary Station we pursued a west-
erly direction over an elevated plateau with gentle slopes, and composed
principally of highly metamorphosed sedimentary strata, the continuity of
which is frequently interrupted by dykes from a hundred yards to a mile
wide, and which extend somewhat irregulary across the plateau, with a
north and south bearing. Our road was crossed by no less than sixteen of
these dykes. They differ but slightly in lithological character from those
previously examined.
This plateau is about twenty miles broad. It is covered with coarse red
sand, fragments of decomposing limestone, and eruptive rocks. The soil is
usually fertile, and clothed with short grass. If means could be provided
for a supply of water during the dry seasons of the year, it would prove
highly productive. Upon its western side the plateau terminates abruptly
in a long line of bold and precipitous escarpments, in places upward of
five hundred feet high. These exhibit near their bases rude projecting
masses of dark red and purple porphyry and other varieties of eruptive
rocks. To the south they decline gradually toward the mesa, and finally
disappear entirely, while the igneous protrusion still continues above the
surface in low gently rounded hills, with a general bearing south 10 de-
grees east. The strata composing the escarpment dip 20 degrees E. S. E.,
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
and they are usually so highly metamorphosed as to be hardly distinguish-
able from igneous rock.
For the next thirteen and a half miles in the direction of the Picacho de
los Mimbres our road led over compact purplish porphyry, amygdaloid, and
basalt, traversed by occasional dykes and veins of greenstone, quartz, and
chalcedony. The surface of the country exhibits a gentle slope to the east,
and is covered with a deposit of coarse red silicious and feldspathic sand
and detritus from ten to a hundred feet in thickness, and containing at its
upper portion agates, cornelians, and pebbles of chalcedony Black ferru-
ginous sand was frequently observed along our route, resembling so closely
the auriferous sand of California as to induce the belief that gold may be
found in this region. Specimens of this sand have been subsequently ex-
amined chemically, but no traces of gold were detected in it.
The Mimbres Mountains near the southern extremity are characterized
by a number of rugged conoidal peaks, the highest of which constitutes
the "Picacho de los Mimbres." It is elevated probably twenty-five hundred
feet above the level of the adjacent valleys. The main axis of the Mimbres
Mountains runs north 42 degrees west. As far as examined the range
consists of a very compact purple porphyritic granite, containing a large
proportion of quartz and a deficiency of mica. On either side occur dykes
of greenstone, red and dark porphyry, and amygdaloid. Between two of
these, and near the base of the eastern slope, a small stream of water known
as Cook's Springs gushes forth, which is constant during the year. The
water is clear, slightly alkaline, and possesses a temperature of 60 degrees F.
It is contained in irregular basin-shaped depressions scooped out of the
porphyry. No sedimentary rocks were anywhere observed in the neigh-
borhood. Upon the western side of the mountains thermal springs are
said to occur, but I was not able to visit this locality.
From near the eastern base of the mountains, and several miles north of
the southern extremity, a broad dyke rises to the height of six or eight
hundred feet, bearing south 12 degrees west. It extends a distance of
twenty-five miles, and intersects the Sierra Florida near its southern ex-
tremity. This dyke consists of compact red porphyry, greenstone, quartz,
and amygdaloid. The extremities only are seen projecting above the sur-
face, its central portion having apparently been removed by erosion.
After leaving the Picacho de los Mimbres we traveled in a southerly di-
rection over continuous beds of igneous rocks. The surface of the country
is for the most part hilly, and thickly strewn with coarse angular frag-
ments of granite, porphyry, quartz, and amygdaloid. The mountains, after
attaining their greatest elevation at the Picacho, descend rapidly towards
the south, and at the distance of about nine miles terminate in a broad
open plain, which connects on the one hand with the valley of the Mim-
bres and on the other with the mesa. This plain presents on both sides a
JOURNAL OF GEOLOGICAL OBSERVATIONS.
109
gentle slope towards the middle, and is thickly covered with coarse red
sand and fragments of igneous rock.
Early on the morning of the 19th inst. we arrived at the Sierra Florida,
a short detached range which rises abruptly from a gently undulating and
ascending plain, and like the Mimbres range, presents a number of rugged
peaks. The highest of these attain an elevation above the base of near
two thousand feet. The direction of the main axis or line of eruption is
north 55 degrees west. The rocks are compact trachyte porphyry and
cellular quartz, both of which appear to be yielding rapidly to the weather,
and present externally a dirty ferruginous brown color. Black iron sand
occurs in great abundance in the neighborhood, and among the loose de-
tritus near the base of the mountains some fine agates and cornelians were
collected.
From the summit of the Sierra Florida a good view may be had of the
valley of the Mimbres, which stretches many miles to the west, and is sur-
rounded on all sides by rugged mountain chains, whose sharp and jagged
peaks scem in the distance to rise one above the other in almost end-
less succession, while through the center of the valley long lines of low
sombre looking hills and ridges indicate the existence of numerous dykes.
In fact the whole of the valley appears to have been the theater of intense
igneous action, and no evidence of the existence of sedimentary strata are
anywhere visible upon the surface. Its floor, as far as we were able to judge
from a distance, appears to be composed of coarse red sand and detritus,
generally thinly covered with short moss-like grass.
mesa.
Having completed our examination as far west as the valley of the Mim-
bres, and determined pretty accurately the geological character of the east,
north, and west boundaries of the district we were directed to explore, our
attention was next directed to the central and southern portions of the
This presents throughout the greater portion of its extent a gentle
slope towards the valley of the Rio Grande, and consists chiefly of thick
deposits of coarse silicious and feldspathic sand, with fragments of eruptive
rocks disseminated through it. The land is covered with short grass, and
is here and there diversified with hills and low ridges, which are arranged
in nearly parallel lines, and are nothing more than the projecting portions of
dykes, chiefly of dark compact basalt and porphyry. A few miles south of
the Boundary Station the hills rise abruptly to the height of several hun-
dred feet, presenting a dark and exceedingly rugged aspect.
On the south side the mesa is bounded by a range of detached hills,
which extend from near the valley of the Rio Grande to within a short dis-
tance of the Sierra Florida. These hills appear to be from two to six hun-
dred feet high, and consist of igneous rocks of a dark and very rough
appearance. To the south they appear to connect with others, which, as we
shall hereafter see, are of quite recent origin.
As we approached the valley of the Rio Grande the surface became
110 JOURNAL OF GEOLOGICAL OBSERVATIONS.
rough and here and there traversed by deep ravines. From some of these,
sections of the Quaternary beds were obtained three or four hundred feet
high, but they do not in general differ from those exposed along the river
valley.
Having again reached the valley of the Rio Grande, we traveled south 32.5
degrees east. At the distance of five miles we came to a heavy deposit of
black basaltic lava, projecting abruptly above the surface to the height of a
hundred and twenty-one feet, with an average width of about a mile. This
is composed near its base of heavy compact basalt with a vitreous luster,
containing small green particles of chrysolite; but as we approached the
summit of the lava stream it gradually assumes the character of a vesicular
basalt, and finally that of highly vitreous scoria. This stream is about two
miles long, and appears to have proceeded northeast from an abrupt trun-
cated cone known as the Picacho de las Mesa. Its surface is for the most
part flat, totally devoid of vegetation, and seems to have undergone but little
or no alteration since the period of its eruption. On nearly every side it
terminates abruptly.
The "Picacho" is also composed of lava, and projects above the lava
stream at its base to the height of about two hundred feet. At the summit
is a shallow basin-shaped depression, near the center of which an artificial
excavation has been made to the depth of about twelve feet. Here the
scoria is light, friable, and resembles highly burnt cinder.
Ten miles south of the "Picacho" is a second cone, about six hundred feet
high, from which a broad sheet of lava proceeds in an easterly course for
the distance of about ten miles, where it terminates abruptly. This stream,
as well as could be determined at a distance, has an average breadth of about
two and a half miles, and does not differ in general appearance from that of
the "Picacho.”
From the character and general appearance of these cones and lava
streams, I am disposed to ascribe their origin to a comparatively recent geo-
logical period. They form a part of an extensive volcanic chain, which
may be traced north and south for several hundred miles.
JOURNAL OF GEOLOGICAL OBSERVATIONS. 111
CHAPTER VIII.
FROM DONA ANA, NEW MEXICO, TO THE HUECO MOUNTAIN, VIA SAN AUGUSTINE
PASS.
The Expedition having been again ordered to the Rio Pecos, it was de-
termined, in order to save time, to adopt the shorter and more direct route,
by way of San Augustine Pass, and from thence intersect our former route
at the Hueco Pass. As the geology of this region is comparatively but
little known, the following observations, taken between Dona Ana and the
Hueco Mountains, may be of some interest:
Mar. 8, 1856. - After leaving Dona Ana we gradually ascended for
several miles over thick deposits of coarse red silicious and feldspathic
sand, and angular fragments of porphyry, granite, and other eruptive rocks.
The surface is everywhere rough and hilly, and often traversed by long
narrow ravines.
Vegetation is sparse, and consists chiefly of coarse bunch grass and mez-
quite bushes.
At the distance of about three miles we reached the Dona Ana Mound, a
solitary peak, which rises to the height of about six hundred feet, and con-
stitutes the most southerly part of the Dona Ana Mountains. Like those
farther north, it is composed of a variety of eruptive rocks, mostly of purple
and slate colors, and although separated from the main range by a valley
several miles in width, it is no doubt contemporaneous with it.
Passing this Mound we entered the Jornada del Muerto at the southern
extremity. Its width here is about twelve miles, but northward it is much
broader. To the east it is abruptly terminated by the Organ Mountains.
The surface is generally smooth, and thinly covered with short moss-like
grass. In crossing it our road for the first six miles was by a gradual de-
scent, over heavy deposits of coarse red sand and fragments of igneous
rocks. Beyond this the surface is in places thickly strewn with small
angular fragments of hard gray and blue crystalline limestone, with Pro-
ductus spirifer, spines of Encrinites, and other Carboniferous fossils. After
traveling fifteen miles we reached the western declivity of the Organ Moun-
tains, and soon after entered the San Augustine Pass, through which we
continued to travel the remainder of the day. Directly south of this pass
the mountains attain an elevation of about three thousand feet. Their out-
line is sharp and jagged, and the peaks project above each other in rapid.
succession, giving to the mountains a highly picturesque appearance. Here
they are composed almost entirely of compact red porphyry and light gray
porphyritic granite, in which feldspar greatly predominates. The porphyry
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was only observed on the western side of the mountains, and forms but an
inconsiderable portion of the range.
Against the western declivity the Carboniferous Limestone is exhibited,
dipping about 80 degrees west, and where it is in immediate contact with
the eruptive mass presents a highly metamorphosed appearance. A short
distance from the mountains it is compact sub-crystalline, of a dark bluish
and gray, and crowded with fossils. In many places the rock is thickly
reticulated with veins of quartz, porphyry, calc, and fluor spar, some of
which present indications of being metaliferous. It is in the limestone of
this neighborhood that the rich mines of argentiferous galena, at present
little known but destined ere long to be extensively and profitably worked,
have been discovered. Magnetic iron ore of a very fair quality also occurs
in this vicinity.
Our way through the Pass led mostly over hard porphyritic granite simi
lar to that last described. This rock forms on either side of the Pass
rough and in places almost vertical cliffs from one to two thousand feet.
high. But a little farther north it diminishes rapidly in elevation, and at a
distance of one or two miles we find it merely in detached hills a few
hundred feet high, and at the same time the Carboniferous Limestone be-
comes largely developed, and soon constitutes by far the greater portion of
the entire bulk of the mountains.
Mar. 9.-This day we traveled for several hours through the Pass, and
then emerged into a smooth open plain, extending north and south as far as
the eye could reach, and having an average width of about thirty miles.
On our road to El Paso we crossed this plain about forty miles farther
south. It presents the same general features here as in its southern exten-
sion. North of us the surface is frequently whitened with saline incrusta-
tions and marls.
