I 

A. CONTRIBUTION TO THE GEOLOGY OF NOkTHEA.STERN TEXAS AND 

SOUTH~RN ~~LA.H0

1 . . By LLOYD WILLIAM STEPHEtSON. 

PURPOSE AND SCOPE OF THE PAPER. 

The region in central and northeastern Texas 

and southern Oklahoma known as the Black 

and Grand prairies abounds in features of interest to physiographers, geologists, and paleontologists, and the pioneer investigators of 

this region must have experienced renewed 

satisfaction in each day's exploration. The 

reports of .Joseph A. Taff, Robert T. Hill, and 

others, published chiefly under the auspices of 

State and Federal surveys, represent with approximate accuracy at most places the general 

distribution of the outcrops of the formations 

i~ this region, and contain detailed descriptiOns of many sections that constitute a 

mine of useful information. The reader of the 

present paper is urged, therefore, to hold as 

most important the general excellence of the 

earlier reports of these authors and to relegate 

the inaccuracies and mistakes to which his 

attention will be called to the relatively unimportant place in which they belong, remembering at the same time that a future generation 

of investigators may find our own shortcomings 

as great as those we now criticize. 

The present report treats of the area shown 

in Plate XVII, which includes Grayson, Fannin, Lamar, Delta, Hunt, and Collin counties ' Tex., and the southern parts of Marshall and 

Bryan counties, Okla. It is based on the results of studies carried on during several brief 

field seasons between the years 1911 and 1917 

inclusive. The results are by no means final: 

but enough facts have been obtained to' justify 

their presentation to those who may be interested in the geology of the region. The purpose of the paper is therefore to set forth the 

present state of knowledge in the areal mapping, in the interpretation of structure, and in 

co~relation, and to indicate certain mappable 

un1ts and structural features that have not 

heretofore been recognized. 

I 

A compakson of Hill's geologic map published in 1901 1 with the map accompanying the 

pre~en~ pa~er reveals at once certain inaccuraCies In his representation of the areal distributi~n of ~he Cretaceous formations which 

require no fp.rther comment. Another striking 

feature of his map consists of the two great parallel faults, ~he Cook Springs and Red River (or 

Preston) faults, which are shown as extending 

from Love and Marshall counties southern 

I ' Oklahoma, far to the southeast through Grayson, Fannih, and other counties in Texas. 

Between the faults is an uplifted block represented as ·8ringing to the surface formations 

that ought normally to be far below the surface. The feported existence of these faults, 

although unverified, has been cited in explanation of certain structural phenomena even as 

far east as northern Louisiana and Vicksburg, 

Miss.2 The Cook Springs fault was first described by Taff 3 in 1893. · In the light ·of the 

facts presei ted on subsequent pages the basis 

for the postulation of these faults in Texas 

disappears. j · 

In 1902 Taff 4 indicated the geographic continuity of t~e Austin chalk and Annona chalk, 

which Hill failed to recognize, but he did not 

realize the magnitude of the upward transgression of u

1

he chalk across the geologic column 

from south to north and east. Gordon 5 in 

1911 mapped with approximate accuracy the 

distributionJ east of the ninety-s~xth meridian of 

the major lithologic units below the Eocene, to -----·t 

· 1 Hill, R. T., ogr phy and geology of the Black and Grand prairies, 

Tex., with detailed descriptions of the Cretaceous formations and special 

reference to artesian waters: U.S. Geol. Survey Twenty-first Ann. Rept., 

pt. 1, pl. 66, 1901. 1 

2 Veatch, A. C., peology and underground water resources of northern 

Louisiana and southern Arkansas: U. S. Geol. Survey Prof. Paper 46, 

p. 68, 1906. 

3 Taff, J. A., Tex~s Geol. Survey Fourth Ann. Rept., pp. 297-298, 1893. 

4 Taff, J. A., Chalk of southwestern Arkansas, with notes on its adaptability to the manufacture of hydraulic cements: U. S. Geol. Survey 

Twenty-second Ann. Rept., pt. 3, pp. 698-700, 1902. 

6 Gordon, C. H.

1

, Geology and underground waters of northeastern 

Texas: U.S. Goo!. Survey Water-Supply Paper 276, pp. 21-25, pl.l, 1911. 

129 
130 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918~ 

and including the Blossom sand, but he erred in 

correlating the Blossom sand with the Eagle Ford 

clay, and although he noted the geographic 

connection of the Annona chalk with the 

Austin he also failed to recognize the upward 

transgression of the chalk in its northeastward 

extension. 

ACKNOWLEDGMENTS. 

In 1911 the writer was accompanied by T. W. 

Stan ton in a brief examination of parts of 

northeastern Texas, including the area in the 

longitude of Paris between the North Fork 

of Sulphur River and Red River, the vicinity 

of Cooper, Delta County, and the vicinity of 

Sherman, Grayson County. Subsequently he 

frequently conferred with Mr. Stanton in regard to the interpretation of the physical and 

paleontologic facts and has greatly benefited 

by his many helpful suggestions. 

0. B. Hopkins, during a brief visit in 1915, 

determined the stratigraphic succession and 

attitude of the Upper Cretaceous rocks that 

appear at the surface m the vicinity of Wolfe 

City, Hunt County, and Gober, Fannin 

County, Tex. He stated his conclusions to 

the writer and indicated certain favorable 

localities for examining outcrops. The area 

was subsequently visited by the writer, who 

traced the several lithologic divisions both to 

the northeast and southwest of Wolfe City, as 

shown on Plate XVII. Mr. Hopkins also obtained by correspondence the logs of several 

wells in northeastern Texas and southern 

Oklahoma, which he generously placed at the 

writer's disposal. 

In December, 1917, 0. B. Hopkins and Sidney Powers accompanied the writer in a supplementary field study of the areas in Grayson, 

Fannin, and Hunt counties where the Cretaceous formations are involved in the Preston 

anticline and 'in the Leonard-Celeste monoclinal nose. The outcrops of key rocks were 

traced, and altitudes were determined at numero1Js points on them by means of aneroid 

readings. ~tfessrs. Hopkins and Powers continued the determination of altitudes during 

the later part of December and the first half of 

January, 1918. H. M. Robinson had in 1917 

made a series of similar altitude determinations on a part of the Preston uplift in southern 

Marshall County, Okla., locally known as the 

Enos anticline. The gener~l results obtained 

by these three men are embodied in the structure contours shown as an overprint in red on 

the geologic map (Pl. XVII). A more detailed report of their results, with particular 

reference to the occurrence of oil and gas, will 

be published later as an economic bulletin. 

Indebtedness is gratefully acknowledged to 

Mr. J. T. Bryant, of Pottsboro, Tex., for information and personal assistance that enabled 

the writer and his associates quickly and advantageously to find and study numerous 

important exposures in northern Grayson 

County, Tex., and southern Marshall County, 

Okla. Mr. Bryant also kindly contributed the 

logs of several wells on the Preston anticline. 

Courtesies were also extended to the writer 

and to his associates by Messrs. R. H. Cook, of 

Denison; M. L. Wilson, of Wolfe City; and J. 

Balch Moor, of Bonham, who furnished well 

logs and placed facilities for field study at 

their disposal. 

LITERATURE. 

The principal publications relating to the 

area treated in the present paper are listed below in chronologie order: 

Shumard, B. F., Notes upon the Cretaceous strata of 

Texas: St. Louis Acad. Sci. Trans., vol. 1, pp. 582-610, 

1860. 

Taff, J. A., and Leverett, S., Report on the Cretaceous 

area north of the Colorado River: Texas Geol. Survey 

Fourth Ann. Rept., pp. 239-354, 2 maps, 1 plate, 1893. 

Hill, R. T., On the occurrence of artesian and other underground waters in Texas, eastern New Mexico, and Indian 

Territory west of the 97th meridian: 52d Cong., 1st sess., 

S. Ex. Doc. 41, pt. 3, pp. 41-166, 19 pls., 1893. 

Hill, R. T., Geology of parts of Texas, Indian Territory, 

and Arkansas adjacent to Red River: Geol. Soc. America 

Bull., vol. 5, pp. 297-338, pis. 12, 13, 1894. 

Hill, R. T., and Vaughan, T. W., The Lower Cretaceous 

Gryphaeas of the Texas region: U. S. Geol. Survey Bull. 

151, 139 pp., 35 pls., 1898. 

Hill, R. T., Physical geography of the Texas region: U. S. 

Geol. Survey Top. Atlas, folio 3, 12 pp., 11 pls., 1900. 

Hill, R. T., Geography and geology of the Black and 

Grand prairies, Tex.: U. S. Geol. Survey Twenty-first 

Ann. Rept., pt. 7, 666 pp., .71 pls., 1901. 

Taff, J. A., Chalk of southwestern Arkansas: U.S. Geol. 

Survey Twenty-second Ann. Rept., pt. 3, pp. 687-742, 

pls. 47-53, 1902. 

Taff, J. A., U. S. Geol. Survey Geol. Atlas, Atokafolio 

(No. 79), 8 pp., 4 maps, 2 columnar-section sheets, 1902. 

Taff, J. A., U. S. Geol. SurveyGeol. Atlas, Tishomingo 

folio (No. 98), 8 pp., 3 maps, 1 columnar-section sheet, 

1903. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XVII 

96° 80' 96°00' g5•ao· 

GEOLOGIC MAP OF PARTS OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA ------~~----------------

' aJ _ l _ 

soopoo 

20 21'\ Mj l,•s J 

Areal geology by L. W. Steph e nson, supplemented by data published by Hil l, Taff, and Gordon, and by data furnis hed by 0 . B. Hopkins, S. Powe rs, and H. M. Robinson 

Structu re contours showi ng the altitude above sea level of the top of the Goodlard limestone, by 0. B. Hopkins, S. Powers, and H. M. Robinso n 

Structure conto urs showing the altitude of the base of the Ector tongue of the AuHin chalk and the base and top of the Annona to ngue of th e Austin chalk, by 0 . B. Hopkins and S. Powers 

·~ <II 

00 

EXPLANATION 

Te 

~ Mi -; for;~ion g land part of t he Wilcox formation ' (Sand and cl4v) 

IJNCONF ORMI T Y 

Navarro formation 

\Calcareous ola11 and sa11 dl 

I 

1>-

a:: 

a:: 

~ w 

tTaylor marl tCalcareotUJ shalu clav) 

Pecan Gap chalk member, Ktp 

Wolfe City sand member, Ktw Brownstown marl 

~ 

t; 

00 

:::.. 

~ Uru:Ludcs Ector tongue (a on map) and 

c.!l Annona tongue (bo1tmap). b tcludu 

lay eqvivalent to part 

of Austin chalk on th west, and in part to the 

Blo som and and 

Brownstown marl on th east 

also. f or convenic11c of mappina. 10 to 35 f eet of unnamed non clulllcu olaV. and san d, down to and including the './i8h.- l bed conglomerate · ·) 

Eagle Ford clay 

(Dar k shal11 olay) 

L ... ~ 

f Kw 1 l. .... ..:.L..-~~ 

Woodbine sand 

(fi'i.?te to coarse sand and clav ) 

UNCONFORMI TY ? 

Wa hita group 

(Includes in a•cendin o order Kiamich.i cl4v, Du.ck Creek formation, Fort Worth limest01•e, and D ni8on f or- rna.t:ion. 

e, avpr<Wimo.te ott tcror> of top of Fort 

WortJ• limutone) 

Trinity sand <Fine sand and clay) 

(Caloar«oWJ glatulonitio ean.d ) 

Th.IJ altitude of the top of the Goodl4nd Limwstone wlrRrc it i8 in'IJolved in the Pruton an.ticline 

i8 r presented b71 the contours in northern Grayson Countv, Tez., and southern Marslwll and Brvan counties, Okla. 

TluJ altitude of the base of the Ector ton.oue of the Austin clullk i8 represented bv th~ contours in th.IJ tJicinitv of Ector and Ravenna, Fannin Count11. Tez. TluJ altitude of tluJ base of the Annona to1~ <:if tluJ A us tin chalk i8 repreaented bv the contours within a f ew miles south. east, and northeast of Bonham, Fannin Cou.ntu, Tex. 

TluJ alti tude of the top of the Annona toncnu of the Austin clullk i8 represented bv the contours in th.IJ vicinitv of Le01wrd, Baileu, Gober, and Honey GrOtJe, Fa11.nin Countv, Tex. 

X -l .9707 

Localit y a t which fossils have been obt ained 

from the Blossom sand. The figures indicate 

U. S. G. S. collection number 

(/) 

:;) 

0 

w 

u 

~ 

tw 

a:: 

u 
GEOLOG"Y OF NORTHEASTERN TEXAS AND SOUTHERN OKLAoliOMA. 131 

Veatch, A. C., Geology and underground-.water resources 

of northern Louisiana and southern Arkansas: U.S. Geol. 

Survey Prof. Paper 46, 422 pp., 51 pls., 1906. 

Gordon, C. H., The chalk formations of northern Texas: 

Am. Jour. Sci., 4th ser., vol. 27, pp. 369-373, 1909. 

Taff, J. A., and Reed, W. J., The Madill oil pool, Okla.: 

U. S. Geol. Survey Bull. 381, pp. 504-513, 1910. 

Gordon, C. H., Geology and underground waters of northeastern Texas: U. S. Geol. Survey Water-Supply Paper 

276, 78 pp., 2 pls., 1911. 

Shannon, C. W., and others, Petroleum and natural gas 

in Oklahoma: Oklahoma Geol. Survey Bull. 19, pt. 2, 

pp. 316-321, 1917. 

TOPOGRAPHY AND DRAINAGE. 

The area shown on Plate XVII lies near the 

northwestern border of the Gulf Coastal Plain 

in northeastern Texas and southern Oklahoma, 

and is a dissected coastal-plain upland ranging 

in altitude from about 530 feet in the southeast 

to 850 feet in places in the northwest. The 

highest points in the area are between Denison 

and Pottsboro, Grayson County, Tex., where 

3everal hills rise slightly more than 900 feet 

above sea level. Red River, which crosses the 

area from west to east in a sinuous course near 

the northern margin, has cut a broad valley 200 

to 300 feet below the general upland, the alti-

. tude of low-water level where the river enters 

the area being approximately 590 feet and 

where it leaves the area not quite 400 feet. A 

little less than the northern half of the area 

is drained by tributaries of Red River. In 

the east; south of the Red River valley, the 

drainage is carried by tributaries of Sulphur River, which flows eastward and joins 

Red River in Louisiana. The southern and 

southwestern parts of the area are drained by 

numerous southward-flowing creeks belonging 

to the Trinity River system. 

The drainageways of the area present many 

good examples of consequent, subsequent, obsequent, and perhaps other classes of streams, 

a detailed description of which is outside the 

scope of this paper. Attention may be called, 

however, to the conspicuous development of 

small tributaries of South Sulphur River, itself 

a subsequent stream, which flow down the 

gentle southward-facing slope of the cuesta 

formed by the Pecan Gap chalk in Delta 

County and the northeastern part .of Hunt 

County, and the similar tributaries of North 

Sulphur River, also a subsequent stream, 

which flow southward on the corresponding 

slope of the cuesta formed by the Annona 

tongue of the Austin chalk in southern Lamar 

and Fannin counties. (See p. 132 and PI. 

XVII.) These are not consequent streams, as 

that term was originally defined, in that their 

courses are not determined in consequence of 

the original slope produced by the uplift of the 

area from beneath the sea, but rather in consequence of the southward slope of the chalk and 

clay formations down whose eroded surfaces 

they flow. With the exception of some of the 

smaller streams in the terraced area along Red 

River the drainage is almost completely adjusted to the structure of the underlying Cretaceous formations, and in general the area 

affords an excellent .example of maturely adjusted drainage on only partly consolidated, 

unequally resistant rocks of gentle monoclinal 

attitude. 

The area falls chiefly within the four physiographic divisions 1 commonly known as the 

Black Prairies, the Eastern Cross Timbers, the 

Grand Prairies, and theW estern Cross Timbers. 

The boundaries separating these divisions are 

approximately coincident with the boundaries 

of underlying formations composed of unequally 

resistant rocks, but these boundaries are not 

everywhere sharply defined. Along Red River 

is a belt of alluvial terrace plains of Pleistocene 

age (see p. 132'), which ranges in width from 2 

or 3 miles where the river enters the area, at 

the west, to 15 miles or more in the northeastern part of the area and which may well be 

classed as a physiographic division distinct 

from each of the four just enumerated. 

The Black Prairies embrace chiefly the areas 

in Collin, Hunt, Delta, Lamar, Fannin, and 

Grayson counties underlain by the marine 

chalks, clays, and marls of the Gulf series. 

(See geologic map, Pl. XVII.) Topographically these areas are characterized in the main 

by nearly level to gently rolling surfaces, 

merging near Red River and the larger creeks 

into hills of moderate relief and smoothly 

rounded slopes. Cuestas of low relief have 

been produced by the relatively resistant chalk 

members of the series as described on a subsequent page. 

The Eastern Cross Timbers include the relatively narrow belt underlain by the Woodbine sand of the Gulf series (see Pl. XVII), 

which extends from the northwestern part of 

1 Hill, R. T., U. S. Geol. Survey Twenty-first Ann. Rept., pt. 7, 

pp. 65-75, pl. 10, 1901. 
132 .SHORTER CONTRffiUTIONS TO GENERAL GEOLOGY, 1918. 

Fannin County west by north through Grayson County to the vicinity of Gordonville and 

thence south along the western border of the 

area mapped. The belt is characterized by 

sandy hills of pronounced relief, supporting a 

growth of blackjack and post oak trees; a 

good example is afforded by the hills within 

.several miles southwest and west of Denison, 

Grayson County. (See Pl. XXVI.) As shown 

elsewhere in this report, however, the Woodbine formation is irregularly bedded, and locally considerable parts of it are composed of 

clay which has produced a gently rolling surface similar to that of the Black Prairies; such 

an area occurs along the central and southern 

parts of the belt of outcrop of this formation 

for a distance of several miles west-northwest 

from Pottsboro, Grayson County. 

The Grand Prairies include the area along 

the south limb of the Preston anticline in northern Grayson County, Tex., and sm~llareas along 

the north limb of the anticline in Marshall 

County, Okla., underlain by the limestones 

and shaly clays and marls of the Comanche 

series down to but not including the Trinity 

sand. (See geologic map, Pl. XVII.) This 

belt resembles the Black Prairies in its gently 

rolling to moderately hilly aspect, but the indurated layers of the Comanche series, including in ascending order those of the Goodland, 

Duck Creek, Fort Worth, "Quarry," and Main 

Street limestones, tend to produce numerous 

small benches and low cuestas in the otherwise smooth to moderately rolling surface; 

these features are well exhibited in Grayson 

County in the northward-facing slope of the 

Red River valley, north of the belt of outcrop 

of the Woodbine sand. The belt of outcrop of 

the sandy strata of the Pawpaw member locally 

produces a narrow belt of timbered, sandy soil 

within the Grand Prairies, which resembles the 

Eastern Cross Timbers. 

The Western, Cross Timbers are represented 

in this area chiefly by a narrow belt that marks 

the crest of the Preston anticline in southern 

Marshall County, Okla., west of Preston Bend 

of Red River, where the sandy strata of the 

Trinity sand come to the surface. Topographically the area is hilly and similar to that of the 

Eastern Cross Timbers. 

The belt of alluvial terrace plains bordering 

Red River includes plains at several levels: 

(1) The present flood plain of Red River is 

narrow along that part of the river bordering 

Grayson County, Tex., but broadens out to 3 

or 4 miles in places along the northern border 

of Fannin and Lamar counties, Tex., and the 

southern border of Bryan County, Okla. (2) 

A well-defined river terrace 45 to 75 feet above 

low-water level of Red River is moderately 

extensive in places along the river valley; the 

village of Preston, in Preston Bend, in the 

northern part of Grayson County, is situated 

on an exceedingly flat portion of this plain, 4 

or 5 square miles in extent, and Woodville, 

about 2-1 miles north of Preston, in Marshall 

County, Okla., stands on a somewhat larger 

portion of the plain. (3) A terrace plain 140 

to 160 feet above water level is represented 

here and there in that part of the valley above 

the mouth of Washita River but occupies extensive areas in the valley below that river; in 

the southwestern part of Bryan County, Okla., 

the alluvial deposits of this terrace form a flat 

sandy plain 8 miles or more in width from 

north to south,. and large areas of the plain occur in the northern parts of Fannin and Lamar 

counties, Tex. (4) Remnants of surficial deposits were observed at still higher altitudes at. 

several places in the area and may represent 

one or more additional terraces. The alluvial 

deposits on these terrace plains effectually 

obscure the Cretaceous formations over many 

square miles in the Red River valley, rendering 

it difficult to determine the areal extent and 

structure of the formations. 

Minor features of the topography that have 

an important bearing on the areal mapping 

and the determination of the stratigraphy and 

structure are the ridges, benches, and stream 

bluffs produced by the more resistant strata of 

both the Comanche and Gulf series. Many of 

these features take the form of cuestas-that is, 

broad, low ridges of great linear extent that 

trend parallel to the strike of the rocks and 

present long, gentle slopes to the east, southeast, or south in the direction of the dip and 

short, steep slopes on the inland side, which 

marks the western edge of the outcrop of the 

harder ridge-forming strata. An example is 

the white rock escarpment of Hill/ which 

marks the western and northern edge of the 

Austin chalk in Grayson and Collin counties 

and which makes a relatively steep descent 

1 Hill, R. T., U. s. Geol. Survey Twenty-first Ann. Rept., pt. 7, p. 

68, 1901. 
GEOLOGY OF NORTHEASTE · N TEXAS AND SOUTHERN OKLAHOMA. 133 

from a portion of the Coastal Plain upland 

that is underlain by the Austin chalk t a belt 

of the upland that lies 75 to 100 feet pr more 

lower and is underlain by the softef Eagle 

Ford clay. Similar examples are t' e relatively steep slopes that mark the orthern 

edges of the Annona tongue of the Austin 

chalk in Fannin and Lamar counties a d of the 

Pecan Gap chalk in Delta, Fannin, H nt, and 

Collin counties. (See geologic map, PI XVII.) 

