The University of Texas Publication No. 4915 August 1, 1949 CLAY DEPOSITS OF THE CISCO GROUP OF NORTH-CENTRAL TEXAS By F. B. PLUMMER, H.B. BRADLEY, AND F. K. PENCE Bureau of Economic Geology Research Laboratory in Ceramics . PUBLISHED BY THE UNIVERSITY OF TEXAS AUSTIN Publications of The University of Texas PUBLICATIONS COMMITTEE E. J. MATHEWS A. MOFFIT C. F. ARROWOOD E. S. REDFORD C. D. LEAKE W. P. WEBB C.H. EADS Administrative Publications E. J. MATHEWS F. L. Cox R. C. ANDERSON J. A. FOCHT L. L. CLICK B. GONZALES The University publishes bulletins four times a month, so numbered that the first two digits of the number show the year of issue and the last two the position in the yearly series. (For example, No. 4901 is the first publication of the year 1949.) These bulletins comprise the official publications of the University, publications on humanistic and scientific subjects, and bulletins issued from time to time by various divisions of the University. The following bureaus and divisions distribute publications issued by them; communications concerning publications in these fields should be addressed to The University of Texas, Austin, Texas, care of the bureau or division issuing the publication: Bureau of Business Research, Bureau of Economic Geology, Bureau of Engineering Research, Bureau of Industrial Chemistry, Bureau of Public School Service, and Division of Extension. Communications concerning all other publications of the University should be addressed to University Publications, The University of Texas, Austin. Additional copies of this publication may be procured from the Bureau of Economic Geology, The University of Texas, Austin 12, Texas THE UNIVERSltv OF TEXAS PRESS The University of Texas Publication No. 4915: August 1, 1949 CLAY DEPOSITS OF THE CISCO GROUP OF NORTH-CENTRAL TEXAS By F. B. PLUMMER, H. B. BRADLEY, AND F. K. PENCE Bureau of Economic Geology Research Laboratory in Ceramics PUBLISHED BY THE UNIVERSITY FOUR TIMES A MONTH. ENTERED AS SECOND·CLASS MA1TER ON MARCH 12, 1913, AT THE POST OFFICE AT AUSTIN, TEXAS, UNDER THE ACT OF AUGUST 24, 1912 The benefits of education and oj useful knowledge, generally diffused through a community, are essential to the preservation of a free govern· ment. Sam Houston Cultivated mind is the guardian genius of Democracy, and while guided and controlled by virtue, the noblest attribute of man. It is the only dictator that freemen acknowledge, and the only security which freemen desire. Mirabeau B. Lamar CONTENTS l'AGE Introduction ······························································-··················································:·····················--·-······.··· 5 GEOLOGY OF THE CLAY DEPOSITS, by F. B. Plummer and H. B. Bradley.........,...................................... 5 Quinn clay --·--··--······--····--····-·---·····---------············------------··-·-·-····--·--·--·······-------'··--·--····-·-···---·--··---·-'·' 5 Taylor deposit ---·--······-·······-····---·-···-----------------------··-··········--··---··--·····--··-··---·-----·-·---·····--------9 DeBusk deposit ·····-···············-··········----·--·-······-··--·····--··················-'·······--·-··-'·--········--·--······---·-····"·: 9 ~~~:~ :::i:ltt :::::::::::::::=::::::::::=::::::::::::::::::::::::::::::::::::::::::::::::::::::::=:::::::~:::~::=::::::=::=:::=:=::::::: ~~ Gallagher deposit ·-·-··-·····----------·-···-·---····-··------------·~------·--·----··--·-----····----·-'--·--·-·-··-------=---12 Fee deposit ······--········-·-··-·-·····-··········-··· ·····-·-···---···········-···-···············-···········-·········-···········--··--·---'-' 12 Wright and Harrell deposit --········-·········--··················-······----····--········-···---·-··-·-·-·-······-···-·---·--··· 13 Beal deposit --······-·--···---~-----·-····-····--·-------------····· ··--······--·····-·····--·---'----·-·····----··· ····--··-·--14 Veal deposit ·············-·····-·····-·-··---····-··-·······--·-···········-··-·····-···-··············-··-·-····-··-···-··---··--·-·-··--·--·· 15 Linderman deposit -······-···---------·--·····-·-----···-····--········---····-···-········--·-·--··-·-···-----···------·-···4-. 15 Curr~~l~; ~~-~-~~-~--:=::::::::::::::=::=::::::=::=::=::::::=::::::=::::::=::=:::~:::~:::::::::=:~~::=::=::::::=::=::=:::::=:::::=:= i~ Gaines deposit -··--··········-········'········-·--·····-····.·······---···-····-·········--··················-·-···-·····-···-··-------------· 18 Byrd deposit . --·················-·····-----···-~---··-----'-···--···-··---~------------···-····-······-··--·-··-----··--·-·-------"' 18 Loudder ranch deposit ············-···-··············-··········-···--····-···············-·····-··-·--··········-··-·-------·--·--·'..... 19 Curry deposit ·-·-···--··----------'-··-----········---------··----·--············-·····--······-·····-----··-···--··--·-'-.:..--.-,...._, 19 Allar Company deposit ························-·············-···············-----·······-----·-··--········-···--·----······---------:.: 20 Crad~~~~d~l:~ L;k~--d~p~~it·-·:=::::_·:.~::::::::::.~:::~::::::=::::::::::::::::::.~::::::::::::::=::~::::::::::.~:~~::=::=:::~~::::::~ ~i Ashburn deposit ··-···-·--·········-··----·-·······-··--·····----··-··-·······················-··-·······-----·-···------'---·-'-' 22 Crystal Falls deposit ···---····-·····-··-···············-··········-············----·----·-··---·-···············--·-··-'·-·············-·: 22 Finis shale ··-······---------·-----·-----·---·-·····-·-------·-···-····--·--·------·-··-····-···-·-········-·······-·-··---·--····------·-·------'-' 23 Weaver exposure ······--·····--··--·----------·····'-------··----···--·--·--------------------------------------------··-24 City of Eastland shale pit -······-··-·······--···········--·······················-···-·······--······-······--'--------:.:.....__.,, 24 Lake Eastland spillway exposure ··-········-··-····-·-······-·············--·······················-·--·-----·····-··-······'....'. 25 ~~~:r~:~:~g~~:~-~--:::.·::::::::::::::=:::.~:=:::::.~::::::===::=::=:::=::::::::::::::~::::::=::===::::===::::=:~~=::::~:~:~::~~~ ~~ CERAMIC TECHNOLOGY OF THE CLAYS, by F. K. Pence...---·· ··-·····-----------···'·--------------------------:..........:.. 26 Introduction ······-····················-················· -·······---·········--················ ·······---··'··----··-·-····-···-----·--·······-·~---· 26 Ceramic tests ·····---·-····--···-··-··'-··-··-------··----··-···-------·······-····--·-····--····--·-··-----···--·-·-------·--·:.:.___,_ __~. 27 Quinn clay ··········---·-·····-···-----········--·············-·····-············-···········--······--·-····-··---···-·····-···········--···-·· 27 Curry clay -·-··········-······----···-··..:··--·-········--------·······-··'·······-··-····-··-·······-·--·-····-··------·-······-·-:.:,_...•L_ 39 Craddock clay ·-----------·····--······-·--····-·········-·········-·-···---··-·-······-··················-·--···------·----------·---------41 Summary and conclusions ············-···-··--·····-····:._.......................................................,·.............,:.:......:.,:. 42 Index ··········-·····--············--··-·-·········--··············-············-··------·-·'---····-···--·····-·····--·····--·-·--···········--·--······--·-······· 43 ILLUSTRATIONS FIGURES }. Cross section of Quinn clay at the Taylor deposit on the south side of the Col~ni~rtBrownwood road, 3.3 miles west of Bangs in Brown County ..............................................