On either side it is enclosed by lofty mountains. Those on the east-the
Sacramento range--appear as a continuous line of bold, rugged, and nearly
vertical escarpments, extending many miles north, the most prominent peak
being the snow clad summit of the Sierra Blanco, from which they decline
in elevation both north and south. In the neighborhood of the Dog Canyon
they do not appear to exceed eight hundred or a thousand feet in height.
Immediately to the west of the Sacramento Mountains, and pursuing a
course nearly parallel with them, occur the range of eruptive rocks already
mentioned as forming a continuation of the Hucco Mountains. Opposite
the mouth of the Dog Canyon they form a ridge several miles in length
with an elevation of seven or eight hundred feet, and thence northward
they diminish in height and are exhibited merely in isolated points for the
distance of forty or fifty miles.
After entering the plain we travelled along the castern base of the Organ
Mountains, which here present an exceedingly rugged appearance, but with
JOURNAL OF GEOLOGICAL OBSERVATIONS.
113
the exception of being occasionally of a deep red hue, the rocks forming them
do not differ from those last described. Our road was mostly over horn-
blende and mica schist, in many places thickly traversed with dykes of
quartz, greenstone, and porphyry, often appearing in low isolated hills and
ridges several miles east of the mountains. All of these rocks yield rapidly
to the weather, and the surface is generally thickly covered with coarse red
sand in which feldspar is freely mingled.
Late in the day we arrived at the Ojo de la Soledad, a clear stream of
running water one or two feet deep, which originates from springs that issue
from the igneous rocks. The water is clear, highly alkaline, and possesses
a temperature of about 68 degrees F.
Mar. 10.-I spent the greater portion of this day in exploring the moun
tains near the Ojo de la Soledad.
They here present an exceedingly rough aspect, and are traversed from
east to west by deep, tortuous canyons, some of them with nearly vertical
walls from a thousand to fifteen hundred feet high. These were found to
consist mainly of coarse granite in which feldspar predominates. The color
varies from light gray to brown and deep red; the mica is usually black
and in very minute scales, while the quartz is often so intimately blended
with the feldspar as to render it difficult to distinguish one from the other.
The altitude of the mountains at this point is from two to three thousand
feet, and their summits exhibit a remarkably sharp and broken outline.
A few miles south the eruptive rocks decrease rapidly in elevation, and
are finally succeeded by upheaved strata of hard crystalline limestone of the
Carboniferous Period, which increases rapidly in thickness and soon consti-
tutes almost the entire bulk of the mountains. This rock presents precipit-
ously to the east, where it exhibits a thickness of about three thousand feet,
with a dip to the west at angles of from 30 to 60 degrees. It is usually
compact, of dark blue and gray colors, with bands of dark argillaceous shale
intercalated, from thirty to a hundred feet thick.
Many of the layers are rich in fossils, and some of them are almost en-
tirely made up of the remains of Crinoidea. Among the fossils collected
from this locality are Productus semireticulatus, Productus several unde-
scribed species, Spirifer Forbesii, Spirifer lineatus, Spirigera hirsuta, Terebru-
tula subtilita, Terebratula lamellosa, Orthis umbraculum, and Phillipsia Meri-
macensis. The sedimentary strata extend as far as the "Puerto del Bracito,"
and are then again succeeded by the eruptive rocks, which continue all the
way to El Paso.
From the evidence collected I am inclined to the opinion that the valley
between the Organ and Sacramento Mountains is mainly, if not entirely,
composed of eruptive and metamorphic rocks.
Mar. 11.-After leaving the Ojo de la Soledad we continued our southerly
114
JOURNAL OF GEOLOGICAL OBSERVATIONS.
course along the eastern base of the mountains for eight or ten miles, over
mica and hornblende schist, with occasional intrusions of quartz, porphyry,
and other eruptive rocks. We then diverged towards the Hueco Moun-
tains, now plainly visible and about forty miles distant. Beyond the
mountains the surface of the country gradually descends for three or four
miles, and is often covered with coarse angular fragments of eruptive
rocks. At the distance of six miles we reached a range of low gently
sloping hills of red porphyry, quartz, and other eruptive rocks; the por-
phyry being in some places so soft as to admit of being crushed between
the fingers. Passing these hills we continued during the remainder of the
day over thick beds of coarse sand, with fragments of decomposing igneous
rocks intermingled. The surface is for the most part flat, and covered
with short bunch grass, and the soil generally of the most unproductive
character.
Mar. 12.- During the entire day's journey we continued to travel over
coarse red sand and detritus of the same character as before. The surface is
in many places slightly undulating, and the soil generally barren, support-
ing only a sparse growth of coarse bunch grass. No limestone or any other
sedimentary rocks were anywhere observed on the road.
Mar. 13. Shortly after leaving camp to-day the surface became much
more hilly, but still thickly covered with coarse sand and detritus of the
same character as above. At the distance of five miles we arrived at a
series of low rounded hills of dark bluish and gray crystalline limestone,
dipping east and southeast at angles of from 30 to 70 degrees, and highly
charged with fossils of the Coal Measures. These hills connect towards
the southeast with the line of cliffs already described as forming the south-
ern prolongation of the Sacrameto range, and the upheaval of the strata is
doubtless due to the protrusion of the Hueco Mountains. Shortly after
passing these hills we reached the Hueco Mountains and entered upon our
old road from the Rio Pecos. During the latter portion of our day's march
the soil was found to improve in character, and in some places was covered
with a thick growth of grass.
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115
CHAPTER IX.
FROM THE HORSE HEAD CROSSING OF THE RIO PECOS TO SAN ANTONIO DE BEXAR,
VIA FORT MCKAVITT, FORT MASON, AND FREDERICKSBURG.
From our permanent camp near the mouth of Delaware Creek to the
Horse Head Crossing of the Rio Pecos our route was over nearly the same
region as that traversed by the Expedition from May 19 to May 26, 1855. I
shall, therefore, in the present chapter, only speak of the geology of that
portion of our return route east of the Horse Head Crossing.
At this crossing the Rio Pecos makes an extensive bend to the southeast,
and presents on both sides low bluff banks of red marly clay. The valley on
either side is broad, moderately fertile, and in places covered with a growth
of excellent grass.
After leaving the river we at first passed over red clay and sandstone,
and at three miles ascended to the summit of a low mesa, and soon after en-
countered thick beds of snow white gypsum and pulverulent limestone,
reposing upon the clay and sandstone. The surface of this mesa is generally
moderately undulating and thickly covered with grass and mezquite bushes.
In several places it is strewn with small angular fragments of dark scoria.
After traveling thirteen and a half miles we arrived at the "Castle Moun-
tains," which stretch irregularly north and south for many miles, and are
nothing more than the borders of the table land terminating percipitously
to the west. They are a continuation of the same cliffs encountered by the
Expedition while en route from San Antonio to El Paso. (See notes of May
18, 1855, Chapter IV.) At this point their height above the valley of the
Pecos is about eight hundred feet, but they decline gradually towards the
north, so that in fifteen or twenty miles they do not exceed two hundred feet
in height. In their southern extension they also decrease in elevation, and
at the distance of forty miles curve gently to the west. They consist of red
clay surmounted with limestone of the Cretaceous System. (See section No.
-.) The thickness of the limestone at the point examined is about seven
hundred feet. It is in some places compact, crystalline, and of a light gray
color, and in others soft, earthy, and disintegrates rapidly. The usual Cre-
taceous fossils were observed in it in the greatest abundance, limited, as at
many other points farther south, chiefly to two distinct bands near the top
and base of the formation. The upper band is about one hundred feet thick,
of a light yellow color, earthy in texture, and is undergoing rapid disinteg-
ration. The lower band is about fifty feet thick, and is compact and sub-
crystalline. From the upper band I collected examples of Cardium Sancti-
Sabæ, Janira Texana, Hemiaster elegans, and Pterodonta subfusiformis.
The clay is highly indurated and of a deep red color. Near its upper
116 JOURNAL OF GEOLOGICAL OBSERVATIONS.
portion thin seams of saccharoid and transparent gypsum are interstratified.
The dip is E. S. E. about 1 degree.
On reaching the summit of the cliffs we found ourselves upon a gently
rolling country, thickly covered with grass and mezquite bushes, stretching,
eastward to the verge of the horizon. South of our line of travel is a still
more elevated plateau, limited by a continuous line of bold rugged cliffs of
compact Cretaceous Limestone from two to three hundred feet high. The
surface of this plateau is also gently rolling, and here and there interrupted
by canyons, some of them with steep declivities several hundred feet deep.
Distance from the Horse Head Crossing of the Rio Pecos to our evening
camp, 214 miles.
Sept. 7.-Our road during this day was over an elevated and gently un-
dulating plateau, with a dark marly soil, supporting in many places a thick
growth of grass and mezquite bushes and exhibiting frequent exposures of
the Cretaceous Limestone. After traveling twelve miles we reached the
Wild China Ponds, a series of shallow basins hollowed out of the limestone.
These are natural reservoirs for water, which may be obtained here seve-
ral months after the close of the rainy season. From this point to Flat Rock
Ponds, situated about fourteen and a half miles distant, there is but little
variety of surface, our road being still over gently undulating country.
Distance, 26 miles.
Sept. 8.—After leaving Flat Rock Ponds our route was still over elevated
prairie, differing but slightly in its geological features from that of yes-
terday. The Cretaceous Limestone is still the prevailing formation, appear-
ing above the general surface in smooth and gently rounded hills from
fifty to two hundred feet high. The country is thickly covered with dark
marly soil, more fertile than any previously encountered, and its aspect.
more pleasing. It bears a heavy growth of grass and mezquite trees.
At about twelve miles we came to a series of shallow basins partially
filled with rain water, similar to those encountered yesterday. A farther
travel of twelve miles and a half brought us to the head of the Rio Concho.
This stream rises in a swampy valley, whose direction is somewhat irregu-
larly east and west. It is limited on either side by long low ridges of Cre-
taceous Limestone. The bed of the stream has an average width of about
twenty feet, and on both sides are steep rocky banks.
Distance, 24½ miles.
Sept. 9. This day our route lay through the valley of the Rio Concho,
which increases rapidly in width as we advance. It is characterized by
rich dark soil, bearing an abundant vegetation, and bounded on either side
by a plateau from two to three hundred feet high, with gentle declivities
down to the level of the valley. These plateaux are traversed by deep
JOURNAL OF GEOLOGICAL OBSERVATIONS.
117
valleys, some of them two or three miles wide, and bearing pretty nearly
east and west.
The river draws its supply of water mainly from springs. A few miles
below the source its average width is about seventy-five feet; its banks are
precipitous, and usually skirted with dense vegetation. The Cretaceous
Limestone still prevails in nearly horizontal strata, and abounds with
fossils.
Distance, 17½ miles.
Sept. 10.-Our road still continues along the valley of the Concho, which
varies from a few hundred yards to several miles in width, and is thickly
covered with a dark and remarkably fertile soil. The surface is diversified
with rounded hills of Cretaceous Limestone from one to five hundred feet
high. At one locality near the river margin the red marly clay and sand.
stone were also exhibited, as shown in the following section:
1. Hard gray Cretaceous Limestone.
2. Indurated deep red clay. 20 fect.
500 feet.
3. Soft, ferruginous, coarse grained sandstone, crumbling rapidly to the
weather. 50 feet.
Sept. 11. — Geological formation the same as before. Our road during
the day was mostly over gently rounded hills from two to four hundred
feet high, separated by deep valleys. The limestone composing the floors.
of the valleys is usually quite soft, disintegrates readily, and is in places.
filled with Cretaceous fossils.
Soil rich and in places supporting a heavy vegetation.
Trees, mostly mezquite, live oak, wild china, hackberry, and pecan.
During the day's march we crossed several tributaries of the Rio Concho,
all of which rise from springs, the water of which is highly charged with
calcareous matter.
Distance, 14 miles.
