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Upper Jurassic Stratigraphy of Some Adjacent Parts of Texas, Louisiana, and Arkansas

GEOLOGICAL SURVEY PROFESS I ON AL PAPER 594-E

Upper Jurassic Stratigraphy of Some Adjacent Parts of Texas, Louisiana, and Arkansas

By KENDELL A. DICKINSON

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

1 GEOLOGICAL SURVEY PROFESSIONol A.L.. PAPER 594-E

A discussion of the nomenclature, lithologi character, thicknesses, and the relation of lithofacies to paleotectonic elements of Upp r Jurassic rock strata

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1968 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY William T. Pecora, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 65 cents (paper cover) CONTENTS

Page Page Abstract______E1 Buckner Formation ______------E13 Introduction ______1 Thickness and distribution ______-_-- 13 Stratigraphic relations ______-- Purpose and scope ______2 13 Structural setting______Lower member ______-- ____ -- 13 3 Upper member ______~ethods ______14 3 Paleotectonic relations ______--- Acknowledgments ______15 6 Cotton Valley Group ___ --- __ -- __ -_------17 ~omenclature ______6 Bossier Formation ______17 Stratigraphy ______9 Thickness and distribution ______-- 17 Norphlet Formation ______9 Stratigraphic relations ______-- 17 Qtongue ______Smackover Formation ______9 18 Paleotectonic relations ______Thickness and distribution ______10 19 Schuler Formation ______---- ______19 Stratigraphic relations ______10 Thickness and distribution ______23 Lower member ______11 Stratigraphic relations ______23 ~iddle member ______11 Ptongue ______23 Upper member ______12 Paleotectonic relations ______24 Paleotectonic relations______12 References cited ______24

ILLUSTRATIONS

Page PLATE 1. Correlation of electric and interpretive sample logs of Upper Jurassic rocks in some adjacent parts of Texas, Louisiana, and Arkansas______In pocket FIGURE 1. ~ap showing area of report in relation to the updip limit of Upper Jurassic rocks and to present major structural features of gulf coast embayment------E2 2. Isopach map of Upper Jurassic rocks and locations of major ancestral structural features______3 3. Diagrammatic cross section showing structural and stratigraphic relations from margin to deeper part of gulf coastembayment------4 4. Chart showing history of nomenclature of Upper Jurassic rocks in gulf coast embayment______7 5. Isopach map of Smackover Formation______10 6. Lithofacies map of upper member of Smackover Formation______12 7. Isopach map of lower member of Buckner Formation ______·______13 8. Isopach map of upper member of Buckner Formation______14 9. ~ap showing relations of anticlines to southern edges and depositional axes of lower and upper members of BucknerFormation------16 10. Isopach map of Bossier Formation ____ ------______18 11. Lithofacies map of Schuler Formation ______------______20 12. Isopach map of Schuler Formation except P tongue------23 13. Isopach map of P tongue of Schuler Formation------24

TABLE

Page TABLE 1. ~ames and locations of some wells in Texas, Arkansas, and Louisian&------­ E5 m

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

UPPER JURASSIC STRATIGRAPHY OF SOME ADJACENT PARTS OF TEXAS, LOUISIANA, AND ARKANSAS

By KENDELL A. DICKINSON

ABSTRACT The Bossier Formation is here redefined to include all dark­ The Smackover and Buckner Formations and the Cotton gray shale above the lower member of the Smackover Forma­ Valley Group, which is composed in ascending order of the tion and below the basal sandstone of the Schuler Formation. Bossier and Schuler Formations, are of definite' Late Jurassic It thus includes' equivalelllts of the middle and upper members age. The Norphlet Formation, although considered to be of Late of the Smackover Formation, all the Buckner Formation, and Jurassic age, is unfossiliferous and its age is unproven. The part of the Schuler Formation. A thin upper part of the Bossier Haynesville Formation, which is composed of part of the Cotton extends northward into the lower part of the Schuler Forma.tion Valley Group and the Buckner Formation, is' not used here. and is here informally termed the Q tongue of the Bossier .The Upper Jurassic rocks are found only in the suibsurface at Formation. depths generally ranging from 1,000 feet along the north edge The Schuler Formation is here redefined to inC'lude all rocks of the gulf coast embayment to 12,000 feet in Louisiana. Their between the top of the Buckner Formation and the base of the thicknesses and lithologic characteristics were affected by con­ Cretaceous rocks, except for the Q tongue of the Bossier F'orma­ temporaneous regional movement along the Sabine uplift and tion. A sandstone and shale tongue that underlies the Q tongue the north Louisiana basin and by local movement of anticlines of the Bossier is here informally termed the P tongue of the and faults along the margin of the gulf coast embayment. The Schuler. In updip areas the Schuler Formation is largely near Smackover and Buckner Forma:tions and the Cotton Valley shore or nonmarine in origin, and in downdip areas to the! south Group are characterized by varied lithology and by lack of it is marine. The near-shor'e or nonmarine facies: consists of lateral cm11tinuity. No regional unconformities are apparent in lenticular light-gray, pink, or reddish-brown fine-grained sand­ the Upper Jurassic rocks. stone and pastel varicolored and reddish-brown shale. The The Smackover Formation is divided into three informal normal marine facies consists of light-gray fine-grained sand­ members-lower, middle, and upper. The lower member con­ stone, clark-gray fissile fossiliferous shale, and some limestone. sists predominantly of d-ark-brown silty to argill-aceous lime­ T·,vo conspicuous unconnected conglomera tic facies are found stone that is commonly laminated. It is recognized over a much in the lower part of the Schuler Formation; one is updip in wider region, particularly in downdip areas, than the middle the nonmarine facies and the other is downdip in the marine and upper members. The middle member, which is predomin­ facies. antly dense limestone, and the upper member, which is pre­ INTRODUCTION dominantly oolitic limestone, are confined to the north margins of the gulf coast embayment in the report area. Southward from The Upper Jurassic rocks are entirely subsurf~e downdip areas the middle and upper members grade laterally units that underlie much of the gulf coast embayment into the Bossier Formation. The Buckner Formation, which in the report area is confined in eastern Texas, southern Arkansas, Louisiana, central to the north margin of the gulf coast embayment, is divided and southern Mississippi, and southwestern Alabama informally into lower and upper members. The lower member, (fig. 1). The Smackover and Buckner Fonnations and which consists mostly of anhydrite and anhydritic mudstone, the overlying Cotton Valley Group which is comprised was deposited in a narrow basin that paralleled the margin of of the Bossier and Schuler Formations are definitely the embayment. It is apparently limited along its south side by of Late Jurassic age. The Norphlet Formation is also a series of salt-cored anticlines that were forming at the time of deposition and were partly responsible for restricting the generally believed to be of Late Jurassic age, but its outflow of hypersaline water from the marginal basin. The lack of fossils makes determination more difficult. It upper member, which consists mostly of mudstone and shale, is overlies the Louann Salt of Jurassic ( ?) age. The Cotton found throughout the area of the lower member and even Valley Group is overlain by the Hosston Formation of farther south where it is thickest. It is apparently limited on Early Cretaceous age. the south by a second series of anticlines. An earlier concept fua:t reef growth within the Smackover Formation was the The Upper Jurassic rocks lie at depths of 1,000-3,000 principal cause of evaporite deposition in the Buckner Formn­ feet at their north edge in southern Arkansas and north­ tion now seems to be incorrect. eastern Texas, at about 12,000 feet in northern Louisi- E1 E2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