GENERAL GEOLOGIC FEATURES. 

The Cretaceous deposits are divisible into 

two great series, a lower, the Comanche series, 

which appears at the surface about the flanks of 

the Preston anticline in the northwestern part 

of the area and has an estimated thickness of 

800 to 1,000 feet, and an upper, the Gulf series, , 

which has an estimated thickness of at least 

3,000 feet and the outcrop of which covers considerably more than half the area. Each of 

these series is separable into subordinate divisions, which are discussed on subsequent 

pages. The Gulf series is unconformably overThe area shown on the geologic ap (Pl. lain by strata of Eocene age which appear at 

XVII) is underlain throughout its ex ent by the southeast in a relatively small part of the 

strata of Cretaceous age, which rest upon a area under discussion. (See Pl. XVII.) In 

buried, moderately smooth basement c mposed general the strike of the s,trata is parallel to the 

of ancient rocks. Just to the north in the inner margin of the Coastal Plain, and the dip 

Atoka and Tishomingo quadrangles Okla., is coastward from this margin at rates ranging 

where the basement comes to the su face, it from 30 feet or less to 80 feet or more to the 

includes Paleozoic sedimentary rocks f Cam- mile. A considerable departure from the prebrian, Silurian,· Devonian, and Carbo iferous vailing regularity in strike and dip occurs in 

age and pre-Paleozoic granites. Th upper the northwestern and central parts of the ar~a, 

surface of the basement rocks is believ1 to be a in connection with. the Preston anticline, depeneplain formed by erosion prior to the de- scribed on pages 159, 160. A less pronounced 

position of the Cretaceous sediments upon it departure from the common monoclinal strucand subsequently tilted slightly coast ard. ture is occasioned by the fold which produced 

The northern boundary of the Or taceous the Leonard-Celeste n1onoclinal nos 2, described 

deposits trends about due west 10 to po miles on page 161. 

north of Red River, and the western bpundary The Cretaceous deposits consist of sand, 

trends south by west through Montag-qe, Wise, shaly clay, calcareous shaly clay, limestone, 

and Parker counties, Tex. Both these bound- and chalk. With the exception of the Trinity 

daries are outside the area shown n Plate sand (p. 134) and the Woodbine sand (p. 145), 

XVII. The tilted peneplained surfac of the both of which wer e laid down in deltas and in 

basement rocks dips to the south ffom the marginal marine waters, all these deposits are 

northern boundary at rates estimated o range of typical marine origin. 

in different places from 50 to 70 feet or more to The boundaries of the formations as indithe mile, and to the southeast from the western cated on Plate XVII are in part very much 

boundary at rates probably ranging fr m 40 to generalized. Whei·e they are established with 

50 feet to the mile. Within the area mapped approximate accuracy for the scale of the map 

the basement rocks lie nearest to th~ surface by the personal observations of the writ0r aP..d 

beneath the crest of the Preston ant cline, in his associates or by published evidence rethe southern part of Marshall Count:r, Okla., garded as sufficiently reliable, the boundaries 

and the northern part of Grayson !County, arc drawn as full lines. Elsewhere the boundTex., where their depth ranges from 3f to 700 aries have been determined by general confeet; they lie deepest i.n the so~ thea~ ern part 1 

si~era~ior:s or by using the ~nv~rified boundof the ar_ea, where thmr depth Is esti ated as · anes IndiCated on maps ot Hill, Taff, and 

between 4,000 and 5,000 feet. Gordon and are drawn as broken lines. The 

The basement rocks are separated rom the geologic formations of the northeastern part of 

overlying Cretaceous deposits by arl uncon- Fannin County and .the northern part of Lamar 

formity representing a long interval of geo- County are little known, owing in part to an 

logic time, including at least the Tri ssic and ~ extensive covering of Pleistocene alluvial terJurassic periods and probably a con iderable j race deposits which largely conceal the Orepart of the Lower Cretaceous epoch. taceous formations in a broad area bordering 
134 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Red River on the south, and in part to the in- Comanche constitutes a closely related lithoadequacy of the field work that has been done logic and paleontologic series. 

in the area. The• writer has not examined the 

boundary between the Woodbine and EaO'le 

Ford formations anywhere in western Grays~n and eastern Denton counties, nor the boundary 

between the Eagle Ford and Austin south of 

the Texas Pacific Railroad in Grayson and Collin counties. The position assigned to the Cretaceous-Eocene contact in Hunt and Hopkins 

counties is based chiefly on the maps of Hill 

and Gordon. 

CRETACEOUS SYSTEM. 

COMANCHE SERIES. 

GENERAL CHARACTER. 

The Comanche series consists of sands, shaly 

clays, marls, and limestones having an estimated thickness in northeastern Texas of 800 

to 1,000 feet. The series has been subdivided 

in Tex_as in ascending order into the Trinity~ 

Fredericksburg, and Washita groups, all of 

which are represented in the area treated in 

this paper. (See Pl. XVII.) In this area the 

series appears in surface exposures only in the 

northern part of Grayson County, Tex., and in 

an adjacent area north of Red River in the 

southern parts of Marshall and Bryan counties, 

Okla., where it has been brought to the surface 

by the uplift that produced the Preston anticline. (See p. 159.) Were it not for this anticline the series would lie buried beneath the 

Gulf series in the area mapped, with the possible exception of its extreme northwestern corner. Hill's classification of the Comanche series in Grayson County is given in column C in 

Plate XVIII. 

The Comanche series is of Cretaceous age. 

Until recently the series has been regarded by 

American geologists as belonging to the Lower 

Cretaceous, but for a number of years certain 

European geologists, notably Douville, 1 have 

regnrded the series as in part Upper Cretaceous. Berry and Knowlton 2 now correlate 

the Washita, the uppermost group of the series 

unquestionably with the Cenomanian (Uppe~ Cretaceous). Whatever may be the position 

of this series with respect to the standard European section, it is reasonably certain that the 

1 Douville, H., Sur que!ques rudistes amencains: Soc. geol. France 

Bull., 3d ser., vol. 28, p. 218, 1900. 2 Berry, E. W., The Upper Cretaceous floras of the world: Maryland 

Geol. Survey, Uppu Cretaceous, pp. 222, 223; 1916. 

TRINITY &\.ND. 

The Trinity group, which is represented in 

northeastern Texas chiefly by sand (the ".Antlers sand" of Hill), is the basal division of the 

Comanche series. According to well records 

this sand is 400 to 700 feet thick in the vicinity 

of Red River in Grayson County, Tex., and 

Marshall County, Okla. Taff, who studied it 

in the Tishomingo quadrangle, Okla., a few 

miles north of Grayson County, states that the 

formation consists of fine, compact incoherent 

sand and scattered lentils of sandy clay, with a 

basal conglomerate a few feet to 50 feet thick, 

which in the western half of the quadrangle is 

cemented with chalky white lime. 3 Pebbly 

lenses occur in the sand in places. 

In the area under consideration the sand is at 

the surface in the axial portion of the Preston 

anticline, in an irregular belt having a maximum width of 7 or 8 miles, extending from a 

point several miles southeast of Rock Bluff, 

on Red River, to the northwest corner of the 

area in Oklahoma, as shown on the geologic 

map (Pl. XVII). · Localities where the sand 

was examined are mentioned or briefly described below. 

At Rock Bluff, Red River, ~ miles south of 

Preston or 8~ miles northwest of Denison, 

Grayson County, Tex. (see Pl. XIX, A), near 

the axis of the Preston anticline, the upper 150 

feet of the Trinity is well exposed, as described 

in the following section: 

Section at Rock Bluff, · Red River, Grayson County, Tex. 

[Altitude at top of section estimated to be 690 feet above sea level.] 

Fredericksburg group (Goodland limestone): Feet. 