Sept. 12. The general features and geology of the country seen to-day
are the same as yesterday. In the declivities of the hills the strata are
exposed often to the height of four or five hundred feet, and occasionally
are crowded with fossils, of which the most common are Ammonites acuto-
carinatus, Cardium multistriatum, and Homomya alta.
After traveling eleven miles we arrived at one of the principal affluents
of the Rio Concho. This is here about seventy-five feet wide, and flows
between bluffs and well wooded banks. The water is clear, calcareous, and
its average depth about five feet.
Distance, 18 miles.
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JOURNAL OF GEOLOGICAL OBSERVATIONS.
Sept. 13. After traveling eleven and a half miles farther through the
valley of the Rio Concho we ascended to the top of the table land, over
which we continued the remainder of the day. At the point of ascent the
Cretaceous Limestone is well exposed, and exhibits a thickness of about
five hundred feet. The strata vary considerably in compactness and color,
and contain bands of chert and rounded nodules of dark flint. Character-
istic fossils of the Cretaceous System occur here in great abundance. The
suface of the table land is usually flat, and occasionally rocky, but more gen.
erally thickly covered with dark rich soil, supporting a fine growth of grass.
Distance, 19 miles.
Sept. 14. Shortly after leaving camp we entered into the broad and fer-
tile valley of the Rio San Saba near its head. This stream rises from a
number of shallow pools which derive their supply of water from springs.
in the vicinity. The water is clear, highly calcareous, and has a temperature
of 69 degrees F. The surface of the valley is diversified with gently sloping
ridges and rounded hills from one to four hundred feet high, and composed
of Cretaceous Limestone in nearly horizontal strata.
At the distance of twenty-two miles from our camp we came to Fort
McKavitt, situated upon a rocky hill near the river. It is surrounded on
all sides by fertile valleys. At this point the Rio San Saba is about sixty
feet wide, flows over a rocky bed, and is bounded on either side by abrupt
walls of limestone. The whole district traversed to-day is a desirable one
to the agriculturist, and destined at no very distant period to be thickly in-
habited.
Distance, about 25 miles.
Sept. 15.-After leaving Fort McKavitt we traveled for several miles
over nearly flat prairie, with dark carbonaceous soil, supporting a thick
growth of grass and mezquite. The country then becomes hilly, and was
traversed from east to west by long low ridges, with precipitous sides, and
composed of gray and light yellow earthy Cretaceous Limestone in nearly
horizontal layers. During the day we frequently crossed the Rio San Saba,
which is a beautiful clear stream with a hard rocky bed. Its width is from
fifty to one hundred feet, and on either side are escarpments of limestone ex-
posed sometimes upwards of a hundred and fifty feet high. The river valley
is from a half to three or four miles wide. In places it is thickly strewn
with rounded flints and coarse angular fragments of limestone.
Distance, 25 miles.
Sept. 16.-After leaving camp we passed over strata of hard gray lime-
stone, with an abundance of flint nodules embedded, and containing but few
fossils. Below these we have soft earthy yellow limestone, densely crowded
with organic remains, the most abundant species being Exogyra Texana,
JOURNAL OF GEOLOGICAL OBSERVATIONS.
119
Natica elevata, Actæonella dolium, Lima Wacoensis, Cardium Hillanum, and
Pterodonta subfusiformis.
These beds have a thickness of about eight hundred feet, and dip west 8
degrees. They prevail for about five miles, and are then succeeded by
heavy deposits of red marly clay and sandstone, which emerge from beneath
the limestone, exhibiting a thickness estimated at from five to eight hun-
dred feet. The clay is highly indurated, of a bright vermilion color, and
interstratified with the sandstone. In lithological character it is not to be
distinguished from that in the vicinity of the Rio Pecos.
After traveling a mile over this formation we came to an extensive out-
crop of hard gray granular limestone, belonging to the Upper Division of
the Carboniferous System, which here is to be seen emerging from beneath
the Cretaceous strata. These rocks are exposed for the distance of about
five miles, and form an anticlinal axis from which the strata dip east and
west at an angle of about 10 degrees.
I found here characteristic Carboniferous fossils in great profusion. The
most common species are Terebratula subtilita, Spirifer Meusebachanus, S. lin-
catus, Fenestella species undetermined, Productus punctatus, P. costatus, and P.
aquicostatus.
Beyond this exposure the Cretaceous strata again appear, and continued
to be exposed at frequent intervals until we reached our evening camp.
The country passed over to-day is rolling and the soil rich.
Distance, 15 miles.
Sept. 17.-Gray and yellow earthy Cretaceous Limestone was largely de-
veloped for several miles along our route to-day, to which succeeded strata
of red marly clay and soft sandstone. At the distance of eight miles we
found thick layers of coarse quartzose sandstone, which differ in a marked
manner from any previously encountered. It is micaceous, of deep red and
black colors, hard, and passes into conglomerate. Its thickness is estimated
at about six hundred feet, and the dip is west at angles of from 10 to 20
degrees. About three miles beyond this point the same beds are highly
contorted and metamorphosed, and are seen reposing on granite.
From this locality to within a short distance of Fort Mason our road was
almost entirely over coarse reddish granite, gneiss, and mica schist. In
places the granite projects above the surface to the height of two or three
hundred feet, imparting to the country a peculiarly rough and sterile ap-
pearance. This range bears nearly north and south, and may be traced a
great many miles in either direction.
At Fort Mason the sandstone is again well developed, presenting in
abrupt hills five or six hundred feet high. The strata are here highly undu-
lated, and dip in various directions at angles of from 20 to 50 degrees. A
short distance beyond Fort Mason eruptive rocks similar to those last men-
tioned again appear.

I.
Section of Strata on Rio San Saba, Sept. 16, 1856.
Cretaceous Limestone. 2.
2. Marly Clay and Sandstone. 3. Upper Carboniferous Limestone.
JOURNAL OF GEOLOGICAL OBSERVATIONS.
121
For the first ten miles after leaving camp the soil was remarkably fer-
tile and the surface hilly and intersected by numerous ravines. Afterwards
the country was rocky and barren.
Sept. 18.-After traveling five miles over igneous rocks of the same
character as those observed yesterday, we again came to thick layers of
coarse quartzose sandstone and conglomerate. The sandstone is hard,
highly ferruginous, and often passes into silicious iron ore. At its junction
with the eruptive rocks the layers are highly folded and metamorphosed,
but a few hundred yards distant present an irregular dip to the cast of
about 40 degrees. Two miles farther these rocks are again succeeded by
granite and other eruptive rocks, which are in places traversed by thick.
veins of quartz. The granite is mostly soft, coarse grained, and of light
gray and red colors. The quartz is compact and milky, and the different
veins are sometimes over fifty feet in thickness. Six miles beyond this the
sandstone and conglomerate reappear, and thence constitute the prevailing
surface formation for the distance of about three miles, after which they
disappear and are no more met with during the remainder of the distance
to our evening camp, being succeeded by eruptive rocks of the same char-
acter as before.
During the day we crossed the Llano River, a small stream of clear
water flowing over a bed composed of eruptive rocks. The surface of the
country is rough and hilly, and supports a scattered growth of stunted oak.
Distance, 22 miles.
Sept. 19. Shortly after leaving camp we again came to compact and
soft Cretaceous Limestone, which continued to be largely developed until we
arrived at Fredericksburg. The surface of the country is generally rough
and broken, and marked by ridges and conical hills of limestone; soil fertile
and in places covered with heavy vegetation. At Fredericksburg the un
derlaying marly clay is well exposed. Beyond this point, however, it disap-
pears, and is not again met with until we approach San Antonio de Bexar.
From Fredericksburg to San Antonio de Bexar our road was over con-
tinuous beds of hard and soft Cretaceous Limestone, which at some points
attains a thickness estimated approximately at about eleven hundred feet.
It, however, does not differ lithologically or paleontologically from that
last described. The surface of the country is generally broken, possesses a
rich soil, and affords every inducement to the agriculturalist.
APPENDIX.
GRAYSON COUNTY.
BY GEO. G. SHUMARD.
The county of Grayson was created by the Legislature of Texas in the
year 1846, and was fully organized in the same year by the election of its
different county officers.
It is situated near the center of the extreme northern tier of counties,
and is bounded on the north by Red River, which separates it from the
Indian Territory, on the east by Fannin, on the south by Collin and
Denton, and on the west by Cooke counties. Its superficial area is a little
over nine hundred square miles, and it contains at this time a white popu-
lation of eight thousand five hundred and eighteen inhabitants, and a
voting population of one thousand and twenty-five persons.
Its surface is undulating, and in places somewhat hilly, and is marked
by four elevated ridges which traverse the county in different directions.
The first and most elevated of these ridges extends from east to west
across the southern portion of the county, and here forms a portion of the
main divide between the waters flowing north into Red River and those
flowing south into the Gulf of Mexico. Its summit is in some places much
more elevated than in others, is usually flat or gently undulating, and varies
in width from a few yards to several miles. This ridge enters the county
in its southeastern portion, and here forms the elevated district upon which
Pilot Grove and Kentucky Town are located. From these points it pur-
sues a westerly course until it approaches a point about midway between
the eastern and western boundary lines of the county; thence it turns north-
west to form the divide between the head waters of Choctaw Bayou and
Range Creek, beyond which its general course to the western boundary
line of the county is a little north of west. The sides of this ridge are usu-
ally gently sloping. In some places they are, however, marked by deep
rocky ravines, and in others are hilly and much broken.
A second ridge traverses the county in a north and south direction, and
forms the divide between the waters of Big Mineral and Choctaw Bayous
in the northern and central portions of the county, and several of the head
branches of the Trinity River towards the south. Near the center of the
county this ridge unites with the one last described, but a few miles farther
south is again seen pursuing a separate course. The sides of this ridge are
usually smooth and gently sloping. In a few places they are abrupt, and
marked by triangular rocky ravines.
A third ridge runs pretty nearly east and west through the southwestern
portion of the county, while a fourth, known as Iron Ore or Pilot Knob
Ridge, pursues very nearly the same general direction in the northeastern
portions of the county. The former is less elevated than either of the
others, and forms the divide between Isle du Bois and Bush Creek.
124
APPENDIX.
The latter, or Iron Ore Ridge, is much more elevated, presents abruptly
sloping sides, and is marked along the summit by a number of conoidal
elevations.
The surface of the county mostly consist of smooth undulating prairio,
here and there diversified with groves of trees. The slopes are usually
gentle, and with the exception of the northeastern and southern portions,
which are somewhat hilly and marked by deep ravines, the surface is but
little broken.
Of these
Grayson county is watered by Red River, which flows along its northern
border, and by numerous creeks, many of which contain a constant supply
of water, while many others go dry during the summer seasons.
creeks those most deserving of note are the Choctaw, Big Mineral, Post
Oak, Tittle Mineral, Shawnee, Iron Ore, Mill, Isle du Bois, Bush, Little
Elm, East Fork, White, Lester Grove, and Pilot Grove Creeks. The
largost and most important of those creeks empty into Red River, and their
beds are usually flat, sandy, and sunk deep below the general level of the
country, while their banks are usually either abruptly sloping or vertical.
The central and northern portions of the county are drained by the differ-
ent streams flowing north into Red River, the two largest of which are the
Choctaw and Big Mineral Bayous, the first flowing through the northeastern
and the second through the northwestern portions of the county, while all
the waters south of the dividing ridge running cast and west flow into the
head branches of the Trinity River. It is worthy of note that with the
exception of a few of the western branches of tho Big Mineral Bayou, all
the creeks flowing in Grayson county have their origin within the limits of
the county, and most of them rise near its center.