•.10 2. Cross section of .Quinn clay at the DeBusk deposit on the east side of ·the Cross Plains road, 16 miles north of Brownwood in Brown County ---------------·--·-··············-···-···--------':.... 10 3. Cross section ofQui_nn clay at the Wilson deposit on the west side of the Rising Stlon• ·--=:-· JOO zoo 300 400 500 600 700 $cale in Feet Fig. 2. Cross section of Quinn clay at the DeBusk deposit on the ea5t side of the Cross Plains road, 16 miles north of Brownwood in Brown County. above the siltstone is covered with grass and talus for the most part but is known to contain some siderite nodules and appears to be less desirable than the lower clay. The lower clay is at least 10 feet thick and may be 15 to 18 feet, as indicated by the diagram (fig. 2). The best clay is overlain by the thin siltstone, by 15 feet of poorer clay, and by 1 foot of limestone. The pit is located adjacent to a good highway, which is to be paved in the near future, and 3.2 miles north of the paved road leading to Brownwood State Park. It is, however, 16 miles distant by road from the nearest railroad at Brownwood. Wilson deposit.-The Wilson deposit is located in the west side of the CiscoRising Star road, 2 miles south of Cisco, Eastland County (Pl. II, locality 11). The exposure consists of a large barren area covering a flat, broad valley between sandstone-capped ridges, and containing two small water holes excavated for obtaining a water supply for cattle. A cross section through the deposit is shown in figure 3. About 10 feet of clay is exposed over the valley bottom, and the clay is overlain on the ridges by a massive deposit of coarse, cross-bedded sandstone and conglomerate having a total thickness of 28 feet. The clay is apparently of fairly good quality hut contains two thin layers of impure much weathered and disintegrated coal 1 inch to 2 inches thick. The upper layer is about 3 feet from the top of the clay, and the second layer is about 5 feet below the top. The clay above the lower coal is maroon, red, and greenish-gray. In places where the clay is oxidized, it grades into yellow and brownish-yellow hues. It is hard, fairly .. :... . :: "···.·.·.· .·. : :.... : ·.... . . ... .. sandstone ...:.· : : ... ... · .. 0 100 200 300 400 500 GOO 700 800 900 Seale in Feet Fig. 3. Cross section of Quinn clay at the Wilson deposit on the west side of the Rising Star road, 2 miles south of Cisco in Eastland County. uniform in quality, and for the most part the slopes of the ridges. In most places free from impurities except iron oxide, the soil and silt washed down from the which apparently is the cause of the varie· slopes is 3 to 5 feet thick. The deposit gated coloration. The clay below the is located on a paved highway only 2 lower thin coal layer is somewhat lighter miles from the city limits of Cisco. in color, somewhat more laminated and Quinn deposit.-The Quinn deposit ismore si].aly, and may have somewhat difthe site of the original discovery of theferent ceramic qualities. Although only pottery clay near Cisco. It is located on 10 feet of clay is exposed, it is estimated that there is at least a total of 20 feet the north side of the Cisco-Eastland highand perhaps 30 feet available for excavaway, 2 miles east of Cisco, Eastland tion over the valley bottom and along County (Pl. II, locality 12). The pit is 50 40 30 zo .10 Ea5tfand-Ci5co H~ Quinn clay Quinn clay 0 100 zoo 300 400 500 600 700 800 Scale in Feet Fig. 4. Cross section of Quinn clay at the Quinn pit on the north side of the Eastland highway, 2 miles east of Cisco in Eastland County. The University of Texas Publication No. 4915 located on the southeast side of a circular hill having clay along its slopes and capped by massive sandstone and con· glomerate, as shown in the cross section through the Quinn pit (fig. 4). Twentyfive feet of clay is exposed on the slopes of the hill and in the walls of the pit, and measurements made of the entire outcrop and of depth of core holes indicate that the total thickness of the clay is 32 feet. The upper 3 feet of the clay is usually weathered or of poor quality and the lower 2 feet, in most cases, contains calcium carbonate and caliche so thin that there remains about a maximum of 27 feet of good quality clay in the section. The clay is variegated in color, varying from maroon and red to grayish-green, bluish-green, and even purple.1 The clay is remarkably uniform in texture containing few concretions, few ironstones, and no siderite, but one thin seam of coal or carbonaceous shale was noted at the bottom of the pit, and in a few places coal plants have been found in the shale. The overlying sandy shale is 4 feet thick, and the sandstone and conglomerate are about 10 feet thick. Accordingly, excavations for the clay are best located along the slopes of the hill below the conglomerate and above the upper Breckenridge limestone, which occurs in the valley about one-third of a mile northeast of the ridge. Knowing the slope of the clay surface, the thickness of the soil, the thickness of the clay above the limestone, and the length of the exposure, it is possible to calculate the amount of available clay in a rectangular 23-acre plot situated along the clay slope with its west edge bordering the sandstone on the hill top. H. B. Bradley found that along the slope the average thickness of the clay below the soil line is 23 feet and that the reserves of clay in a 23-acre rec tangu I ar tract situated as mentioned above amounts to approximately 800,000 cubic yards. Gallagher deposit. -The Gallagher clay deposit (Pl. II, locality 12a) borders the Quinn deposit on the west and extends 1The upper 9 feet of the clay in the Quinn pit is reddish and bluish-gray in color and burns to a light buff. The lower 11 feet of clay is ye1low, dark red, and maroon and burns to a light pastel-red or pinkish-red color. completely around the sandstone-capped hill just described with the exception of the acreage held by Mr. Guy Quinn. The Gallagher pit is across the fence west of the Quinn pit, and the deposit is in every way similar to that on the Quinn land except that the available reserve of clay is much larger. For a cross sectional view of this deposit, see figure 5. Mr. 40 .,, Quinn clay 100 zoo 300 400 500 Scale in Feet Fig. 5. Cross section of Quinn clay at the Gallagher pit on the north side of the Eastland highway, 2 miles east of Cisco in Eastland County. Gallagher has built a small pottery plant west of his pit for manufacturing ornamental pottery aI\d is preparing to erect a plant for manufacture of brick and tile on a tract of land on the north side of the hill. Thus these excellent clay deposits in the vicinity of Cisco and Eastland are beginning to be developed rather extensively. Fee deposi·t.