Hard massive limestone .. . . . . .. . . . .. .. .. .. .. . 10 

~~~:St~~a:.' .. ~~~~~~-~-~~~~~~} w~~=b:r ~- ~ .~{ ~ Trinity sand(" Antlers sand" of Hill): 

Light-gray, mostly fine argillaceous irregularly 

bedded compact sand, with subordinate 

lenses of fine sandy clay and some pebbly 

lenses; in the lower 30 feet are interbedded 

lenses of purplish clay having a maximum 

observed thickness of 6 feet................. 150 

163 

In a bhiff of Red· River 1! miles above Rock 

Bluff, 1i miles south by east of Preston, 30 feet 

3 Taff, J. A., U.S. Geol. Survey Geol. Atlas, Tishomingo folio (No. 98), 

p. 6. 1903. 
U. S. GEOLOGICAL SURVEY 

A 

Tishomingo quadrangle, 

Oklahoma Tatf, Tishomingo folio (No. 98) 1903 

B C 

Grayson County, Texas 

Stephenson Hill, 21st Ann. Rept., Pt. VII 1918 1901 

Grayson 

marl 

member 

/ 

/ 

/ 

/ 

/ 

/ 

/ 

~ ~ 

!i Grayson maris 11/

1 

~<i'~"-~===~ivl~~e~Yo~~t 

r::B,-e in"7Cgt on---,-li e-st:-- ne'...-_ _--- --

Pawpaw 

sa ndy 

member 

Pawpaw 

beds 

Bokchito 

format1 on 

Caddo 

limestone 

K1am1chi 

format1on 

Good land limestone 

Trinity sand 

---...... --.......... 

..................................... 

? ----------

Denton 

m~~·~ er 

Fort Worth 

limestone 

Duck U) 

fo~~:~on ~ c 

0 

0- - - -

:J "'Quarry e limestone 

'W U) 

We no 

formation 

Ostrea 

c.arinata bed 

Duck Creek 

format ion 

~ 1.' 

------------ ~ 1-------f 

Kiamichi 

clay 

Kiamitia 

clays 

Goodlan~-L. l Goodland limestone l1mestone 1 ~ 

- ·- -· Wa ~~S. farrna~.Q~-

Walnut./ 

shaly 

rnemDer 

Trinity 

sa nd Antlers sands 

~ 

/ 

:PROFESSIONAL PAPER 120 PLATE XVIII 

D 

South of Brazos River 

in central Texas Hill, 21st Ann. Rept., Pt. VII 1901 

Del Rio clay 

/// ~ g / 1 t~ 

E 

Austin quadrangle 

A ~!i\~f~l~a(~~.a¥6) . 1902 

Georgetown 

limestone 

/ ""'" 

/// .'l-=-~-~1.~K-_,., ia~;,~;t2i~a!....:-c="Ta~ -v-:._--l- --------t-------1 

/ 

Edwards 

lime5tone 

Comanche Peak 

limestone 

Walnut 

format ion 

Paluxy sand 

Glen Rose 

forma tion (chiefly limestone) 

?--------+---------1 ? ______ _ 

Basement 

sand s 

Edwards 

limestone 

·,,'',,. \\,,.____Comanche Pea k 

~',',,,~ime~tone ' 

Walnut clay 

Glen Rose 

formation (chiefly limestone) 

-----------+--------1 

Travis Peak formation 

Feet 

1,1 00 

g2 

\(]j) 

ro 

"!:: 1,000 ..c 

If) 

ro 

3: 

900 

800 

g0 

~ 

1f 

.0 

If) 

-6 

~ 700 

l.L 

600 

500 

400 

g- 300 2 

\(]j) 

>- "!:: 

c 

c 

r--

200 

100 

0 

CORRELATION TABLE SHOWING 

TO THE f'OR 

HE RELATION OF THE SUBDIVISIONS OF THE COMANCHE SERIES IN GRAYSON COUNTY, TEX., 

TIONS OF THE SAME SERIES IN OTHER PARTS OF TEXAS AND OKLAHOMA. 

GEOLOGY OF TEXAS AND SOUTHERN OKLAHOMA. 135 

of Trinity sand es~entiall 

scribed is exposed benea 

tocene terrace alluvium. 

In the public road 1! ~·les west of reston 

30 or 35 feet of Trinity s nd outcrops in the 

steep westward-facing slo e of the Re River 

valley, and the Goodlan limestone f r1ns a 

ledge at the crest of the hill, about 6 0 feet 

above sea level. Pebbly lenses were n t ed in 

the Trinity at this locality 

At Henderson Ferry on Red River, miles 

west by south of Rock Bl ff, the upper 40 feet 

of the Trinity is moderat ly well expo ed and 

consists of fine to coarse .ray and yell w sand 

with1small mechanically included frag ents of 

· clay and slightly indurate sand. The sand is 

overlain by the Goodland limestone, in luding 

the Walnut member at its ase, which i poorly 

exposed. 

Good exposures of the 

southern part of Marshall 

headwater branches of and Creek, n1iles 

south by west of Kingstf n; in the v Hey of 

Buncombe Creek, 2! to 8 iles north b east of 

Willis Ferry; and in the alleys of B 'er and 

House creeks, 3 to 8 miles north and no thwest 

of Willis Ferry. 

The northwesternmost locality wh re the 

Trinity was examined by the writer is on the 

northeastward-facing slope of the Re River 

valley about a mile south, ast of Orlen , in the 

extreme northwestern parp of Grayson ounty, 

Tex. Here the Goodlanq limestone c ps the 

hill, forming a rocky ledge at its cres at an 

altitude of about 750 feetjl and 75 feet r more 

of the Trinity appears in he steep slop below 

the Goodland. 

South of the Red Rive region in T xas the 

middle portion of the 'Frinity beco es calcareous, and s.outh of Brat os River is s parable 

according to Hill 1 in asc nding order nto the 

basement sands, 127 feet the Glen R se formation, chiefly limeston , 315 feet; nd the 

Paluxy sand, 190 feet. till farther s uth, at 

Austin, the Pa.luxy sand is apparent} represented by li1nes.tone in t e upper par of the 

Glen Rose, so that the T inity is sepa able in 

ascending order into :fly two pa ts-the 

Travis Peak formation, c nsisting of c nglomerate, grit, sand, clay, an calcareous b ds, 100 

feet; and the Glen Ro e formation, chiefly 

limestone, 450 feet. (See Pl. XVIII.) 

I Hill, R. T., U. S. Geol. Survey Tw nty-first Ann. Rep ., pt. 7, pp. 

153-154, 171, 1901. 

FREDERICKSBURG GROOP. 

GOODLAND LIMESTONE (INCLUDING WALNUT SHALY 

. MEMBER). 

The Trinity sand is overlain by the Fredericksburg group, which in northeastern Texas 

is represented by the Goodland limestone, only 

13 to 20 feet thick. The Goodland outerops in 

a narrow area on the flanks of the Preston antidine, surrounding the area of outcrop of the 

Trinity sand (see Pl. XVII), in northern Grayson County, Tex., and in southern Marshall 

and Bryan eounties, Okla. Along the south 

side of the anticline the Goodland dips south 

by west at rates ranging from 40 to 300 feet or 

more to the mile. The steepest known dip 

oecurs about a mile and a half northeast of 

Pottsboro. (See strueture eon tours, Pl. XVII.) . 

The basal 3 to 6 feet of the Goodland linlestone eonsists of layers of persistent hard thinbedded coquina-like limestone with interbedded 

thin layers of dark marly shale, whieh are in 

this paper called the Walnut shaly member. 

These beds were not recognized by Hill 2 in the 

type section at Goodland, in Choct aw County, 

Okla. He says: 

Proceeding westward along the ~ncient Ouachita shore 

line from Arkansas into Texas, the Exogyra texana beds 

(the Walnut clays and Gryphaea breccia) are missing until 

the escarpment is reached north of Marietta, in the Chickasaw Nation [Love County, Okla.], where they first appear, 

thinly represented beneath the Goodland limestone. 

In 1894 3 and again in 1901 4 Hill restrieted 

the term" Goodland" to the n1assive limestone 

between the underlying Walnut elay, which 

he regarded as forn1ing the upper part of the 

"Antlers" (Trinity) sand, and the overlying 

Kiamiehi clay. In .the Atoka folio 5 and again 

in the Tishomingo folio, 6 Taff included the 

Walnut elay in the Goodland, and this usage 

has subsequently been followed by Taff and 

other authors. Although the United States 

Geological Survey has adopted Taff's usage of 

Goodland, the present writer is of the opinion 

that future investigations will demonstrate the 

appropriateness of restricting the application 

of the name to the massive limestone above 

the interbedded shaly clay and coquina-like 

limestone, here called Walnut shaly member, 

in accordanee with Hill's original usage. 

2 Geol. Soc. America Bull., vol. 2, pp. 502-'-514, 1891. 

a Geol. Soc. America Bull., vol. fi, pp. 303, 304, 1894. 

• U.S. GeoL Survey Twenty-fir~t Ann. Rept., pt. 7, pp. 216-222, 1901. 

• U.S. Geol. Survey Geol. Atlas, Atoka folio (No. 79), 1902. 

e Idem, Tishomingo folio (No. 98), 1903. 
136 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Southward from Grayson and Cooke counties 

in Texas the Walnut member becomes thicker, 

and in Tarrant and Johnson counties it assumes 

the importance of a formation rather than a 

member; here it consists of alternating hard 

and soft thin-bedded limestone and marl and 

reaches a maximum thickness of 140 or 150 

feet. Still farther south, in Hood and Somervell counties, the thickness again decreases to 

approximately 90 feet, and in the vicinity of 

Austin, Travis County, it is only 15 feet. 

(See Pl. XVIII.) The type locality of the 

Walnut member is at Walnut · (or Walnut 

Springs), in Bosque County. 

Above the Walnut member the Goodland 

consists of 10 to 15 feet of liard massive persistent limestone, which weathers white. This 

limestone form.3 conspicuous outcrops and is 

therefore a valuable key rock in determining 

structure from surface exposures. It is easily 

recognizable in well borings, its position so 

closely above the Trinity sand preventing its 

confusion with other limestones in the overlying Washita group. As a rule, the drillers do 

not differentiate the few feet of lirnestone and 

marl of the Walnut member at the base of the 

Goodland limestone. Characteristic fossils of 

the Goodland limestone are Gryphaea marco·ui 

Hill and Vaughan, Exogyra texana Roemer, 

Remondia robbinsi (White), Oerithium bosquense Shun1ard, and Schloenbachia acutocarinata (Shumard). The importance of the 

Goodland as a key rock warrants a fairly full 

description of its occurrence about the flanks 

of the Preston anticline. 

One of the easternmost outcrops of the 

Goodland near the crest of the Preston anticline is in the banks of a small creek entering 

Shawnee Creek just below the pumping station 

at the city lake, 4 miles northwest of Penison. 

The creek near its mouth is intrenched in the 

limestone to a depth of 6 to 7 feet, and the 

limestone is overlain by a few feet of alluvium. 

Upstream the top of the limestone gradually 

becomes lower with respect to water level, and 

within a few hundred yards it passes beneath 

the bed of the creek. At Bears Ferry, Red 

River, It miles north by east of the city lake, 

the top of the Kiamichi formation is about 25 

feet above water level, showing that the Goodland is here 15 or 20 feet below water level. 

Within a mile west of Bears Ferry the Goodland rises above water level and forms a gradually rising ledge in the northward-facing siope 

of the Red River valley westward to Rock 

Bluff, where the base of the limestone lies a 

little more than 150 feet above the river. 

The section at Rock Bluff is described on 

page 134. 

West of Rock Bluff the Goodland appears in 

both slopes of the Little Mineral Creek valley, 

but its southward dip carries it below the surface. in the bed of the creek at a point approximately 4i miles north of Pottsboro. A 

fine exposure of the limestone is afforded by a 

bluff on this creek 4! miles north of Pottsboro. 

(See Pl. XIX, B.) 

Section on Little Mineral Creek ·H miles north of Pottsboro, 

Grayson County, Tex. 

[Altitude at top of section estimated to be 615 feet ahove sea level.] 

Feet. 

Soil. . . . . • • • • • . • • • • . . • • • . • . • . • . . . . . . • . • . • • • • • • • • 2 

Fredericksburg group (Goodland limestone): 

Massive limestone ...................... _ . . . . 13 

Walnut shaly member: Hard thin-bedded 

coquina-like ,limestone containing Ostrea sttbovata Shumard, Gryphaea marcoui Hill and 

Vaughan, Trigonia sp., and Anomia sp., 

with interbedded thin layers of dark marly 

shale........ • • . • • • • • • • • • • • • • • • • • •• • • • . • . • • 6 

21 

Both the massive limestone and the underlying Walnut shaly member are well exposed 

in a branch in the eastward-facing slope of 

Little Mineral Creek, .6 miles north of Pottsboro (3 miles north of Fink), where · a thin 

earthy calcareous layer in which cone-in-cone 

structure was well developed was noted about 

a foot below the top of the Walnut member. 

On the divide between Little Mineral Creek and 

Red River the Goodland extends northward to 

a point 7 miles north of Pottsboro, where the 

altitude of its top is about 720 feet above sea 

level. The limestone here lacks less than 2 

miles of closing to the north over the crest· of 

the Preston anticline, its absence in this interval being due to erosion which has removed 

the Goodland from the underlying Trinity. 

(See p. 137 and Pl. XVII.) 

At He~derson Ferry, Red River, 6! miles 

north by west of Pottsboro, the base of the 

Goodland is only 35 or 40 feet above water 

level, and upstream from the ferry, within an 

estimated distance of 1 or 2 miles, it finally 

comes down to water level and crosses into 

Oklahoma. beneath the Pleistocene and Recent 

alluvial deposits of the Red River valley. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XIX 

A. TRINITY SAND AND LOOSE SLABS OF GOODLAND LIMESTONE AT ROCK BLUFF (OLD 

MARSHALL BLUFF) ON RED RIVER, 8Y:;l MILES NORTHWEST OF DENISON, GRAYSON COUNTY, 

TEX. 

The upper 150 feet of the Trinity is exposed in the bluff. The Goodland limestone,. which immediately overlies 

the Trinity, forms a ledge along the crest of the bluff, and large masses of rocks broken from it have fallen down 

the slope, giving rise to the name Rock Bluff. 

B. GOODLAND LIMESTONE ON LITTLE MINERAL CREEK IN NORTHERN GRAYSON COUNTY, 

TEX. 

The massive Goodland limestone is underlain by the Walnut shaly member (the undermined portion). 

GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 137 

Northwest of Henderson Ferry, in Marshall 

County, the southward-dipping limestone appears in the valley slopes of the southwardflowing creeks tributary to Red River and was 

especially noted along two small creeks respectively 3 and 3! miles east of Willis Ferry. 

North of Willis Ferry the Goodland crops out 

in both the east and west slopes of the ridge 

separating Buncombe and Brier creeks, and 

its continuity is interrupted at only one place 

on the crest of the ridge, where it has been 

eroded away. At a point estimated to be 

about 3! ~iles west by north of Willis Ferry 

the Goodland again crosses Red River into 

Grayson County, Tex., where, gradually rising 

to the northwest in the northeastward-facing 

slope of the river valley, it finally forms the 

crest of the hill overlooking the valley about 

a mile southeast of Orlena. The Trinity sand 

appears in the slopes of this hill below the 

Goodland. 

On the north limb of the Preston anticline 

the Goodland crops out in the valley of Rock 

Creek south of Kingston, in Marshall County, 

Okla., and is especially well exposed in a 

branch about 3! miles south by west of Kingston. The section here shows the upper massive limestone, underlain by the Walnut shaly 

member, and this in turn by the Trinity sand. 

Down the valley of Rock Creek from this 

locality the limestone appears in the southwestward-facing slope, gradually descending 

toward water level until, in the vicinity of the 

big bend a mile or two west of Woodville, it 

crosses the Red River valley beneath the 

Pleistocene and Recent alluvial deposits and 

reappears on the Texas side of the river in the 

hills in the northern part of Preston Bend, 

Grayson County. A good exposure of the 

limestone was noted in the public road on the 

westward-facing slope of the Red River valley 

1! miles west of Preston, where it is underlain 

by 30 or 35 feet of Trinity sand that outcrops 

in the slope below the limestone. This locality 

is less than 2 miles north of the northernmost 

occurrence of the limestone in the south limb 

of the anticline on the divide between Little 

Mineral Creek and Red River. (See p. 136.) 

The limestone here and in other outcrops in 

this vicinity dips to the northeast at an angle 

sufficient to carry it 40 or 50 feet below water 

level at Thomson Ferry, a mile north of Preston, Tex. 

East of Preston the Goodland again crosses 

the Red River valley beneath alluvial deposits, 

and although not traced in detail it was examined in an outcrop at the foot of a terrace 

scarp at the edge of the Red River bottom 

about half a mile north of Bears Ferry, in 

Bryan County, Okla. Here the top of the 

limestone is 30 or 35 feet above water Ie·v-el. 

South of Red River in Cooke County, Tex., 

the Goodland gradually increases in thickness. 

It is regarded as the time e:Juivalent of the 

Walnut clay, and of the Comanche Peak and 

Edwards limestones of central Texas, which 

south of the Brazos River valley have a combined thickness of over 250 feet; still farther 

south the Edwards c•ntinues to thicken, being 

300 feet thick in the vicinity of Austin, Travis 

County (see Pl. XVIII), and .520 feet thick 

in Uvalde County, whereas the Walnut and 

Comanche Peak become _thinner, the •former 

being only 15 feet and the latter 40 feet thick 

in the vicinity of Austin. 

WASHITA GROUP. 

LITHOLOGY AND SUBDIVISIONS. 

The Washita group con sis· s chiefly of marine 

shaly clay, marl, and interbedded subordinate 

limestone, having a total estimated thickness in 

northern Grayson County of 415 feet; toward 

the top there is a sandy member, the Pawpaw 

(seep. 142), which is the only conspicuous exception to the nonsandy character of the group 

in this area. The limestone, though subordinate in thickness to the clay and marl, forms 

several definite bands that have individual 

physical characteristics and contain index 

fossils which render them readily traceable 

throughout the area; they have also been 

approximately correlated by means of the fossils with beds of corresponding age in cen.tral 

and southwestern Texas. The limestones are 

therefore valuable key beds in determining the 

geologic structure of the deposits. 

The group has been subdivided by Hill 1 and 

Taff. 2 Although Hill's nomenclatural treatmentis not in all respects precise and consistent, 

the succession of beds described by him has been 

substantially verified. He recognized the following divisions, named in ascending order 

(see Pl. XVIII): (a) The Preston beds, sub1 U.S. Geol. Survey Twenty-first Ann. Rept., pt. 7, pp. 240-292,1901. 

2 U. S. Geol. Survey Geol. Atlas, Atoka folio (No. 79), 1902; Tisher 

mingo folio (No. 98), 1903. 
138 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

divided into the Kiamitia clay, thickness 40 

feet, which rests upon the Goodland limestone, 

and the Duck Creek formation (clay, marl, 

and limestone), thickness 100 feet; (b) the 

Fort Worth limestone, thickness 35 feet; (c) 

the Denison beds, subdivided into (1) the 

Denton subgroup, thickness 45 feet; (2) the 

Weno subgroup, including the Marietta or 

Weno formation, thickness 115 feet; the 

Quarry limestone, thickness 2 feet; and the 

Pawpaw beds, thickness 45 feet; and (3) the 

Pottsboro subgroup, including the Main Street 

limestone, thickness 8 feet; and the Grayson 

marl, thickness 25 feet. 

The divisions recognized by Taff in the 

Tishomingo and Atoka quadrangles, Okla., 

which correspond to the Denison beds of Hill, 

include in ascending order the Kiamichi formation, equivalent to the "Kiamitia" clay of 

Hill; the Caddo limestone, equivalent to the 

Duck Creek formation and the Fort Worth 

limestone; the Bokchito formation, equivalent 

to the Denton subgroup and the Weno subgroup (Marietta or Weno formation and Pawpaw beds) of Hill; and the Bennington limestone, equivalent to Hill's Pottsboro subgroup (Main Street limestone and Grayson 

marl). (See Pl. XVIII.) 

classification of the group, modified somewhat 

for the sake of simplicity and greater clear· 

ness, is adopted, as shown in Plate XVIII, 

colun1n B. The changes include the dropping 

of the apparently unnecessary terms Preston 

beds, W eno subgroup, and Pottsboro subgroup. 

KIAMICHI CLAY. 

The Kiamichi clay is named for Kiamichi 

River, on which it is typically exposed in 

Choctaw County, Okla. In Grayson County 

the Kiamichi clay, which includes .all the beds 

between the Goodland and Duck Creek formations, is 40 or 50 feet thick and consists 

chiefly of dark carbonaceous shaly clay, with 

thin platy layers of siliceous limestone interbedded with the clay in the lower few feet and 

with thin layers of gray impure fossiliferous 

limestone in the upper 10 or 15 feet. The 

writer has not seen the full thickness of the 

formation, and the description is based partly 

on the statements of Taff and Hill. The section at Thomson Ferry, given below, which 

includes the upper part of the formation, was 

examined by the writer. (See Pl. XX.) 

This locality is on the north limb of the Denison anticline. 

South of Grayson and Cooke counties, Tex., Section at Thomson Ferry, on the right bank of Red River, in 

hi Grayson County, Tex., 2 miles south of Woodville, Okla. the Was ta group, as a whole, becomes thinner, at the same time gradually assuming a Duck Creek formation: 

different lithologic character. In the Austin Layers of limestone interbedded with subordinate layers of dark shaly calcareous clay, quadrangle (see Pl. XVIII) the Georgetown the limestone hard and nodular in the upper 

limestone, which is only 80 feet thick, appears part, softer and less nodular below, especially 

to represent all of the Washita group of in the lower 2 feet. Fossils recognized: KinGrayson County up to and including the gena sp., Exogyra plexa Cragin, Plicatula sp., 

basal part of the Main Street limestone, a Gryphaea washitaensis Hill, Hamites jremonti 

Marcou (?), Schloenbachia (two or three total thickness of at least 385 feet. However, species) ..••••••••••••••••••••••.•••••••••• the upper part of the ~1ain Street limestone Kiamichi clay: 

and the Grayson marl, which, together have a Layers of gray impure, very fossiliferous limethickness of about 30 feet, become thicker stone with thin interbedded layers of dark 

toward the south and are represented in the calcareous shaly clay; the limestone layers 

contain vast numbers of Gryphaea, chiefly G. Austin quadrangle by the Del Rio clay and navia Hall ................................• 

Buda limestone, which have a combined Dark shale with layers of Gryphaea-bearing 

thickness of about 125 feet. limestone resembling the limestone in the 

Hill's classification of the group is given in overlying division but more widely spaced. 

Plate XVIII (p. 134), which also includes col- Fossils recognized: Gryphaea navia Hall, 

h · h 1 · · h h b Trigonia sp., and Plicatula sp .••••••••..... umns s owing t e corre atwn wit t e su -

Feet. 

15 

7 

divisions of the group recognized by Taff in The Gryphaea-bearing limestones in the upthe Tishomingo quadrangle, Okla., by Hill in per part of the Kiamichi clay are characteristic 

the region south of the Brazos River valley, and persistent and form excellent key beds in 

and by Hill and Vaughan in the A~stin quad-~ determining the structure of the rocks in this 

rnngle, Tex. In the present report Hill's area. They were noted also on the north 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XX 

A. TOP OF KIAMICHI CLAY, OVERLAIN BY LIMESTONE MEMBER OF DUCK CREEK FORMATION, IN BLUFF ABOVE THOMSON FERRY, RED RIVER, 11 MILES NORTHWEST OF DENISON, 

GRAYSON COUNTY, TEX. 

B. SLABS OF GRYPHAEA-BEARING IMPURE LIMESTONE FROM THE UPPER PART OF THE 

KIAMICHI CLAY AT THE LOCALITY SHOWN IN A. 

The shells belong chiefly to the species Gryphaea navia Hall. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXI 

A. EARTHY FACIES OF THE LOWER PART OF THE FORT WORTH UMESTONE ON THE 

OKLAHOMA SIDE OF RED RIVER AT THE MISSOURI. KANSAS & TEXAS RAILWAY BRIDGE 

5 MILES NORTH OF DENISON. GRAYSON COUNTY. TEX. 

B. FOSSIL FUCOIDS (il) ON THE UNDER SIDE OF A SLAB OF FORT WORTH LIMESTONE. AT 

THE LOCALITY SHOWN IN A. 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 139 

limb of the Preston anticline in a branch of f Section on Duck Creek and in a cut ojthe St. Louis & San 

Rock Creek at a public road crossing 3 miles Francisco Railroad 2i miles north of Denison, Grayson . County Tex. south by west of Kingston, Marshall County, ' 

Okla. On the south limb of the anticline they Fort Worth limestone: 

were examined along the Preston road a short Four or five layers of nod·.Ilar impure argillaFeet. 

ceous fossiliferous limfstone interbedded distance south of Rock Bluff (see p. 134); along with gray shaly clay •.......•.............. 8 

the road leading down to Henderson Ferry, Duck Creek formation: 

5! miles north by west of Pottsboro; and in Gray shaly calCareous clay with interbedded 

the be<i. of Little Mineral Creek, 3! miles north layers of impure non ledge-forming limestone 

22 

20 

of Pottsboro. at intervals of 2 or 3 feet ................. .. 

Concealed ........ . .............. , .......... . 

DUCK CREEK FORMATION. 

The Duck Creek formation, which is typically exposed on Duck Creek north of Denison, 

in Grayson County, consists of approximately 

100 feet of limestone and gray to greenish-gray 

shaly calcareous clay, which intervene between 

the Kiamichi clay below and the Fort Worth 

limestone above. In the lower 35 or 40 feet 

the limestone alternates with the clay in layers 

6 to 12 inches thick, in about equal proportions; in the upper part of the section the clay 

predominates, the limestone layers being rather 

soft and separated by intervals of 2 to 3 feet 

or more of clay. The limestones in the lower 

35 or 40 feet are characterized by keeled and 

nonkeeled ammonites, many of which reach 

a diameter of 2 feet or more. One layer of 

white, chalky limestone 3 or 4 feet thick 35 or 

.40 feet above the base of the formation and 

2 or 3 feet of gray calcareous clay that immediately underlies it contain great numbers of 

large ammonites and form a zone that has 

been recognized in outcrops over a large area 

in Texas and Oklahoma and was used by 

Messrs. Hopkins, Powers, and Robinson as a 

key in the determination of structure. The 

keeled ammonites belong chiefly to the genus 

Schloenbachia, several species of which have 

been differentiated. The nonkeeled forms belong chiefly to the species Pachydiscus brazoensis (Shumard). The limestones also contain some of the remains of the problematic 

organisms (fucoids ~), such as occur in great 

numbers and of larger size in the Fort Worth 

limestone. (See p. 140 and Pl. XXI, B.) The 

most complete section of the Duck Creek formation exan1ined by the writer is on Duck 

Creek and in a cut of the St. Louis & San Francisco Railroad where it comes close to Duck 

Creek, 2-1 miles north of Denison. 

Greenish-gray calcareous clay from which 

weather numeroirs specimens of Plicatula cf. 

P . incongrua Conrad and small rusty ammonites, probably the young of Pachydiscus and 

Schloenbachia, also a few specimens of Gryphaea washitaensis HilL ....... . ............ . 

Ledges of limestone with interbedded layers 

of gray shaly clay, poorly exposed; the limestone, especially one layer near the top, contains numerous keeled and nonkeeled ammonites, many of which are of large size 

(maximum, 2 feet in diameter) ............ . 

Alternating beds of ammonite-bearing limestone 

and gray shaly clay, about half and half, 

15 

20 

well exposed in bluff along the creek . . . . . . . 20 

Other exposures of the limestones forming 

the lower part of the Duck Creek formation 

were observed by the writer in a small branch 

of Little Mineral Creek at the crossing of the 

road leading to Henderson Ferry, 4! miles 

north of Pottsboro; in the road leading down 

to Henderson Ferry about a mile west by 

north of the locality just mentioned; and at 

Willis Ferry (Oklahoma side), 13 miles northwest of Pottsboro, Tex. The upper part of the 

Duck Creek, consisting of calcareous clay, 

which lacks conspicuous layers of limestone, 

is well exposed in a bluff on the north side of 

Red River, about half a mile above Willis 

Ferry. These localities are on the south 

lin1b of the Preston anticline; the section at 

Thomson Ferry, on the north limb of the anticline described on page 138, reveals the basal 

15 feet of the limestone. 

FORT WORTH LIMESTONE. 

The Fort Worth limestone, named from the 

city of Fort Worth, Tarrant County, Tex., 

consists in the vicinity of Red River north of 

Denison, Grayson County, of about 25 feet of 

gray nodular earthy limestone interbedded 

with layers of dark shaly clay, followed above 

by . 8 to 10 feet of heavy-l)edded hard cream-
140 SHORTER CONTRIBUTIONS TO GENERAL GFOLOGY, 1918. 

colored chalkj limestone. This limestone resembles the limestone portion of the underlying 

Duck Creek formation, from which it may be 

distinguished by slight litho logic differences, 

by the more common occurrence of pectens, 

by the presence of echinoids in greater number 

among which are Hemiaster elegans Shumard, 

Exogyra walkeri White (a large smooth species), 

Nautilus texanus Shumard, and Schloenbachia 

leonensis Conrad. 

DENISON FORMATION. 

and of larger size, and by the greater abun- DENTON CLAY MEMBER (INCLUDING "OSTREA CA.RINATA 

dance and larger size of the problen1atic fucoidlike rmnains described below. The Fort Worth 

is immediately overlain by the Denison formation. A good exposure of the lower 25 feet of 

the formation is afforded by the bluff of Red 

River at the north end of the bridge of the 

Missouri, Kansas & Texas Railway 5 miles 

north of Denison, on the north limb of the 

Preston anticline. (See Pl. XXI, A.) Here the 

impure nodular limestone layers range in 

thickness from a few inches to 2 feet, and the 

interbedded shaly clay composes half or more 

of the bulk of the material. The limestone 

layers are fossiliferous and the most numerous 

and conspicuous forms are keeled ammonites, 

some of which have a maximum diameter of 

18 inches, and echinoids. An interesting and 

characteristic feature of these limestones is 

the problematic fucoid 0) remains or casts of 

borings ( ~) which line the underside of some 

of the limestone layers. Good examples are 

shown in Plate XXI, B. The upper part of 

the formation is well exposed in the bank of a 

small branch about a third of a mile northeast 

of the Missouri, Kansas & Texas Railway 

bridge just east of the railway track; here 

the Fort Worth is overlain by 15 feet of reddish 

terrace sand. 

The upper heavy-bedded cream-colored limestone of the Fort Worth is exposed at many 

places on the south limb of the Preston anticline in Grayson County and was observed 

in a cut of the Missouri, Kansas & Texas Railway 2 miles north by east of Denison; on the 

Bears Ferry road 1! miles in an air line northwest of the post office at Denison; on the 

Preston (Rock Bluff) road 3! miles north of 

the Missouri, Kansas & Texas Railway, near 

the head of a branch of Little Mineral Creek; 

on the public road 2! miles in · an air line 

northeast of Pottsboro; and on the Henderson 

Ferry road 31 miles north of Pottsboro, an 

eighth of a mile north of Fink. This upper 

massive part of the Fort Worth limestone conBED"). 

Hill 1 originally applied the name Marietta to 

beds, chiefly shaly clays, 160 feet thick,· between the Fort Worth limestone below and imperfectly defined so-called North Denison sands 

above. Later he reclassified the Denison formation, as shown in Plate XVIII, column C, 

introducing the name Denton subgroup, from 

Denton Creek, Denton County, for the lower 

45 feet of the original Marietta, including 

the "Ostrea carinata bed" at its top, and 

applying the name Weno formation to 

the beds which lie between the 1 Denton 

and the ''Quarry'' limestone and include 

most of the upper part of the original 

Marietta. In one of his tables in the same 

paper 2 he somewhat loosely applied the name 

Marietta to the beds between the Denton and 