Good timber, suitable for fuel and building purposes, is very abundant in
the northern and western portions of the county, as well as along all the
different streams, which are usually densely clothed with trees Small
groves of trees are also occasionally seen dotting the uplands of the contral
and southern portions of the county. The principal varieties of trees occur-
ring upon the uplands are post and blackjack oaks, interspersed occasionally
with hickory, black walnut, and more rarely mezquito trees-the last inen-
tioned variety being only seen in the western and southwestern portions of
the county. Along the river and creek bottoms the principal growths are
Overcup, Spotted, P'in, Black, Red, Chincapin, Post, and Live Oaks; Cotton-
wood, Hackberry, l'ecan, Box Elder, Black Walnut, Sycamore, Bois d'Arc,
smooth and rough bark Hickory, Persimmon; White, Black, and Prickly
Ash; two varieties of Dogwood; Wild China, Chickasaw Plum, Mulberry,
Rod and Black Haw, IIoney and Black Locust, Swamp Willow, Sassafras,
Black and Green Brior, Red Bud, Red Cedar, Gum, Spicewood, Pawpaw,
and Wild Cherry trees.
Grayson county is settled by an industrious, moral, and thriving com-
munity. The principal articlos of produce of the county are maize, or
**
* According to the statistical returns for 1859 there are in successful operation in tho
county, four high schools, two of which are located within the town of Sherman, one in
Kentucky Town, and one in Pilot Groyo, and forty-two common schools, which are located
in various portions of the county. There are also oightoon churches in the county, viz
Six Prosbyterian, ono Protestant Methodist, six Mothodist Episcopal South, oue Primitivo
Baptist, and throo Missionary Baptist churches. The county contains eight towns. Sher-
man, the county soat, is a pleasant, flourishing town, situated near the centre of the county,
on the east side of Post Oak Crook, on the northern portion of the Saul Blagg and southern
portion of the J. B. McAnair headright surveys. The town was located in 1848, and incor-
porated by the Logislaturo in January, 1849. It occupios an area of one square mile, and
contains an industrious, thriving population of 613 inhabitants. It contains a good brick
APPENDIX.
125
Indian Corn, wheat, and oats. Considerable attention is also there paid to
the raising of stock.f
Scientific Geology.
The rock formations of Grayson county are all comprehended in the three
systems known to geologists as Quaternary, Tertiary, and Cretaceous.
*
**
**
**
*
*
3%
#:
*
2:
QUATERNARY SYSTEM.
Under this head is included all the rock deposits of more recent origin
than the Tertiary formation. This system attains in Grayson county a ver-
tical development of over a hundred feet, and is best exhibited along the
banks of the different streams, where vertical sections of these deposits are
often exposed to the thickness of forty or fifty feet.
The Quaternary deposits of this region consist: 1st, of Alluvium; 2d,
Loess; and 3d, Pebbles.
I. ALLUVIUM.
The Alluvium is the most recent of all the Quaternary deposits, and con-
sist of: 1st, Soils; 2d, Sands; 3d, Clays; 4th, Pebbles; 5th, Calcareous
Tufa; 6th, Bog Iron Ore.
1. Soils. As will hereafter be seen, the soils of the county vary consid-
crably in character. They are usually composed of the debris of more
ancient formations, together with decomposed vegetables and animal re-
mains. The rocks of this region being usually soft and therefore easily
acted upon by atmospheric influences, the soils, as might be expected, are
correspondingly thick. For a full description of these soils the reader is
referred to the article upon the economical geology of Grayson county.
2. Sand. There are several varieties of sand occurring in Grayson
county, one of the principal of which belongs to the valley of Red River,
and is fully described in the report upon that stream. (See Geology of Red
River.) The others are very abundant in the northwestern and northeastern
portions of the county, as well as in the beds and along the banks of most of
the principal streams. They usually consist of very fino particles, which
are in some localities composed almost entirely of pure silex, and in others
of silex more or less intermixed with calcareous matter. Their color varies
from light gray to brown and yellow. In some places they are largely in-
termixed with small rounded black ferruginous pebbles, and also often con-
tain numerous fish teeth. These sands are mainly derived from the disin-
tegration of the soft sandstones of the Tertiary and Lower Cretaceous
Systems. The pebbles and fish teeth are derived from the conglomerate
and sandstone of the Lower Cretaceous Group.
These sands often accumulate to the depth of eight or ten feet in the beds
court house, two churchos, two schools, two hotels, two large livery stables, and soven
storos, with an aggregato capital investod of near two hundred thousand dollars. Ken-
tucky Town, Pilot Grove, McComb, Whitesboro, and Farmington are all thriving villages
located in the county. Proston, on Red River, was at ono time a town of considerable im-
portance, but is not now in a flourishing condition. There are at present one saw mill and
fiftoon flouring or grist mills in the county, of which four aro workod by stoam, throo by
wator, and nine by oxon.
†The number of cattle in the county in 1859 was 29,192, and of horses 3667.
126
APPENDIX.
..ว
of the different streams, while in the northeastern and northwestern por-
tions of the county their thickness has been estimated at from twenty to
thirty feet.
In the vicinity of Walnut Creek, in the northwestern portion of the
county, thick beds of coarse green calcareo-silicious sand, containing small
scales of black mica, are met with. It is derived from the disintegration of
the coarse green sandstone of that vicinity.
3. Clay.—Alluvial deposits of calcareo-argillaceous clay are of frequent
occurrence along the different streams in the county. They are usually
highly indurated and compact, and vary in color; that occurring along Red
River being usually deep red, while those in the interior of the county pre-
sent various shades of blue, brown, and yellow. These clays are mainly
derived from the disintegration of the argillaceous beds of the Lower Cre-
taceous formation. They sometimes contain a notable quantity of gypsum,
and if found in sufficient quantity would constitute valuable fertilizers.
4. Pebbles of hard gray limestone and yellow sandstone occur abundantly
in the beds of most of the streams in the county. They are usually small
and rounded, and are all derived from the destruction of the limestone
and sandstone of the Cretaceous System, whose characteristic fossils they
often contain. In the beds of Post Oak and Choctaw Creeks thick accumu-
lations of Ostrea, derived from the neighboring strata, are often met with.
In many places the surfaces of the prairies are strewn with small rounded
pebbles of quartz, jasper, and other silicious rocks. From their appearance
these have evidently been transported from a distance, as no rocks of the
samo character are found in situ in the county.
5 and 6. Culcareous Tufa and Bog Iron Ore. In a few localities deposits
of these characters have been discovered in the county, but they do not oc-
cur in sufficient abundance to merit a separate consideration.
The deposits thus far described constitute the principal alluvial forma-
tions of Grayson county. They are all derived from the destruction of the
older rocks, caused by the separate or united action of water, air, and frost,
and are still in process of formation from the same causes.
II. LOESS.
The Loess formation, whose existence in Texas was first published by
myself in 1852 (see Marcy's Report), is largely developed in Grayson county.
It is usually exposed in the form of vertical bluffs along the different
streams, and here attains a general thickness of forty or fifty feet. The
best exposures of this formation in the county are met with along the banks
of Red River, and Post Oak, Choctaw, and Big Mineral Creeks, where good
vertical sections of it thirty or forty feet in thickness are frequently exhib-
ited. Wherever examined it has been found reposing upon beds of pebbles,
and the line of division between the two is by no means distinct, the one
formation gradually running into the other.
This formation is here composed of highly indurated compact silicious
and calcareo-silicious clay. That exposed along Red River is made up of
alternating bands of marly clay and fine silicious sand, and is usually
deeply colored with red oxide of iron, while that occurring in the interior
of the county is usually much less ferruginous, of a light yellow color, and
homogeneous in character. Not unfrequently it contains small rounded
pebbles of white carbonate of lime and silicious rocks, and is sometimes,
especially towards its upper portion, thickly marked with decayed roots of
vegetables.
APPENDIX.
127
This formation is rich in organic remains, consisting mainly of terrestrial
and fluviatile shells. These shells are quite numerous, are generally in a
good state of preservation, and are equally distributed through every por-
tion of the formation. Fragments of fossil wood and decayed bones are
also sometimes met with in this formation.
III. PEBBLES.
As already remarked, the Loess is usually found resting upon beds of
pebbles. These occupy the same geological position as those composing the
drift in other States, but differ from them in general composition. They
are evidently mainly derived from the destruction of Cretaceous strata, are
usually quite small and well rounded, and consist of hard light gray lime-
stone and silicious rocks. The silicious pebbles are mostly confined to the
sections exposed along the valley of Red River, while those exhibited in
the interior of the county are usually composed of calcareous rocks. In the
latter fossils of the Upper Cretaceous system are abundantly exhibited.
They are also occasionally intermixed with fraginents of fossil dicotyledon-
ous wood. These pebble beds vary in thickness from one to five feet,
though usually they do not exceed in this respect two feet. Many of them
have evidently been transported from a distance, and their deposition must
date anterior to the formation of the loess beds. In a few localities they
are observed loosely cemented with calcareous and ferruginous paste.
Many of the pebbles already described under the head of alluvium as
occurring upon the surfaces of the prairies probably belong to this period,
as beds of the same character of rocks are met with several feet in thickness
beneath the loess west of Grayson county.
TERTIARY SYSTEM.
The Tertiary System is well developed in Grayson county. It is limited,
however, to the north, no rocks of this class being found in its central or
southern portions. Towards the northeast these rocks are well exposed,
and there form the elevated ridge known as Iron Ore or Pilot Knob Ridge.
In this situation they present an average width of four or five miles, and a
general thickness of over two hundred feet. A little east of this they are
seen extending much farther south. Immediately west of Iron Ore Ridge
these rocks disappear entirely, giving place to strata of Lower Cretaceous
age, but again make their appearance near the head of Little Mineral
Creek, and thence continue uninterruptedly as far as the western boundary
of the county. Towards the northwest they constitute almost the entire
area watered by the western branches of Big Mineral Bayou.
In Iron Ore Ridge sections of these strata are exposed to the thickness of
one hundred and fifty feet, and their general thickness in the county can
not fall far short of two hundred and fifty feet.
These rocks, according to their different lithological as well as paleonto-
logical characters, are here divided into three distinct groups, which we
shall name, 1st, Upper Arenaceous Group; 2d, Middle or Green Sandstone
Group; and 3d, Gypseous Clay Group.
1. UPPER OR FERRUGINOUS GROUP.
The strata composing this division are about one hundred and thirty feet
in thickness, and occupy the superior position. They vary considerably in
128
APPENDIX.
character, being in some places quite hard and firm, and in others quite soft,
or but little more than loosely coherent sand. They usually occur in mas-
sive beds, and the divisional lines between them are generally very indis-
tinct and often not at all visible. These strata are subdivided according to
their lithological character into two distinct groups, which we shall call
upper and lower ferruginous groups.
1. Upper Ferruginous Group.-The rocks of this division occupy the
summit of the formation, and are abundantly encountered along the more
elevated portions of Iron Ore Ridge, and also upon the summits of many of
the Tertiary hills in the northwestern portions of the county. Their average
thickness is estimated at about fifty feet. They consist of hard, yellow, red
blue, and ferruginous brown calcareo-silicious sandstone-the percentage
of carbonate of lime being usually very large. The rock is usually very
compact, and the quartzose grains are scarcely distinguishable in it. It
breaks with an uneven fracture, and its freshly fractured surfaces are
usually of a light blue color and exhibit a glistening luster, but turn dull
earthy and ferruginous colored upon exposure. This rock is highly ferru-
ginous and frequently passes into silicious iron ore. It occurs in massive
beds, and the plains of stratification are usually very indistinct. Owing to
the large percentage of iron it contains, this rock, whenever exposed, is
found to be undergoing rapid disintegration, and is often from the same.
cause filled with irregular cavities, some of them a foot or more in diameter.
2. Lower Ferruginous Group.-These rocks occupy a position immediately
below the last, and are exhibited wherever the Tertiary strata are seen in
Grayson county. Their average thickness is about seventy-five feet. Good
vertical sections of these rocks are frequently exposed along Iron Ore Creek
and throughout the entire northwestern portions of the county. They con-
sist of sandstone, which is generally quite soft, being often nothing more
than loosely coherent sand. Its usual color is light yellow, from which it
passes into shades of red, brown, and gray. It is often highly ferruginous
and not unfrequently passes into impure silicious iron ore.