gs• 36·r------~------~------~ ' TENNESSEE \ I OKLAHOMA r ARKANSAS I

~----t.I SO___ 100..J I MILES

GULF oF 28·~--~L_------~

FIGURE 1.-Area of report (crosshatched) in relation to approximate updip limit of Upper Jurassic rocks and to present major structural features of gulf coast embayment. ana and eastern Texas, and at even greater depths in tion of new structural concepts. Further investigations central Louisiana and southeastern Texas where they into the petrography and origin of each unit are under­ have not been penetrated by drilling. In southern way, and reports on these subjects are planned. The Mississippi rocks of Late Jurassic age have been found revision of stratigraphic· nomenclature in this report below 20,000 feet. The Upper Jurassic rocks maintain includes a rank change of one unit and the redefinition relatively uniform thicknesses in downdip areas, but of several formations. The impracticability of using the they thin to a featheredge along the northwest, north, same formational nan1es for widely different sedimen­ and northeast margins of the gulf coast embay1nent. tary facies is demonstrated. No new formal terms are The thickness of the Upper Jurassic rocks in the report proposed and an attempt is made to follow original area is shown in figure 2, and the structural and strati­ definitions. graphic relations between the northern (updip) and The nmnenclature used here is based primarily on the southern ( downdip) parts of the report area are a study of rocks in the western part of the ancestral shown in figure 3. The nearest outcrops of Upper J u­ north Louisiana basin and of rocks on the ancestral rassic rocks are in the Malone Mountains of south west­ Sabine uplift and, therefore, may not be entirely suit­ ern Texas, and in Mexico and Cuba. able for use in the east Texas basin or in other parts of the gulf coast embayment. Each basin within the PURPOSE AND SCOPE gulf coast embayment has a somewhat distinctive de­ This report presents a revised nomenclature and some positional and lithologic character. Formational unit new stratigraphic interpretations made on the basis of names, such as Smackover and Schuler, may be gener­ new data, the reevaluation of old data, and the applica- ally applied throughout the embayment, but to a large UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E3