-The Fee clay deposit is situated on the south side of the CiscoBreckenridge highway, 2 miles northeast of Cisco and one-half mile east of the Fee ranch house (Pl. II, locality 13). The exposure is along the side of the road ditch and on the slopes of a rather steepO? ided valley leading south from the road. This deposit (fig. 6) is apparently in every way similar to the Quinn and Gallagh.er deposits and is located only 1 mile to the north. Below a slumped limestone block, the thickness of the best quality of clay at this locality is estimated to be about 18 feet, while the amount exposed is only about 4 feet. The thickness of the clay above the slumped block is about 8 feet, and only the top 5 feet is exposed. The clay as exposed in the ditch near the bottom of the section is dark 10 U tr Brtcktnrid e limtstont --- ~ ~ Scale in Feet ~ . ~ Fig. 6. Cross section of Quinn clay at the Fee deposit on the south side of the Breckenridge highway, 2 miles northeast of Cisco in Eastland County. maroon red, stiff, colloidal, free from silt and marl, but containing some calcium sulphate in the form of transparent selenite crystals. The clay on the sides of the valley is overlain by about 28 feet of clay and sandy clay ~nd covered with sand and detritus from the sandstone on the top of the hillside. The upper sandy clay in turn is capped by 15 to 30 feet of coarse sandstone and conglomerate; a small exposure of limestone in a bed about 1 foot thick occurs between the pure stiff clay and the sandy clay above. The limestone outcrop is small, badly slumped, and is not shown on the map; however, it is thought to represent the southernmost exposure of lower Crystal Falls limestone in Eastland County. This limestone in many places marks the top of the best quality Quinn clay. This Fee ranch exposure is the nearest Quinn clay outcrop to the city of Eastland and is advantageously located on a good highway. Wright and Harrell deposit.-This deposit is located one-half mile east of Lake Cisco on the north side of Sandy Creek valley, 3.6 miles north of Cisco, Eastland County (Pl. II, locality 15). The clay is exposed along a steep south-facing escarpment forming the north side of the valley. Slope wash and gully cutting have removed much of the soil, leaving exposed one of the most complete sections of Quinn clay to be found anywhere 1n Eas~land County. Altogether, about 24 feet .of clay out of a total of 34 feet of secti(in. is. available for inspection and sampling, as indicated by figure 7. The clay, like that described from other exposures, is a dark 100 Couu s and ~nd conglom tr&h: fall5 limt~tont Fig. 7. Cross section of Quinn clay at the Wright and Harrell deposit, north of the State Fish Hatchery and one-half mile east of Lake Cisco dam in Eastland County. maroon clay, oxidized to brown and yellow colors and mixed with masses of clay which are bluish-green and bluish-gray. The clay rests upon the upper Breckenridge limestone and is overlain by a sandy fossiliferous limestone thought to be the lower Crystal Falls bed. The clay is quite uniform in quality from top to bottom and for the most part is fairly free of foreign matter, although it contains a few iron concretions and a few nodules of ferruginous material. Above the Crystal Falls limestone there is 65 feet of sandstone and conglomerate which forms a steep bluff that weathers into large blocks which fall down the slope, and in many places completely obscures the clay with a thick layer of sand and sandstone talus. The steepness of the scarp and the thickness of the overburden would handicap commercial development, but the locality is noteworthy because the gullies along the scarp have exposed to view the most complete sectfon of Quinn clay to be seen anywhere. Doubtless good sites for clay pits -can be opened by removing the sandstone overburden with a scraper or bulldozer. The exposure is only one-half mile east of the Cisco-Moran paved highway and 3.6 miles north of Cisco, so that this locality is quite accessible. Beal deposit.-This clay deposit is located on the east side of the north-south highway, l l,i miles due south of the Breckenridge High School in Stephens County (Pl. Ill, locality 2la). The exposure is in a ditch along the east side of so Crystal Falls limestone 40 clay 30 the road and below a low north-facing escarpment capped by limestone near an old abandoned oil well. About 5 feet of rather deeply weathered clay is exposed, and the total thickness of the deposit is probably not more than 30 feet, because at this locality a lentil of sand comes into the lower part of the section replacing Lhe upper Breckenridge limestone and extending up into the Quinn clay, a distance of 10 to 15 feet. 2 A measurement made one-half mile south of the locality indicated 30 feet of clay containing some sand in its lower portion, as shown in the profile and cross section, figure 8. Because of the siltstone and sandstone lentil the general uniformity of the Quinn clay is modified. It is thinner, more sandy at the base, and contains impurities not found generally at other places. In fact the clay is of such quality that the exposure would not be included in this list of promising localities except for the fact that it is the nearest locality to the city of Breckenridge. It is located where the clay can be examined and sampled easily. Much of the clay is bluish-green in color with reddish-maroon and brownish-red hues. It is compact, hard, and cut by many cracks and joint fractures. Many iron concretions are on the surface, and other types of nodules of undetermined composition undoubtedly are present. The pit which has been excavated to obtain the sample, however, indicated a fairly good 2In addition a siltstone layer 18 inches thick occurs 17 feet below the lower Crystal Falls limestone. sandstone Seal• in Feet Fig. 8. Cross section of Quinn clay at the Beal deposit on the east side of the road l 1i4 miles south of the Breckenridge High School in Stephens County. ' clay of about typical appearance, and it is possible that the nodules noted on the surface may have come down from the limestone horizon above. The clay rests upon a coarsely grained, cross-bedded sandstone about 12 feet thick and is overlain by a thin much weathered and broken limestone about 1 foot in thickness. The overburden of soil and limestone is about 3 to 5 feet and, therefore, the opening of a pit will not he difficult, if, upon further testing, the clay proves to be of economic value. Veal deposit.-The Veal deposit is located on the west side of the BreckenridgeW oodson highway, 5 miles north of Breck· enridge and 1.6 miles south of the road fork to Crystal Falls in Stephens County (Pl. IV, locality 22). About 12 feet of Quinn clay 1s exposed m a ditch and along an east-facing escarpment on the side of a small hill, capped by limestone and large boulders of sandstone, immediately west of the highway. The clay here is separated into two divisions by a siltstone or fine-grained sandstone 6 inches in thickness. The position of the siltstone in the section is shown in figure 9. The lower portion of the clay is about 19 feet thick and the upper about 10 feet. About 12 feet of the lower clay is exposed. It is a dark maroon to brick-red, hard, compact, much jointed clay. The lower 8 or 10 feet appears to be free from contamina· tion and of very good quality. The upper 10 feet is badly weathered. The upper portion of the clay above the siltstone is poorly exposed, the surface being covered with many siderite and other types of iron nodules, and it is concluded that the lower clay is superior to the upper portion. A large area of the lower clay is exposed along the road side on both sides of the hill with little overburden except the ui;:ual depth of soil. The exposure, therefore, is a most favorable one for opening a clay pit, located as it is on a paved highway only 5 miles north of the city of Breckenridge. Linderman deposit.