The quartzose
grains are usually very distinctly exhibited and very fine. This rock gener-
ally occurs in heavy massive beds, but in some instances it is found thin
bedded, and is sometimes marked by thin bands of hard blue calcareo-
silicious sandstone, and at others, especially towards the base, with thin
scams of indurated blue, red, and yellow argillaceous clay. In a few in-
stances the beds have been found to contain scattered small silicious peb-
bles. This rock is in places highly fossiliferous. The fossils are usually
limited to two distinct bands, one occurring near the summit and the other
towards the base of the formation. These bands vary in thickness from
one to three feet, and are usually composed almost entirely of Ostrea firmly
cemented into a breccia with calcareous and silicious matter. The teeth
and vertebra of fish are also occasionally found in these rocks.
The following section, taken from the bank of Iron Ore Creek at a point
where the creek cuts through a portion of Iron Ore Ridge, will exhibit the
character and position of these rocks:
SEC. 128.
1. Hard blue and yellow fine-grained glistening calcareo-silicious sand-
stone, when freshly fractured blue, but turning yellow upon exposure.
30 feet.
2. Soft, rapidly crumbling, fine-grained yellow silicious sandstone. 10 feet.
APPENDIX.
129
3. Fossiliferous band composed of ostrea cemented with calcareo-silicious
matter. 3 feet.
4. Soft, fine-grained, yellow, rapidly crumbling sandstone, with fossils near
the base. 15 feet.
5. Indurated blue and yellow clay with selenite. 5 feet.
6. Lignite. 3 feet.
7. Indurated blue clay with selenite and lignite in small particles. 5 feet.
8. Soft yellow clay with fossils.
5 feet.
II. MIDDLE OR GREEN SANDSTONE GROUP.
Occupying a position immediately below the group last considered we
have a series of deposits differing from them both in lithological and pale-
ontological characters. These rocks are limited to the northwestern portion
of the county, where sections of them are exposed below the yellow sand-
stone of the preceding group near fifty feet in thickness. The best sections
of these strata are exhibited along Walnut and Cedar Creeks, these streams
having cut through the formation to the depth of forty or fifty feet.
The principal rocks of this group consist of sandstone and clay. The
sandstone varies somewhat in character, being both soft and hard, and
massive and thin bedded, or even schistose. Its color is usually deep green,
from which it passes into various shades of red, yellow, and brown. It is
composed of coarse quartzose grains cemented by silicious and calcareous
inatter. In some instances the percentage of lime is very large, in which
case the quartzose grains are usually distinct and imbedded in it.
In some
places it is highly micaceous, the mica existing in the form of small scales
of black and yellow colors. Near the summit of the formation the rock is
usually much harder than towards the base, the lower beds being usually
quite soft and often but little more than loosely coherent sand.
This sandstone is everywhere thickly marked with concretionary masses,
which vary in size from a few inches to several feet, and are usually of a
spheroidal form. They are the same in composition, but always much
harder than the surrounding rock. They are distributed promiscuously
through the layers, and are sometimes composed of concentric layers, but
more generally they are homogeneous in structure and never exhibit any
traces of the plains of stratification marking the surrounding rocks.
rock also in places contains numerous flattened nodules from one to three
inches in diameter, of hard, compact, earthy, blue and green argillaceous.
limestone.
The
The clay occurs interstratified with the sandstone in layers of from one to
three inches in thickness, and also in small irregular masses disseminated
through the sandstone. It is usually argillaceous, compact, and indurated,
and varies in color from green to blue, yellow, and red. In some localities
it is highly arenaceous.
These rocks are sometimes rich in organic remains. The fossils are lim-
ited, however, to a few species, and consist mostly of ostrea.
Fossil wood is unusually abundant in this formation. It usually occurs
in the form of distinct logs, which are imbedded in the sandstone, and con-
sist of sections of the trunks of exogenous trees. These are very numerous.
In one locality no less than eight of them were counted. They vary in dia-
meter from one to three feet, and are often ten or fifteen feet in length.
They are usually found occupying a horizontal position, and their general
appearance would seem to indicate that they had been drifted to their pres-
ent position previous to their mineralization. The ligneous structure of the
130
APPENDIX.
wood is most perfectly preserved, and the medullary rays and fibrous tissue
are very distinct. The mineralizing substance is carbonate of limo. This
fossil wood is usually quite soft, of light gray, brown, and yellow colors, and
at a little distance can hardly be distinguished from partially decayed logs.
Like recent wood, it splits very readily in the direction of the grain, and can
be easily separated into distinct fibres.
III. GYPSEOUS CLAY GROUP.
This division occupies the base of the Tertiary System of Grayson county,
and consists of gypseous clay, sandstone, lignite, and limestone. Its general
thickness is about seventy-five feet, and good sections of it are met with
along Iron Ore Creek in the northeastern portion of the county, and also
along most of the principal western branches of Big Mineral Bayou.
The clay composes by far the greater portion of this division.
It is usu-
ally argillaceous, and of a deep blue color. In some places it is largely inter-
mixed with fine silicious sand. Its color also often changes to red, yellow, pur-
ple, green, gray, and brown. In some instances all these different colors are
exhibited in the same section, giving to the rock a variegated or ribboned-
like appearance.
This clay is usually highly indurated and exhibits a
schistose character. It is generally largely intermixed with selenite, which
is disseminated through it in the form of minute lenticular crystals. Some-
times these are so numerous as to constitute a fourth or fifth of its bulk, and
the water flowing through this formation is consequently generally bitter
and disagreeable to the taste. In a few instances thin seams of selenite
have been detected traversing the clay horizontally, and in others the clay
appears reticulated with the selenite. Small septaria, composed of hard
compact blue argillaceous limestone, are also sometimes met with in the
clay.
The limestone occurs mostly in the form of flattened nodules imbedded in
the clay. These are generally from one to two inches thick, and vary in
width from a few inches to one or two feet. They are usually hard, com-
pact, and of an earthy texture. They are of an iron rust color externally,
but when broken exhibit various shades of blue and brown. These nodules
usually occur in the clay in the form of distinct bands or layers which are
nearly horizontal. Sometimes several of these bands are witnessed in the
same section.
The sandstone and lignite occur interstratified with the clay. The
former, or sandstone, exists in seams from a fourth of an inch to six or
eight feet in thickness, the thicker beds being usually divided by very thin
partings of clay. This rock varies in color from light yellow to gray, brown,
red, and black, its most usual color being yellow. It is composed of fine
quartzose grains loosely cemented with silicious and ferruginous matter.
The rock is thin bedded, and the thinner seams are usually pleated. In
some instances its texture is hard and firm, but more generally the rock is
soft and rapidly crumbling.
The lignite occurs distributed through the clay and sandstone in small
irregular masses, and also in distinct seams which are interstratified with
the clay.
These seams vary in thickness from one to four feet, their usual
thickness being about three feet, and are generally nearly horizontal. In
some localities sections are exposed exhibiting two seams, one above the
other, the spaces between them being occupied with sandstone and clay.
In nearly all the sections examined the lignite has been found, both above
and below, in direct contact with the clay. The lignite is either of a dark
APPENDIX.
131
brown or black color, and is sometimes compact and homogeneous in com-
position, and at others exhibits distinctly the ligneous fibres of the original
wood. In some places it is largely intermixed with selenite in the form of
small lenticular crystals.
The rocks of this group are sometimes found to be rich in organic re-
mains. The fossils usually occur in the limestone nodules. Fragments of
fossil bones have also been found in one of the lignite beds.
ECONOMICAL GEOLOGY.
SOILS.
As might be anticipated from the varied character of the formations just
described, the soils of Grayson county differ greatly in character and pro-
ductiveness. For convenience of description we will arrange them under
the heads of the different formations to which they belong, and will accord-
ingly describe them as, 1st, Alluvial; 2d, Tertiary; 3d, Upper Cretaceous;
and 4th, Lower Cretaceous. By adopting this plan the reader will have no
difficulty in determining the area occupied by each class of soils by glancing
over the county maps accompanying this report.
1. Alluvial Soil. The alluvial soil of the portion of the county border-
ing on Red River has already been fully treated of in the agricultural por-
tion of the report upon Red River Valley, and its description need not be
repeated here. We will merely remark that for productiveness and ease
of cultivation it justly ranks among the very best soils in the State.
The creek bottoms in the interior of the county are usually thickly
clothed with alluvial soil. This soil is generally productive, and in all
respects well adapted for cultivation. It varies somewhat in composition,
being in some places highly argillaceous, and in others more or less mixed
with calcareous and arenaceous matter. It is usually of a dark color, loose
and porous, and well adapted for the retention of heat and moisture. It is
generally clothed with luxuriant vegetation, consisting of trees, vines, and
dense undergrowth. Among the trees the most abundant species are Over-
cup, Spotted, P'in, Black, Red, and Chincapin Oaks; Hackberry, Pecan, Box-
elder, Black Walnut, Sycamore; White, Black, and Prickly Ash; Dogwood,
Chickasaw Plum, Red and Black Haw, Honey and Black Locust, Swamp
Willow, Bois d'Arc, Sassafras, Black and Green Brier, Redbud, Red Ce-
dar, Gum, Spicewood, and occasionally Pawpaw.
Vines are unusually abundant in these regions. They consist principally
of the grape, of which there are several varieties, and the poison oak
(Rhus toxicodendron), while the undergrowth is of such a character as usu-
ally accompany rich alluvial soils.
These soils are well adapted to the cultivation of corn, wheat, oats, as
well as that of almost every other article of produce suited to the climate.
Tertiary Soils.-The soils overlying the rocks of the Tertiary System are
usually less productive than the preceding varieties. Some of them are,
however, vory favorably constituted, and afford abundant crops of corn,
wheat, and oats. These soils are mainly derived from the decomposition of
the rocks of the Tertiary strata, and consequently vary in character, being
in some places highly arenaceous, in others argillaceous, and in others more
or less mixed.
The first variety, or arenaceous soil, is not very productive, and but
poorly adapted for cultivation. It is well exhibited along Iron Ore Ridge,
132
APPENDIX.
as well as at some points in the extreme northern portion of the county.
It usually consists of fine yellow silicious sand, with occasionally more or
less admixture of carbonate of lime and iron. This soil generally supports
a good growth of Blackjack and Post Oak trees, which are usually accom-
panied by but little undergrowth.
The argillaceous or clay soil is much less abundantly distributed than
the preceding variety, being limited to a few small localities only. It
usually contains in its composition a large percentage of gypsum, and being
generally compact and impervious to water is of but little value for agricul
tural purposes. It is usually covered with short grass, and trees are but
seldom observed upon it.
The third variety or mixed soil is composed of sand and clay in various
proportions, with often a large admixture of carbonate of lime, gypsum,
and iron. It is often of a dark or nearly black color when freshly plowed,
but turns yellow upon exposure. This soil absorbs heat readily, is usually
retentive of moisture, and is therefore well adapted to the cultivation of
the different staples usually cultivated in this region of country. It is
abundantly seen in the northeastern portion of the county, and is the pre-
vailing soil throughout the entire region watered by the western branches.
of Big Mineral Bayou. It is often densely clothed with trees, the two prin-
cipal varieties of which are Post and Blackjack Oaks.
Cretaceous Soils.-Like those of the Tertiary system, the soils of the Cre-
taceous period vary considerably in character. Those overlying the rocks
of the upper division of this group are usually very favorably constituted
and highly productive, yielding in abundance almost every article of pro-
duce adapted to the climate. Of these soils there are two principal varieties.
The first is confined to the region immediately north of Iron Ore Ridge.
This soil is usually porous and absorbs heat and moisture readily. Its color
varies from dark brown to red and black. It is composed of lime, sand,
and clay in various proportions, and generally possesses a highly retentive
sub-soil. It supports in places a good growth of Post and Blackjack Oak
trees. The second, or "black-waxy soil," is too well known throughout the
State to require a description in this place. With a few local exceptions it
occupies the entire region south of Iron Ore Ridge, colored on the county
map as Upper Cretaceous. It is usually of the most productive character,
yielding in abundance wheat, corn, oats, and rye. This soil appears unfa-
vorable, however, to the growth of trees, and the region occupied by it usu-
ally consists of undulating prairie or prairie thickets.