ishes, La. The total area is approximately 9,800 square miles. STRUCTURAL SETTING The tectonic elements that existed in the gulf coast embayment during Late Jurassic time have remained unchanged to the present, except that their axes have shifted. During the Late Jurassic Epoch the Sabine uplift occupied the west half of the present report area and the north Louisiana basin occupied the east half. The axis of each tectonic feature shifted eastward, however, so that the pre.sent Sabine uplift occupies most of the report area 'and the north Louisiana basin lies directly to the east of the uplift (fig. 1) . Both the ancestral and present Sabine uplifts are separated from the north margin of .the gulf coast embayment by a northeast-trending extension of the east Texas basin. Smaller basins have been formed along the margins of the gulf coast embayment because of the concurrent growth of synclines and anticlines. According to Born­ hauser (1958), gravitational flowage of the underlying Louann Snlt formed many of these folds, but some folds, according to Fowler (1964), resulted from other tectonic activity. Parts of the Mexia-Talco and south Arkansas fault systems and other normal faults are present in the report area (fig. 1). The Mexia-Talco fault system borders the north margin of the enst Texas basin and apparently extends into the report area from the west in southern Bowie County, Tex. The .south Arkansas fault system extends from ,the southwest corner of Arkansas, east and northeast across Miller and Lafay­ ette Counties in the report area, and then eastward across south-central Arkansas. These fault systems and the Pickens-Gilbertown fault system of Mississippi and Alabama are generally parallel to and south of the northern limit of Upper Jurassic rocks in the gulf coast EXPLANATION embayment. Control wells --3500-- • Isopach Many of these faults bound grabens that formed near Entire Upper Jurassic Dashed where approximate. penetrated Interval 500 feet the crests of anticlines. Movement along these faults was / associated with the formation of salt domes or salt­ Upper Jurassic cored anticlines during the Late Jurassic. Another large partly penetrated fault, the Rodessa, .strikes northeastward across Marion FIGURE 2.-Isopach map of Upper Jurassic rocks and locations County, Tex., and adjacent parts of Louisiana and of major ancestral structural features. Arkansas (fig. 1). METHODS extent they must be redefined in each local basin or other Rotary drill cuttings and (or) cores were examined names must be applied _(Murray, 1961, p. 290). from 40 wells. Electric logs from 39 of these wells and The area of this report lies in the northwestern and from an additional 150 wells were studied. For well north-central parts of the gulf coast embayment (fig. names and locations see Dickinson ( 1968}. Supplemen­ 1) and includes Bowie, Cass, ~!arion, Harrison, Panola, tary data were obtained from commercial sample logs, and Shelby Counties, Tex.; Lafayette and Miller especially if samples were not available to the author. Counties, Ark.; and Bossier, Caddo, and DeSoto Par- Where interpretive sample logs based on commercial ~

Southwestern Northwestern Louisiana · FEET BELOW Arkansas (downdip area·-North SEA LEVEL (updip area) Louisiana basin) 26 18 19 22 24 25 28 29 30 31 33 34 4000

Coalescing 5000 sandstone ~ units in 0 Schuler ;:c r-3 6000 Formation t<_:j ;:c n 7000 0

~;:c 8000 TOP OF I JURASSIC ·~:-· o " " __ H ==· 0 t:d Marine I -,;---~~~~--~=:;t- ~ 9000- facies Schuler H 0z lJ). 10,000 r-3 Bossier Formation 0 c 11,000 t<_:j 0 5 10 MILES ,...,,, -- ~ t:rrrut:r;~;; ~------~"N hi ------;:c 12,000 VERTICAL EXAGGERATION orp et Formation > X 20,8 t"l c EXPLANATION t<_:j 33 Well No. ------0 --R------R------R- t"l Formation boundary Member or informal boundary Facies boundary Boundary of updip 0 Dashed where approximate Dashed 1vhere approximate red sandstone beds ~ 1Total depth Well projected to line of section 1 Of Sloane (1958)

FIGURE 3.-Diagrammatic cross section of Upper Jurassic rocks showing structural and stratigraphic relations from margin to deeper part of gulf coast embayment. UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TE~AS, LOUISIANA, ARKANSAS E5 percentage logs are presented in the illustrations of th~s samples are highly interpretive and may not be logged report (pl. lA, B, 0), the interpretations shown are in the ,same way by other geologists. Little credence was those of the author. All rota.ry drill cuttings from wells given to those sa1nples that appeared to be excessively in the report area were contaminated from caving contaminated. The wells from which data were taken farther up the hole; consequently, logs made from these for plate 1 and figure 3 are listed in table 1.

TABLE 1.-Names and locations of some wells in adjacent parts of Texas, Arkansas, and Louisiana

Derrick floor No. on pl. 1 and fig. 3 Company Well name and No. Location elevation (feet above sea level)

TEXAS Bowie County

1______W. M. Coats ______S. H. Hall L ______Bowie County School 376 Land. 2 ______W. T. Phillips and others ______T. & P. Railroad l______J. Kittrell A-329______374 3 ______Ray and others ______P. S. Cork L ______M.E.P. & P. RR. Co_____ 368 4 ______Cities Service Petroleum Co ______Johnson "Y" 1______John Maulding A-399____ 343 5 ______Tidewater Oil Co ______I. G. Talley L------J. S. Herring A-263______291 6------Gulf Oil Corp ______J. Veatch 1______Jacob McFarland______240

Cass County

7 ______Shell Oil Co ______J. M. Lasater L ______H. R. Latimer A-650 ___ _ 354 8 ______Trunkline Gas Co ______C. M. McWhorter and others L _____ W. Wimberly A-1133 ___ _ 346 9 ______H. L. Gist and Herring Drilling ____ _ T. R. Harrell L ______J. Styles A-939 ______364 10 ______Texaco, Inc______M. C. Thompson!______B. M. Dorriss ______455 11 ______Sunray Mid-Continent Oil Co. and T. J. Mays !______W. Sonaho A-250 ______309 others. 12 ___ ------Humble Oil & Refining Co ______South Atlanta Gas Unit !______Ciriaco Conti A-238 ____ _ 304 13 ______Pan American Petroleum Corp ______Giraud Gas Unit L ------G. S. Young A-1161_ ___ _ 347

Harrison County

14 ______Pan American Petroleum Corp ______Davis Gas Unit A-2 ______L. Watkins A-750______283

Marion County

15 ______San Jacinto Oil & Gas Co ______M. Cowherd 1______C. Massenton A-289_____ 311