-The nearest deposit of Quinn clay to the city of Graham in Young County is located on the west side of the road leading south to Eliasville, 0.9 of a mile south from the Graham· C>.., 0 0 2! 0 0 !:::: 0 0 !,!! 0 - ..c: t: 0 = "' ~ 13 lJ'l ;..-; j = 0 ~ 0 8 0 f3: +-41 ~of! ~ .E~ 41 ~..,,, ~·en g c/) ij "' ~ 41 -5 8 a) = 0 0 0..,. 0 0.., = -~ Woodson highway (Pl. V, locality 27). The clay is exposed along the road ditch adjacent to a low east-facing escarpment capped by lower Crystal Falls limestone. The total thickness of the clay at this locality is 31 feet. Of this only about 6 feet is exposed. A profile and graphic section of the clay are shown in figure 10. of some form of iron so that the chunks which break off along the fracture lines are coated with a deep red color. When the coloring matter is scraped off, the rest of the clay is grayish-green. It is clear that in this shallow near-surface exposure the red coloring matter, in most cases distributed more or less uniformIy through 300 400 500 GOO 100 800 900 1000 1100 1200 1300 Scale in Feet Fig. 10. Cross section of Quinn clay at the Linderman deposit on the west side of the Eliasville road, 0.9 mile south of the intersection with the Graham-Woodson road, 10 miles west of Graham in Young County. 100 zoo The clay is maroon, brick-red grading in spots into grayish and bluish-green colors. It is hard, breaks with curved fractures, is highly plastic when wet, and apparently is fairly free from contaminating materials, at least none were encountered in the pit excavated in collecting the sample. There are, however, a few ironstone concretions and other nodules on the surface of the outcrop. On the whole, the clay at this place looks to be of fair quality, but the distance of the locality from Graham, 10 miles, is an unfavorable factor in development. Smith deposit.-The Smith deposit is located on the north side of the GrahamNewcastle highway, 5 miles east of the road leading to Fort Belknap in the town of Newcastle, Young County (PL V, locality 30). The clay is exposed in the road ditch in front of a very low eastfacing outcrop of lower Crystal Falls limestone. The total exposure is about 4 feet. The total thickness of clay at this locality, calculated by proj ecting the upper Breckenridge limestone westward from its outcrop one-half mile to the east, as indicated by figure 11, is 35 feet-a figure which is tentative since t!1e exact angle of dip of the Breckenridge limestone at this place is unknown. The clay is greenish-gray, hard, much cracked and fractured so that it is excavated easily into irregular-shaped chunks. The cracks and crevices in the clay are filled with a dark maroon stain the clay, is concentrated in the cracks and thin crevices. The clay is reported to be white burning. There is little overburden except soil over the clay. A very large area nearly 2,000 feet along the highway is exposed, and if upon core drilling or deeper excavating, the clay proves to be of good quality, this site will be quite favorable for a clay pit. Chemical and mineralogical composition.- Oniy limited information on the chemical and mineralogical composition of the Quinn clay is included in this section of the report. Additional data will be found in the section in which the ceramic properties of the clay are discussed. Analysis of clay from Quinn pit, 2 miles east of Cisco. (Bruce Williams Laboratory, Joplin, Missouri) Percent by weight Si02 ···-------------------------------------------64.32 AI20a -------------------------------------------21.11 Fe20a --------------------------------------------2.92 Ti02 ----------------------------------------------1.73 MnO ----------------------------------------------2.4 p.o. --------------------------- ---------------------0.03 so. -----------------------------------------------0.02 CaO -------------------------------------------0.25 MgO --------------------------------------------0.03 K.O ----------------------------------------------0.53 Na20 --------------------------------------------1.78 *Ignition loss ----------------------------6.96 *Mostly combined water, volatile basic oxides, and carbonaceous material. Clay Deposits of Cisco Group, North-Central Texas 17 amounts of other constituents except sodium oxide and titanium oxide. The low calcium oxide content is a noteworthy and desirable property of this clay. Dr. R. E. Grim of the I11inois State ples of a number of the clays described in the report, employing the differentialGeological Survey kindly examined sam thermal technique. His results for samples of Quinn clay are given below. 3 Mineral composition of Quinn clay. Mont. Illite mol'illoniteKaolinite Quinn pit % Oocality 12) ____ Smith deposit ~ Oocality 30) ____ trace CURRY CLAY Name.-The Curry clay is named for the Curry farm located 5 miles south and 2% miles west of Breckenridge, Stephens County, where the clay is excellently exposed and where it was first sampled and tested for making pottery. (See PL III, locality 20.) Stratigraphic position.-The Curry clay occurs between the upper and lower Crystal Falls limestone layers, just above the Quinn clay in the areas where the thick sandstone deposits ·of the Parks Mountain and its probable equivalent, the Cisco Lake sandstone, do not occur (Pls. VI, Thus the Curry clay VII, and VIII). is not found to any extent in Eastland County but is well developed in Stephens· County from near the south county line north as far as the city of Breckenridge. It occurs also in Young County west of Graham-WoodsonGraham between the road and Newcastle. There is a thin sec tion of Curry clay also in Brown County near Grosvenor. Description and thickness.-The Curry clay closely resembles the Quinn clay in It is purplish-redgeneral appearance. 0 or ption \. '\. 8.0 '\. ' ' ' 4.0 ' ....... 0.006 04 02 Cone Number curves of Quinn clay from Cutbirth anv QUINN CLAY, LOCALITY 9 Pl. I DeBusk deposit.-East side of Cross Plains road, 16 miles north of Brownwood and 0.5 mile northeast of Panther Creek School, Brown County (fig. 2). Raw color: reddish-brown Lime content: none Plasticity: good Drying shrinkage: 6.5% FIRING TEST (fig. 23) Cone Percent total Percent Number Color shrinkage ab'9orption 06 04 02 1 +;; a': ~ 8.0 4.0 light red light red reddish-brown reddish-brown 20.0 \, \ \ \(-Absorption \ \ \ \ _.....\,.-Fig. 23. Absorption and total shrinkage curves of Quinn clay from DeBusk deposit, Brown County, and Rising Star deposit, Eastland County. 04 02 Cone Number 8.0 13.9 11.5 9.5 14.5 2.5 15.5 3.7 Plafe I , Locality 9 16.0 12.0 QUINN CLAY, LOCALITY 10 Pl. II Rising Star highway deposit.-One tenth mile west of Rising Star highway, 3 miles south of Cisco, Eastland County. Raw color: purple Lime content: none Plasticity: good Drying shrinkage: 8.0% FIRING TEST (fig. 23) Cone Percent total Percent Number Color shrinkage .:1b•mrption 06 light reddish-buff 9.5 12.1 04 reddish-buff 12.5 7.4 02 reddish-tan 14.0 2.1 1 reddish-tan 16.0 1.4 20.0 16.0 8.0 4.0 Plafe .II, Localify 10 ' \. "~ .\. Abs or ption \ \ \ \ \ "'---..., 04 02 Cone Number QUINN CLAY, LOCALITY 11 Pl. II Wilson deposit.-Lower 8 feet of clay, west side of Rising Star highway, 2 miles south of Cisco, Eastland County (fig. 3). Raw color: gray Lime content: none Plasticity: good Drying shrinkage: 6.5% FIRING TEST Cone ~umber Color 06 light red 6.5 12.9 04 light red 9.0 9.4 02 lil!ht reddish-brown 12.0 4.6 I reddish-brown 13.0 1.9 (fig. 24) Percent total Percent shrinkage absorpt;on 20.0 IG.O 12.0 ' ' ' c.sTotal shrinkage g ' 0.. 