Pawpaw divisions. As the name Marietta is 

preoccupied for sandstone in the Dunkard 

group of Pennsylvania, West Virginia, and 

Ohio, its use in the Denison section seems 

undesirable. 

The lower 5 feet of the Denton is a strongly 

calcareous clay of a decided marly character. 

This is followed by 35 feet of shaly, less calcareous clay, which in turn is followed by 3 to 5 

feet of highly fossiliferous impure limestone, 

composed largely of the shells of Gryphaea 

washitaensis Hill but containing also a few 

large echinoid spines and other fossils, among 

which are considerable numbers of Ostrea carinata Lamarck, a fossil which suggested the 

name "Ostrea carinata bed." The Denton 

member appears in imperfect exposures along 

the St. Louis & San Francisco Railroad 1 ~ to 

2 miles north of Denison. 

The "Ostrea carinata bed'~ appears in many 

small exposures along the south limb of the 

Preston anticline and is an excellent key rock, 

chiefly because of the presence of 0. carinata 

Lamarck, a peculiar and easily recognizable 

fossil. This stratum is exposed on the St. 

. d . · · 1 d 1 Hill, R. T., Geol. Soc. America Bull., vol. 5, p. 303, 1894. Stitutes a good key b~ , OWing t~ I~S e ?e- 2 Hill, R. T., U.S. Geal. Survey Twenty-first Ann. Rept., pt. 7, p. 

forming character and Its characteristic fossils, Jus, 1001. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXII 

A. UPPER PART OF THE WENO CLAY IN THE EAST BANK OF WASHITA RIVER AT THE 

FRISCO RAILROAD BRIDGE 2}4 MILES WEST OF PLATTER, BRYAN COUNTY, OKLA. 

The material exposed in the bank comprises shaly clay and subordinate interbedded layers of sandstone. 

E . UPPER PART OF THE WENO CLAY IN A CUT OF THE FRISCO RAILROAD A MILE NORTH 

OF THE STATION AT DENISON, GRAYSON COUNTY, TEX. 

A ledge of the "Quarry" limestone, which overlies the Weno, appears at the extreme top of the section. 
U. S. GEOLOGICAL SURVEY . PROFESSIONAL PAPER 120 PLATE XXIII 

A. MAIN STREET LIMESTONE IN A CUT OF THE MISSOURI, KANSAS & TEXAS RAILWAY 

3 MILES WEST OF THE STATION AT DENISON, GRAYSON COUNTY, TEX. 

B. "QUARRY" LIMESTONE, UNDERLAIN BY THE WENO CLAY, IN A CUT OF THE FRISCO 

RAILROAD THREE-QUARTERS OF A MILE NORTH OF DENISON, GRAYSON COUNTY, TEX. 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 141 

Louis & San Francisco Railroad 1! miles north 

of Denison and was seen also on the Missouri, 

Kansas & Texas Railway 1!- miles north of 

Deni.son; on the l~ears Ferry road about 1! 

n1iles in an air line northwest of the post office 

at Denison; in the headwater branches of Shawnee Creek, 3! miles west by north of the post 

office at Denison; and at Fink post office, 3 

miles north of Pottsboro. Messrs. Hopkins 

and Powers noted outcrops of a stratum that 

carries 0. carinata Lamarck and apparently 

represents the "Ostrea carinata bed" stratigraphically 55 feet above the Fort Worth limestone, at two localities on the north limb of the 

anticline in Marshall County, Okla., namely, 

3t miles southeast of Kingston, in the NE. 

i sec. 3, T. 7 S., R. 6 E.; and 2! miles east of 

Kingston, in the SE. i sec. 28, T. 6 S., R. 6 E. 

WENO CLAY MEMBER. 

The Denton clay member is overlain by 115 

feet of dark-gray shaly clay _ with subordinate 

thin partings, lenses, and layers of fine gray to 

yellow sand, some of which are indurated to 

ledge-forming sandstone. To this rna terial 

Hill 1 gave the name Weno formation, from the 

small village of W eno, on Red River 5 miles 

northeast of Denison, Grayson County, which 

does not appear on recent maps and is apparently abandoned. Hill in ·the same paper also 

used the name Weno in a broader ("subgroup") sense, to include both th~ Weno clay 

member and the overlying Pawpaw sandy 

member, a usage not followed in the present 

paper. Sand layers are numerous, th1ugh subordinate to the clay, in the upper 35 f-eet of the 

division in cuts of the St. Louis & San Francisco Railroad about a mile north of the station 

at Denison (see Pl. XXII, B), where one lens 

has a maximum thickness of 1! feet. At the 

same locality the clays contain many small 

flattish ferruginous concretions, probably derived by oxidation from concretions of iron carbonate, and some small concretions of marcasite. Fossil pelecypqds and gastropods in a 

good state of preservation are numerous in the 

clays, sands, and ferruginous concretions in 

these upper beds, among which were recognized Nucula sp., Ostrea quadriplicata Shumard, Protocardia texana (Conrad), Oyprimeria 

1 Hill, R. T., U.S. Geol. Survey Twenty-first .Ann. Rept., pt. 7, PP. 

121, 274, 1901. 

sp., Oorbula (three species), Oymbophora sp., 

Turritella sp., Auchura mudgeana White, Engonoceras serpentinum (Cragin). 

The Weno clay weathers down to smooth 

surfaces and is as a rule poorly exposed on the 

uplands and valley slopes. In addition to the 

section in the railroad cut just described, a 

good exposure of strata believed to represent a 

portion of the Weno clay and certainly representing either this clay or the Pawpaw member 

is afforded by Carpenters Bluff, on Red River 

below the bridge of the Missouri, Oklahoma & 

Gulf Railway, 7 miles in an air line due east of 

Denison. Hill mapped the area in which this · 

bluff is included as belonging to the Woodbine 

formation, though Taff had at an earlier date 

recognized that the outcrop at the bluff belonged to the Washita group. This exposure 

is about on the southeastward-plunging axis of 

the Preston anticline. 

According to Messrs. Hopkins and Powers 

the Weno clay in the north limb of the Preston 

anticline in l\1:arshall County, Okla., is about 

135 feet thick, or 20 feet thicker than in the 

south limb in Grayson County, Tex. A fine 

exposure of the upper 50 feet of the Weno, 

overlain by the ''Quarry" limestone, is afforded 

by a bluff on the left bank of Washita River at 

the crossing of the St. Louis & San Francisco 

Railroad 2! miles west of Platter, Bryan 

County, Okla. A vjew of this bluff, taken at 

a low stage of water, is shown in Pl. XXII, A. 

The beds here consist predominantly of greenish 

shaly calcareous clay, with an interstratified 

layer of sandstone 5 or 6 feet below the 

"Quarry" limestone and several layers of thin 

flaggy sandstone 25 to 40 feet below the 

"Quarry." Well-preserved fossil shells, many 

species of which are identical with those collected in a cut of the St. Louis & San Francisco 

Railroad a mile north of Denison in Grayson 

County, Tex., are abundant in some layers of 

the clay and in some of the indurated layers. 

Several well-preserved fragments of crustaceans 

were found in the talus. 

About 20 feet of dark shaly clay of the W eno 

member, containing poorly preserved fossils, is 

well exposed in the left bank of a branch just 

east of the Missouri, Kansas & Texas Railway, 

1! miles south of Colbert, Bryan County, Okla.; 

this locality also is on the north limb of the 

Preston anticline. 
142 • SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

PAWPAW SANDY MEMBER (INCLUDING "QUARRY" 

LIMESTONE). 

The W eno clay member is overlain by approximately 50 feet of more or less irregularly 

bedded clays and sands, including at the base 

a persistent layer of sandy limestone 1 to 4 feet 

thick, known as the "Quarry" limestone. Calcareous clay predominates in the lower half of 

the division above the "Quarry" limestone, and 

sand and interbedded laminated sand and clay 

predominate in the upper half. Good exposures, particularly of the upper part of the 

member, occur in the headwater branches of 

Pawpaw Creek within the corporate limits of 

the eastern part of Denison. 

The "Quarry" limestone is a sandy bluishgray limestone that weathers yellow and purple 

and contains considerable numbers of Ostrea 

quadriplicata Shumard. Ostrea subovata Shumard is rather sparingly represented. A good 

exposure is afforded by a cut of the St. Louis 

& San Francisco Railway three-quarters of a 

mile north of the station at Denison (see Pl. 

XXII, B), where it is 2 feet thick and the lower 

3 to 12 inches is conglomeratic. The somewhat 

scatt ered pebbles in the conglomeratic portion 

consist of waterworn calcareous sandstone, 

sandy limestone, and calcareous and ferruginous concretions, the largest 3 inches or more 

in length. A few borings into the top of the 

underlying Weno clay, filled with material characteristic of the limestone, were noted. As the 

base of the limestone is sharply separated from 

the underlying clay and is somewhat undulating, the contact appears to mark an unconformity, though the time represented by it was 

probably short. The limestone in this section 

is overlain by 4 feet of clay, above which is another layer of similar limestone 6 inches to 1 

foot thick, which shows the lenticular character of the rock and which apparently connects 

the "Quarry" limestone more closely with the 

overlying Pawpaw member than with the underlying Weno clay. In this connection it may 

be mentioned that Messrs. Hopkins and Powers 

have noted in Marshall County, Okla., several 

layers of sandy limestone in the Pawpaw member that resemble the "Quarry." 

Other outcrops of the limestone were examined in Grayson County in the bed of a small 

branch of Smith Creek just south of the Missouri, Oklahoma & Gulf Railway, 4-! to 5! 

miles east of Denison; in a ditch and in a field 

south of the Missouri, Oklahoma & Gulf Railway about 2! mile~ east of Denison; at a 

culvert of the Missouri, Oklahoma & Gulf Railway about 2 miles east of Denison; in a northsouth public road 1 t miles east by north of 

Pottsboro; in an east-west road at two· creek 

crossings 2 miles north of Pottsboro; in the 

Henderson Ferry road 2! miles north of Pottsboro, a quarter of a mile south of Fink; , and in 

the public road a quarter of a mile west of 

Fink. 

On the north limb of the Preston anticline the 

"Quarry" limestone outcrops at the crest of the 

steep part of the bluff on Washita River at the 

crossing of the St. Louis & San Francisco Railway in Bryan County, Okla. (see p.141), where 

it overlies the Weno clay and is overlain in turn 

by clays and sands of the Pawpaw member. 

Poor exposures were also noted near the public ' 

road leading to Kingston, about 3 miles northwest of Woodville, in Marshall County, Okla. 

Messrs. Hopkins and Powers state that in the 

latitude of Kingston and farther north there is 

no definitely recognizable "Quarry" limestone, 

but several beds resembling it; 3 miles east of 

Kingston they examined a section which included four distinct layers of ·sandy limestone 

each resembling the "Quarry" and each containing Ostrea quadriplicata Shumard. Mr. 

Hopkins noted an outcrop of a sandy glauconitic 

limestone rese'mbling the "Quarry" 4 miles 

east of Kingston, Marshall County, in the center of the west line of sec. 35, T. 6 S., R. 6 E., 

from which he obtained a specimen of a bryozoan which R. S. Bassler refers to the genus 

Domopora. 

The section described below shows the relation of the Pawpaw member to the overlying 

Main Street limestone member. (See Pl. 

XXIV, B.) 

Section in a small headwater branch of Pawpaw Creek .fust· 

east of the subway under the Missouri, Kansas &: Texas 

Railway south of the station at Denison, Tex. 

Main Street limestone mem her: 

Irregular nodular layers of hard limestone 6 to Feet. 

18 inches thick,. interbedded with soft yellow 

marl a few inches to 6 inches thick; the under 

side of the lowest limestone layer is roughly 

nodular. Exogyra arietina Roemer f\CCurs 

abundantly in the upper 2 or 3 feet. . . . . . . . . 8 

Gray, faintly laminated sandy and calcareous 

(marly) clay, coarsely sandy in the basal fe}V 

inches; in the basal 6 inches are numerous 

small ferruginous concretions and a few flattish, partly oxidized iron carbonate concretions; one apparently water-worn quartzitic 

sa.ndstone pebble was noted................. lt-2 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXIV 

A. WOODBINE SAND IN A CUT OF THE MISSOURI, KANSAS & TEXAS RAILWAY lYz MILES 

WEST BY SOUTH OF THE STATION AT DENISON, GRAYSON COUNTY, TEX. 

The Woodbine here is a partly indurated ferruginous sand, containing irregularly distributed thin ironstone plates. 

E. MAIN STREET LIMESTONE UNDERLAIN BY THE PAWPAW SANDY MEMBER OF THE DENISON 

FORMATION NEAR THE SUBWAY SOUTH OF THE MISSOURI, KANSAS & TEXAS RAILWAY 

STATION AT DENISON, GRAYSON COUNTY, TEX. 

The Pawpaw member, as exposed at this locality in a headwater branch of Pawpaw Creek, comprises laminated crossbedded sand and clay. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXV 

A. SAND AND CLAY OF THE WOODBINE FORMATION AT HYATTS BLUFF, ON RED RIVER 

5 MILES NORTHWEST OF RAVENNA, FANNIN COUNTY, TEX. 

B. FERRUGINOUS SAND OF THE WOODBINE FORMATION IN THE SHERMAN ROAD, 2 MILES 

SOUTHWEST OF DENISON, GRAYSON COUNTY, TEX. 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHER.N OKLAHOMA. 143 

Unconformity (?). 

Pawpaw sandy member: 

Thinly laminated, strongly cross-bedded gray 

clay and sandy clay with thin sand partings 

and some larger lenses of fine yellow sand; 

numerous thin iron crusts occur in the partings; some comminuted plant fragments 

Feet. Main Street limestone member-Continued. 

Greenish-gray sandy calcareous clay marl with 

scattered white clay pebbles and ferruginous 

concretionary clay nodules along the base, 

some of which suggest having been mechaniFeet. 

cally included . ...•.•.•••.•.•.•••••.•••••.. ll--ll 

Unconformity (?). 

were noted __ ........ ; .................... . 6 Pawpaw sandy member: 

The upper 6 feet of the Pawpaw is also well 

exposed beneath the Main Street limestone on 

the Missouri, Kansas & Texas· Railway at the 

iron overhead bridge 3 miles west of the st ation 

~;tt Denison. (See below and Pl. XXIII, A.) 

Here the Pawpaw consists of current-bedded, 

laminated sand and clay with highly fossiliferous thin lenses of ferruginous oxidized soft 

sandstone. Among the fossils recognized were 

Nucula sp., Protocardia texana (Conrad), Oymbophora sp., Oorbula sp., Anchura mudgeana 

White, and Engonoceras serpentinum (Cragin). 

The Pawpaw member produces a narrow belt 

of sandy soil between the clay soils of the Weno 

and those of the overlying Main Street limestone and the Grayson marl. The topogr aphy 

produced by the sandy beds of the Pawpaw is 

similar to that characteristic of the outcrop of 

the Woodbine formation of the Gulf series. 

MAIN STREET LIMESTONE MEMBER. 

Current-bedded greenish-gray fine sand, with 

fine clay laminae and subordinate lenses of 

laminated clay. Highly fossiliferous thin 

discontinuous lenses of ferruginous oxidized 

soft sandstone with many molds and internal 

casts of fossil mollusks; soft molds and internal casts occur also in the soft sands. (See 

list, above.) Maximum exposed thickness .. 6 

The limestone is poorly exposed on Main 

Street east of the railroad tracks in the eastern 

part of Denison and is well exposed in some of 

the branches and on the slopes about the headwaters of Pawpaw Creek in the same vicinity. 

One section is described on page 122. (See 

also Pl. XXIV, B.) 

Other exposures of the limestone were noted 

along the south limb of the Preston anticline 

in Grayson County, in the bed of a headwater 

branch of Iron Ore Creek just north of th0 

Missouri, Kansas & Texas Railway, 5! miles 

west of the station at Denison and a quarter 

of a mile east of a north-south public road; The Main Street limestone, named from expoor exposures showing dips of 20° or more 

posures on Main Street in Denison, consists, in in a :ow strike ridge extending from a point 2 

Grayson County, of 8 to 20 feet or more of miles east of Pottsboro northwestward for a 

heavy-bedded hard limestone, with subordi- distance of 2 miles; in the bed of a headnate interbedded layers of unconsolidated cal- water branch of Little Mineral Creek on the 

careous marl, and is characterized by the Hender2on Ferry road 2! miles north of Pottspresence of Exogyra arietina Roemer, particu- boro, seven-eighths of a mile south of Fink; 

lady in the upper part, and of Kingena waco- poor exposures along the east-west public road 

ensis (Roemer) in the lower part. One of ·the three-fourths of a mile . to 1! miles west of 

best exposures of the limestone is afforded by Fink; on the same road near the heads of 

a cut of the Missouri, Kansas & Texas Railway · 21 2 1 2.a. d 31 ·1 t f F' k . f h . D . ravines 4 , -z , 4 , an -s- mi es wes o In , 3 miles west o t e statwn at enison. (See 1 · b th G 1· h .. h Pl. XXIII A.) ?ver a1n y e rayson rna: , w Ic appears 

' I Hl several poor exposures ; In the bed of a 

Section in cut of ~issouri, K~nsas & Texas Railway 3 miles small southward-flowing branch of Mill Creek 

west of the statwn at D,emsoAl-, Grayson County, Tex. about 4 miles west by north of Fink; along a 

Residuum ~nd creep: . . . . Feet. north-south public road 2 miles east ,by south 

Browmsh loam contammg m ?laces along 1ts of Cedar Mills. on a public road on the westbase a great number of ferrugmous sandstone . ' . fraoments and boulders derived from the ward-facmg slope of the Mineral Creek valley 

W;odbine sand. 00. 00...................... 2-6 11 miles east . y south of Cedar Mills; in a 

Main Street limestone member: sm.all branch at the turn of the road just south 

Irregular layers of limestone 3 to 4 feet thick, . of Cedar Mills; on the northward-facing slope 

with discontinuous interbedded lenses of soft of the Sandy Creek valley just north of Cedar 

marl, underlain by 3 to 4! feet of massive 

hard limestone having an undulating nodular Mills; at the crossing of a public road over a 

base ; Exogyra arietina Roemer is common in headwater branch of Brier Creek 5 miles norththe upper layers........................... 7! west of Gordonville; and on the southeast 
144 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

crest of Brushy Mound, 9 miles· northwest of 

Gordonville. 

The Main Street limestone was not seen in 

place by the present writer on the north limb 

of the Preston anticline, but Messrs. Hopkins 

and Powers state that they have seen it well 

exposed at the following localities in Oklahoma: In Bryan County on the south bank of 

Rock Creek along the public road, 2 miles 

northwest of Platter; and in Marshall County 

a mile west of Washita River; on the south 

bluff of Washita River at the southeast corner 

of sec. 7, T. 7 S., R. 7 E.; 2 miles northeast of 

Woodville, in the center of the east line of 

sec .. 19, T. 7 S., R. 7 E.; and 4 miles north of 

Woodville, in the NW. t sec. 1, T. 7 S., R. 6 E. 

According to the geologic map of the Tishomingo quadrangle, which joins the Denison 

quadrangle on the north, the Bennington 

limestone of Taff, which includes the Main 

Street limestone, enters the Denison quadrangle 2 or 3 miles west of its northeast corner. 

GRAYSON MARL MEMBER. 

GULF SERIES. 

GENERAL CHARACTER. 

The Gulf series is composed of sands, shaly 

clays, chalks, and calcareous clays and sands 

(marls), which have an estimated thickness of 

approximately 3,000 feet in the area under 

consideration. In the southwestern part of 

the area the succession of formations in the 

series is, in ascending order, a·s follows: Woodbine sand, Eagle Ford clay, Austin chalk, Taylor marl (including the Wolfe City and Pecan 

Gap members; see pp. 155-156), and Navarro 

formation. Toward the north the lower part 

of the Austin chalk merges, with some intertonguing, into conterrfporaneous nonchalky 

sands and clays, and the upper part of the 

Austin transgresses to a?fhigher position in the 

geologic column, so tha·t· in Fannin and Hunt 

counties the following succession of mappable 

units is recognizable: Woodbine sand, Eagle 

Ford clay, unnamed clays and sands beneath 

the Austin chalk, Ector tongue of Austin chalk, 

unnamed clay in the vicinity of Bonham, AnThe topmost division of the Denison forma- nona tongue of Austin chalk, Taylor marl 

tion and of the Washita group, known as the (includingWolfeCity and Pecan Gap members), 

Grayson marl, consists of 15 to 25 feet of light and Navarro formation. Still farther to the 

grf1enish-gray calcareous clay or marl with northeast, in Lamar, Delta, and Hopkins 

lumps of white lime and several nodular thin counties, the .succession of units is as follows: 

layers of limestone. The fossils carried by the Woodbine sand (exposed at Arthurs Bluff, on 

m.arl include species of Gryphaea, Pecten, Tri- Red River), Eagle Ford formation (largely 

~7onia , Plicatula, Protocardia, · Turrilites, and concealed by terrace deposits), unnamed sands 

Hoplites, of whi~h Gryphaea mucronata Gabb is and clays (also largely concealed), Blossom 

perhaps the most common. sand, Brownstown marl, Annona tongue of 

The marl is poorly exposed above the Main Austin chalk, Taylor mar( and Navarro formaStreet limestone about the headwater·branches tion. The age relations of the units just 

of Pawpaw Creek, in · the eastern part of Deni- named in different parts of the area are diason. The best exposure examined was in a pit grammatically represented in the correlation 

south of the Mi~souri, Oklahoma & Gulf Rail- section given in Plate XXX, 0 (p. 155). 

way about a quarter of a mile east of the sta- The Gulf series is referable in its entirety to 

tion at Denison, where a thickness of 16 feet of J the Upper Cretaceous, though, as indicated on 

the marl was noted. page 134, it may not include representatives of 

Other exposures in Grayson County occur in the lowermost part of the Upper Cretaceous. 

the banks, of headwater branches of Iron Ore The nature of the contact separating the Gulf 

Creek near the Missouri, Kansas & Texas Rail- series from the underlying Comanche series 

way 5i to 5! miles west of Denison; in the has not been satisfactorily determined in northbank of a headwater branch of Little Mineral eastern Texas. Probably it is that of unconCreek near the crossing of the Henderson Ferry formity, the basal formation of the upper. 

road, 2~ miles north of Pottsboro and seven- series, the Woodbine sand, having been deposeighths of a mile south of Fink; and at intervals ited in the shallow waters of the transgressing 

on and near the public road leading west from sea, in the deeper waters of which the succeedFinkfor a distance of about 4 miles. ing truly marine sediments of the series were 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXVI 

A. TOPOGRAPHY IN THE HILLY AREA UNDERLAIN BY THE WOODBINE SAND ~4 MILES 

SOUTHWEST OF DENISON, GRAYSON COUNTY, TEX. 

View looking northeast toward the old waterworks plant. 

B. A DETAIL OF TOPOGRAPHY IN A SMALL BRANCH VALLEY UNDERLAIN BY THE WOODBINE SAND lYz MILES SOUTHWEST OF DENISON, GRAYSON COUNTY, TEX. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXVII 

A. CONTACT BETWEEN THE EAGLE FORD CLAY AND THE AUSTIN CHALK IN A QUARRY 

OF THE TEXAS PORTLAND CEMENT CO. 3 MILES WEST OF DALLAS, TEX. 

The contact between the Eagle Ford clay and the Austin chalk is approximately marked by the crest of the prominent 

bench in the foreground. 

B. "FISH-BED CONGLOMERATE" (P) IN THE BED OF A BRANCH 3 MILES SOUTH OF RAVENNA, 

FANNIN COUNTY, TEX. 

The indurated conglomeratic layer is immediately underlain by somewhat argillaceous fine marine sand, which here 

forms the topmost stratum of the·Eagle Ford clay. _ 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 145 

laid down. Toward the south the Woodbine 

sand becomes progressively thinner, finally 

disappearing in :McLennan County, south of 

which the Eagle Ford clay rests directly upon 

the Buda lim~stone of the Comanche series. 

The absence of the Woodbine in central and 

southwestern Texas would therefore seern to 

indicate unconformity, unless the age equivalent of the vVoodbine lies in the relatively thin 

sediments that compose the Buda limestone, a 

supposition which seems highly improbable 

and which has no basis of known fact. 

WOODBINE SAND. 

The Woodbine sand, named from the village 

of Woodbine, . in Cooke County, is the basal 

division of the Gulf series in northeastern 

Texas. It is a highly variable formation, consisting of strongly current-bedded, more or less 

ferruginous sand and laminated shaly clay, 

with some interbedded layers of lignite and 

lignitic clay. On account of the irregularity 

of the bedding it is scarcely possible to determine 

the thickness of the formation from surface 

outcrops, but it is reasonably certain that in 

Grayson County the thickness is not less than 

300 or 400 feet and may be as great as ~00 feet. 

A well at Ladonia, in the southeast corner of 

Fannin County, penetrated between depths of 

1,800 and 2,425 feet about 62.5 feet of sand and 

clay which are interpreted as belonging to the 

Woodbine. As stated above, the Woodbine 

becomes progressively thinner toward the 

south, finally disappearing in McLennan County. 

The formation is traceable eastward frmn Grayson County through Texas and into Arkansas, 

where it is believed to be represented by a part 

at least of the Bingen sand. 

The scope of this paper will not permit a 

detailed account of the many different lithologic aspects of the formation, for which the 

reader is referred to the sections described by Hill 

and Taff in the papers listed on pages130-131. 

Hill recognized two subdivisions of the Wood-

'bine-a lower member, called by him the Dexter sands, consisting of an estimated thickness 

of 160 feet of "brown and yellow ferruginous 

sandstone heavily laden with siliceous ironstone," and an upper 1nember, called b.v him 

the Lewisville beds, consisting of 150 feet or 

more of "laminated lignitic sands and sandy 

clays, interstratified with brown sands, ferruginous reddish-brown sandstone, shell sandsto;-10, and argil1 aceous shelly · sandstone which 

con ta.ins large lenslike calcareous concretions 

and laminated argillaceous sandstones at the 

top." Sand seems to predominate over clay, 

producing a pronounced sand-hill type of 

topography, as in the country immediately 

southwest and west of Denison; but locally 

clay makes up the bulk of the . formation, 

producing a smoothly rolling surface, as in the 

belt of country northwest of Pottsboro. (See 

p. 132.) 

Fossil leaves have been obtained from the 

lower member (Hill's Dexter sands) of the 

Woodbine near Denison. The upper member 

(Hill's Lewisville beds) yields a peculiar shallow marine fauna that differs markedly from 

the Cretaceous faunas either below or above it 

in Texas. This fauna is be.st known from 

exposures on Timber Creek, 3 or 4 miles west, 

southwest, and south of Lewisville, Denton 

County, Tex., and though it includes a relatively small number of species is rich in individuals, which largely make up certain lenses 

and layers of the formation. The following are 

some of the species· that have been described: 

Area (Barbatia) micronema (Meek), numerous. 

Ostrea soleniscus Meek, very numerous. 

Modiolus filisculptus Cragin. 

Cytherea leveretti Cragin. 

Cerithium tramatensis Cragin. 

Cerithium interlineatum Cragin 

The fossiliferous strata of the upper member 

are represented in Grayson County, though 

they are not so conspicuously exposed as they 

are on Timber Creek in Denton County. 

Fossil plants have also been collected from 

beds regarded as representing the Woodbine 

formation at Arthurs Bluff, on Red River 15 

miles north of Paris, in Lamar County, Tex. 

The Woodbine sand outcrops in a belt a few 

miles wide along the south limb of. the Preston 

anticline (see geologic map, Pl. XVII) and in a 

north-south belt along the western border of the 

area mapped. The belt of outcrop wraps 

around the southeastward-plunging nose ·of the 

Preston anticline in northwestern · Fannin 

County, Tex., and passes northward into Oklahoma, where it extends in a broad belt to the 

northwest and north, and to the east down the 

Red River valley. Exposures of the Woodbine . 

at three localities are shown in Plates XXIV, .A, 

and XXV, A and ·B. . 
146 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

The formation may be studied to advant"age 

on sandy hills along the northern margin of the 

belt of outcrop between Pottsboro and Cedar 

Mills, in Grayson. County; in road and railroad 

cuts and creek beds between Denison and 

Pottsboro, and for several miles southwest of 

Denison; in cuts of the Missouri, Kansas & 

Texas Railway in the western outskirts of Denison, Grayson County (see Pl. XXIV, A) ; in roads 

and stream banks and beds in the hilly country 

within 6 or 7 miles east-southeast of Denison; 

on sandy hills in the northwestern part of 

Fannin County; and at Hyatts Bluff, on Red 

River just above the mouth of Caney Creek, 6 

miles northwest of Ravenna, Fannin County 

(Pl. XXV, A). 

Hyatts Bluff, not heretofore described, is 

half a mile long and 45 feet high and trends 

N. 28° E. Reddish terrace sand forms the 

upper 20 feet of the section, beneath which are 

25 feet of Woodbine strata consisting of soft 

cross-bedded glauconitic sandstone; darkgreenish, more massive soft glauconitic sandstone; small lenses of pebbly sand; and dark 

shaly clay. The main bedding planes are 

fairly persistent and dip perceptibly downstream. One persistent sandstone stratum 

2! feet thick, overlain by a lignitic band a foot 

thick, was traced from a point where it is 20 

feet above water levsl for 1,800 feet along the 

face of the bluff to a point where it passes beneath water level. · The dark shaly clay forming the portion of the section that is stratigraphically highest in the Woodbine contains 

concretions of iron carbonate, some of which 

are fossiliferous, and there is one layer of darkgreenish glauconitic soft sandstone containing 

the abundant remains of a poorly preserved 

molluscan fauna that inhabited a shallow sea. 

The photograph reproduced in Plate XXV, A, 

was taken where the lignitic band lies at water 

level and is· overlain by 4 or 5 feet of shaly, 

easily eroded clay. The conspicuous projecting ledge is highly cross-bedded sandstone along 

the base of which are discontinuous small lenses 

.of conglomerate. 

EAGLE FORD CLAY. 

The Woodbine sand is overlain by the Eagle 

'Ford clay, a formation named from E~gle Ford, 

a village 6 miles west of Dallas, where . it is 

typically exposed. The formation consists 

.chiefly of dark bluish-gray to nearly black 

shaly clay which is as a rule gypsiferous and 

more or less bituminous; in places crystals of 

selenite weather from the clay in great numbers. In Grayson and Fannin counties the 

formation has an estimated thiqkness between 

300 and 400 feet. Thin, platy layers of sand,. 

stone and sandy limestone, some bearing the 

imprints of small costate and keeled ammonites, occur in the formation, particularly 

in the central portion. Flattish calcareous 

nodules occur in the lower part of. the formation, and oval to spherical hard limestone septaria are characteristic of the upper part. In 

the upper 20 or 25 feet of the formation in the 

vicinity of Sherman the dark clays are interstratified with beds of sand, one of which, 15 

to 20 feet below the base of the Austin chalk, 

_carries vast numbers of the ~mall fluted oyster, 

Ostrea lugubris Conrad. Ten feet below the 

base of the Austin chalk, which in Grayson 