Lower Cretaceous Soil.-There are four varieties of soils in the county de
rived from the decomposition of the Lower Cretaceous strata.
The first of these is mainly derived from the yellow sandstone, and con-
sists of fine yellow silicious sand, with an admixture of clay, lime, and iron.
It is both porous and retentive of moisture and is moderately fertile.
The second variety, or mixed soil, occurs near the junction of the sand-
stone and marly clay. It contains in its composition clay, sand, gypsum,
and carbonate of lime in variable proportions. From its constituents this
soil has all the clements of fertility, but owing to the general predominance
of clay over the other ingredients is but poorly adapted to withstand drought,
and on that account is not productive.
The third variety is derived principally from the marly clay or septaria
beds, and is composed of argillaceous clay, more or less mixed with gypsum
and carbonate of lime-there usually being a deficiency of sand. Its color
varies from blue to gray, yellow, and chocolate. This soil, which, along
with the preceding variety, is known in the county as chocolate soil, is
APPENDIX.
133
sometimes productive, but much more generally it is too compact, which
causes it to stand the drought but poorly and renders it of but little value
for agricultural purposes. This soil is abundantly met with in the region
watered by most of the eastern branches of Big Mineral Bayou. It is usu-
ally covered with short grass.
The fourth variety, or Cactus soil, differs from the preceding variety in
being composed almost entirely of tenacious argillaceous clay of nearly
white, light gray, or blue colors. It is very compact, being altogether im-
pervious to water and bakes hard in the sun. With the exception of an
occasional stunted growth of cactus, or common prickly pear, it is usually
devoid of vegetation. This soil is quite limited in its extent, being confined
to small isolated areas, and may be considered as totally worthless for agri-
cultural purposes.
These compose the principal varieties of soil in Grayson county. Other
varieties are occasionally met with, but they occupy a very limited area, and
are, therefore, unimportant. Most of these soils are very favorably consti-
tuted and are capable of abundantly producing every article of produce
adapted to the climate, while a few of them are found deficient in one or
more of the elements necessary for good soils. These deficiencies, however,
can usually be very readily supplied by a judicious admixture of other soils
occurring in the vicinity.
AGRICULTURE.
Among the different articles of produce cultivated in the county the
most important are Indian corn or maize, wheat, oats, and cotton.
In
Indian Corn.-This valuable grain is extensively cultivated in every por-
tion of the county.* Some of its soils, however, are found much better
adapted for its growth than others, and the average yield, therefore, varies
in different portions of the county from ten to forty bushels per acre.
Red River Valley as well as upon many of the creek bottoms in the interior
of the county the average yield per acre is not less than forty bushels, while
along the summit of Iron Ore Ridge in the northwestern portion of the
county it often falls as low as ten bushels per acre. The average annual
crop throughout the county may be safely estimated at about twenty-seven
bushels to each acre cultivated. It may here be proper to state that this
estimate is made not for a single year, but for a period of seven or eight
years. During favorable seasons crops of fifty or sixty bushels of corn to
the acre cultivated are by no means uncommon in the alluvial as well as in
some of the better classes of upland soils in the county.
There are many different kinds of seed made use of in the county. The
most usual varieties planted, however, are the gourd-seed and white and
yellow flint. Sometimes these are kept distinct, but much more frequently
they are suffered to become mixed, so that no one particular variety can be
distinguished. The most favorable scason for planting is in the latter part
of March or the beginning of April, and for gathering about the latter part
of September or the beginning of October. In preparing the ground for
the reception of the seed preference is almost always given to deep plowing,
as by this means the corn is enabled the more effectually to withstand the
season of drought and is not so liable to be affected by the spring frosts.
* According to the statistical returns for the year 1858 the number of acres of land in cul-
tivation in corn in Grayson county during that year was 12,359. The amount of corn pro-
duced in the county during that your would, therefore, according to the above estimate,
amount to nearly three hundred and thirty-four thousand bushels.
134
APPENDIX.
Tho corn crops of this region are but little affected by the weevil or by
disease of any character. They are sometimes, however, soverly injured by
drought, which has in several instances caused a partial or entire failure of
the crop.
Wheat This cereal is extensively cultivated in almost every portion of
the county, and as an article of produce ranks second in importance only to
that of corn.
Like the latter, the amount produced in different portions of
the county varies according to the different character of soil; in some regions
twenty-five or even thirty bushels to the acre cultivated being by no means
an uncommon crop, while in others the annual amount produced per acre
rarely exceeds ten or cleven bushels. The soils of the county best adapted
for its cultivation appear to be those overlying the upper division of the
Cretaceous System and the Red River and creek bottom alluviums. Fair
average crops are also produced from some of the soils overlying the arena-
ceous beds of the Tertiary and lower division of the Cretaceous Systems, but
as a general rule these latter are much better adapted for the growth of
corn and cotton than for wheat.
The annual average crop upon all the soils throughout the county may be
estimated at about eighteen bushels of wheat to each acre in cultivation.
According to the statistical returns for the year 1858 the number of acres
cultivated in wheat in the county was seven thousand two hundred and
forty-three. The amount of wheat produced in the county during that year
would, therefore, according to the above estimate, be over one hundred and
thirty thousand bushels.
In preparing the ground for the reception of the seed preference is given
by many to deep plowing; others, however, appear to prefer light plowing,
and for various reasons think it best. The usual time for planting is from
the first of September to the first of October, and for gathering, about the
first of June. The wheat crops of this region are sometimes seriously in-
jured by drought and late frosts, but are generally little liable to the dis-
cases that sometimes so seriously affect the wheat crops in other portions
of the United States. They are here sometimes slightly affected with the
rust and smut, but these diseases seldom do much damage. The weevil are
also sometimes a little troublesome to the wheat when in the stack, but
seldom do any damage after the wheat is threshed out.
Ouls.--Oats grow well in almost every portion of the county, but like the
former articles, are often injurod by drought. They are also sometimes
seriously affected with the rust. In the year 1858 the entire crop of oats
in the county was destroyed from this cause. The average annual crop
throughout the county is estimated at about thirty-eight bushels to each
acre in cultivation. On the better varieties of soils forty-five or fifty bush-
els to the acre would seem to be an average crop, and during favorable
seasons we sometimes hear of crops of seventy or seventy-five bushels to
the acre, while crops averaging sixty bushels per acre are by no means
uncommon upon some of the better varieties of soils in the county.
The usual time for planting oats is in the latter portion of February and
the beginning of March, and for gathering, about the twentieth or twenty-
fifth of June.
Cotton.-Owing to its remote situation from market but little attention
has heretofore been devoted in this county to the cultivation of the great
staple-cotton. The result, however, of the few experiments that have been
made are sufficient to induce the belief that this may hereafter become a
profitable cotton growing district. Many of the soils of the county are
very favorably constituted for the growth of cotton, and a number of its
APPENDIX.
135
planters are beginning to turn their attention towards its cultivation. Its
average yield, as far as tried in the alluvial portion of the county bordering
on Red River, is from four hundred and fifty to five hundred pounds of
lint cotton to the acre. Upon the uplands the soils best adapted for its
growth appear to be the Tertiary and Lower Cretaceous sandy soils, upon
which crops as high as four hundred pounds of lint cotton to the acre have
been produced. The calcareous soils overlying the rocks of the upper
division of the Cretaceous System do not appear to be so well adapted for
the growth of this article, the plants upon these soils dying out before they
arrive at maturity. The kind of seed preferred in this region is a variety
of the Mexican known as the Petty Gulf.
Chinese Sugar Corn. This article grows most luxuriantly in every por-
tion of the county. It but seldom requires much care in its cultivation,
receiving generally but little attention after being planted, and besides its
valuable saccharine qualities, yields an abundance of excellent fodder.
hye. Some attention has been paid in the county to the cultivation of
this article. It usually grows well, and the crops but seldom fail.
Burley. Most of the soils of the county are well adapted to the culti-
vation of this article. But for want of a market but little of it is at present
cultivated. Wherever tried in the county it has been found to grow well.
Tobacco.—This article has been successfully cultivated in various portions
of the county. The plant here grows most luxuriantly and speedily attains.
a large size, but the leaves are usually thinner and lighter than those of
Virginia and Kentucky. The tobacco is of excellent flavor, and would com-
mand a good price in the market.
Garden Vegetables, such as potatoes, onions, cabbage, beets, turnips, pars-
nips, melons, peas, beans, as well as almost every other article adapted to
the climate,―grow well in the county.
Fruit. Some varieties of fruit, such as peaches, plums, and grapes, ap-
pear to grow well upon many of the soils of the county. Apples and pears,
however, do not appear to grow well. Many attempts have been made to
cultivate these two articles in this region, but with a few exceptions they
have proved unsuccessful. Wild grapes and plums are very abundant upon
many of the alluvial soils of the county. The principal variety of the latter
is a small sweet plum known as the Chickasaw plum, while the former pre-
sent several varieties, among which the Post Oak, Mustang, and common
Winter Grape are the most abundant species. They are usually confined
to the river or creek bottoms. In the former situation the vines are often
so thickly matted together as to render travel in that region exceedingly.
difficult.
Grasses. Many efforts have been made in this region to cultivate the
more common grasses of the United States, such as clover, timothy, and
blue grass; but, while a few of them have succeeded, most of them have
proved unsuccessful. Other grasses, however, of more limited cultivation
in the United States have been here tried with much more favorable results.
Among the most prominent of these may be mentioned the Millet, IIunga-
rian, and Bermuda grasses, all of which have been found to grow luxuri-
antly in almost every portion of the county. They usually require but little
care in their cultivation, and are found to answer all the purposes of the
other varieties of grass usually cultivated farther north.
Among the indigenous grasses a number of varieties occur, all of which
are highly nutritious, and being generally much better adapted to the soil
and climate than the foreign varieties, could be here cultivated with but
little labor or expense. Among these the most important is the mezquite,
136
APPENDIX.
which is found growing luxuriantly in the southwestern as well as in other
portions of the county. I am not aware that any effort has been made to
cultivate this valuable grass in the county, but it is the universal opinion of
its citizens that it could be here cultivated without any difficulty, while in
other portions of Texas, as well as in some of the adjoining States, its cul-
tivation has been tried with complete success. This grass is highly nutri-
tious, and horses and cattle usually prefer it to all other varieties.
SPRINGS.
Grayson county possesses numerous springs of water, many of which are
permanent, while others go dry during the summer season. The water
varies considerably in character. That flowing from the arenaceous beds
of the Tertiary and Lower Cretaceous and the limestone of the Upper
Cretaceous Systems is usually clear, wholesome, and agreeable to the taste,
while that flowing from the gypseous clay of the Tertiary and Lower Cre-
taceous groups is usually highly impregnated with the salts of iron and
other impurities, and is bitter, nauseous to the taste, and unfit for use. The
latter variety is limited to the northern and western portions of the county;
that found towards the east being usually good and agreeable to the taste.
In the northwestern portion of the county several springs occur which are so
highly impregnated with sulphate of iron as to produce when drunk rapid
emesis and other symptoms indicative of severe gastro-intestinal disorder.
Medicinal Springs.-Several springs with water possessing valuable medi-
cinal qualities occur in the county. One of the most important of these is
situated on Sec. 48, No. 15, University land, and flows from sandstone of
the Tertiary formation. The water is clear, cool, and agreeable to the
taste, is strongly impregnated with iron, and deposits a heavy sediment of
brown and yellow oxide of iron upon standing. The spring furnishes an
abundant supply of water during the entire year, and it may hereafter be-
come a favorite resort for invalids.