8.0 \. " ~Absorption \. \.. " 4.0 ' ' ' ' ...., 0.0 06 04 02 Cone Number Plate ff, Localify II (Uwer 8 ft. of clay) QUINN CLAY, LOCALITY 12 Pl. II Quinn pit.-North side of Cisco-Eastland road, 2 miles east of Cisco, Eastland County (fig. 4). Raw color: red, brown, green, and gray Lime content: none Plasticity: good Drying shrinkage: ? FIRING TEST Cone Number Color 06 pink 04 tan 02 light brown 1 brown zo. · · (fig. 24) Percent total shrinkage Percent absorption 8.0 13.4 10.0 7.7 13.5 0.2 13.5 0.3 12.0 Plate JI, Locality 12 1'.0 ... !ii L " .. \ 0. \ e.o \ \...-Absorption 4.0 \ \ \ \ o.~, oz 04 Cont t>lumber Fig. 24. Absorption and total shrinkage curves of Quinn clay from Wilson deposit and from Quinn pit, Eastland County. QUINN CLAY, LOCALITY 13 Pl. II Fee deposit.-South side of Breckenridge highway, 2 miles northeast of Cisco, Eastland County (fig. 6) . Raw color: gray and red Lime content: low Plasticity: good Dry shrinkage: ? FIRING TEST (fig. 25) Cone Percent total Percent Number Color shrinkage absorption 06 light buff 7.5 12.3 04 light buff 9.0 10.1 02 light tan 10.0 4.9 1 tan 12.5 2.4 20.0 Plate :II, Locality 13 16.0 12.0 Total 8.0 4.0 \ '\:'-Abso rption \ \ ' ' ....... ....... ' 0.0 QUINN CLAY, LOCALITY 15 Pl. .II Wright and Harrell deposit.-Upper 8 feet of clay, one-half mile east of Lake Cisco dam, 0.1 mile north of fish hatchery, Eastland County (fig. 7). Raw color: gray Lime content: small amount Plasticity: good Drying shrinkage: 7.0% FIRING TEST (fig. 25) Cone Percent total Percent Number Color shrinkage absorption 06 reddish-buff 8.0 13.5 04 reddish-buff 11.0 7.9 02 reddish-tan 13.0 3.2 1 light reddish-brown 13.5 0.4 20.0 Plate :II, LOC'11ify 15 (Upper 8ff. of clay) 16.0 12.0 \ '\ Absorpt ion 8.0 '~ . ' ' ' 4.0 ' ' ....... 0.0 ' ' ' .... 06 04 02 06 04 02 I Cone Number Cone Number . Fig. 25. Absorption and iota! shrinkage curves of Quinn clay from Fee deposit and Wright and Harrell deposit, Eastland County. \ ::7. .\ Absorption \ \ QUINN CLAY, LciCALITY 15 QUINN CLAY, LOCALITY 15 Pl. II Pl. II Wright and Harrell deposit.-Middle 2 Wright and Harrell deposit.-Lower 4 feet of section, one-half mile east of Lake feet of clay, one-half mile east of Lake Cisco dam, 0.1 mile north of fish hatchery, Cisco dam, 0.1 mile north of fish hatchEastland County (fig. 7). ery, Eastland County (fig. 7). Raw color: almost black (carbonaceous) Raw color: purple Lime content: none Lime content : low Plasticity: good Plasticity: good Drying shrinkage : 5.5% Drying shrinkage: 6.5% FIRIN~ TEST (fig. 26) FIRING TEST (fig. 26) Cone Percent total Perceut Cone Percent total Percent Number Color shrinkage absorption Number Color shrinkage abiJorption 06 light reddish-pink 7.5 19.7 06 light reddish-pink 8.0 14.0 04 light reddish-brown 11.5 13.5 04 light reddish-pink 10.5 8.1 02 reddi&h-brown 13.5 7.4 02 light reddish-brown 11.5 4.4 1 reddish-brown 13.5 5.6 1 brown 13.0 2.9 2c.c 20.0 Plat e JI , Locality 15 \ (Middle i?ff of sectio:>) \ Plate II, Locality 15 (Lower 4 rf of clay) \ \ 16.0 . 16.0 \ V Absorpt;on \ 12.0 12.0 8.0 8.0 4.0 4.0 c.o '----~-'----~--'--~--' 06 04 02 ~~ni. Nvmber Fig. 26. Absorption and total ~hrinkage curves of Quinn clay from Wright and Harrell deposit, Eastland County. \ \ 04 02 Cone Number QUINN CLAY, LOCALITY 16 Pl. II Cisco Country Club deposit.-East side of old Breckenridge-Cisco road, L6 miles north-northeast of Lake Cisco dam, ~astland County. Raw color: grayish-green Lime content: high Plasticity: good Drying shrinkage: 7.5% FIRING TEST (fig. 27) Cone Percent total Percent Number Color shrinkage absorption 06 light reddish-pink 11.0 04 light reddish-brown 13.5 02 reddish-brown 13.5 1 reddish-brown bloated 20.0 Plate II, Locality 16 16.0 8.8 0.9 1.6 4.4 -----···Blo3ted 8.0 \ \ \ ~Absorption 4.0 \ \ _,,// \ / \ / ~----if 0.0 ~------~-~-~ 06 04 02 Cone Number QUINN CLAY, LOCALITY 17 Pl. II Old Breckenridge-Cisco rou.d deposit. East side of road, 1 mile south of Eastland- Stephens County line, Eastland County. Raw color: red Lime content: none Plasticity: good Drying shrinkage: 7.5% FIRING TEST (fig. 27) Cone ::'-iumber Color Percent total" shrinkage Perct:n t absorptioi: 06 04 02 1 light light deep deep red red brown brown 9.5 13.0 16.0 16.0 12.00 6.02 0.26 0.13 20.0 Plate JI, Locality 17 16.0 !".,.STotal shrinkage 12.0 \ \ 8 .0 \'Absorption \ \ \ 4.0 ' \ \ \ ' 0.0 ~---~---'--'==== 06 04 02 Cone Number Fig. 27. Absorption and total shrinkage curves of Quinn clay from Cisco Country Club and old Breckenridge road deposits, Eastland County. QUINN CLAY, LOCALITY 18 QUINN CLAY, LOCALITY 21A Pl. III Pl. III Sandy Creek bridge deposit.-West side Beal deposit.-East side of road 1.25 of old Breckenridge-Cisco road, 0.15 mile miles south of Breckenridge High School, south of Sandy Creek bridge, Stephens Stephens County (fig. 8) . County. Raw color: gray Raw color : red and gray mottled Lime content: none Lime content: none Plasticity: good Plasticity : good Drying shrinkage: 8.0% Drying shrinkage: 8.7% FIRING TEST (fig. 28) Cone Percent total Percent FIRING TEST (fig. 28) Number Color ahrinkage absorption Cone Number Color 06 pink 04 ·pink 02 tan 1 tan 20.0 16.~ 12.~ c .. " ' u .. n. e.J 4 .0 0.0 06 Percent total Percent 06 shrinkage absorption 04 11.90 02 12.0 8.40 1 15.5 1.06 16.0 0.13 Plate Ill, Locality 18 L ' ' \ -c.Absor ption \ \ \ \ \ \ \.. . 04 02 Cone Number Fig. 28. Absorption and total shrinkage curves bridge and Beal deposits, Stephens County. pink-gray 10.0 17.00 pink-gray 11.5 12.10 gray-green 16.5 0.29 gray-green 18.0 0.43 Plate JI!, Locality 21 10.C ' ' ' ' ' ~Total shrmkoge 12.0 '\~lAtsorption 8.0 \ \ \ 4.J \ \ \ 0.0 ~--~-~-~--~ 06 04 02 Cone N:Jmber of Quinn clay from Sandy Creek QUINN CLAY, LOCALITY 22 Pl. IV Veal deposit.-West side of Woodson highway, 5 miles north of Breckenridge, Stephens County (fig. 9). Raw color: red Lime content: none Average drying shrinkage: 7.6% Water of plasticity: dry basis, 29.4%; wet basis, 22.8% Average dry modulus of rupture: 667 lbs./sq. in. Average fired shrinkage at cone 02: 8.4% Average fired modulus of rupture at cone 02 : 8420 lbs./sq. in. Remarks: Bars made with de·airing extruding machine. Clay worked satisfactorily. Oxida· tion complete on fired bars. FIRING TEST (fig. 29) Cone Percent total Percent Number Color shrinkage absorption 06 04 02 1 orange orange red red 9.5 13.5 15.5 18.0 12.50 9.65 5.25 0.00 20.0 Plate IY, Locality 22 IG.O 12.0 ' 8.0 4.0 shri nka~e 0.0 L--~-'-------'--- 06 04 02 Cone Number ' ' "\.~Absorption I ' ' ' ' '\ \ \ \ \ \ \ QUINN CLAY, LOCALITY 23 Pl. IV Hubbard Creek crossing deposit. North side of Crystal Falls-Breckenridge road, 1 mile southwest of Crystal Falls, Stephens County. Raw color: red and gray Lime content: none Average drying shrinkage: 7.9% Water of plasticity: dry basis, 27.8%; wet basis, 21.8% Average dry modulus of rupture: 804 lbs. / sq. in. Average fired shrinkage at cone 02: 8.2% Average fired modulus of rupture at cone 02 : 7900 lbs. /sq. in. Remarks: Bars made with de-airing extruding machine. Oay worked satisfactorily. Oxida· tion complete on fired bars. FIRING TEST (fig. 29) Cone Percent total Percent Number Color shrinkage absorption 06 orange 10.0 12.40 04 orange 11.0 9.80 02 red 15.0 2.20 I red 16.0 0.38 20.0 Plate IY, Locality 23 16.C '"\ Fig. 29. Absorption and total shrinkage curves of Quinn clay from Veal and Hubbard Creek crossing deposits, Stephens County. shrinkage \ 8.0 \2-Absorption \ \ \ 4 .0 \ ' \... .................... ....,, 0.0 '---~-'-------''------' OG 04 02 I Cone Number QUINN CLAY, LOCALITY 26 Pl. V Cotten deposit.