County overlies the Eagle Ford, is a conglomeratic layer of gray sandstone, carrying numerous more or less rounded phosphatic pebbles, 

shells of Ostrea alifera Cragin, and fish teeth, 

of which shark teeth are common. This is the 

"fish-bed conglomerate" of Taff, 1 which in 

the opinion of the present writer (see p. 149) 

should not be included in the Eagle Ford but 

should be regarded as the base of the sediments that have their typical expression in the 

Austin chalk. 

The formation outcrops in an east-west belt 

through the northern part of Grayson County 

and the northwestern part of Fannin County~ 

but the belt is sharply deflected to the south in 

northwest~rn Fannin County, where it passes 

around the southeast end of the Preston anticline. In the northern· part of Fannin County 

the formation passes under the Pleistocene 

terrace deposits of the Red River valley; east 

of Fannin County the only place where it has 

been certainly recognized in surface outcrops 

is Garretts Bluff, in the northwestern part of 

Lamar County. Two localities where the formation can be advantageously studied in 

northern Fannin County are at Sowells Bluff, 

on ' Red River 5 miles northwest of Ivanhoe, 

and in deep ravines in the westward-facing 

slope of the Red River valley 6 miles north of 

Ivanhoe. At the last-named locality, where 

approximately 140 feet of strata are exposed, 

the upper part of the section exhibits a larger 

1 Texas Geol. Survey Fourth Ann. Rept., for 1892, pp. 299-304, 1893. 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 147 

proportion of sandstone than is typical of the slope of the I Mill Creek valley 2 miles in an air 

for:rp.ation, and some beds of the sand~t.one are line southwrst of Bells, where it is underlain 

cross-bedded, simul~ting the Woodbine sand. by 15 or 20 feet of fine gray massive marine 

Below this dominantly sandy portion, 40 or 50 sand. The [base of the Austin chalk appears 

feet below the top of the section, is a gravel at a higher level in the same road a short dislayer generally less than a foot thick, composed tance east f the outcropping ledge of sandchiefly of dark, smooth pebbles which have not stone, from !which it is separated by 10 or 15 

yet been critically studied. This may repre- feet of poorly exposed strata, apparently clay. 

sent the "fish-bed conglomerate," in which From th1 vicinity of Bells eastward these 

case both the pebble layer and the beds above upper sand~ beds of the Eagle Ford have proit, including the dominantly sandy strata, duced a narrrow belt of country characterized 

should, in the writer's opinion, be excluded by sandy sbil and rougher topography than 

from the Eagle Ford formation. Character- that exhibi ed by the adjacent land either to 

istic Eagle Ford fossils have been obtai:J?-ed the north orlto the south. Outcrops of the perfrom wells in northeastern Louisiana. 1 sistent "fishlbed conglomerate" occur here and 

West of Sherman and Denison the belt of there just apove the sand and serve 'as a check 

outcrop bends nearly due south and is tra:ceable to the correlation of this sandy member of the 

through Texas to the Rio Grande, which it Eagle Ford) which crosses the headwaters of 

intercepts in Kinney and Valverde counties. Caney Cree~ 2! miles southeast of Bells and, apWell records show the formation to be 535 feet proximate!~ paralleling this creek, swings 

thick in the. western par~ of Collin County, around the plunging nose of the Preston antiTex., and 460 to 485 feet in the vicinity of cline and e:xltends to the northeast past Lesleys 

Dallas; south of Dallas it becomes thinner, schoolhouse) Ector, and Ravenna, in Fannin 

reaching a minimum of about 30 feet at Austin; County. The' 'fish-bed conglomerate" is more 

southwestward and westward from Austin the fully descri ed on pages 148-149. 

thickness again increases, being 75 feet or more The uppe~ part of the Eagle Ford formation 

in the Uvalde quadrangle and about 250 feet in is exposed f a branch west of a north-south 

the Brackett quadrangle. road and sor th of an east-west portion of the 

The sandy beds at the top of the Eagle Ford same road 4 miles south of Ravenna. Immehave been traced from the vicinity of Sherman diately belor the conglomerate at the locality 

eastward through Grayson County and north- shown in Bllate XXVII, B, is 5 feet of fine 

eastward to about the north.:.central part of argillaceous marine sand, near the top of 

Fannin County. Good exposures of the sandy which was ebserved a large piece of lignite. 

·beds occur in the vicinity of Bells in eastern Within about a quarter of a mile farther down 

Grayson County. A mile west of Bells the the branch I occur good exposures of typical 

east-west public road that runs about a quarter dark shaly gypsiferous clay of the Eagle Ford 

of a mile south of the Texas & Pacific Railway formation; interbedded with this clay are 

crosses a layer of ferruginous·sandstone at the subordinate ! layers of fine-grained sandstone 

head of a northward-flowing branch of Mill and a few layers and lenses of gray calcareous 

Creek, which probably represents the ''fish-bed 1 earthy roc~ that exhibits finely developed 

conglomerate." (Seep. 146.) The sandstone cone-in-cone structure. In places thick layers 

is underlain by 4 or 5 feet of dark greenish-gray of this earthy rock surround apparently conmassive sand, and in succession down the ·cretionary nh.asses of limestone. Several speciravine follow 35 or 40_ feet of more or less argil- mens of Ostr!ea lugubris Conrad were f0und loose 

laceous fine sand, With layers of soft yellow in the bed of the _creek below the outcrop of the 

sandstone at intervals, and about 40 feet of conglomera e and probably came from some 

dark shaly gypsiferous septaria-bearing clay, bed in the Jpper part of the Eagle•Ford. 

typical of the Eagle Ford clay. Some of the common fossils of use in recog- , I Another good exposure of the sandstone nizing the !Eagle Ford formation are Ostrea 

layer ("fish-bed conglomerate'') occurs in an lugubris Cofuad, 0. alifera Cragin, fish teeth 

east-west public road on the westward-facing belonging t b the species Ptychodus whipplei 

Marcou, Inloceramus labiatus Schlotheim, I. lMatson, G. C., The DeSoto-Red River oil and gas field, La.: U.S. 

Geol. survl)y :au11. 661, p.us, 1917. fragilis Hall and Meek, and small keeled a1nmo-
148 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

nites belonging to Prionotropis or Prionocyclus, 

or to both. Of these the first three occur only 

in the upper 40 or 50 feet of the formation. 

AUSTIN CHALK. 

TYPICAL AREA. 

The Austin chalk is typically exposed in the 

vicinity of Austin, Travis County, Tex., where 

it rests upon the Eagle Ford clay, is approximately 410 feet thick, and consists of white 

chalky limestone in beds of varying thickness, 

with interbedded marly layers in its upper twofifths. Some of. the common fossils that are 

especially characteristic of the formation are 

the following: 

Inoceramus undulato-plicatus Roemer. 

Ostrea aff. 0. diluviana Lamarck (uppermost part). 

Grypha?a aucella Roemer. 

Exogyra ponderosa Roemer (upper half). 

Exogyra laeviuscula Roemer (upper half). 

Radiolites austiriensis Roemer. 

Mortoniceras texanus (&emer). 

The Austin chalk extends from the Rio 

Grande in Maverick County, Tex., eastward by 

way of Uvalde to San Antonio, thence northeastward to Austin, and thence northward by 

way of Waco and Austin to Grayson County. 

From Austin northward the chalk thickens, 

and its upper surface appears gradually to 

transgress upward across the geologic column, 

or, in other words, to become younger, until 

in the latitude of Sherman the uppermost bed. 

of chalk is considerably younger than the top 

of the chalk at Austin and occupies a .position 

stratigr31phically 400 or 500 feet higher. The 

exact ., m~np.er in .which this upward transgression ta!<es place, whether by a gradual rise or by 

minor tongues of chalk at successively higher 

positions, has not been .determined, very little 

detailed field work having been done in the 

intervening area. 

DEVELOPMENT IN NORTHEASTERN TEXAS. 

SALIENT FEATURES. 

In the Sherman-Greenville section the Austin chalk is probably not less than 1,000 feet 

thick. In the eastern part of Grayson County 

and the western part of Fannin County, however, the lower two-fifths or more of the chalk 

becomes impure and gradually passes laterally 

into nonchalky sands and clays and only 

slightly chalky clay marls. In a section drawn 

through Bonham, Fannin County, and Commerce, Hunt County, the succession of recog .. 

nizable and mappable litl:wlogic units is .decidedly different from that in the latitude of 

Austin. In Collin, Hunt, and Delta counties 

other lithologic changes have taken place in 

beds above the chalk, representing the upper 

part of the Taylor marl, and these changes add 

further contrast to the section in northeastern 

Texas as compared to that in the Austin region. 

These relations are diagrammatically shown in 

Plate L~X, 0. 

In the Bonham-Commerce section the following divisions, named in ascending order, toget~er represent the chalk and its equivalents 

in this area: A band of basal non chalky clay 

and sand 10 to 35 feet thick, with the "fishbed co:p.glomerate" described below, at its base, 

all mapped with the Ector tongue; the Ector 

tongue of the Austin chalk; an unnamed transitional clay in the vicinity of Bonham (p.150); 

and the Annona tongue of the Austin chalk. 

(See Pl. XXX, 0.) 

In the longitude of Paris, Lamar County, the 

chalk and its equivalents include imperfectly 

known beds, probably clay, sand, and marl, 

representing the eastward extension of the 

Ector tongue and part of the clay in the vicinity of Bonham; the Blossom sand; the Brownstown marl; and the Annona tongue of the Austin chalk. (See Pl. XXX, 0.) 

UNNAMED CLAYS AND SANDS CONTEMPORANEOUS WITH 

BASAL PART OF TYPICAL AUSTIN CHALK. 

Phosphatic pebbles occur in the base of the · 

Austin chalk, immediately above its contact 

with the underlying Eagle Ford formation, in 

a quarry of . the Texas Por.tland Cement Co., 

3 miles west of Dallas, Tex. (See Pl. XXVII, 

A.) In Gray;son County, Tex., a conglomeratic layer, a few inches to 30 inches thick, 

called by Taff 1 the "fish-bed conglomerate," 

occurs 10 feet below the base of the chalk, with 

beds of shaly clay and sand intervening. From 

Grayson County the conglomerate extends eastward into Fannin County, where from west to 

east the interval between the conglomerate and 

the base of ·the overlying chalk, which is here 

the Ector tongue of the Austin, gradually increases until in the vicinity of Ector and Ravenna it is not less than 35 feet. Between 

Ector and Ravenna, in Fannin County, the 

material in this interval is mostly greenish calI Texas Geol. Survey Fourth Ann. Rept.,pp. 303,304, 1~93. 
U. S. GEOLOGICAL SURVEY 

A. ANNONA TONGUE OF AUSTIN 

LEONARD, 

The beds, which dip perceptibly downstream, 

PROFESSIONAL PAPER 120 PLATE XXVIII 

BANK OF A CREEK S>-2 MILES WEST OF 

COUNTY, TEX. 

massive layers of chalk interbedded with shaly layers 6 

to 2 feet thick. 

NNONA TONGUE OF AUSTIN CHALK IN AN ABANOF HONEY GROVE, FANNIN COUNTY, TEX. 

GEOLOGY OF NORTHEASTER TEXAS AND SOUTHERN OKLAHOMA. 149 

careous shaly clay becoming more or less sandy, 

with lenses of sand and sandstone in th lower 

10 feet. Lithologically the clay is of ighter 

color than the typical clay of the Eagl Ford. 

The "fish-bed conglomerate" is well e posed 

in a branch west of a north-south pubrc road 

3 miles south of Ravenna, where it f rms, a 

ledge across the bed of the stream. ( ee Pl. 

XXVII, B.) At this place it consists of a conglomeratic layer about 10 inches thic composed of coarse calcareous sand, grayi h and 

brownish phosphatic pebbles, a few ebbles 

of quartz and chert, and scattered shar teeth. 

One specimen of Ostrea alifera Cragin as obtained from the conglomerate at anoth routcrop in an east-west road about a quart r of a 

mile northwest of this locality, where also a 

thin interbedded layer of earthy r estone 

exhibiting cone-in-cone structure was noted. 

One pebble from the conglomerate was examined qualitatively by W. B. Hicks the 

chemical laboratory of the United Stat s Geological Survey and found to be composed chiefly 

of calcium phosphate. The conglom ~ate is 

here about 35 feet below the base of th Ector 

tongue of the Austin chalk (see Pl. X , 0), 

and apparently the intervening stra a are 

chiefly greenish shaly clay. 

A gravel bed that may represent the northeastward continuation from the pr ceding 

locality of the "fish-bed conglomerate" is described on pages 146-147. 

The significance of the "fish-bed co glomerate" in the geologic history of this art of 

Texas has not been definitely dete 

Heretofore the conglomerate, togethe with 

the 10 to 35 feet of clay and sand that in ervene 

between it and the overlying chalk, . ha e been 

regarded as forming the uppermost part of the 

Eagle Ford. The conglomerate, lying immediately above sftndy beds that are obvio sly of 

shallow-water marine origin, strongly s ggests 

a temporary uplift of the sea bottom of t is area 

above sea level, followed soon after by readvance of the sea and the formation of the pebble 

bed as a basal conglomerate marking. the beginning of the cycle of deposition that has i s typical expression in the Austin chalk. Thi interpretation, if found to be correct, woul 

to necessitate the exclusion of the co 

erate and the overlying clay and san from 

the Eagle Ford. Such Eagle Ford fo sils as 

the conglomerate may be found to cont in can 

be explained as having been mechanically introduced from underlying Eagle Ford strata in 

place. 

ECTOR TONGUE. 

The Ector tongue of the Austin chalk, a thin 

tonguelike projection of chalk frorn the basal 

beds of the main body of the Austin, has ·been 

traced, by means of a few outcrops and the 

black soils to which the chalk weathers, from 

western Fannin County northeastward to a 

point about a mile and a half southeast of 

Ravenna. (See Pl. XVII.) Ector, from which 

the tongue is named, is a few hundred yards 

west of the belt of outcrop, which is rather 

strongly deflected where it passes around the 

southeastern nose of the Preston anticline. 

Only 10 or 15 feet of the chalk was seen in the 

best exposures, and it probably does not exceed 50 feet in thickness in the vicinity of 

Ector. The Ector tongue is underlain by shaly 

clay, which apparently grades into the chalk 

through a thickness of only a foot or two of 

material. This clay, together with thin beds 

of sand and a basal col'iglomerate ("fish-bed 

conglomerate") associated with it, are re-· 

garded as distinct from the Eagle Ford forma·· 

tion and as more closely related in origin to the 

overlying Austin cl;lalk and its equivalents. 

(See above.) These basal beds are mapped 

with the Austin chalk and its extension; the 

Ector tongue. No exposures of the- Ector 

tongue showing clearly its relation to the clay 

of Austin age that overlies it were seen. 

The chalk is poorly exposed in the public 

road north of the Texas & Pacific Railway 

about a quarter of a mile east of Ector. 

Another exposure appears in an east-west 

public road about 3 miles north by east of 

Ector, or 51 miles northwest of Bonham; here 

several feet of the chalk is underlain by clay, 

the passage from the clay to the chalk apparently being transitional through a thickness of 

a foot or more of material. 

In other exposures revealed by a small branch 

and gullies west of a north-south public road 

3 miles south of Ravenna the weathered rock 

has the appearance of typical chalk of the 

Austin and yielded the characteristic fossils 

Gryphaea aucella Roemer and Radiolites austinensis Roemer. As noted above, the "fishbed conglomerate" crops ouc in the bed of 

the. branch and in an east-west public road less 
150 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

than a quarter of a mile west of this locality, and Ostrea plumosa Morton. These fossils, 

in a position about 35 feet stratigraphically though in themselves not conclusive evidence, 

lower than the base of the chalk. combined with the lithologic evidence menThe belt of chalk of the Ector tongue crosses 

the old Bonham-Ravenna road about 1! miles 

southeast of Ravenna, where the chalk was 

seen in a small, poor exposure in the road ditch. 

This is the easternmost locality at which this 

chalk ha~ been recognized, and its identification farther east would probably be accomplished with difficulty, owing to the extensive 

covering of Pleistocene alluvial deposits in a 

broad belt south of Red River in Fannin and 

Lamar counties. It is assumed for the present 

that the chalk loses its identity toward the east 

by merging into contemporaneous nonchalky 

clays or sands. 

The structure contours in the vicinity of 

Savoy, Ector, and Ravenna shown in Plate 

XVII indicate the altitude above sea level of 

the base of the ~ctor tongue. 

TRANSITIONAL CLAYS NEAR BONHAM. 

tioned above indicate that the glauconitic clay 

represents the Blossom sand. A layer of impure sandy limestone exposed in a small 

branch at the crossing of the road to Prospect 

Church, 3 miles northwest of Dodd City, Fannin County, yielded Aguilaria?, Inoceramus 

sp., Ostrea plumosa Morton, Gryphaea aucella 

Roemer, Baculites asper Morton, and Prionotropis ?. These fossils indicate• that this locality also lies within the belt of clay representing 

the Blossom sand. 

The upper part of the clay in the vicinity of 

Bonham above the glauconitic band is greenish · and waxy and contains a few calcareous 

septaria; it represents the Brownstown marl, 

which, in the vicinity of Pari-;, lies above the 

Blossom sand and below the Annona· tongue of 

the Austin chalk. (See Pl. XXX, 0.) 

In Plate XXX, 0, the clay in the vicinity of 

Bonham is represented as merging toward the 

The Ector tongue of the Austin chalk is over- west through calcareous clay into the Austin 

lain in the west-centr~ part of Fannin County chalk. That this interpretation is correct, 

by greenish-gray waxy clay, weathering yel- and that the merging takes place gradually 

lowish green, which "in the Bonham region through a considerable linear distance, apappears to occupy the entire interval of approx- pears to be confirmed by all the observations 

imately 400 feet above the Ector tongue and that have been made in the area. On the 

below the Annona tongue of the Austin. Ex- strike of the clay in the area between Bells 

posures of the clay appear in roads and streets and Whitewright, in eastern Grayson County, 

both north and south of Bonham and in the the rock underlying the surface is composed 

ditches of the roads leading to·the north, north- largely of impure argilla·ceous chalk and chalky 

west, west, and southwest. As considerable clay that appear to be transitional, and even as 

areas bordering Bois d'Arc Creek are covered far ·west as the vicinity of Luella, in the east::. 

by terrace clay derived chiefly -from the under- central part of Grayson County, a considerable 

lying Cretaceous clay, it is in places difficult to thickness of the Austin is a highly argillaceous, 

determine whether the more or less weathered slightly bituminous shaly chalk or chalky clay. 

materials are residual from the undisturbed This facies of the Austin is exposed in gullies 

older clay or from the reworked terrace deposits. 'in the small branches of Cedar Creek near 

A little above the middle of this body of clay I Luella and in the northward-flowing branches 

is a band of glauconitic clay, of undetermined 1 and northward-facing slopes of Choctaw Creek 

thickness) that is lithologically identical with north of Luella. 

pockets or lenses of glauconitic clay in the The lower part of the clay in· the vicinity of 

Blossom sand near Paris, Lamar·County. This Bonham has not been traced farther east than 

band has been recognized in poor exposures in the central part of Fannin County,· beyond 

street ditches south of the railroad in Bonham, which in northeastern Fannin and northern 

and in somewhat better exposures on the Ran- Lamar counties the strata are largely obscured 

dolph road 5 and 6! miles by the road south- by an extensive cov'ering of Pleistocene · alluwest of Bonham. At the last-mentioned local- vial terrace deposits and are therefore imper-· 

ity the clay is calcareous and strongly glau- fectly known. However, the distribution and 

co,nitic and contains fragments of a large relations of the clay seem to indicate that 

species of Inoceramus, Ostrea congesta Conrad, eitlrer it or equivalent material that is litho-
GEOLOGY OF NORTHEASTE TEXAS AND SOUTHE N OKLAHOMA. 151 

logically different, such as sand or m 

tends eastward stratigraphically bene 

Blossom sand. (See Pl. XXX, 0.) 

ex- I still farther east igher beds successively become chalky 

the marl, so that wi hin a comparatively short distance only 

· the upper part o the chalk formation as it occurs farther 

south is true c alk. In other words, the white chalk 

ANNONA TONGUE. transgresses upw rd in the series of Cretaceous rocks from 

The division to which the name ona is the vicinity of S erman, Tex., eastward into Arka~sas. 

now applied was originally called the " White It is not uite clear from this quotation 

Cliffs chalk" by Hill/ from White Cliffs village whether Taff egarded the Annona as actua\ly 

and bluff, on Little River, Little River ounty, younger than he upper part of the type Austin, 

Ark. Because "White Cliffs" was p eoccu- or whether t e la~t sentence of the quotation 

pied as a formation name, Hill, in 19 1,2 re- refers only to an upward transgression of the 

named the chalk Annona, from the t wn of base of the c alk. 

Annona, in Red River County, Tex. e new Gordon 6 al o reco'gnized the continuity of 

name was inappropriate, for Annona is sev- the Austin a d Annona but did not detect the 

eral miles south of the belt of out rop of upward trans ression of the top of the chalk 

the chalk, but the na.me has become s com- across the ge logic column from Austin northmonly used that it should be retained, ith the ward. He t erefore combined the Annona 

understanding, however, that the cha k does chalk and un erlying Brownstown marl under 

not outcrop at Annona-in fact, the section the name Au tin group, which he represented 

at White Cliffs, Ark., should continu to be as occupying the time interval of the typical 

regarded as the type locality of the div'sion. Austin of cen ral Texas. 

Hill 3 regarded the Annona as strat graph- The Anno · a tongue in northeastern Texas 

ically higher than the Austin as devel ped in consists of 40 or 450 feet of bluish-gra-y brittle, 

its type area, for he says: more or less rgillaceous chalk, which breaks 

It is not known what has become of the Austin chalk in with a cone oidal fracture and weathers to 

this section [Paris, Tex.], but my hypothesis, b eked by white bald sp ts such as are typical of the area 

some evidence, is that to the southward it has bee faulted farther south in Texas underlain by the main 

down. The Anona (White Cliffs) is an entirel distinct body of the A stin chalk. The chalk is slio-htlv 

and higher bed, for it is underlain by the Taylor Exogyru ' b · t · f h 1 f t · 11 ° v 

ponderosa) marls, which overlie the Austin chalk. 1 umifn~ush, . e.s samdp e~d rdom .prac. lea Y any part o 1 t . a 1ng a eCI e b1 tum1nous odor 

In a later report 2 he says: when struck with the hammer and yielding 

The chalky (Anona) beds (the White Cliffs ch lk of the small quantit es of oil by destructive distillawriter's Arkansas section) outcrop at Clarksville a d thence tion. The A ona has been traced almost convia Paxton [Roxton] and Honey Grove nearly to Bonham · 1 · t1nuous y fro a point north of Annoria, in 

but are not known south of thesQ points. The iter has 

considered this chalk to represent a higher hori ,on than Red River Co nty, through Lamar and Fannin 

the Austin chalk, but its exact rel~tionship is s bject to, counties to t ·e southwestern part of .Fannin 

future determ~na~ion. Cou;nty~ wher it is found to be continuous with 

Outcrops of chalk north tff Windo and the-upper par of the ·main body of the Austin 

Honey Grove, in Fannin County, w ich in chalk (see PI · XVII and Pl. XXX, 0), and 

reality lie within -the belt ~ of outcrop of he An- for that rea.so it is here regarded as a tongue 

nona, were regarded by Hill4 as belon ing to of the Austi · formation. No good exposure 

the Austin. . . , .· . was found sh wing the relation of the Annona 

Taff 5 recognized the geographic conti uity of tongue to the . nderlying Brownstown marl, into 

the Austin and Annona and also the f t that which, howe ' er, the chalk probably merges 

the lower part of the Austin is represe ted in • through a .ve tical transition zone. 1 

northeastern Texas by beds that are not typical The upper to 10 feet of the Annona in parts 

chalk.! He.;m_ys: ___ . . .. . . . of northeast Texas consists 'of soft, tough, 

The lower part· of the thick chalk formation of north uniform chal , which weathers to a soft cream 

Texas changes to marl in the vicin:lty of Sher an, and color and is c pable of being readily sawed into 

1 Arkansas Geol. Survey Ann. ·Rept.-for 1888, vol. 2, pp. 7-89, 1888 2U. S. Geol. Survey Twenty-first Ann. Rept., pt. 7, p. 34 , 1901. ' 

a Geol. Soc. America Bull., vol. .5, p, 308, 1894. 

4 U. S. Geol. Survey Twenty-first Ann. Rept., pt. 7, pl. 66 1901. 

5 U. S. Geol. Survey Twenty-second Ann. Rept., pt. 3, p . 698-699, 

fig . .58, 1902 . . 

building bloc s. It has been used locallv in 

the construe ion of foundations, chim~eys, 

dwellings, st 1res, churches, and courthouses. 

6 Gordon, C. H., 

21-25, 1911. 

. S. Geol. Survey Water-Supply Paper 276 pp, 
• 

152 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

As a building stone, this rock appears to be BLOSSOM SAND. 

durable and is of pleasing appearance; in its 

toughnes8 und lack of brittleness the rock is in The sand to which the name Blossom is apstrong contrast to the chalk immediately under- plied was first recognized by Veatch 1 in wells 

lying it and to the ordinary chalks of the Cre- at Clarksville, Red River County, where it 

taceous formations of the Gulf Coastal Plain. constitutes an important water-bearing forThe building-stone facies appears to be rather mation; he called it the "sub-Clarksville sand.'' 

sharply separated from the overlying Taylor Gordon 2 renamed the sand the Blossom sand 

marl and fonns a persistent stratum that has member of the Eagle Ford clay, correlating it 

been traced from a point south of Atlas, in especially with the sandy beds that form the 

Lamar County, to Bailey, in Fannin County. upper part of the Eagle Ford in the vicinity of 

It was not seen in the vicinity of Leonard, Sherman, in Grayson County, an interpretaFannin County, but rock of apparently iden- tion which, as shown by the abundant evidence 

tical physical character crops out on the hills presented in this paper, is incorrect. 

4 miles east of McKinney, in Collin County, The Blossom sand, which Gordon described 

where it has been quarried for building stone, as "brown sandy ferruginous glauconitic beds 

and similar rock has also been quarried about in~erlaminated with thin beds of clay, is over4 miles east of Allen, Collin County. la1n by the Brownstown marl and forms a belt 

About 13 miles east of Clarksville the ..._<\nnona of sandy country several miles wide extendpasses under the alluvium of Red River ing westward through Red River County north 

beneath which it is concealed to the Arkansa~ of Clarksville; thence westward through Lamar 

boundary, but the chalk reappears at Rocky County, where Blossom and Paris are on the 

Comfort, in the southwestern part of Little outcrop; thence westward into Fannin County, 

River County, Ark., and again at White Cliffs, . where north of Dodd City it merges into clay 

on Little River in the same county. It passes (see Pl. XXX, 0), chang1ngits topographic and 

as a narrow belt through the southeastern part much of its lithologic character. However, 

of Howard County and thins and disappears in the clay into which it merges toward the west 

the western part of Hempstead County. retains its characteristic glauconitic content 

~he set of structure contours on the geo- and is traceable ps.st the south side of Bonham 

log1c map (Pl. XVII), extending from the area to a point about halfway between Ector and 

north of Honey Grove southwest by west to Randolph. Some facies of the sand are strongly 

Randolph, Fannin County, indicates the alti- calcareous and are chalky in appearance. 

tude above sea level of the sloping base of the Fossil evidence indicates that the Blossom 

Annona tongue of the Austin chalk; the broad sand corresponds in age to the upper part, 

eastward deflection of these lines south of Bon- perhaps the upper half, of the Austin chalk as 

ham marks the eastward extension of the developed in the type area in Travis County. 

plunging nose of the Preston anticline. The The fossils list din the table below have been 

set of contours extending from the area south collected at · a ~fficient number of localities 

of Honey Grove, southwest by west past Gober between Blossom, in Lamar County, and a 

and Bailey to Leonard, Collin County, indi- point southwest of Bonham, in Fannin County, 

cates the · altitude of the top of the Annona to amount to a virtual tracing of the beds 

tongue; the slight eastward deflection of these throughout this distance of about 50 miles. 

lines northeast of Gober. probably approxi- At least eleven of the species are common to the 

mately marks the dying out of the uplift that Austin chalk of the type area, whereas no Eagle 

produced the Preston anticline. The some- Ford species appear in the list. Synchroneity 

what more pronounced southward deflection with the upper part of the type Austin is espeof these same contour lines at Leonard ~arks 

another structural feature that is described 'on 

page 161 as the Leonard-Celeste monoclinal 

fold. 

1 Veatch, A. C., Geology and underground water resources of northern 

Louisiana and southern Arkansas: U. S. Geol. Survey Prof. Paper 46, 

p, 25, 1906. . . . ' 

2 Gordoo, C. H., Geology and underground waters of northeastern 

Texas: U.S. Geol. Survey Water-Supply Paper 2761 p. 19, 1911. 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 153 

cially indicated by the following forms: Inoceramus aff. I. deformis Meek, Ostrea congesta 

Conrad, Ostrea aff. 0. dil1wiana Linne, Gryphaea 

aucella Roemer, Exogyra ponderosa Roemer, 

Liopistha elegantula (Roemer)~ and Baculites 

asper Morton. 

The paleontologic evidence that the Blossom sand is younger than the Eagle Ford is 

supplemented 1 y the lithologic evidence, for 

hand specimen of glauconitic clay collected 

on the Randolph road 5 to 6! miles southwest 

of Bonham, Fannin County, in a bed that is 

stratigraphicall >r well above the top of the 

Eagle Ford, a1 e identical in physical aspect 

with specimens from undoubted Blossom sand 

near Paris, Lan ar County. 

Fossil spec ie ~ from the Blossom sand in Fannin, Lamar, and R d River counties, Tex. 

Blossom sand. 