Panola County

16 ______Chicago Corp ______Allison Bros. L ______J. Hughes A-278 ___ ----- 297

ARKANSAS Lafayette County

Section Township Range W. s. 17 ______Arkansas Louisiana Gas Co ______H. F. Russell L ______- _ 3 15 25 251 18 ______T. M. Evans and others ______Osborne L ______16 15 24 281 19 ______D. Crow and G. B. Christmas ______Alford L ______25 16 25 234 20 ______L. Taubel and others ______Tatum 1______18 16 22 255 2L ______Coulston Drilling Co ______Cornelius Est. l______---- _ 32 16 23 271 22 ______Janlyn Oil Co ______Barker 1______34 17 25 227 23 ______Janlyn Oil Co ______Cabe L ______- ______------1 18 24 264 24 ______Tennessee Gas Transmission Co _____ M. Friend______---_ 9 19 25 255 25 ______Austral Oil Co., Inc., and Olin Gas International Paper Co. 1______34 19 24 248 Transmission Co.

Miller County

26 ______McAlester Fuel Co ______S. Hervey A-L ______Sec. 1, T. 15 S., R. 26 W_ 252

288-724-68--2 E6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

TABLE 1.-Names and locations of some wells in adjacent parts of Texas, Arkansas, and Louisiana-Continued

Derrick floor No. on pl. 1 and fig. 3 Company Well name and No. Location elevation (feet above sea level)

LOUISIANA Bossier Parish

Section Township Range W. N. 27 ______Co ______1 ______Carter Oil E. Smith 1 ______2 23 13 262 28 ______Barnsdall and Sohio Oil Cos ______Carter Burton 26 23 13 368 29 ______Feazel Interests and others ______L. English L ______-- ______Co ______1 ______33 22 12 341 30 ______Carter Oil Crystal-Whited 26 21 12 241 31 ______Union Producing Co ______1 ______Modica 1 ______32 19 13 231 32 ______Phillips Petroleum Co ______Kendrick 22 19 11 231 33 ______Union Producing Co ______1 ______34 ______Section 13 Unit 13 17 12 200± Gulf Refining Co ______Hodges 20------24 16 12 172

Caddo Parish

Section Township Range W. N. 35 ______Co ______Pitts 5 ______--_____ ------36 ______Arkansas Louisiana Gas M. 1 ______11 23 16 244 R. W. Norton ______Paynes 27 23 16 231