Wells. Wherever natural springs do not exist in the county water can
always be obtained artificially by means of wells, which need seldom or
never be very deep, a constant supply of water being usually obtained be-
tween the depths of fifteen and fifty feet beneath the surface.
In only a
few instances has it been found necessary to go beyond the depth of forty
feet for this purpose.
MATERIALS FOR CONSTRUCTION.
Grayson county is well supplied with materials for construction. As we
have already seen, good building timber is abundant in various portions of
the county, while rock materials sufficiently firm and durable for all ordin-
ary purposes occur abundantly in the Tertiary and Upper and Lower Cre-
taceous Systems of the county.
In the Tertiary System the hard blue and yellow rock described as occur-
ring abundantly in the upper portion of Iron Ore Ridge would furnish a
moderately durable building stone. It contains in its composition, however,
a large percentage of carbonate of lime, and would, therefore, not answer
well as a fire stone. The hard blue and gray limestones of the Upper Cre-
taceous and the blue glistening calcareo-silicious sandstone of the Lower
Cretaceous Systems, would all furnish cheap and durable materials for
building. Some of the former are sufficiently hard and compact to receive
a good polish.
APPENDIX.
137
Brick Clay.-Clay suitable for burning into bricks is abundant in various
portions of the county, and bricks manufactured in this region will, for
beauty and durability, compare very favorably with any other bricks manu-
factured in the State.
Lime suitable for burning into quick lime is very abundant in connection
with the Cretaceous hills of the county.
Hydraulic Lime. The septaria of the septaria beds would furnish a
good quality of hydraulic cement. From the abundance of these septaria
in various portions of the county this valuable material can here be manu-
factured in very large quantity. Rock suitable for the manufacture of
hydraulic cement also occurs abundantly in the upper beds of the Tertiary
System in the northeastern portions of the county.
Sand sufficiently sharp for mortar is abundant in the northern portion of
the county as well as in the beds of most of the streams.
Gypsum. This article is abundant in the county. It usually, however,
occurs in the form of selenite, disseminated in very fine crystals in the
clays of the Tertiary and Lower Cretaceous Systems. In some of these
clays it is so abundant as to constitute a fourth or fifth of its bulk, and
would afford an excellent fertilizer to the poorer varieties of soil in the
county. In some localities the selenite occurs in masses several inches in
thickness, and might be collected in sufficient quantity to be profitably
manufactured into Plaster of Paris.
Potter's Clay.-Clay suitable for pottery occurs abundantly in connexion
with the Tertiary strata along Iron Ore Creek, and in the northwestern
portion of the county. The clay of the Lower Cretaceous System usually
contains a very large percentage of carbonate of lime, and is therefore unfit
for burning into pottery.
In many
Lignite.-Extensive beds of lignite occur in connexion with the Tertiary
strata in the northeastern and northwestern portions of the county. It is also
found disseminated in small particles through the clays and sandstones of
the Lower Cretaceous formation in various other portions of the county.
The thickness of the former varies from one to four feet, and sometimes two
distinct seams, separated by partings of clay and sandstone, are visible in
the same section. The lignite varies considerably in character.
places the woody structure is still visible in it, while in others it is homo-
geneous in texture, and exhibits no traces of organization. Its color varies
from dark brown to jet black, and it exhibits different degrees of hardness.
Generally it is hard, breaking with a smooth fracture, but crumbles readily
into a brown powder upon exposure to the atmosphere. In some places it
is largely intermixed with iron and selenite, the latter in the form of
minute crystals disseminated promiscuously through the mass. Fragments
of bones and other fossils have been found in connexion with these beds.
This lignite is as a fuel inferior in quality to the true coal, but may be
made to answer many of the purposes for which the latter is used. The
few experiments heretofore made with it in the county by blacksmiths have
proved unsuccessful. But this may be owing to the trials only having been
made with such as has been exposed for a long while to the weather. It
burns with a strong penetrating odor and a bright flame.
METALLIC ORES.
Iron. The ores of iron are abundantly associated with the Tertiary strata
of this region. The principal ore is a dark brown hematite, which is usually
quite porous and very largely intermixed with silicious matter. In some lo-
138
APPENDIX.
calities it is sufficiently pure to admit of being wrought, but much more
generally it contains too much silex to admit of being worked with profit.
Red Hematite.-Argillaceous hematite is found in the northwestern por-
tion of the county.
Sulphuret of Iron occurs in small irregular masses, sometimes beauti-
fully crystalized, in the clays and sandstones of the Tertiary and Cretaceous
Systems. Owing to its bright metallic lustre it is often mistaken for gold.
Lead. Small crystals of sulphuret of lead, or galena, have been found in
connexion with the Upper Cretaceous strata in several portions of the
county. There are, however, no evidence of this material occurring in suf-
ficient abundance in any portion of the county to admit of its being profi-
tably worked.
ROAD MATERIALS.
Most of the pebbles occurring so abundantly in the bed of Post Oak Creek
as well as those of many other streams in the county would furnish tolerably
good road materials. The hard limestone in the northeastern portion of
the county and the blue glistening sandstone of the Tertiary and Lower
Cretaceous Systems would also answer for this purpose.
MARLS.
Calcareous Marl, composed of nearly pure finely pulverized carbonate of
lime, is found in connexion with the Upper Cretaceous strata in the south-
eastern portion of the county. It would afford a valuable fertilizer to some
of the more arenaceous soils of the county.
A very fair quality of calcareous substance as a fertilizer also exists in
the marly clay of the Lower Cretaceous strata.
Silicious Marl.-This valuable fertilizer occurs in the northwestern por-
tion of the county, where it is derived from the disintegration of the green
sandstone of the Tertiary strata.
Table of Average Produce on the different Soils in the County.

Red River Creek Bot-
Lands.
tom.
Upper Ter-
tiary of
Iron Ore
Lower Ter- Upper Cre- Lower Cre-
Lower Cre-
Lower Cre-
tiary.
taceous
Calcareous
taceous
Ridge.
Sandy.
taceous
Clay mix'd.
taceous
Clay.
Corn (bush.)
40
35
10
25
30
30
25
18
Wheat,
20
20
10
16
20
16
15
10
Oats,
แ
50
40
30
40
35
Cotton (lbs.)
500
350
300
300
APPENDIX.
139
GEOLOGICAL SURVEY OF TEXAS.
ABSTRACT FROM THE REPORT SUBMITTED TO THE LEGISLATURE AT ITS EIGHTH
SESSION, BY B. F. SHIUMARD, M. D., STATE GEOLOGIST.
In the commencement of our Geological Survey it was thought advisable
to make a reconnoissance of as large a district of the State as possible, in
order to form some idea of the general character and boundaries of the
formations, previous to our more detailed surveys of counties. These
general lines of exploration have now been extended over a considerable
portion of Eastern and Middle Texas, and sections have been made as
follows:
1st. A section from Austin to Houston, one hundred and seventy-two
miles.
2d. From Hempstead to Sour Lake in Hardin county, one hundred and
twenty-two miles.
3d. From Sour Lake through Hardin, Tyler, Jasper, Sabine, San Au-
gustine, Nacogdoches, Rusk, Harrison, Cass, to Red River in Bowie, three
hundred miles.
4th. From Henderson in Rusk, through Cherokee, Anderson, Freestone,
Limestone, to Waco in McLennan, one hundred and eighty miles.
5th. From Austin through Williamson, Bell, McLennan, Bosque, John-
son, Parker, Palo Pinto, to Fort Belknap in Young, two hundred and forty
miles.
6th. From Fort Belknap through Buchanan, Eastland, to Camp Colorado
in Coleman, one hundred miles.
7th. From Camp Colorado through Brown, Lampasas, Burnet, to Austin,
one hundred and fifty miles.
8th. From Austin to San Antonio, thence through Bexar, Atascosa, Live
Oak, to Corpus Christi in Nueces, one hundred and eighty miles.
9th. From Corpus Christi through Refugio, Goliad, De Witt, Gonzales,
Caldwell, to Austin, one hundred and sixty miles.
10th. From Corsicana in Navarro through Limestone, Falls, to Belton
in Bell county, one hundred miles.
In making these preliminary surveys careful sections of the strata have
been made at all points of outcrop within reasonable distances of the routes
traveled, and the thickness, stratigraphical order, dip, and mineral and
fossil characters of the various beds have been determined with as much
precision as possible. Frequent barometrical observations were made to
ascertain the elevation of the country above tide-water, and much attention
has been directed to obtaining a correct knowledge of the topographical
features and the kinds and quality of timber of the districts explored.
Besides accomplishing the above, we have made detailed surveys of the
counties of Grayson, Red River, Lamar, Bowie, Cass, Fannin, Rusk, Na-
varro, McLennan, Bosque, Coryell, Calwell, Guadaloupe, Burnet, Wash-
ington, and partial surveys of Travis, Bastrop, Fayette, and Young.
It will thus be seen that besides a general survey extending over a vast
district, we have made minute and final surveys of fifteen counties, and
partially surveyed several others.
During the winter and part of the spring months the several members
of the corps were actively engaged in the geological rooms and laboratory,
140
APPENDIX.
unpacking, labeling, classifying, and arranging the extensive collections of
geological specimens accumulated there, in making analyses of soils, rocks,
minerals, ores, coals, etc., and in constructing maps, sections, and diagrams,
for illustrating our reports.
The investigations of the Geological Survey have already developed re-
sults of the highest interest.* It is now known that within the limits of
Texas, occur the most complete series of geological formations to be found
in any State in the Union, ranging, as they do, from the Potsdam Sand-
stone of the Paleozoic era to the latest Tertiary, and presenting an aggre-
gate thickness of many thousand feet. A thorough and systematic study
of these different geological groups cannot fail to afford results of the
highest scientific and practical value.
Our partial explorations show the existence of an extensive coal forma-
tion in the northern part of the State, that will exercise a most important
influence on her future welfare and prosperity. We are not now able to
define the precise boundaries of the Texas Coal Measures. To do this with
precision would require a much more detailed investigation than the lim-
ited time at our disposal has permitted us to make. It may, however, be
stated as a reasonable estimate, that the area occupied by the coal strata
can not fall short of four or five thousand square miles. Taking Fort
Belknap as a starting point, we have found this formation to extend unin-
terruptedly southeastwardly to Patrick's Creek in the S. W. part of Parker
county, a distance of more than sixty miles; westwardly about forty miles;
and southwardly beyond Camp Colorado in Coleman county, say one
hundred miles. We have not traced it in its northward extension more
than six or eight miles from Fort Belknap, but it is highly probable that it
reaches into Archer, Baylor, and Clay counties. It is also probable that
the same formation is developed in San Saba and some of the counties
adjacent.
The strata composing the Coal Measures of the region we have described
have a thickness estimated at not less than three hundred feet, and consist of
quartzose and argillaceous sandstones, limestones, grits, and conglomerates;
argillaceous and calcareous shales; fire, potter's, and pipe clays; and coal.
Some of these strata, and particularly the limestones and shales, are filled
with organic remains, among which we have recognized many species
which are highly characteristic of the Coal Measures of Missouri, Kentucky,
Illinois, and Iowa. The shales also frequently contain large and beautiful
crystals of selenite, and rounded masses of excellent iron ore. The coal at
all of the localities examined reposes either on fire-clay or shale.
In Young and Buchanan counties outcrops of coal occur at a number of
points, and in the former county it has been struck at many places in exca-
vations for wells. We have here recognized four distinct coal seams, vary-
ing from six inches to five feet, and presenting an aggregate thickness of
eight or nine feet. At the mouth of Whisky Creek, near Fort Belknap, is
an interesting exposure, exhibiting three distinct coal beds, separated by
bands of limestone, fire-clay, sandstone, and shale, and the whole sur-
mounted by sandstone and conglomerate.
In regard to the quantity of coal, we do not speak in extravagant terms
when we assert that in the region under consideration there is an abund-
ance of this most valuable mineral fuel to supply the present and future
*It is not possible to give here the results of our operations the prosent season, since the
parties are now in the field, and I have not access to their notes and specimens.