-East of Wagon Timber Branch, 0.2 mile north of Crystal Falls road, and 4 miles west of Eliasville, Young County. Raw color: gray Lime content: none Plasticity: good Drying shrinkage: 8.5% FIRING TEST (fig. 30) Cone Percent total Percent Number Color shrinkage absorption 06 light pink 10.0 11.9 04 light pink 10.0 10.2 02 cream 10.5 6.9 1 cream 11.5 5.1 20.0 Plate Y, Locality 26 16.0 12:0 ...._,s-Absorption ............ g 0. ' 8.0 ' ' ' .................... ...... "<> 4.0 0.0 L------~-'---~---' 06 04 02 Cone Number Fig. 30. Absorption and total shrinkage Linderman deposits, Young County. QUINN CJ.AY, LOCALITY 27 Pl. V Linderman deposit.-West side of Elias· ville road, 0.9 mile south of Graham· Woodson road, 10 miles west of Graham, Young County (fig. 10). Raw color: reddish-purple Lime content: none Plasticity: good Drying shrinkage: 9.5% FIRING TEST (fig. 30) Cone Percent total Percent Number Color shrinkage absorption 06 light red 10.5 11.4 04 light red 11.5 9.3 02 light red 14.5 6.1 1 light red 14.5 4.6 20.0 Plate Y, Locality 27 · 16.0 12 .0 ~ c ........... ~ v ~ '-y-Absorption ~ 8.0 ' ' ' '--....... .... .... ""' 4.0 0.0 L----'---~---''-----'-~ 06 04 02 Cone, Number curves of Quinn clay from Cotten and QUINN CLAY, LOCALITY 29 Pl. V Dixon deposit.-One-fourth mile north of Brazos River, 1 mile east and one-half mile south of old Fort Belknap, Young County. Raw color: reddish-purple Lime content: none Plasticity: good Drying shrinkage: 10.0% FIRING TEST (fig. 31) Cone Percent total Percenl Number Color shrinkage absorption 06 light red 13.5 7.4 04 light red 14.5 3.6 02 dark reddish-brown 16.0 0.0 1 dark reddish-brown 16.5 0.0 20.0 Plate Y, l ocality 29 12.0 e.o '-.'-.5Abscrption 4.0 ' ' ' ' ' ' ' 0.0 '---'---''-~--"'---06 04 02 Cone . Number Fig. 31. Absorption and total shrinkage Smith deposits, Young County. QUINN CLAY, LOCALITY 30 Pl. V Smith deposit.-North side of Graham road, 5 miles east of Newcastle, Young County (fig. 11) . Raw color: gray-purple Lime content: none Plasticity: good Drying shrinkage: 7.5% FIRING TEST (fig. 31) Cone Percent total Percent Number Color shrinkage abaorptjon 06 light cream 7.5 12.4 04 light cream 7.5 10.4 02 light cream 11.5 6.1 1 cream 12.5 4.5 20.0 Plat e J7, locality 30 16.0 12.0 c ... v ... a. 8.0 t--r---" Total shrinkage ' ' ' -..... ....... ............. ...., 4.0 0.0 '---'----''---'---'---'--~ OG 04 02 Cone Number curves of Quinn clay from Dixon and CURRY CLAY, LOCALITY SA CURRY CLAY, LOCALITY 19 Pl. I Pl. III Byrd deposit.-0.1 mile north and 0.1 Loudder deposit.-71/4 miles south and mile east of Grosvenor, Brown County 21/4 miles west of Breckenridge in north( fig. 12). east corner of section 2263, Stephens County (fig. 13) . Raw color : red Lime content: large Raw color: gray-pinkPlasticity: good Lime content : none Drying shrinkage: 6.1 % Plasticity: good Drying shrinkage: 7.5% FIRING TEST (fig. 32) FIRING TEST (fig. 32) Cone Percent total Percent Number Color shrinkage abeorption Cone Percent total Percent Number Color shrinkage absorption 06 pink 6.5 14.10 04 pink 6.5 11.20 06 cream 8.0 12.9 02 dark pink 10.0 6.98 04 cream 8.0 11.8 1 red 11.0 4.20 02 cream 8.5 9.1 1 cream 8.5 7.9 20.0 20.0 Plate .Ill, Locality 19Plate I. Locality 8A 16.0 16.0 '-"('-Absorption ..._~Absorption 12.0 12 .0 - .......... ' "\ ' ' + ' ~ ', - 'o... Q. a.oh--------~---..::-:...,:;: 8.C " Total shrinkage Total shrink.age 4 .0 ~.o 0.0 ~~~~-~----'-~-~ 0.0 ~~~---'------'---~ 06 C4 02 06 04 02 Cone Number Cone Numbe r Fig. 32. Absorption and total shrinkage curves of Curry clay from Byrd deposit, Brown County, and Loudder dep"sit, Stephens County. CURRY CLAY, LOCALITY 28 CURRY CLAy' LOCALITY 20 Pl. V Pl. III Allar Company deposit.-2.4 miles Curry deposit.-21/4 miles west and 5 west of McCan Bridge on south side of miles south of Breckenridge, south of Graham-Woodson highway, 0.4 mile west Curry ranch house, Stephens County of Eliasville road fork, Young County (fig. 14). (fig. 15). Raw color: dark gray-black Lime content: none Raw color: reddish-brown Lime content: none Average drying shrinkage: 8.5% Plasticity: good, sticky Water of plasticity: dry basis, 31.0%; wet Drying shrinkage: 7.0% Sample showed high percentage of scum. basis, 23.8% Average dry modulus of rupture: 863 lbs./sq. in. Average fired shrinkage at cone 02: 7.2% FIRING TEST (fig 33) Average fired moduluo of rupture at cone 02 : Cone Percent total Percent 8990 lbs./sq. in. Number Color shrinkage absorption Remarks: Bars made with de-airing extruding machine. Clay worked satisfactorily. 06 Oxidation complete on fired bars. 04 buff 12.5 6.2 02 light tan 15.0 0.6 FIRING TEST (fig. 33) 1 dark tan 15.0 0.0 Cone Percent total Percent Number Color shrinkage absorption 06 light red 9.5 12.7 04 light red 12.0 9.5 02 light reddish-brown 13.5 9.0 1 reddish-brown 16.0 3.8 JG. O ' 'u.,t!:_Absorption --...... zo.o zo.o Plate Ill, Localify RO Plafe JZ", Locality 28 IZ.0 1: .. t ' ' ' \ Cl. 6.0 8.0 \ \ \'1:,.-Absorption 4.0 \. 4.0 ' \, \ \. '--- 0.0 ~_ OG ..___..___.. 04 Cone ___...__ 02 Number ___. 04 Cone oz Number· Fig. 33. Absorption and total shrinkage curves of Curry clay from Curry pit, Stephens County, and Allar Company deposit, Young County. CRADDOCK CLAY, LOCALITY 24 CRADDOCK CLAY, LOCALITY 31 PL IV PL II Crystal Falls deposit.-0.1 mile west of City of Cisco deposit.-1500 feet west Crystal Falls on south side of road, Stephof Cisco Junior College and 150 feet east ens County (fig. 18). of Craddock Lake, Eastland County (fig. 16). Raw color : purple-gray Lime content: none Raw color: red-gray Plasticity: good Lime content: none Drying shrinkage: 8.5% Average drying shrinkage: 6.5% Water of plasticity: dry basis, 29.2%; wet FIRING TEST (fig. 34) basis, 22.6% Cone Percent total Percent Average dry modulus of rupture: 504 lbs./sq.in. Number Color shrinkage absorption Average fired shrinkage at cone 02: 6.5% 06 reddish-pink 9.5 13.7 Average fired modulus of rupture at cone 02: 04 reddish-pink 9.5 12.2 5870 lbs./sq.in. Remarks: Bars made with de-airing extruding 02 reddish-pink 11.5 9.1 1 reddish-tan 12.5 6.2 machine. Clay worked satisfactorily. Oxidation complete on fired bars. FIRING TEST (fig. 34) Cone Percent total Percent ~umber Color shrinkage absorption 06 light reddish-pink 6.0 15.6 04 reddish-pink 8.0 12.l 02 light reddish-brown 11.5 5.7 l reddi&h-brown 12.5 2.0 20.0 20.0 Plate .l1L, Locality 24 Plate II, Locality 31 16.0 16.0 ~Absorption ' ' ' 12.0 12.0 "' \ \ ~ ~ ~ \ cl'. cl'. \ \ 8:0 8.0 \ \ 4.0 4.0 ' ' ' ' ' "" 0.0 ~-~-'----'----~ 06 04 02 04 02 Cone Number Cone Number Fig. 34. Absorption and total 3hrinkage curves of Craddock clay from Crystal Falls deposit, Stephens County, and City of Cisco deposit, Eastland County. shrink.age The foregoing data set forth the performance of the clays when prepared by the normal plastic process. In the manufacture of art pottery and specialty products, the process of fabrication known as "casting" is of equal importance. In this process the clay is made into a "slip" with water and the ware formed