ACKNOWLEDGMENTS middle members are approximately equivalent to Discussions of the stratigraphy with several geologists the lower and middle parts of the formation as de­ were helpful in the formulation of concepts presented scribed by Weeks; the upper member is generally in this paper. Many others lent substantial aid by the same as his Reynolds oolite zone except that it providing well information and samples. Especially locally contains additional oolitic beds and dolo­ helpful were Robert W. Eaton, independent geologist; mite. Only the lower member can be recognized James W. Harrison, Pan American Petroleum Corp.; throughout the report area. In the ancestral north Jim H. Cox, Phillips Petroleum Co. ; and William "'\V. Louisiana basin and on the ancestral Sabine uplift, Brewton, Humble Oil & Refming Co. strata equivalent to the middle and upper members consist of dark-gray shale and are in the present NOMENCLATURE report included in the Bossier Formation. 3. The Buckner Formation is used here as described The nomenclature of Upper Jurassjc rocks in this by Weeks (1938) and not as a member of the area has been controversial and has been subject to peri­ Haynesville Formation as proposed by Philpott odic revision because new drilling continually produces and Hazzard ( 1949). The Buckner includes those more information. The history of nomenclature together rocks overlying the Smackover Formation and un­ with that used here is shown in figure 4. The usages derlying the Cotton Valley Group as these units adopted for this paper and the justification for changes are defined herein. The Buckner is divided into are presented as follows : two informal members-an upper member that is 1. The Norphlet Formation is used here as originally predominantly red mudstone and a lower member defined by Hazzard, Spooner, and Blanpied (1947) that is predominantly anhydrite. The members are to include strata overlying the Louann Salt and easily separable on sample and electric logs except tmderlying the Smackover Formation. in the eastern part of Lafayette County, Ark., 2. The term Smackover Formation is used here for the where the entire formation is thin, and along the unit originally defined by Weeks (1938, p. 964) as downdip limit of the lower member in Cass County, the Smackover Limestone. In the present report Tex., where the upper member is more evaporitic. the Smackover Formation includes strata overly­ The term Buckner will not be applied to beds of ing the Permian ( ~) Eagle Mills Formation and equivalent a.ge of offshore marine origin because underlying the Buckner Formation; the Smack­ the evaporites, which characterize the Buckner, over is herein divided into three informal mem­ were deposited only in linear basins around the bers-lower, middle, and upper. The lower and margin of the Gulf Coast embayment. Weeks imlay Swain Hazzard, Spooner, Philpott and Shreveport Geol. Forgotson Mann and Thomas . (1938) (1943) (1944, 1949) and Blanpied (1947) Hazzard (1949) Society (1953a, b) (1954) (1964) ThiS report ~ -c ..-. Dorch eat Knowles 8 t"'.l .Q p;j 1U lij 1: Member Limestone E ro a. a. a. c." ~ Cto ton a. ._ c ·- :::1 :::1 :::1 :::1 c ~______,. a. ~ Valley Formation g Lf .!!! -g e Schuler e Schuler e Schuler e ._g ::I c:: (T"+h . .._ c ro (.!) (.!) (.!) (.!) ro H" Sh I 8 o I. onl~n, (.!) ~ _g t: >. Formation >. Formation >. Formation >. E ICO a e (5 ~ Ul Cotton . Portlandian, ~ ~ ~ ~ Shongaloo ~ ~ ~ ~ 1 ~ >. Schuler 0 Ul Valley Format1ont and = u...... Member Not discussed ~ ~ co co LL. ~--- ~ Formation 1-f 8 9 (Mesozoic) Kimmeridgian4) ~ cn c: c: ~ ~ ~ Terryville • ~ c c: .£ o o o ::J Sandstone c: o +-- :::: :::: ::::.r::~o ~ 8 8 8 8 ~ ~ 1 Bossier Bossier Bossier ~~Jir Bossier c7l Bossier 8 ~ ~ f\ Form~tion Formation Formation Formation Formation ~ t-1 1(Portlandian and ~ ·- -'------~ s \ K" "d · 4) "> ~ r..--...... --.._--....-.___...... !.J..J..""J ~ r'l 1m men g1an ~ _ ~ p tongue~ '"' Haynesville Haynesville c :(' Formation Formation ..g Upper .; Buckner Haynesville . E memberS c -~ Formation1 Buck~er Buckner Formation Not discussed o < ..g (Mesozoic) :Forma.tlo~ 6 Formation Buckner Buckner ~ ~ 4 E Buckner (Kimmendglan > Membe r a. M em b er cQ) Lower '-o ~ Formation at base :::1 at base ti member u.. ~ (Kimmeridgian4,5) e ~ ~ Reynolds ~ (.!) ------... 1-3 oolite Reynolds Reynolds Reynolds c Upper .~ zonez oolite2 oolitez oolite2 ..g member· ~ ~ e ~ ~1-3 co ... Ul Smackover Smackover Smackover Smackover Smackover g Smackover Lf Middle Limestone 1,3 Formation Formation Limestone Formation -J Formation ~ member 0 4 l:zj (Mesozoic) (0xfordian4) (Oxfordian ) Not discussed Not discussed ~ 1-----""::__­ u 1-3 Lower E Lower member cn member ~ ~ -?~ ~ ? ~~~------~~------+------1 -~ EFagle ~ills Eagle Mills Eagle Mills Norphlet Norphlet Norphlet Norphlet ~ ormation Formation F0 rmation · · 0 (Permian') (O f d" 4) • Formation Formation Formation Formation · x or 1an (0xfordlan4) 1-- 9 UJ. 1 Preliminary description published by Shearer (1938) after approval by Shrev~port Geological Society 2 Of local usage j 3 Term first appeared in Bingham (1937) 4 European Upper Jurassic stages s Imlay (1952) put the Buckner in the Oxfordian as a Smackover equivalent ~ 6 Considered the Buckner Formation as passing downdip into the upper part of the Smackover Formation 7 Recognized Dorcheat and Shongaloo Members of Schuler Formation, which is restricted to the northern or near-shore part of the area 8 Restricted to the southern or offshore area UJ.~ 9 Includes proposed Cadeville, Bodcaw, Vaughn, McFearin, and Justiss Tongues UJ.>

FIGURE 4.-History of nomenclature of Upper Jurassic rocks in gulf coast embayment. Dashed lines are used for contacts not discussed.