~~~_Y I Clav of :5 stone of BIOs- '0 

Bios- som ;!!1 

som age. ~ 

age. ~ 

Vermes: 

Serpula sp. . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ·X X X 

Mollusca: 

N ucula sp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . • • . . . . . . . . . . . . . . . . . . . • . . . . • . . .. ? ... 

f~f~1F-:-:-~-~-~-\/\// ;y; ~ ~H~ \J) __ ~~> ~-- ):: }:: ·:;-: /\;;:: 

Inoceramus aff. I. deformis Meek.... . .. . . . . . .. . . . . . . . . . . . . . . X 1· .. . . . .. . . . X .. ~;. . . .. . . . X 

Inoceramussp. (1) ......•.............. . . .. .. .•.................... . .......•........ A X 

Inoceramus sp. (2)............. . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . X 

Ostrea congesta Conrad......... . . . . . . . . . . . . . . . . . . X X X X X X 

Ostrea plumosa Morton. . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . X .. _ . . . . . . . . . . . . . X X X 

Ostrea aff. 0. diluviana Linne....... . . . . .. . . . . .. . . .. . . . . . .. .. X . .. . . . . . . . . . . . . . . . . . . . . .. . . . X · Gryphaea aucella Roemer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X X X X EX;ogy~a ponderosa Roemer........... . . . .. . X X X X . .. .. . . .. . . . . .. . . .. .. .. .. . . . . X 

Tr1gon1a sp ....... . .... . ........ . ........... _ . _ . . . . . . . . . . . . . X . . . . X .................. I ... -.. 

~:~~~~ i;~~:~~~~~~~~~~ ~-0-~~~~:: ~ ~:: ::: ~:: : ~ ~ ~ ~ ~ : ~ ~ ~: ~ -- -. ~ :: ~ ~ ~ ~:: ~: -- ~-. ::::: ~ : ~::: J. ~ .. Lima sp. . . . . . . . • . • . . • . . . . . . . . . . . . . . . . .... _ . . . . _ . _ . . . . . X X . . . . . . . . • . . X . . • . . . . . . . . . . .... - Spondylus sp... ... . ... ... .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ........ . ........ - Clavagella sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ........... -.. - - ....... -.. -- · · · · -- Liopistha elegantula (Roemer)? .................. _..... X . . .. .. .. .. .. .. . . . .. . .. .. . .. . X 

V eniella sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . ... - . ----I· --· · -· -· · · · · · · ----· · · -· Card~um spi~lmani. Conrad......... . .. X .... --1-.. . . . .. .. .. .. . . .. . . ........ -..... ---- ..... -- X 

Cardmm(Cnocardmm) sp ............ l X ......... .. . ---- -- X · ···· ······ -·-··· ····-- ······ ······ 

8~~~~~i~~i ~P ~ : : : : : : : : : : : : : : : : : : : : ~ ~ .. x . . : : : : : : .. ~ . . . . ~ . . . . ~ . . : : : : : --~ --~ : : : : : : ~ : : : ~ : : : : : : : : : : : : 

.X.enophora sp ......................... . _ . _ . . . . . . . . . . . . . . . . . . X . X .................. -.... . 

Gyrodessp ............................... . . . ..... .. .......... . ... . .......... X -····- 1---·-- •••••• 

Volutodermasp.................... . . ..... ...... X X .•.. X X ------ ---·-- -···~-

Anisomyonsp ............................. . ..... . ........... X ·.·.·.-_ -__ ··_·_·_~ ::~~:: :::::~ :::::: :::::~ Nautilussp ......•......................... ----- ---·- · X _ Hamites sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X ............. . ........ -.... - - - - -· · BaculitesasperMorton............... ...... ...... ? X X ? X X X 

Placenticeras sp. . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X .............................. - -.. Prionotropis?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . .... . 

Vertebrata (fish): . I 

Corax falcatus Agassiz .. . ............. 1

. • • • • . • • • • • • • • • • • • X . • • • . . . . ......•. - ----· · -· · · · · -· · · · · ? 

Otodus sp ...................•..... ·j·..... . . . . . . X .........•... .......•.... -- .. ,. -· · · ·------ · · · · · · 
154 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

BROWNSTOWN MARL. 

The Brownstown marl in its type area in 

Arkansas 1 consists of about 600 feet ( n of blue 

or gray calcareous clay or marl lying above the 

Bingen sand and below the Annona tongue of 

the Austin chalk. In northeastern Texas the 

Brownstown overlies the Blossom sanrl and 

underlies the Annona tongue, but its thickness 

probably does not exceed 300 or 350 feet. In 

Texas the marl resembles In a general way that 

of the type area, though some of it consists of 

gray waxy clay that is only slightly calcareous. Calcareous septaria have been observed 

in the clay in places in Lamar and Fannin 

counties. In general the soils produced by the 

Brownstown are of gray aspect and are in 

fairly strong contrast to the deep black soils of. 

the Annona chalk on the south. The Brownstown marl extends westward, merging into the 

upper part of the clay in the vicinity of Bonham, Fannin County, and this clay in turn 

merges toward the west into the Austin chalk, 

as described on page 150. 

The paleontologic character of the Brownstown marl has been only superficially studied. 

Probably the most common fossil species other 

than those of microscopic size is Exogyra pon-

_lerosa Roemer, which is very abundant in 

places in Texas and Arkansas. The follo·wing 

3pecies have been recognized in the formation 

in Arkansas: 

Hamulus major Gabb. 

Hamulus onyx Morton. 

Ostrea pl umosa Morton. 

Exogyra ponderosa Roemer. 

Anomia argentaria Morton. 

Paranomia scabra (Morton). 

Liopistha (Cymella) bella (Conrad)? 

Crassatellites conradi (Whitfield)? 

Cyprimeria depressa (Conrad). 

Corbula crassiplica Gabb. 

Turritella quadrilira Johnson. 

Raculites asper Morton. 

When the Upper Cretaceous section of 

northeastern Texas is compared with that of 

Colorado River in Travis County near Austin 

it appears that the Brownstown marl is the 

equivalent in age of the lower part of the 

faylor marl. This relation is indicated by 

red line c in Plate XXX, 0. 

1 U.s. Geol. Survey Prof. Paper 46, p. 25, 1906. 

TAYLOR MARL. 

TYPICAL AREA. 