by pouring the slip into plaster molds. Sample from locality 12 was used in determining the most favorable specifications governing the composition of a casting ' slip. This was found to be as follows: To a given amount of dry clay add 60% water, 0.06% sodium silicate solution ( 40° Baume), 0.30% barium carbonate. (All percentages are based on weight of dry clay used.) This will make up a casting slip carrying the maximum percentage of clay solids. _____ The barium carbonate introduced into the above formula is for the purpose of precipitating soluble salts which would otherwise concentrate at the surface of the ware and form "scumming." This scum ming would render the glazing of the ware more difficult. However, normal results can be obtained with suitable glazes ap plied to products made up according to the foregoing formula. The performance of the clay in fabrica tion by the casting process showed the following unfavorable factor: 1. A rather slow casting rate due to slight tendency to gelling; probable maximum production two casts per day. The following are favorable factors: 1. Good mold release. 2. Very little cracking in spite of rather high drying shrinkage. SUMMARY AND CONCLUSIONS The one property of the clays treated in this report which tends to approach the danger limit is the rather high total shrinkage obtained at the temperature of optimum density. It will he noted that in the major number of samples this total shrinkage is in excess of 12.5 percent. This is somewhat high for the use of this material in heavy structural clay products hut does not disqualify it for art wares. It is preferable that the total shrinkage should not exceed 11 to 121h percent. There are a number of localities, however, which do not exceed this figure. The favorable factors applying to wares fabricated by either plastic or slip casting process are: 1. Good plasticity and working prop· erties. 2. Satisfactory drying behavior. 3. High strength 0£ dried product. 4. Satisfactory firing range in which adequate density is reached at low temperature of Cone 04 to Cone 02. It is recommended, therefore, that the prospective users of clays from the area covered in this report select those of the lower shrinkage and which fire to such light or dark shade as may he desired. ,,,, \\" ",,,, " \\ \\ \\-" " 11\\ \\ \\ \\ \\ ,, \~ ,, \\ \\,, \\,, ,, \ " ./··· .• ·.. umn clay in Bro Cwn ounty h ·s owmg the exte t fn o outcrop d than e principal exposures. ·· ·~·· EXPLANATION .~{"'"'~ ~ .Trinity group. . . . . . . . . • (sand and eonglomerat J u c LGWU Cry5t&I Fall$ lilnC$font .....-cdz -~ ~ ~ Quinn clay •• , • • •=> ~ • • • • • • • • • . z it Upptr Srttktnridge limutont Lower Brtckc~ridge limestone • , Known gtologic boundary. • , ... . Inferred gtologic bo dun ary.•• •• . -----.. ..... .~Projtctitd lint of section line.0: mn!.und stcfio(additional unmusured s:Cf.' . . . .ions shown by Locali ty number.. .. ·· ····· ····· Te~t "ample. , .. •. s location of sample) •.{point of arrow ~how ·. • • • • • • • Fo.ssil locaiity • . • • , • • Mint or quarry.... . . . .. ..... . . .....').(' \ N f=c:::i:=c::i:~or~• .;::::1111mc::llMile ScAtE Plate I TheU · · n1vera.1ty of Texu Publ"u:ation 4915 ) :.7 y · ~··. --···...~../ v N~d \_ (, r II II II " I/" \\ .,11 " ,1" ,1\\ ,, ..· ! 11 1/ \\ I/ \\ ---:/:"' --.~..~~ .. _.JV;. ___ _ -'"'--:;;::.--- · ~ ~ . .,,:< . ·.f .•... -~ ~ -c ... '.-Cbu.. .-Cbl ' • . ,_______. xx x) ····© · • • • ••S--+ . .. .... ,., .. ,.+ The Univeraity of T exas Publication 4915 Plate II \ I f (, ·<.,) ,) 72 ~. ..J: ., 74 ) J\I 69 · ··~·'-\ \ ...~··./._c_ '-67 l _________ so 70 ,. 508 /' ~/ 44 ( ( '· Kt .../ ; ...r- EXPLANATION ~~r .. . t< ...'.) E]] ~ < Trinity group. . • . . . . . . . . . . . . . i:'> Kt ·:'::'· __, t; (sand and conglomerate) <:=.· · : ::.:=. v "' Cisco Lakt sandstone . . . . . . . ...-Ccs - Lowtr Crystal Falls limHtone . ... ...-Ccl Quinn clay ..... ............ . ~ Upptr 8~cktnridgt limestone .... . . -Cbu- Known geologic boundary. . . . . . • . . . Inferred geologic boundary . .... . .•. ----Pro} edcd line of section .. .. . . . . . . B' B' Lint of musurrd section . . • • . . • •. . ~--- (additional untMasurtd sections shown by xxx) £,';:\ Locality number . • • . • .. • • • • • • • • • • . . • . •.. ~ Test nmplt .•.••• . •.••.•. ••.••• , ••.. s( point of arrow shows loca!~n of sample) Fossil lou11ity . . • • • . • • . . • · .......... ...... .+ Mine or quarry . • . ••• .•••• ••• ••••. ••• • •• ~ 0 o.s . jMilt E=! SCALE Kt f Map pf Quinn clay in northern Eastland County showing the extent of outcrop and the principal exposures. The Univer•ily of Te1u Publication 4915 Plate Ill RJ , \" II \\ \\ \I 1~' 7 // (( ii"'',,,, \I '(.. \\ \\ \\ II II " • 2960 19 II II II " " \\ JI II \\ ==~=-.:::.::::;:~\ 83 . .2959 . 18 32 l 36 / " ..../ 17 16 17 18 '~---~,,........II ii ' \\ \\ ../"'-"··· ' ------~--26 25 ...~ 35 2954 .... ... 2955· //,, //,,,, 2019 · · ·~· . --~ . . • • • "1 1· • . . ~I . • • IJ, •,, JI. JO ·: 0 . . o{.J' . -<.· . \/" . r: \; . . -~ . • C' f, r,:,,1, I 202() .. ,{II I I \,,,, " 454 23 3SIJ3 . ll • II ·II· H• 11. ·\ \. ~ ~ ll 34 II II II II II II II " II ~======== 3390 -------- 13_387 l I I I I I ~I"/\\ I';; II // . " II II II,,,, .J389 3388 "II II II 3373 ((J ,,,,,, II II II II II II II II II II II,, ,, n"· II II II ---47 9379 3381 . I LXPLANATION Upper Crytt•I f•lls limuton1 ,,,,,, ",,,,,,,, \ II II ii 3f75]-____ l3374 --ODl - -PARKS 3380 \ 2038 17 46 .ccu Curry ci.y •••.••.. .. '. ....... -~ j Lowv Crysh1I f.illlls Umtston. ••• , , ••• ~Ccl - CNinn ,...,, ·• •••••• ' ••• • • , , , , • • Upper Br1dllnriclge li1111•-htne.. .. .. .-Cbu- Known geologic boundary .• • Inferred geologic boundary. •• ... ..----~ jcc.tcd line. of section. , •• .. c11o---1c' Linc of" ft'ICISVf"td ttdlon. . • . . • • •. • • •,______ (addition~! unmusurrd setfioM shown by·xxx) · loc&llty number • • • • •. • , , •• , ., , .• • , , , •••• @ T1.t ·.ample·. • •·.: • •••• • • • •••••· ••.. • •••.• •s~ (point of ........ -- of -,Jt) fo..·i1 locollity. • .. .. •. • • • .. • ... • • • • • • • • • • • • • , + 0 O.S 1Mile ====~=c::::::E~ ~ap of Quinn and. Curry clays in southern Stephens County showing the extent of outcrop and the principal exposur~. 1168 \ 111'7 )t..· 1211 1219 122Z IZ23 IZ24 ,, " " "" ~, ".:::-::=:::::= II II II II C' 5 2 /·' ..""YOUNG STEPHENS , "' u Map of Quinn clay in northern Stephens County showing the extent of outcrop and the principal exposures. ZS 1.152 1951 1948 /J57 1.158 /J59 1341 [xPLANATION LoMr Crystal falls 1i1M1tont. • • • .-eel- Qvinn c\•y ••.•. •.• . ..•. •• ....- Upper B~cMnridg• !i11tstonc. , •.•• •.--cbu- Known geologic. . bound1ry ....••••••••-----Inferred 9cologk. boundary...••• , •• , , -----Pro) ectcd lint of $tetion ... . , , .. , • , . c'··--·C' Lint of muar.urtd stc:fion ....•..•••• , _____.., (additional unmtasurtd sections sh0wn by X)l(X) Locality numbtr .•..........••• . •••••.. @ · Test samplit• .. •..•••... . ••••••• •• ••• s_... (point of arrow tholn Joc1tlon of $ample) Fouil '°'11ity •......• •. .•••.•• ········+ 0 o.s f N ScALt Plate lV The University of Texas Publication 4915 • 2085 20~ The Univet'.sity of Texas Publication 4915 Plate V ~-· • D' ' ' ,..zz \, ' ' ' ' ' ' ' \ ' ' ) )) ",, " " -· "' ___FJ ) r~I ,-:.~~'".