t_:rj '-1 E8 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

4. The Haynesville Formation of Philpott and I-!azzard well, faulting that seems to be confined to beds (1949), as defined by them, is not used because older than the Cotton Valley, and the extreme (1) it includes a widespread identifiable unit, the range of thickness of beds older than the Cotton Buckner Formation, (2) its upper part is litho~ Valley indicate that a regional unconformity ex­ logically 1nore like rocks of the Cotton Valley ists at the top of the Haynesville Formation. As Group, (3) apparently no regional unconformity discussed above, the colors are not stratigraph­ or distinct lithologic break is present at its top, and ically consistent and the other conditions are better ( 4) the Buckner Formation is not equivalent to explained by the growth of salt-cored anticlines any part of the upper rocks originally included in concurrent with deposition (Bornhauser, 1958; the Haynesville Formation. The Haynesville was Dickinson, 1963). As was recognized by Sloane defined to include the Buckner Formation of Weeks ( 1958, p. 6), the variable thickness of the Haynes­ (1938) as a member and the lower part of the over~ ville Formation need not be the result of post­ lying Cotton Valley Group (Goebel, 1950; Chap~ Haynesville erosion. Bornhauser (1958, p. 352) man, 1951). The rocks included in the Haynes~ stated, "All anticlinal folds in the western ville Formation are here separated into the Gulf Coast show a marked thinning over their Buckner Formation and the Cotton Valley Group crests and a corresponding thickening of section in accordance with W ee:k's original usage (fig. 4). down their flanks into adjacent synclinal areas." Retention of the Buckner as a formational unit l-Ie also stated that "this thickening may increase is desirable because it is lithologically more per­ as rapiclly as 200 to 300 percent per mile." sistent and is recognizable over a much wider area The faulting which, according to Chapman than is the Haynesville Formation. Characteristic ( 1951), characterizes pre-Cotton Valley strata is sections of the Buckner Formation have been de­ found only in the crestal grabens of salt-cored scribed in central Mississippi by Djckinson (1963) antielines in the East Haynesville and nearby Col~ and on the west side of the East Texas basin by quitt oil fields (Shreveport Geological Society, Swain (1949), both sections being far removed 1953b, p. 63; 1958, p. 186). These anticlines are from the present report area. known to have formed because of flowage of con­ The predominant lithology of the Haynesville tained salt. The upper limit of the faulting is con­ Formation, except the Buckner Member, is trolled, therefore, by the time of salt movement, white, light-gray, or pink fine-grained sandstone as pointed out by Bornhauser (1958, p. 360), and and gray shale very similar to parts of the overly­ is not directly related to a regional tectonic episode. ing Cotton Valley Group. That the red color of Correlation of electric and sample logs shows the Haynesville rocks can be used to differentiate that the updip parts of the Buckner Formation then1 from overlying rocks of the Cotton Valley underlie, and are not equivalent to, the downdip Group as claimed by Goebel (1950) and Chapman clastic rocks of the I-Iaynesville Formation (pl. ( 1951) can be true only locally. For example, at the l.A., B). In some areas the Buckner Formation is type section of the overlying Schuler Formation missing, but this is apparently due to nondeposi­ (Swain, 1944), a basal red sandstone of the Schuler tion or local erosion at the end of Buckner deposi­ overlies white to gray sandstone of the Jones tion (Goebel, 1950). sand (local usage) which according to Goebel For all the foregoing reasons the name Haynes~ ( 1950) is part of the Haynesville Formation. White ville ought to be abandoned for regional use as a and gray sandstone was reported by Swain (1944, rock-stratigraphic unit. Such action is not taken p. 593) just above the Buckner Formation in the now, however, because the na1ne may be useful Ohio Oil Co. Taylor well 15, sec. 15, T. 23 N., R. locally and because correspondence with E. G. An~ 8 W., Claiborne Parish, La. No red sandstone in one derson, Louisiana Geological Survey, indicates well and only 40 feet of red sandstone in another that he believes the name is useful. well was reported in the Haynesville Formation 5. The Bossier Formation is redefined to cmnprise the in vVebster Parish, La., by Martin, Hough, Raggio, original formation as defined by Swain ( 1944, p. and Sandberg ( 1954, p. 33-34). A preponderance of 591) and the underlying sequence above the lower white, light-gray, and tan sandstone and only a 1nember of the Smackover Formation as used in minor amount of red sandstone were found in the the present report (pl. 1B). This interval of rocks Haynesville Formation in several wells in the vicin­ lies between depths of 8,140 and 8,627 feet in the ity of the Haynesville oil field. type well, Phillips Petroleum Co. Kendrick well 1, According to Chapman (1951) and Goebel sec. 22, T. 19 N., R. 11 W., Bossier Parish, La. (1950), the color change, steep dips in at least one (pl. 1B, no. 32 on cross section). Redefinition is UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E9 necessary because the added basal sequence con­ nized on the ancestral Sabine uplift. Also, the sists of dark-gray calcareous shale very similar double usage of some names has caused confusion. lithologically to the overlying Bossier Formation The name applied by Mann and Thomas for each in the type well and because the added sequence is tongue of the Terryville, except the Bodcaw, was easily differentiated from the Buckner Forn1ation taken from one of several informal units within or the underlying lower n1ember of the Snlack­ the tongue. The Cadeville Tongue, for example, is over Formation. The basal sequence, herein added not the same stratigraphic unit as the Cacleville to the Bossier, was referred to by Swain ( 1944, sand of infonnal usage, and, further, the Cadeville p. 592) as the Buckner Formation, by Imlay Tongue is found in areas where the Cadeville sand (1943, p. 1429) as "marine beds probably equiva­ is not present. The term Bodcaw was proposed lent to the Buckner Forn1ation," and by Arper prior to the work of 1\fann and Thomas by Sloane ( 1953) as the Smackover Formation. The rede­ (1958). fined Bossier Formation is virtually the same as 7. The Cotton Valley Group is used here as originally that proposed by Mann and Thomas ( 1964). defined by S·vvain ( 1944) to include the Bossier The tongue of the Bossier Formation that ex­ and Schuler Formations. tends updip into the Schuler Formation is infor­ 8. The Louark Group is not used here because it is not mally referred to here as the Q tongue (fig. 4, adequately defined. In the original usage by the pl. 1A, B). Shreveport Geological Society ( 1953b, p. 63), the 6. The Schuler Formation is redefined to include the Louark Group consisted of the Norphlet, Smack­ original fonnation as defined by Swain (1944, p. over, and Haynesville Formations. 