The Taylor marl is typically develope~ in 

the vicinity of Taylor, Williamson County, 

and in Travis County, Tex., where it consists 

of 540 feet or more of "bluish unctuous marly 

clay ·which weathers into yellow la1ninated 

subsoil and black surface soil." 2 The formation conformably overlies the Austin chalk 

and is in turn conformably overlain by the 

Navarro formation. The most common and 

conspicuous fossil in the Taylor is Exogyra 

pondero?a Roemer, which is particularly abundant in the lower part of the formation but 

which is also common in places 111 the upper 

part of the formation. 

DEVELOPMENT IN NORTHEASTERN TEXAS. 

SALIENT FEATURES. 

The Taylor marl of northeastern Texas 

occupies the interval between the underlying 

Annona tongue of the Austin chalk and the 

overlying Navarro formation and has an 

·estimated thickness of 500 to 600 feet of strata. 

The correlation diagram (Pl. XXX, 0) shows 

that the Taylor of this area represents only 

t~e upper part, perhaps not more than the 

upper half, of the formation as developed in 

its type area in Williamson and Travis counties. This difference in the time limits of the 

formation is due to the upward transgression 

of the top of the Austin from Travis. County 

northward. ' Approximately the lower 475.feet 

of the Taylor as developed in Fannin and Hunt 

counties consists mainly of gray or bluish-gray 

calcareous shaly clay or marl, some portions of 

which are finely sandy; these deposits are of 

similar lithologic character to the typical 

Taylor marl of central Texas. 

The ·basal part of the .Marl brook marl of 

southwestern Arkansas, which rests upon the 

Annona chalk and contains Exogyra ponderosa 

Roemer, probably corresponds to at least a 

part of the Taylor marl of northeastern Texas. 

The upper part of the Marlbrook, which carries 

Exogyra cancellata Stephenson, though perhaps continuous with the Taylor, is younger 

than the Taylor and corresponds in age with 

2 U. S. Geol. Survey Geol. Atlas, Austin folio (No. 76), columnar 

section 1, 1902. 
U. S. GEOLOGICAL SURVEY 

A. BASAL BEDS OF THE PECAN GAP CHALK IN A CUT OF THE 

RAILWAY HALF A MILE EAST OF THE STATION AT PECAN 

FOSSILIFEROUS CONCRETIONARY LAYERS OF CALCAREO 

CITY SAND IN A CUT OF THE GULF, COLORADO & SANTA 

BY NORTH OF WOLFE CITY, HUNT COUNTY, TEX. 

U. S. GEOLOGICAL SURVEY 

C\) 

5 oo'-1 

0 

soo'-

,000 

sod2 ,coO2 , so..: 

rUNCONrOI?MtTY~n--.L.-~ 

f;~g;;: zone \ :~~~a:fi~n 

pondiY

.Exqgyra ro~ a j T~X~~r zone 

Austi n ---·cha l k 

Eagle Ford clay 

c. 

5. 

soo' 

PROFESSIONAL PAPER 120 PLATE XXX 

N. 

'a 

~ z 1.. 

~~ ]11 .Q 

~ ,!d ~ 

"'~ Ill Ejp, .~ ~0 

)._ ,..; 

Top of woodb2~~nd, bas ofEa 

soo' 

A. STRUCTURE SECTION (A-A, PL. XVII ) ACRO TRE PRESTON ANTICLINE FROM A POINT 3 MILES WEST OF THE NORTHEAST CORNER OF THE 

DENI ON QUADRANGLE, BRYAN COUNTY, OKLA., VIA WOODVILLE, FINK, AND POTI'SBORO, TO SHERMAN, GRAYS0N COUNTY, TEX. 

NE . 

L I ......... ----..,._...- V' v 

ton_g_ue of - Top of Annona Aust i n chalk 

soo' 

sea.l.e-vel Sea.Uve1- o' 

soo' 

To_£ of woodb1ne sand I ,ooo' 

Est1mated op of Comanche 

ser,es -t,soo' 

Est1mated to of Good land l irnesto,.,e -2,000' 

2,500' 

B. STRUCTURE SECTIO (B-B, PL. XVII ) ACRO THE LEONARD-CELESTE MONOCLINAL NOSE FROM LADONIA. FANNIN COUNTY, VIA WOLFE CITY 

AND ELE TE, HUNT COUNTY, TO A POINT 2 MILES WEST BY NORTH OF FARMERSVILLE, COLLIN COUNTY, TEX. 

Wood b1 ne sa nd 

The red lines a., b, c, d, and e connect beds of equal a e. The !onnatioiUI are all more or I variable m composition both horizontally and vertically, 

and the symbols represent only the dominant litholoai character tructural d fonnati ns are disregarded 

I !rz 0 5 7 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. ·· 155 

the base of the Navarro-that is, with the 

beds containing Exogyra cancellata-that lie 

above the Pecan Gap chalk member of the 

Taylor. This age relation is explained by an 

assumed transgression of the Taylor marl 

upward in the geologic column from Hunt and 

Fannin counties, Tex., eastward toward Arkansas. 

The clay is overlain by the Wolfe City sand 

member, described in greater detail below, 

and this in turn is followed by the Pecan Gap 

chalk member of the Taylor, also described 

below, the estimated thickness of which is 

between 25 and 50 feet. 

WOLFE CITY SAND MEMBER. 

The Wolfe City sand member of the Taylor 

marl consists of 75 to 100 feet of fine calcareous gray sand or sandy marl with a few 

round, oval, or irregular concretions of calcareous sandstone. The sand weathers ·to 

greenish yellow. Near the middle of the 

member is a more or less persistent iayer of 

highly fossiliferous calcareous sandstone of 

varying thickness, which contains a moderately 

large but as yet only superficially studied 

molluscan fauna. (See Pl. XXIX, B.) Some 

beds of calcareous clay occur in the upper part 

of the member, between the indurated layer 

and the overlying Pecan Gap cha1k member. · 

Several incomplete sections of the sand are 

described below. 

Wolfe City, Hunt County, is situated on the 

sand, but only small, poor exposures were seen 

within the town limits. The following section, 

representing about the middle portion of the 

member, is afforded by a cut of the Gulf, 

Colorado & Santa Fe Railway, 1!- miles east 

by north of Wolfe City. (See Pl. XXIX, B.) 

Section in cut of Gulf, Colorado & Santa Fe Railway, 1~ 

miles east by north of Wolfe City, Tex. 

Feet. 

Wo1fe City sand member of Taylor marl: 

Among the fossils recognized in the indurated layer in the preceding section were the 

following: 

Inoceramus sp. 

Pecten sp. 

Liopistha (Cymella) bella (Conrad). 

Cardium (Criocardium) sp. 

Leptosolen biplicatus Conrad. 

Corbula crassiplica Gabb. 

Cymbophora sp. 

Panope sp. 

Gastrochaena sp. 

Turritella trilira Conrad. 

Anchura? 

Pugnellus sp. 

Morea sp. 

Schizobasis sp. 

Baculites aspe.t: Morton. 

Scaphites (two or more species). 

The sand and characteristic included concretions are exposed in shallow cuts of the railroad for the next 2 or 3 miles to the east. 

Good exposures of the sand occur in ditches 

paralleling the Gulf, Colorado & Santa Fe 

Railway four-fifths of a mile to 1 mile east of 

Pecan Gap, Delta County, where the aggregate thickness revealed is probably 25 or 30 

feet. The Pecan Gap chalk is exposed stratigraphically above the sands in a cut about half 

a mile east of Pecan Gap. 

In the public road at Webb Hill, on the 

northward-facing slope of the South Fork of 

Sulphur Creek, 4! or 5 miles sou th..west of 

Wolfe City, the indurated layer exposed in the 

section 1! miles east by north of Wolf City caps 

the hill and is underlain by about 30 feet of 

well-exposed yellowish-green calcareous sand, 

followed below by 40 or 50 feet of similar material poorly exposed. 

Exposures of the Wolfe City sand and the 

characteristic calcareous concretions were observed in and near· the public road 1 to 2 miles 

south of Kingston, Hunt County, in a publicroad ditch, 4! or 5 miles north by east of Floyd, 

Hunt County, and in hill slopes south of the 

Missouri, Kansas & Texas Railway, about 2t 

miles west of Farmersville, Collin County. 

The Wolfe City :sand member has thus been 

Poorly exposed yellowish, highly calcareous 

sand from which we-1ther many small irregular 

gray sandy concreuons of calcium carbonate. 

Contains Exogyra ponderosa Roemer, Anomia 

argentaria Morton, and Ostrea plumosa Morton 8 definitely traced from a point east of Pecan 

Irregular concretionary layer of yellowishgreen fine highly fossiliferous sandstone. 

See list of fossils below .................... . 

Fine yellowish-green calcareous sand with 

poorly preserved fossil prints ...••••••••••••• 

1-2! 

Gap, in Delta County, to a point southwest of 

Farmersville, in Collin County, though its 

boundaries have been only approximately 

6 determined. 
156 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

PECAN GAP CHALK MEMBER. 

The uppermost member of the Taylor marl 

in northeastern Texas consists of about 50 

feet of bluish-gray, slightly bituminous, more 

or less argillaceous and sandy chalk, weathering to light gray and white, to which the nan1e 

Pecan Gap chalk member is here applied. 

The chalk contains a moderately large fauna, 

most species of which are poorly preserved. 

The lower 10 feet of the chalk is typically exposed in a cut of the Gulf, Colorado & Santa 

Fe Railway half a mile east of Pecan Gap, 

Delta County, where the section is as follows: 

S ection in cut of Gulf, Colorado & Santa Fe Railway, half 

a mile east of Pecan Gap, Tex. 

Pecan Gap chalk member of Taylor marl: Feet. 

Lima sp. 

Paranomia sp. 

Pholadomya sp. 

V eniella sp. 

Cras·satellites sp. 

Cardium spillmani Conrad. 

Gastrochaena sp. 

Xenophora leprosa Morton? 

Gyrodes sp. 

Anchura sp. 

Pyropsis sp. 

Volutoderma sp. 

Actaeon? 

Nautilus sp. 

Turrili tes? 

Baculites asper Morton? 

Baculites sp. 

A thickness of 5 feet of the chalk was examined in the bed of the south fork of Sulphur 

Creek near Wilsons Crossing, 4~ or 5 miles due 

south of Wolfe City, and poor exposures were 

noted in public roads 1 to 3 miles west of WilBlue massive chalk, weathering to light gray 

and white, becoming sandy , and containing 

many phosphatic casts of mollusks in the 

lower 2 or 3 feet (see list below) . .....••.••. .. 

Wo-lfe City sand member of Taylor marl : 10 SOD$ Crossing in Hunt County. The chalk 

outcrops in the vicinity of Whiterock, a village 

4 miles 'northeast of Kingston, Hunt County, 

2 where it is overlain by yellowish, somewhat 

sandy clay marl, and poor exposures of argil2 laceous chalk were seen in places along the 

The fossils obtained from the Pecan Gap public road for 4 or 5 miles south by west of. 

Fine yellow argillaceous sand with numerous 

borings filled with chalky material from 

above ...... . . . . .. . .. . . .. .. .. . ... . .... . .. . . 

Dark to almost black fine sandy clay, poorly 

exposed .............. . ... . ............... . 

chalk at this locality are listed below: Whiterock. The chalk also extends at least 2 

Cucullaea sp . 

Ostrea plumosa Morton. 

Exogyra ponderosa Roemer. 

Anomia argentaria Mortou. 

Crassatellites sp. 

Cardium sp. 

Gastrochaena sp. 

Gyrodes sp. 

Anchura sp. 

Volutoderma sp. 

Actaeon sp. 

Nautilus sp. 

Baculites asper Morton? 

Baculites sp. 

Another good exposure of the chalk is in 

the bed and banks of a small stream on the 

Cox place, 3 miles east by south of Wolfe City. 

Here the fresh chalk is bluish gray and slightly 

bitumindus, and weathers light gray and 

white. The maximum thickness observed at 

any one place along the branch is 6 feet. 

Fossils were recognized as follows: 

Cucullaea sp. 

Inoceramus sp. 

Ostrea plumosa Morto11. 

Gryphaea vesicularis Lamarck, var. 

Exogyra ponderosa Roemer. 

wiles north of Whiterock, where cisterns have 

been dug into a sandy facies of the member at 

several farmhouses. The chalk belt is crossed 

by the Missouri, Kansas & Texas Railway 

(McKinney branch) at Farmersville, Collin 

County, small exposures appearing on and near 

the railway for a mile or more both east and 

west of the station. The belt is also crossed by 

the St. Louis & Southwestern Railroad about 

midway between Nevada and Lavon, Collin 

County, where an outcrop of the chalk was seen 

in the bank of a small creek. 

The largest collection of fossils yet obtained 

from the Pecan Gap chalk was made by Mr. 

and Mrs. D. A.. Saunders, of Greenville, Tex., 

on the Jim Burnett farm, 6 miles northwest of 

Greenville, 1 mile west of Kellog, Hunt County. 

This collection was sent to theN ational Museum 

for identification and was studied, though not 

critically, by the writer, who recognized the 

following forms, many of which were too poorly 

preserved for specific identification: 

Hemiaster aff. H. lacunosus Slocum. 

Hemiaster sp. 

Serp~la (two or Ip.ore species). 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 157 

Cucullaea (two or more species). 

Pteria sp. 

Inoceramus sp. 

Ostrea sp. 

Gryphaea vesicularis Lamarck, var. 

Exogyra ponderosa Roemer. 

Exogyra ponderosa var. erraticostata Stephenson. 

Exogyra costata Say (a small, nontypical form). 

Pecten quinquecostatus Sowerby. 

Pecten sp. 

Anomia argentaria Morton. 

Lima sp. 

Trigonia sp. 

Pholadomya sp. 

Modiolus sp. 

Clavagella armata Morton? 

Liopistha (Cymella) sp. 

Liopistha protexta Conrad? 

Cuspidaria aff. C. jerseyensis Weller. 

Crassatellites sp. 

Radiolites austinensis Roemer. 

Tenea sp. 

Cardium sp. 

Cyprimeria alta Conrad? 

Legumen ellipticus Conrad. 

Martesia sp. 

Pleurotomaria sp. 

Gyrodes petrosa (Morton). 

Gyrodes sp. 

Turritella sp. 

Anchura (two species). 

Pugnellus sp. 

Pyropsis (two species). 

Liopeplum sp. 

Volutoderm~ sp. 

Actaeon? 

N au til us sp. 

Baculites (two or three species). 

Turrilites (two species), 

Scaphites (three or four species). 

Corax falcatus Agassiz (shark teeth). 

Lamna sp. (shark teeth). 

· Gordon 1 recognized the chalk member to 

which the narne Pecai}. Gap is here applied, but 

he regarded it as a part of the Navarro formation a:nd correlated it with the "Saratoga" 

chalk member of the Marlbrook marl of southwestern Arkansas. The Pecan Gap fauna, 

however, belongs to the upper part of the 

Exogyra ponderosa zone, whereas that of the 

"Saratoga" is referable to the upper part of the 

E. canceUata subzone of the Exogyra costata 

zone, which is definitely younger and higher. 

The possibility is recognized that the Pecan 

Gap chalk may transgress upward in the geologic column fron1 Delta Gounty, Tex., eastward toward Arkansas, being continuous with 

the "Saratoga" chalk in Arkansas; however, it 

1 U.S Geol. Survey Water-Supply Paper 276, p. 2~, 1911. 

has not been traced across the interval, although an attempt was made to find it south of 

Clarksville in Red River County-. In view of 

the adverse evidence afforded by the faunas, 

therefore, the assumption that the two chalks 

are identical and continuous is !lot justified by 

the present known facts. 

NAVARRO FORMATION. 

The Navarro formation in northeastern 

Texas cohsists of marine calcareous shaly 

clays, san,dy clays, fine gray sands, and argillaceous sands with local indurated portions in 

the form of calcareous septaria or concretionary 

sandstone layers. These deposits are estimated to attain a thickness of not less than 800 

feet. The formation is probably susceptible of 

separation into at least three members but has 

not yet been studied in this arf~a in sufficient 

detail, either stratigraphically or paleontologically, to admit of mapping the subdivisions, 

even approximately. · 

The lower 300 or 400 feet of the formation 

consists of gray calcareous shaly clay or marl 

that produces a dark-gray or black soil and 

carries a distinctive fauna, the nwst significant 

species of which are Exogyra canceUata Stephenson, found at several localities near Cooper and 

Greenville, and Anomia tellinoides Morton, 

found at one locality near the Texas & Midland 

Railroad 2 miles west of Cooper. This is the 

Exogyra cancellata subzone, which forms the 

basal part of the E. costata zone and which has 

been traced throughout the Atlantic and Gulf 

Coastal Plain from New Jersey to Kaufman 

County, Tex., and has been recogpized at 

Ciudad del Maiz, San Luis Potosi, Mexico, 

about 440 miles south of Eagle Pass, Tex. This 

subzone is represented in southwestern Arkansas by the upper half or more of the Marlbrook 

marl with the exce.ption of approxi1nately the 

upper half of the ."Saratoga" chalk member, 

which forms the upper 20 to :~5 feet of the 

Marl brook. 

The basal clays of the Navarro are overlain 

by fine gray sands and more or less sandy clays, 

100 feet or more in thickness, which have been 

only superficially studied in northeastern Texas, 

where they have yielded only a few poorly preserved fossils. These beds correspond approx- . 

imately to the Nacatoch sand of southwestern 

Arkansas, which carries a moderately large 
158 SHORTER·· CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

fauna, and to the sandy beds in the vicinity of 

Kaufman County and near Chatfield and Corsicana, Navarro County, Tex., which have 

yielded a large and incompletely described 

fauna. The sandy beds are therefore to be 

correlated approximately with the middle 

portion of the Exogyra costata zone of the Atlantic and Gulf Coastal Plain. 

Farther south in Texas, from the vicinity of 

Corsicana, Navarro County/ to Mexia and 

Groesbeck, Limestone County, 2 sand that has 

been correlated with the N acatoch sand of 

Arkansas is overlain by over 500 feet of shaly 

clay that probably represents the Arkadelphia 

clay of Arkansas. This higher clay has not 

been recognized within the area shown on 

the map accompanying the present report, and 

there is some evidence that it has been cut out 

by a northwestward overlap of Eocene strata. 

The boundary between the Navarro formation 

and the Eocene has, however, not been traced 

in detail in this area. 

TERTIARY SYSTEM. 

EOCENE SERIES. 

The southeastern part of the area under consideration, including most of Hopkins County 

and the southeastern part of Hunt County, is 

underlain by deposits of sand and Clay of 

Eocene age, belo:p.ging in part to the Midway 

formation and in part to the Wilcox formation, 

which overlies the Midway. The Midway 

rests upon the ·Navarro formation of the Upper 

Cretaceous, from which it is separated by an 

erosion unconformity representing a long interval of geologic time. This statement is based 

not upon observations made in this particular 

area, where the contact has not been accurately determined and traced, but upon the 

known fact that throughout the Atlantic and 

Gulf Coastal Plain the unconformity separating 

Upper Cretaceous deposits. from the overlying 

Eocene represents a very long time, during 

which this vast region was above sea level 

undergoing erosion, prior to the later marine 

submergence and deposition of Eocene strata. 

1 Matson, G. C., and Hopkins, 0. B., The Corsicana oil and gas field, 

Tex.: U.S. Geol. Survey Bull. 661, pp. 218-221, pis. 19 and 20, 1917. 

2 Matson, G. C., Gas prospects south and southeast of Dallas: U.S. 

Geol. Survey Bull. 629, pp. 21, 22, pl. 7, 1916. 

STRUCTURE. 

GENERAL RELATIONS AND ATTITUDE OF THE 

DEPOSITS. 

An examination of a generalized ge0logic 

map of the south-central United States woulJ 

show that the vast stretch of the Coastal Plain 

bordering the Gulf of Mexico is underlain by a 

series of sediments of Cretaceous, Tertiary, and 

Quaternary age, and that north and west of the 

Coastal Plain in Arkansas, Oklahoma,. and 

central Texas rocks of much greater age, formed 

during Paleozoic and pre-Paleozoic time, appear 

at the surface. In reality the ancient rocks 

underlie the entire Gulf region, forming a supporting basement for the younger rocks, which 

overlap and conceal them as far northward and 

westward as would be indicated on the g-eneralized geologic map. Along this boundary the 

upper peneplaned surface of the ancient basement rocks dips beneath the younger deposits, 

becoming deeper gulfward until along the coast 

it probably lies too deep to be reached by 

modern well-drilling methods. 

In the area in northeastern Texas now 

under consideration the basement rocks do 

not appear at the surface, but they outcrop 

farther north, 10 to 30 miles north of Red River, 

in the southeastern part of Oklahoma, and farther west, in Montague and Wise counties, Tex. 

In the northwestern part of the area shown on 

the geologic map (Pl. XVII) the basement 

rocks lie in places within 350 feet of the surface, 

and in the southeast corner of the area, where 

their depth is greatest, they are estimated to 

lie between 4,000 and 5,000 feet b@low the 

surface. 

The dip of the upper surface of the basement 

rocks ranges from 40 feet or less to the mile 

in the western part of the area to 70 feet o.r 

more to the mile in places in the east-central 

part. At Bowie, Montague County, Tex., 

near the western edge of the outcrop of Cretaceous rocks, the altitude of the surface of the 

basement rocks is approximately 1,100 feet 

above sea level; at Farmersville, .Collin County, 

90 miles east by south of Bowie, the basement 

is estimated to lie about 2,800 feet below sea 

level, making a general dip of 43 feet to the 

mile in the intervening area. . Near Boggy 
GEOLOGY . OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 159 

Depot, in Atoka County, Okla., the contact 

between the basement rocks and the overlying 

Cretaceous strata is about 550 feet above sea 

level; near Wolfe City, Hunt County, Tex., ·64 

miles south by east of Boggy Depot, the basement rocks are estimated to be 2,800 feet 

below sea level, indicating a general dip of 

52+ feet to the mile. Locally, however, the 

dip of the basement surface is probably much 

greater than 52 feet and may reach several 

hundred feet to the mile. These figures are 

based partly on assumed thickllesses, particularly of the formations composing the Comanche 

series, and are subject to correction when the 

facts are known. 