-" II ·-. " " " " //,, // // I/ BRAZOS [XPLANATION 3 Lower Cry$f1\ Ftllt lini•stoti• . z i! ~ => ~ Qu\nn tl•y ~ lnftrrtd gtol<>gic bwndary .. Lint Qf m•asured stcf iQn. (addilionill vnmf&5Vi"l'd HcfiQns ! hown by xxx) LQcality numbt r . Test ~ample . . . . • . . {paint {If arro1¥ 3~3 location of s~111 plr) Mint or quarry . .-ct>u.----- . D·--n· .s~ ····~ 0 O.S IMile \-==-=..t::=-=== SCALE I~ Map of Quinn clay in Young County showing the extent of outcrop and the principal exposures. -' The University of Texas Publication 4915 Plate VI .,• Creek L&• ~Btlknap La. ® ... -Concealed . . ..... Crystal Falls .Byrd Gl'O$vtnor ,Thrifty BR OW .N A' ,Bar-gs • Brownwood .~ .. .... :.·..:.... · .. .. :: LINE.--Breckenridge. Ls.---A-NN£ Ls. -Lower Breckenridge La. ISO l;,i~\~l: Co119lomerate lZ5d 5and or Sandstone ~ Limestone 100 .... ., ~ I w ® ...J - Shale Sith.tone . . 8 Sandy Shale Siderite ~ ~ ~ ~ Clay Exposed Clay Section EXPLANATION I -s ' Position of Test Sample ® Map Locality; Plate I -?Correlation Lines ,.:i L' fr. ' •.'1 .. ,., :,·:·p ' © @,@,e-® <( Sandstone. <..> Lake 50 40 30 Quinn Clay. s 20 10 ----DATUM SSW 0 2 3 4 s 10 13 HORlZ.ONTAL SCALE·-Miles Vertical sections of Quinn and Curry clays through Brown County showing stratigraphic position, lithology of overlying strata, thickness, and position of interbedded siltstone lentils. 0 3 ... ,· .. . .. ... ·.·~ Q ·."' ~....;. ,r-,_ ~: ~~ • . · .. .. ·.... .·. '• ...... . . . .. . . . . . .. .· .. <:)' ·9 . • : IS0," ': ·a·. .·:a ~. ·.••0' • ' ."' . is .••. .. ·.. .. '. .. @ Quinn Clay 10 I I ® · · · ci:.s:.2.'·:·:: :~· ::·:. ·.:.:G_::_::....:::: ... :· .. ·:.':': .: ...:...:. :_._ \ 1~ 3; HORIZONTAi,. SCALt -Milt$ ~ I Vertical sections of Quinn, Curry, and Craddock clays through Eastland and Stephens showing stratigraphic position, lithology of overlying strata, and variation in thickness. 40 45 The University of Texas Publication 4915 ~ • i:: I w § ..J s ISO 100 ® -$ -T""' :.:: .' .. .. ·. 40 ---? o '·,• :9:.;,;. .•o.· ..,.._,... 1- -----....., ---· "---· Quinn Clay 10 ~}S ~~-e"2J-~~~~-- O -81------Top of Upper Brcektnridgt Ls.--- Plate VII ~ ~ ~ Conglomtr.+t: Si!tsfont Exposed Clay Ste~ ~ ~ -s Ld ~ Strid or Sandstone Sandy Shale Sidcrit1 Position of Test Samplt ® 1----. --Ntw,astl1 C<>al $ -Craddix.k Cl<1y -Grass and s~a -lowtr 6reckt.nridge ls.. --~ Limestone Clay Coal Map Locality, Pl.aft II - _,_ D Sandy Clay Conct1led Corril1tion lints EXPLANATION I Ill E.aslland c;~•[. ' EASTLAND >I> !z51' ~0 u u @ ~·~ "' "' Cwry Clay .. ... ·.· -.:.. _---?-- g ~ ---rop of Upper Crystal F'af/s li1r1estont j it;; ~-s -----"""-'..----- -;i__ < . -----· 5 ' .":_'.~::: ': ..·. . .--...._ =---Top Ls -----~;~1r------------C_'_'~'Y~C~l•~y--------------,~~ ....... .. i:~....~·5>.~---=-=-or Lowtr Cty't~I fa ll• - ...; . ·. S". ..' . -s Quinn Clay .·. . . .. . ·: .. · : ?> c;·.:=:::;: ,.·,~;·:~,.,.;m. ,,z:::.,~,.~,.,.,.,,z. q_~-~~~r:.-:5'------------Sitts+onc---------------1,,,,,,. --------------------- 5 - ~ .. , . . . . ·.... ·.···.· . ···: -.·... :.··.. '-. ·· · · ·· · · · · · ·· ·. · · · · · · ·· · · · · · · .) --~-¥~-"tFCi-~--01iinn Clay .. :_i..~.. ~·. _·.. . ' .. ~-_-::··.:·"~ (~.··." ~~· .·.~. ·.·~·.·~...~ ·;·:...... ' -.;,... :........:. . -· _. .-· . ~· .;....--" ............ 9vinn cl•y Top of Vpptr . 6r1cl\4nridgt L.I. ---==-==.,..==='------------------"-~ -:_ ~ · .~J;..:.f-l:~f-'::::=----------------------------·~~!-------DATUM LIN[ ·~·~·~~· -N "The University of Texas Publication 4915 Plate VIII 90 >... zl>:::> It ll so 70 60 ~I~ ~lei "I~~ ~ ~ (/) 40 30 20 10 I SSW a-to' I I I I ~ ~ D' Conglomtratt Shalt Position of Test Sample ~ • [2J ~ @ Graham Sand or Sandstont Clay Map Locality, Plate .m • ~ ~ ~ Limtstone ExpoS(d Clay Section Correlation Line E.XPLANATION Boftom of Upper Crystal F"alls Ls. @ @ Curry Clay Top of Lower Crystal F"a lls Ls. s Top of Lower Crystal Falls Ls. s Quinn Clay Quinn Clay LINE ----------Top of Upper Breckenridge Ls. ---------------- Top of Upper Breckenridge L_s. --------------DATUM () z 3 4 5 10 IS HORIZONTAL SCALE. -Milts Vertical sections of Quinn and Curry clays through Young County showing stratigraphic position, lithology of overlying strata, and thickness. INDEX absorption formula, clay : 26 Allar Company deposit: 18, 20, 40 analysis, Curry pit clay: 20 Finis shale: 25 Quinn pit clay: 16 Ashburn deposit: 21, 22 Athens: 5 Bangs: 6, 7, 9, 10, 18, 27, 28 Beal deposit: 7, 9, 14, 15, 35 Belknap limestone: 21, 22 Bradley, H . B.: 12 Brady: 7, 27 Brazos River: 6, 7, 8, 38 Brec;enridge, vicinity: 6-9, 12-15, 17-22, 32, 34-36, 39, 0 -Cisco road deposit: 7, 34 high school: 7, 9, 14, 35 limestone, upper: 6, 12, 14, 16, 17, 23 Brownwood: 7, 9, 10, 18, 25, 30 Buffalo: 7, 18, 28 buff-burning clay: 12, 26 Butler, B. A.: 23 Byrd deposit: 18-19, 39 ceramic technology of clay: 26 Choate, Don : 25 Cisco, vicinity: 5-14, 18, 22, 25, 26, 30-32, 34, 35 Ohamber of Commerce: 5 Clay Products Company: 5 Country Club deposit: 7, 34 group: 5, 23 junior college: 21, 41 Lake sandstone: 8, 17, 18 City of Cisco deposit: 411 City of Eastland shale pit: 24, 25 clay, absorption formula: 26 buff-burning: 12, 26 ceramic technology of: 26 Craddock: 21-23 Curry: 17-21 fabrication: 42 Quinn : 5-17 Clemens, Eugene C. : 5, 25 Coleman: 7, 9 Colorado River: 6, 7, 27 bridge deposit: 7, 27 Cotten deposit: 7, 37 Craddock clay: 5, 21-23 firing tests: 41 measured sections, table of: 21 mineral composition: 23 noteworthy localities: 21-23 stratigraphic position: 21 thickness: 21 Craddock Lake: 21, 22 deposit: 21-22, 41 Cross Plains: 7, 9, 10, 18, 30 Crystal Falls, vicinity: 6-8, 15, 21-23, 36, 37, 41 deposit: 21, 22-23, 41 limestone: 6 Curry clay: 5, 17-21 chemical composition: 20 firing test: 39-40 measured sections, table of: 18 mineralogical composition: 20 noteworthy localities: 18 stratigraphic sections: 18 thickness : 17 Cutbirth deposit: 7, 29 Dean, D. P. : 25 DcBusk deposit: 7, 9, 10, 30 Dixon deposit : 7, 38 Eastland, vicinity: 5-7, 9, 11, 12, 23-26 Chamber of Commerce: 5 sandstone : 23, 25 Eliasville : 7, 15, 16, 18, 20, 37, 40 Eureka Baptist church: 7, 28 Fee deposit: 7, 9, 12-13, 32. Finis shale: 23 chemical analysis: 25 noteworthy localities : 24-25 stratigraphic position: 23 thickness: 23 firing tests, Craddock clay: 41 Curry clay: 39'--40 Quinn clay: 27-38 Fort Belknap: 6, 16, 38 Gaines deposit: 7, 18, 29 Gallagher Clay Products Company: 5 deposit: 7, 9, 12 George deposit: 7, 28 Gonzales limestone: 24 Graham: 7, 9, 15-18, 37, 38, 40 Grim., R. E.: 17, 21, 23 Grosvenor: 6-8, 17-19, 29, 39 Harbison-Walker Refractory Company : 5 Harpersville formation: 6 Harrell and Wright deposit: 7, 9, 13, 32, 33 Home Creek limestone: 23 · Hornberger, Joseph, Jr.: 23 Horton, Horace: 5 Hubbard Creek: 7, 8 Crossing deposit : 7, 36 Lake Cisco: 7, 9, 12, 32-34 Lake Eastland spillway exposure: 24 Linderman deposit: 7, 9, 15-16, 37 Lone Star Gas Company: 25 Lonsdale, J ohn T.: 17, 21, 23 Loudder ranch deposit: 18, 19, 39 Maddoy, Gene: 25 McCan bridge: 18, 20, 40 mineral composition, Craddock clay: 23 Curry clay: 20 Quinn clay: 16-17 Moore, R. C. : 6, 23 Moran: 14 Newcastle, vicinity: 7, 9, 16, 17, 38 coal: 22, 23 noteworthy localities, Craddock clay: 21-23 Curry clay: 18 Finis shale: 24-25 Quinn clay: 8-16 old Breckenridge-Cisco road deposit: 7, 34 Panther Creek school: 7, 30 Parks Mountain sandstone: 5, 6, 8, 17 Plummer, F. B.: 6, 23 Plummer, G. A.: 25 Quinn clay: 5-17 chemical composition: 16-17 development: 5 extent: 6 firing tests: 27-38 geology: 5 mineralogical composition: 16-17 not