598) and an additional underlying sequence. In the type well, Lion Oil Refining Co. and Phillips STRATIGRAPHY Petroleum Co. Edna ~forgan 1, sec. 18~ T. 18 S., NORPHLET FORMATION R. 17 vV., Union County, Ark., the original Schuler Formation extends fron1 depths of 5,410 to 7,475 The Norphlet Fonnation consists of 34 feet of red and feet; in the present report it is extended to a depth gray shale in reel and gray partly conglmneratic sand­ of 7,600 feet. The added sequence, which is mostly stone at the type section in the Gulf Refining Co. "\V en1er light-gray sandstone and dark-gray shale, extends Saw l\iill Co. well 49, sec. 5, T. 16 S., R. 16 W., Union to the south beneath the Q tongue of the Bossier County, Ark. In the report area, although sample data Formation; this unit is informally referred to here are sparse, it consist9 of light-gray to brown, friable, as the P tongue of the Schuler Formation. It was poorly sorted sandstone and conglomeratic sandstone, included in the Bossier Formation by Swain gray shale, and anhydrite. The Norphlet Formation (1944), and part of it was included in the Haynes­ ranges in thickness from 15 to about 70 feet in the area ville Fonnation by Goebel ( 1950). The Jones sand but it is generally about 50 feet thick. According to Haz­ of local usage is included in the P tongue. The zard, Spooner, and Blanpied (1947), it unconformably present nomenclature provides a clear lithologic overlies the Louann Salt and conformably underlies the separation; it places nearly all interbedded sand­ Sn1ackover Formation. The relation of the Norphlet to stone and shale in the Schuler and all dark-gray the updip sections of the Eagle Mills Formation of marine shale that is devoid of sandstone in the vV eeks ( 1938) is unknown. Bossier Forn1ation. The Shongaloo and Dorcheat SMACKOVER FORMATION Members proposed for the Schuler Formation by Swain ( 1944) are not used in this report. The Smackover Formation consists of gray to brown The do·wndip marine part of the Schuler For­ dense and oolitic lilnestone (pl. 1A, B). Fossils-mostly mation to the south (pl. 1A, B) was divided into algae, forams, and mollusks-are common but not three formations-the Terryville Sandstone, the abundant in the Smackover. The lower member is dark­ Hico Shale, and the Knowles Limestone-by l\iann gray argillaceous silty lin1estone, the middle member is and Thomas ( 1964). They also named five tongues brown dense limestone, and the upper member is light­ of the Terryville Sandstone, which are, in ascend­ brown to dark-gray oolitic, pisolitic, and intraclastic ing order-the Justiss, the McFearin, the Vaughn, limestone that is commonly porous. The upper member, the Bodcaw, and the Cadeville. These terms are from which much petroleum is produced, has been do­ not being used in this report because of the cmn­ lomitized to various degrees in the northwestern part of plex intertonguing between some of them and be­ the report area. A reference section of the Smackover cause they are not present or are not easily recog- frmn the report area follows. ElO SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Reference section of the Smackover Formation and partial sections THICK~'ESS AND DISTRIBUTION of adjacent formations The Smackover Formation generally thickens from [Logged from cuttings; Pan American Petroleum Corp., Giraud Gas Unit well 1, its updip edge southward to the north margins of the George S. Young Survey A-1161, Cass County, Tex. Derrick floor elevation, 347 feet above sea level] ancestral Sabine uplift and the North Louisiana basin, Thick- except where it thins locally over anticlines (fig. 5). ness IJepth (feet) (feet) Southward from the north margins of the North Louisi­ Buckner Formation-upper member ana basin and the ancestral Sabine uplift the upper and (lower part): middle members of the Smackover grade rapidly into Shale, reddish-brown, silty, anhy- dritic; white to reddish-brown, the Bossier Formation and only the lower member per­ finely crystalline anhydrite ______10, 915-11, 060 145 sists (pl. l.A., B). The maximum recorded thickness of Dolomite, tan to gray, dense ______11, 06D-11, 07 5 15 the Smackover in the report area is 1,292 feet in north­ Smackover Formation-upper member: ern Bossier Parish, La. (fig. 5). The north edge of the Limestone, medium-dark-gray, non­ formation trends eastward across northwestern Bowie porous, oolitic, pisolitic, and very dolomitic with fine dolomite County, Tex., and north of the report area it trends rhombs in matrix having a trace eastward to northeastward (Vestal, 1950; Arper, 1953). of sparry cement and intraclasts; medium-dark-gray, sugary dolo- STRATIGRAPHIC RELATIONS mite containing a few relict The Smackover Formation conformably overlies the oolites ______11, 075-11, 119 44 Norphlet Formation in most places, but it may discon­ Limestone, medium-brown, dense, arenaceous, pelletoid; containing forinably overlie the Eagle Mills Formation of Hazzard, abundant scattered fine dolomite rhombs, a few oolites, and a few anhydrite inclusions______11, 119-11, 202 83 Smackover Formation-middle member: Limestone, medium- to dark-gray, dense, silty, fossiliferous, contain­ ing scattered fine dolomite rhombs and anhydrite nodules______11, 202-11, 230 28 Limestone, grayish-brown to dark­ grayish-brown, slightly fossilifer­ ous, dense, slightly arenaceous, pelletoid; containing some an­ hydrite, dolomite, and a few euhedral quartz grains______11, 23D-11, 437 207 Limestone, mottled brown, dense, platy, somewhat arenaceous, fossiliferous, containing very deli­ cate concave shells and argilla- ceous partings______11,437-11, 733 296 Smackover Formation-lower member: Limestone, tan to dark-brown, platy, partly laminated, partly pelletoid, containing foraminifers______11, 733-11, 890 157 Limestone, light-gray to dark­ brown, dense, silty, laminated, containing much pyrite and a little native sulfur______11, 89Q-12, 007 117 EXPLANATION Total, Smackover Formation ______• ---400--- 932 Control well ---500--- Norphlet Formation (upper part): Isopach Sandstone, tan, unconsolidated, Dashed where approximate IntervallOOjeet generally fine-grained and an­ gular but containing a few FIGURE 5.-Isopach map of Smackover Formation in area coarse subrounded grains______12, 007-12, 030 23 where upper member is present. UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS Ell