The geologic map ~Pl. XVII) shows that 

the strike of the beds composing the Cretaceous formations of northeastern Texas is approximately east in the eastern parts of Lamar 

and Delta counties; it swings around toward 

the south, farther west and southwest, in Fannin and Hunt counties; and becomes south by 

a few degrees west in the southern parts of 

Hunt and Collin counties. The dip is gulfward at right angles to the strike except locally, where the normal attitude of the beds 

has been disturbed by earth movements. · The 

general dip is probably somewhat less than the 

inclination of the surface of the basement 

rocks on which the Cretaceous beds rest. The 

general range of dip is believed to be from 30 

feet or less to the mile to 80 feet or more to the 

mile, but there is evidence that locally, as 

along the southern limb of the Preston anticline near Pottsboro, the beds may dip as much 

as 300 feet to the mile. 

The uniform monoclinal attitude which so 

generally characterizes the Cretaceous formations of the Gulf Coastal Plain is interrupted 

in this area by at least two pronounced deformations, the Preston anticline and the LeonardCeleste monoclinal nose, which are described 

below. Other similar deformations, though 

probably much smaller, may be discovered as 

a result of future more detailed investigations. 

Faulting of small magnitude occurred in 

places in the area, probably as a result of the 

movements which produced the folds; positive 

evidence of small faults was obtained at several 

localities. The building-stone facies of the 

Annona tongue of the Austin chalk exposed in 

the quarries and small branch streams at and 

within a few hundred yards southeast of Gober, 

in the southern part of Fannin County, is considerably disturbed by faults of small displacement; one fault running approximately 

northeast exhibits a displacement of 15 feet. 

At the crossing of a public road over Choctaw 

Creek 3i miles north by east of Luella, Grayson County, a fault trending N. 5f) 0 E. exhibits 

a displacement of 8 inches. Messrs. Hopkins 

and Powers indicate on their structure map a 

fault of relatively small displacement southeast of Bonham, Fannin County, which involves the basal strata of the Annona tongue 

and the clay that immediately underlies the 

chalk. (See Pl. XVII.) 

PRESTON ANTICLINE. 

The Preston anticline is a plunging upfold of 

Cretaceous strata that is most conspicuous in 

the southern parts of Marshall and Bryan counties, Okla., and the northern part of Grayson 

County, Tex., but is measurably Jnanifested in 

the direction of its southeastward-trending axis 

as far as the vicinity of Gober in Fa,nnin County, 

Tex. The approximate position of the axis of 

the anticline is indicated on Plate XVII by a 

dashed line. 

Where the anticline is best developed in the 

Red River valley, northwest of Denison, the 

Comanche series of formations, which would 

normally be buried beneath the overlapping 

younger strata of the Gulf series, have been 

warped upward approximately 800 feet, and 

the beds of the overlying Gulf series have thus 

been subjected to erosion, which has entirely 

removed not only the Gulf series but also much 

of the underlying Comanche series from a considerable area along the axis of the uplift. 

Here the outcrops of the formations of the 

Comanche series parallel the sides of the anticline and wrap about its southeastward-plunging nose in typical fashion; the strike of the 

formations of the area, which would normally 

range from west to southwest, is distin~tly 

bowed to the southeast where the formations 

cross the axis of the anticline, and this deflection of the strike is manifested at least as 

far to the southeast as Gober, Fannin County. 

From the vicinity of Preston Bend in northern Grayson County, where the rnaximum uplift of the Cretaceous strata above the position 

they would have occupied had there been no 

folding is approximately 800 feet, the amount 

of deformation gradually decreases to the south-
160 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

east alorig the axis of the fold, and near Gober, 

Fannin County, the uplift is very slight. 

Section A in Plate XXX is drawn approximately at right angles to the axis of the anticline from a point near the northeast corner of 

the Denison quadrangle, in Bryan County, 

Okla., southwest to a point 31 miles north of 

Fink, Grayson County, Tex., thence south to a 

point 1 mile north by west of Pottsboro, thence 

south-southeast to Sherman. The surface 

profile is based on the data recorded on the 

Denison topographic map, and the structure 

lines are based partly on outcrops and partly 

on data afforded by wells. This section is 

believed to be approximately accurate where 

it crosses the main part of the anticline north 

of Pottsboro, the position of the lines there 

having been checked against the structure contours established by Messrs. Hopkins and 

Powers. (See Pl. XVII.) 

The structure contours shown on Plate XVII 

are generalized from larger-scale maps prepared 

by Messrs. Hopkins, Powers, and Robinson, as 

elsewhere explained. Their method was to determine the altitude of key rocks at as many 

points as possible, by means of aneroid readings 

corrected for changes of atmospheric pressure 

by barograph records obtained simultaneously 

at the bases from which the field work was 

done, and to supplement these surface observations with data afforded by all available 

well records. 

The contours on the main part of the Preston 

anticline in the northern part of Grayson 

County, Tex., and the southern parts of Marshall and Bryan counties, Okla., show the 

altitude above sea level of the top of the Goodland limestone. The extension of the anticline 

into Fannin County is indicated by the southeastward deflection of the contours showing 

the altitude of the base of the Ector tongue of 

the Austin chalk in the vicinity of Ector, by a 

less. pronounced deflection of the con tours 

showing the base of the Annona tongue of the 

Austin chalk between Dodd City and Randolph, 

and by only a faint bending of the contours 

showing the top of the Annona tongue northeast of Gober. The last-mentioned place is 

approximately at the point where the anticline 

dies out toward the southeast. A shallow 

syncline parallels the anticline along its northeast side in Fannin County, as indicated by a 

deflection to the northwest of the several sets 

of contours. A structural terrace on and 

slightly south of the plunging nose of the anticline is indicated by the spacing of the contours 

2 to 6 miles northeast of Pottsboro, Grayson 

County. 

The dip of the strata of the Comanche series 

away from the axis of the Preston anticline 

ranges from a few feet to a little more than 300 

feet to the mile. · In general, the south limb 

is a little steeper than the north limb. The 

steepest part of the anticline is on the south 

limb in a northwest-southeast stretch about 3 

miles long northeast of Pottsboro (see Pl. 

XVII), where, as indi~ated by the contours, 

the maximum dip of slightly more than 300 

feet to the mile is attained by the Goodland 

limestone. This relatively strong dip is also 

clearly manifested in outcrops of the Main 

Street limestone, the next to the highest member of the Denison formation, whose strata in 

conjunction with the "Quarry" limestone form 

a low strike ridge beginning about 2 miles east 

of Pottsboro and extending in a northwesterly 

direction for about 2 miles. Along this ridge 

the Main Street limestone, though poorly exposed, obviously dips strongly to the southwest, in places as much as 20° or even more. 

The pronounced narrowing in the belt of outcrop of the Woodbine .formation resulting 

from the unusually steep inclination of the 

strata in this belt was perhaps the chief 

basis for the postulation of the so-called 

Cook Spring fault by Taff 1 and Leverett and 

byHill. 2 

The nature of the earth movements that produced the Preston anticline is imperfectly 

known, though the assumption is warranted 

that the movements had tneir origin in the 

basement rocks that underlie the overlapping 

Cretaceous sediments. As the axis of the anticline trends approximately parallel to most of 

the major faults and folds in the Arbuckle 

Mountains in Oklahoma, the assumption also 

seems warranted that this uplift is directly related to the Arbuckle uplift, and that the folding ·of the Cretaceous strata was merely incidental to the upb?wing of these older basement 

rocks. 

!Texas Geol. Survey, Fourth Ann. Rept. for 1892, pp. 297,298, 1893. 

2u. s. Geol. Survey Twenty-first Ann. Rept., pt. 7, pp. 384, 385, pi 

66,1901. 
GEOLOGY OF NORTHEAST'ERN TEXAS AND SOUTHERN OKLAHOMA. 161 

LEONARD-CELESTE MONOCLINAL NOSE. 

The structure contours showing the altitude 

above sea level of the top of the Annona tongue 

in the vicinity of Leonard in southwestern 

Fannin County, Tex., are deflected rath~r 

sharply to the south. (See Pl. XVII.) This 

deflection is also clearly manifested in the out·-

crop of the Annona, the strike of whose upper·-

most beds in· the vicinity of Leonard shows n 

distinct bulge to th~ south. A similar and even 

stronger southward or southeastward deflec·-

tion is exhibited by the belts of outcrop of the 

Wolfe City sand and Pecan Gap chalk mem:-

bers of the Taylor marl between ·Celeste and 

Greenville, in Hunt County. (See Pl. XVII.) 

These are the surface manifestations of a fold 

in the underlying Cretaceous strata of the kind 

described by F. G. Clapp 1 as a monoclinal nose. 

For convenience this fold is called the LeonardCeleste monoclinal nose. The areal distribution of the formations of the Gulf series in 

Fannin, Collin, and Hunt counties strongly 

suggests that this fold is the deflected southward extension of the Preston anticline, and 

this was the interpretation at first placed upon 

the structure. However, the structure contours on the base of the Annona tongue established by Messrs. Hopkins and Powers (see 

Pl. XVII) indicate that this relationship is only 

apparent, the Leonard-Celeste fold being separate from the Preston anticline, though 

doubtless closely related to it both physically 

and in manner and time of origin. The axis 

of the fold appears to trend south by east 

through Leonard and a mile or so west of 

Celeste and Kingston, Tex. 

The surface evidence of the existence of this 

fold appears to be corroborated by the records 

of two wells nearly in line with the general 

strike of the formations-one near Wolfe City, 

where the top of the Annona tongue of the 

Austin chalk was struck at a depth of about 

510 feet (160 feet above sea level), and the other 

at Celeste, where the Annona was reached at 

a depth of only 300 feet (360 feet above sea 

level). Section B, in Plate XXX, drawn 

approximately at right a.ngles to the axis . of 

the fold, from Ladonia, Fannin County, west 

by south to a point 1-! miles northeast of Wolfe 

City, in Fannin County, thence southwest by 

way of Celeste to a point 2 miles west by north 

1 Geol. Soc. America Bull., vol. 28, p. 572, fig. 8, 1917. 

of Farmersville, Collin County, shows this upbowin()' of the strata in thevicinity of Celeste. 

The s~rface profile in this section is based in 

part on railroad elevations and in par·t on a~eroid barometer readings, and the structure hnes 

are based on surface outcrops and on data 

afforded by the wells at Celeste and Wolfe City 

previously mentioned and by one well at Ladonia. The depth to the Woodbine in these 

three wells, if their logs are properly interpreted, 

apparently confirms the evidence afforded by 

the chalk. At the southwest end of the section 

~ear Farmersville the Annona, s estimated 

from surface outcrops and assumed thicknesses, 

has again sunk back to a level approximately 

the same as near Wolfe City, or a little deeper. 

OIL AND GAS PROSPECTS. 

Oil and gas have frequently been found in the 

upbowed or anticlinal portions of strata that 

have been subjected to warping or folding by 

earth forces, and although these substances 

are not confined exclusively to such structural 

features, no argument is needed to convince 

the practical operator that his best chance of 

success in untested territory lies where folded 

strata are known to exist. The Preston anticline and the Leonard-Celeste monoclinal nose, 

described. above, will therefore not fail to attract the attention of persons interested in the 

discovery of reservoirs of oil and gas. 

In this paper only the more obvious conclusions in regard to the occurrenee of oil and 

gas, which might be readily deduced by any oil 

geologist or practical oil operator from ~he facts 

already presented, will be briefly discussed. 

A more detailed discussion of the structural 

features of this area and an adjoining area on 

the northwest in Oklahoma, with particular 

reference to the occurrence of oil and gas in 

both the Cretaceous and underlying basement 

rocks, will be given. by Messrs. Hopkins, Powers, 

and Robinson in an economic paper to be published later. 

The most conspicuous part of the Preston 

anticline, in Grayson County, Tex., and 

Marshall and Bryan eounties, Okla.:, has already 

been recognized by oil prospectors, and 

test wells have been drilled on different parts 

of the uplift. · Gas reported to corne from the 

lower part of the Trinity sand at depths of 

less than 700 feet has already been discovered 

near the axis of the anticline in the southern 
162 SHOR'l'ER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

part of Marshall County, where .at least a A traveler passing to the southeast along the 

dozen test wells have · been drilled. Of these axis of the anticline would cross successively 

wells six, located in a· group· in the southeast the outcropping strata of the sandy formations 

corner of T. 6 S~, R. 5 E., and the northeast .mentioned above, with intervening bands of 

corner ofT. 7 8.,: R. 5 E., are classed as pro- nonsandy clay and chalk, each ill turn dipclueing gas wells, and each of three of thep1 is ping below· the surface down the nose of the 

roport.ed to yield fron1 1,500,000 to 2,500,000 anticline. After crossing the limestones and 

cubic feet of gas daily. This pool is known as the clays of the Comanche series above the Trinity 

Enos gas field. In June, 1918, an oil well near he would come first to the narrow belt of sand 

the crest of the anticline in sec. ·23, T. 7 S., of the Pawpaw sandy member of the Denison 

R. 5 E., was completed in the Trinity sand at formation near the northeast corner of Graya. depth of 260 feet and was reported to pro-. son County, the wider sandy belt of the Woodduce 20 barrels of oil daily. Showings of oil bine in the northwest corner of Fannin County, 

or gas, or both, have been reported from the and the narrow strip of sand forming the 

Trinity sand in some of the other wells pene- uppermost part of the Eagle Ford formation 

trating the strata involved in the anticline. at Ector, in Fannin County. 

The Madill oil field/ farther north in Marshall A well on the axis of the anticline near the 

County, in the southeast corner ofT. 5 S., R. 5 northwestern part of Fannin County would 

E.,·which yields small commercial quantities of start in the Woodbine sand, below· which it 

an exceptionally light grade oil from the Trinity would encounter two of the possible oi1 or gas 

sand,

2 is not connected with the Preston anti- bearing sands, the Pawpaw and the Trinity. 

cline but with another distinct though approxi- The top of the Pawpaw would probably be 

mately parallel fold, as shown by an unpub- reached at depths of 50 to 500 feet and the 

lished structure contour map prepared by top of the Trinity at depths of 500 to 1,000 

Messrs. Hopkins, Powers, and Robinson. feet, the depth depending on the exact location 

Of the geologic subdivisions involved in the of the well. · 

Preston anticline and its extension to the A well at Ector would start in the sand at the 

southeast in Fannin County, four are com- top of the Eagle Ford and would penetrate the 

posed in part of sandy strata, which exhibit a Woodbine sand at an estimated depth of 400 

sufficient degree of porosity, at least in their to 900 feet, the sandy beds of the Pawpaw at 

outcropping portions, to fit them to serve as an estimated depth of 925 to 975 feet, and the 

reservoirs for the storage of oil or gas. They Trinity sand at an estimated depth of 1,300 to 

are, in ascending order, the Trinity sand, the 1,800 feet. 

Pawpaw Bandy member of the Denison forma- A well starting at the top of the Annona 

tion, the Woodbine sand, and sandy beds in chalk northeast of Gober would penetrate the 

the upper part of the Eagle Ford clay. sandy beds at the top of the Eagle Ford at an 

The occurrence of gas and some oil in the estimated depth of 800 to 900 feet, the WoodTrinity sand along the axis of the fold in bine sand· at an estimated depth of 1,300 to 

the southern part of Marshall County, Okla., 1,850 feet, the sandy beds of the Pawpaw at an 

has already been demonstrated. The amount estimated depth of 1,900 to 1,950 feet, and the 

of gas ·and the volatile products of oil that Trinity sand at an estimated depth of 2,300 to 

may once have been contained in the sand 2,800 feet. 

and have since escaped where the formation is So far as known to the writer no wells have 

exposed in the crest of the fold can, of course, been drilled that would serve as an adequate 

only be conjectured. The Trinity dips below test of the occurrence of oil or gas in the 

the surface on the plunging nose of the anti- Leonard-Celeste nionoclinal fold. The deepest 

cline in the Red River valley, about 5! miles well concerning ·which information has been· 

north by west of Denison; obtained is the 1,554-foot water well at Celeste, 

perhaps a mile or a mile and a half east of the 1 Tatf, J. A., and Reed. w. J. The Madill oil pool, Okla.: u.s. Geol. axis of the fold. . This well is believed to have 

Survey Bull. 381, pp. 504-513, 1910 

~Oklahoma Geoi. survey Bull. 19, pt. 2, pp. 316-320, 1917. reached· the uppermost sandy stratum of the 
GEOLOGY OF NORTHEASTERN TEXAS AND SOUTHERN OKLAHOMA. 163 

Woodbine formation at a depth of 1,535 feet. 

The sandy beds at the top of the Eagle Ford 

were not recognized in the well and may here be 

represented by nonsandy cl~y. The sandy 

beds of the Pawpaw would be reached here at 

an estimated depth of 2,200 fe~t, and the top 

of the Trinity sand at an estimated depth of 

2,600 feet. 

At Greenville, which is probably near the axis 

of this fold, all the possible oil sands of the 

Cretaceous, except the Nacatoch, would be 

penetrated by a well probably less than 3,500 

feet deep. These would include, in descending 

order, the Wolfe City sand member of the 

Taylor marl, the sandy member at the top of 

the Eagle Ford, which would probably be very 

thin and might be represented entirely by 

clay; the sands of the \Voodbine formation; 

the Pawpaw sandy member of the Denison; 

and, finally, the Trinity sand. 

In pointing out the existence of the folds described above the writer does not wish to be 

understood as urging the probability of the 

occurrence of oil and gas in association with the 

folds, though he feels that the facts warra~t an 

optimistic attitude on the subject. 

Four factors are generally regarded as essential to the occurrence of oil and gas-an adequate source of hydrocarbons, such as petroliferous shales or clays; porous beds intimately 

connected with the source to serve as reservoirs; suitable structure for the concentration 

of the oil and gas; and suitable hydrostatic 

conditions. Two of these factors appear to be 

favorable in this area; porous formations for 

the retention of the oil are present, and structural folds exist similar to those in which oil and 

gas are known to have accumulated elsewhere. 

The factor of source, although less completely 

known, also appears to be favorable, for the 

chalks and some of the clays that intervene 

between the sandy formations are distinctly 

bituminous. In regard to the fourth factor, 

there is no known reason why the ground-water 

conditions in the Cretaceous beds of this area 

should be essentially different from those of the 

other oil and gas fields of the Gulf Coastal 

Plain. 

SUMMARY. 

1. Areal geolog_v.-Important revisions in the areal distribution of the formations of both the Comanche and Gulf 

series, as previously mapped in this' area, are indicated in 

P,late XVII, and three new mappable units are recognized, 

including the Ector tongue of the Austin chalk and theWolfe City sand member and Pecan Gap chalk member of 

the Taylor marl. 

2. Stratigraphy.-A new interpretation of the stratigraphic and age relations of the formations of the Gulf 

series based on the following facts is presented (see Pl. 

XXX, G): (a) The recognition of the so-called "fish-bed' 

conglomerate" of Taff (seep. 149) as the probable base of 

the cycle of sedimentation which has its typical ex_pres- , 

sion in the Austin chalk; (b) The recognition of a relatively thin tongue of chalk, the Ector tongue, extendingnortheastward from the base of the ma:in body of theAustin chalk in the vicinity of Ector, Fannin County; 

(c) the eastward merging of approximately the basal half 

of the Austin chalk, with the exception of the Ector tongue, 

into equivalent nonchalky clay in Fannin County: (d) 

the correlation of the Blossom sg,nd with the upper part. 

of the typical Austin chalk of Travis County, Tex., in-· 

stead of with the upper part of the Eagle Ford formation, 

as previously correlated (see pp. 152-153 and Pl. XXX, G)~ 

(e) the upward transgression in the geologie column of theupper part of the Austin chalk from Travis County 

northward; (j) the recognition . of the Annona ("WhiteCliffs") chalk of Hill as a large tongue connected with the 

main body of the Austin chalk; (g) the discrimination of theWolfe City sand and Pecan Gap chalk as upper mappablemembers of the Taylor marl. 

3. Structure.-The structural feature in the northern 

part of Grayson County, Tex., and the southern parts of 

Marshall and Bryan counties, Okla., heretofore regarded' 

as an uplifted fault block which brought the formations· 

of the Comanche series to the surf~ce, where normally 

they would lie deeply buried, is shown to be instead an 

anticlinal uplift, the Preston anticline, with which, so far 

as known, no major faults are directly associated. A 

newly recognized structural feature, called the LeonardCeleste monoclinal fold, in southwestern Fannin andl 

northwestern Hunt counties, is described. Structure 

contours have been established by Messrs. Hopkins, 

Powers, and Robinson, showing the altitude above sea level 

of the top of the Goodland limestone about the flanks 

of the Preston anticline, and Messrs. Hopkins and Powers 

have established contours showing the altitude of the base· 

of the Ector tongue and the base and top of the Annona. 

tongue of the Austin chalk in certain areas in Fannin. 

Grayson, and Hunt counties. (See Pl. XVII.) 

4. Oil and gas.-A brief statement of the factors controlling the occurrence of oil and gas w-ith particular 

reference to this area is given, and the hope is expressed that 

future prospecting may result in the diseovery of these 

substances in commercial quantities somewhere in association with the Preston anticline or with the LeonardCeleste monoclinal fold.