APPENDIX.
141
demands of the State for centuries. With reference to the quality of the
Texas coal, it may be stated that it will compare favorably with most of
the coals which are wrought in Missouri, Illinois, and Iowa. In general
appearance and weight it resembles very closely the coal of St. Louis,
Missouri, and Belleville, Illinois.
The following analysis, made by Dr. Riddell, in the State Laboratory,
shows the chemical constitution of an average specimen from a bed three
and a half feet thick, exposed on Whisky Creek two miles north of Fort
Belknap:
Total matter volatile at red heat.
Weight of coke...
Amount of moisture expelled at 212°
Additional matter volatile at red heat.
Fixed carbon (coke)
Ash (ochreous brown).
•
44.136
55.864
100.000
7.8689
36.2671
52.8060
3.0580
100.0000
According to Dr. Riddell, this coal cokes without changing its form, and
burns with a bright yellow flame.
For the sake of comparison we subjoin the following analysis, by Prof.
J. D. Whitney, chemist of the Geological Survey of Iowa, showing the
composition of a specimen from Van Buren county, Iowa, regarded as one
of the best coals in that State:
Moisture
•
Volatile and combustible..
Fixed carbon...
Ash..
5.30
37.98
54.35
2.37
100.00
Besides the coal area just described, it is highly probable that productive
coal beds will be discovered in the extreme western part of the State, as
we have indisputable evidence of the existence of the true coal measures in
that region. Should future researches develop the existence of workable
seams of coal in this portion of our State, they will prove a fertile source of
wealth, and their value can scarcely be overestimated.
Connected with the Tertiary formation, which occupies a vast area in
the eastern and middle portions of the State, are extensive beds of brown
coal, or lignite, which will, I think, be of great service to the public. Our
detailed examinations in Rusk show that a large portion of this county is
underlaid by deposits of this material, exposures of which occur at a great
many localities. The beds examined vary from six inches to eight feet in
thickness and are associated with bituminous shale, fire and potter's clay,
soft quartzose, and argillaceous sandstone, impure limestone, and iron ore.
At a number of localities visited the lignite appears to be of good quality
and adapted for the ordinary purposes of fuel. It varies greatly in charac-
ter in different sections of the county, some specimens exhibiting the
142
APPENDIX.
woody fiber with tolerable distinctness, while others show no traces of or-
ganic structure, being dull, shining black, and very compact in texture.*
In the N.E. corner of Cass county, at "Stone Coal Bluff," examined by
Dr. G. G. Shumard, is a bed of lignite ten feet thick, which resembles the
bituminous coal of Fort Belknap, both in external character and chemical
composition, and it is quite probable that it may be employed to advantage
in the manufacture of iron. Regular scams of lignite of more or less value
have been discovered by different members of the corps, in the counties of
Grayson, Harrison, Caldwell, Guadaloupe, Bastrop, Anderson, and Fayette,
and we have heard of many other localities in various sections of the Stato
which we have not yet been able to visit.
Brown coal, or lignite, is in general inferior to true bituminous coal,
which belongs to an older geological formation, nevertheless its importance.
has usually been underrated. In Germany and Prussia large quantities of
lignite are annually mined to supply the inhabitants with fuel, and the
Tertiary brown coal of the Pacific coast has been successfully employed for
purposes of ocean steam navigation. It is estimated that the heat given
out by lignite is about one-third more than that of wood. The better va-
rieties of Texas lignite may not only be used as fuel, but it is also probable
that some of them may also be employed for the manufacture of illumi-
nating gas.
Among the combustible minerals may also be mentioned the occurrence
of Petroleum, which has been observed at several points in the State. The
most important locality visited is at Sour Lake in IIardin county, where
this substance may be collected in considerable quantity from the surfaces
of the remarkable acid springs adjacent to the lake. The earth for some
distance around these springs is also so highly charged with bitumen as to
be employed for purposes of illumination and to some extent as a fuel.
In addition to her coal deposits, Texas embraces within her limits vast
accumulations of iron ore, which require only judicious expenditures of
labor and capital to be converted into fertile sources of wealth.
Until the commencement of the present survey, it was not known that
we had workable deposits of iron, except in one or two localities.
But our
labors have demonstrated the important fact that we have a vast iron region
in the eastern part of the State, embracing considerable areas in Cass, Har-
rison, Rusk, Panola, Smith, San Augustine, and Shelby counties.
deposits belong to the Tertiary era, and consist chiefly of hematites and
limonites, of which there are several varieties. We have also found in
this district extensive beds of carbonate of iron.
The ore
According to Dr. G. G. Shumard, Cass county alone is capable of sup-
plying a number of furnaces with an abundance of excellent iron ore for
many years. The ore occurs here in regular layers, which sometimes
attain a thickness of fifty feet. The only iron furnace our State can boast
of is located in this county. It was erected several years since, by Mr.
Nash, and has been in nearly constant, and I believe profitable, operation.
*An example of this variety, from the neighborhood of Iron Mountain P. O., analyzed by
Dr. Riddell, gave the following rosult:
Specific gravity 1.094.
Moisturo expelled at 212°,
Matter volatilo at rod heat.
Fixed carbon..
Ash...
15.701
4.105
79.137
1.057
100.000
APPENDIX.
143
up to the present time. The ore is mined near the furnace, and the kinds
proferred are a porous variety of hematite, termed by the proprietors
"honey-comb ore," and compact brown hematite. The pig metal and cast-
ings produced from these ores are of excellent quality, and command a
high price in the market.*
Our detailed examinations in Rusk county have developed the occur-
rence of almost inexhaustible deposits of workable hematite, similar to that
found in Cass, while our general surveys in Cherokee, Nacogdoches, and
the other counties above enumerated, have convinced us that farther ex-
plorations will reveal there also the existence of equally extensive accumu-
lations of this important element of State wealth.
Other deposits of iron occur in the Tertiary strata in the Middle Division
of the State, but so far as our observations have been carried these ores
are inferior to those found in the East. In the counties of Caldwell and
Guadaloupe, examined by Dr. Riddell, are heavy deposits of iron ore,
but they contain such a large proportion of silex, in the form of sand,
as to render them generally unfit for profitable smelting. We have fair
workable ores from Bastrop and Llano counties, but further researches are
necessary before we can give a positive opinion respecting their value.
Throughout the region of the Coal Measures in the northern part of the
State, we frequently find bands of argillaceous iron ore interstratified with
the gypseous shales, while the surface of the ground is often thickly
strewn with masses of rich iron ore from the size of a filbert to that of the
double-fist. In Young and Buchanan counties these ores are often quite
abundant in places, and they appear to be well dapted for smelting, al-
though our investigations have not been sufficiently minute to enable us to
determine whether they occur in sufficient quantity to be wrought with
profit.
Lead-In the districts examined, no important deposits of lead have yet
been found, but we have received from different parts of the State speci-
mens of galena, or sulphuret of lead, which induce the belief that future
researches will develop the existence of valuable veins of this metal. Thus
we have samples of remarkably rich ore from the western part of the State,
near El Paso, the Wichita Mountains, and Fort San Saba. In Llano
county occurs an interesting ore, the molybdate of lead, which is quite rare
in mineralogical collections.
* Dr. Riddell's analysis of an average specimon of the honey-comb variety from the Nash
mines yielded the following result:
Specific gravity, 2.2891.
Moisture and matter volatile at red heat..
12.227
Silica....
8.122
•
Por-oxide of iron..
79.604
•
•
Loss..
.047
100.000
Dr. Riddell's analysis of a specimen taken from an extensive oro deposit in Rusk county,
about four miles east of Sulphur Springs, gave:
Specific gravity, 3.3245.
Alumina..
•
Silicious matter insoluble in acids.
Per-oxido of iron...
Water...
1.0360
8.7941
71.7826
•
18.3873
•
100.0000
The specimen analyzed represents a variety that is very common throughout the iron
region of this part of the State.
144
APPENDIX.
Copper.-According to Dr. Geo. G. Shumard, small rounded masses of
the oxide and carbonate of copper occur distributed abundantly over the
surface of the country towards the sources of the Big Wichita, Brazos, and
Red rivers, and it is not improbable that productive veins of copper will be
found in this region.
We have also remarkably fine specimens of native carbonate and oxide
of copper from the extreme western part of the State.
Silver.-All the sulphurets of lead that we have seen from Texas are
more or less argentiferous. A specimen analyzed by Dr. Riddell contains
nearly nine ounces of silver to the ton of ore.
Gypsum. This valuable material has a vast development both horizon-
tally and vertically in our State. According to Dr. Geo. G. Shumard,* who
has had fine opportunities for exploring the gypsum district in Texas and
the adjacent territories, it occurs in the greatest abundance in the country
watered by the upper portion of the Canadian, Red, Big and Little Wichita,
Brazos, and Pecos Rivers. On Red River the gypsum beds are from a few
inches to thirty feet thick. On Delaware Creek, a few miles below its
source, they are sixty feet, while between the Big Wichita and Brazos
Rivers there are hills nearly seven hundred feet high composed almost en-
tirely of this material. It is usually of pure white, more or less granular,
and sometimes resembles loaf-sugar. Occasionally it assumes the character
of fibrous gypsum, selenite, and compact alabaster. We have also found
gypsum in the form of selenite somewhat abundantly disseminated through
the marls of the Cretaceous Period in Grayson county, and those of the
Coal Measures in Young and Buchanan. The crystals are frequently quite
large, and form beautiful cabinet specimens. The gypsum field of Texas
is believed to be the largest in the world, and capable of supplying all the
demands of the South and West for thousands of years.
In several counties we have discovered extensive deposits of potter's,
pipe, and fire clays, and inexhaustible beds of calcareous marl. Limestones,
sandstones, and other materials adapted for building purposes, have also
been met with in nearly every portion of the country examined. In Bur-
net county we have found extensive tracts underlaid by building rocks of
great beauty and durability, and there occurs here a beautiful variegated
limestone of remarkably fine texture, which receives a good polish, and
forms a handsome marble for ornamental work. A considerable district
in this county is likewise occupied by a rather coarse red granite, which, if
properly selected, may be advantageously employed in the construction of
such works as require great strength and durability. In the State of
Missouri a rock of the saine kind is frequently employed for mill-stones,
for which purpose it is tolerably well adapted.
In the counties of Young and Rusk valuable beds of hydraulic limestone
occur, and
we have collected specimens from other parts of the State
which appear to possess hydraulic properties, but farther experiments are
necessary before we can decide positively upon their value.
Our collection of soils, clays, rocks, ores, coals, and fossils, is quite ex-
tensive, and already embraces many objects of great interest and rarity,
and contains many species new to science. The suite of organic remains is
especially large and valuable. These, when carefully studied, will throw
considerable light on some disputed points in the geology of the West and
Southwest.
* Unpublished report on the Geology of the U. S. Expedition, under Capt. J. Pope, for
boring artesian wells, etc.
APPENDIX.
145
The agricultural department of the survey has received a full share of
our attention. The different varieties of soils and subsoils have been care-
fully collected for chemical analysis, and we have spared no exertions to
ascertain the kinds of crops to which they are best adapted, and the proper
methods of cultivating and improving them. And here we would earnestly
call the attention of our farmers to the advantages to be derived from a
more thorough system of cultivation than is generally practiced. An ex-
amination of our soils in different sections of the State has fully confirmed
us in the opinion, aiready expressed to many, of the great benefits that
would result from subsoil plowing. We have conversed with many intelli-
gent farmers who have subsoiled their lands, and all agree that the increase
of crops by this system has been strongly marked. In most cases the in-
creased profits have been from twenty-five to thirty-five per cent, and in
some instances the profits have been more than doubled In districts sub-
ject to severe droughts the method here recommended is specially applica-
ble. We could cite examples where, during the present unprecedented
dry season, subsoiled lands have yielded from twenty to twenty-five bushels
of corn to the acre, while lands adjoining, of precisely the same character,
have produced by the superficial method scarcely ten bushels.

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