Spooner, and Blanpied (1947) in some updip areas. The and was not found in every well, but where laminated Smackover is conformably overlain by the Buckner limestone is not found, the lower member can be recog­ Formation in much of the updip area. In most downdip nized because of its dark-brown color and silty or areas the Bossier Formation conformably overlies the argillaceous character. lower member of the Smackover Formation; in a nar­ The thickness of the lower member ranges from 49 row belt along the north margin of the ancestral North feet in southern Bowie County, Tex., to 369 feet in south­ Louisiana basin the Bossier lies directly on the upper western Bossier Parish, La. The thickness is somewhat member of the Smackover. arbitrarily determined in a few wells, because the mem­ The hypothesis that the Buckner Formation is a back­ ber grades upward into the dense limestone of the mid­ reef deposit of the Smackover Formation has long been dle member of the formation or into the Bossier popular (Hazzard, 1939; Ballard, 1964). This hypoth­ Formation. esis embodies the following concepts: The lower member is recognizable over a much wider 1. The deposits of the reef zone are represented by the region, particularly downdip, than the middle and up­ upper part of the Smackover Formation itself. per n1embers. Although its limits west of the project 2. Both the upper part of the Smackover and the lower area are unknown, it is recognized as far east as member of the Buckner are progressively younger southeastern Mississippi. basinward. 3. During the deposition of the lower member of the MIDDLE MEMBER Buckner its depositional basin migrated seaward. The middle member of the Smackover Formation 4. The Smackover "reefs" restricted the flow of sea consists predominantly of dense brown limestone that water that resulted in the deposition of the Buck­ commonly contains anhydrite. It is also locally dolo­ ner evaporites. mitic, pelletoid, stylolitic, fossiliferous, oolitic, or silty. The back-re.ef hypothesis is now believed by the The upper part of the middle member is dolomitized in writer to be incorrect for the following reasons: the northwestern part of the report area where the 1. The relatively uniform thickness of the Smackover upper member is also dolomitized. The middle member Formation is not consonant with reef growth varies in color from light to dark brown to dark gray. (fig. 5). It is usually lighter in color in the upper part and in 2. The Smackover Formation does not consist of reef­ updip areas. type rock. Only a small part of the total volume of The middle member includes an updip and a down­ the rock consists of fossils. According to Wells dip clastic facies. The updip facies is found in the vicin­ (1942), the few corals that have been found in the ity of the Eylau field in eastern Bowie County, Tex., Smackover are not reef corals. where it consists of pink, tan, gray, and reddish-brown sandstone and reddish-brown siltstone and mudstone 3. A typical evaporite basin has an inner salt facies (Swain, 1949, p. 1213-1214}. The downdip clastic facies surrounded by an anhydrite facies and an outer is found in northeastern Bossier Parish, La., near the carbonate facies (Briggs, 1958). This distribution downdip limits of the member. This facies consists of of lithofacies is the result of deposition in a sta­ light- to dark-gray fine-grained somewhat calcareous tionary basin rather than in a migrating basin. The lithofacies in the lower member of the Buckner sandstone, dark-gray silty platy to fissile fossiliferous calcareous shale, gray hard silty fossiliferous siltstone, Formation approximates this distribution (fig. 7), and it is therefore concluded that the Buckner was and gray hard silty fossiliferous limestone. In Kinsey and Kinsey C.A. Antrim well 1, sec. 30, T. 22 N., R. not deposited in a basin that was migrating sea­ ward as the reef hypothesis demands. 11 W., Bossier Parish, La., 512 feet of core from the middle mem·ber consists of 36 percent sandstone, 35 per­ 4. The barrier that restricted the flow of sea water, cent shale, 19 percent limestone, and 10 percent silt­ which resulted in the deposition of eva porites, stone. The middle member grades into the Bossier For­ apparently was a series of salt-cored anticlines that formed concurrently with deposition (fig. 9}. mation, south of Marion County, Tex., and south of northern Caddo and Bossier Parishes, La. LOWER MEMBER The sparse data available indicate that the middle The lower member of the Smackover Formation is member makes up about two-thirds to three-fourths of composed of dense dark-brown silty to argillaceous the total thickness of the Smackover Formation. The slightly fossiliferous limestone and calcareous siltstone thickness trends of the middle member are about the that is commonly laminated and pelletoid. The lami­ same as those of the total Smackover. From an edge in nation is difficult to recognize in rotary drill cuttings northern Bowie County, Tex., the member thickens El2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY southward to a maximum of 790 feet in northern Bossier The depositional facies roughly parallel the margin Parish, La. It is only 319 feet thick on the north flank of the gulf coast embayment. These facies, from north of the ancestral Sabine uplift in central Marion County, to south, are as follows: A, a light-brown to light-gray and it apparently is also thinner over local anticlines. oolitic limestone facies; B, a light- to medium-brown oolitic, pisolitic llinestone facies; C, a dark-gray oolitic, UPPER MEMBER pisolitic limestone facies; :and D, a dark-gray oolitic, The upper member of the Smackover Formation is pisolitic limestone facies containing interlensing beds of characterized by oolitic limestone that also commonly light-gray to white fine-grained sandstone. A fifth fa­ contains intraclasts, pisolites, anhydrite, solid hydrocar­ cies, north of facies A, may be an arenaceous nea,rshore bons, native sulfur, and various local sulfides and sul­ facies, but few data ,are available. fates. A dolomitized facies and four depositional facies The dolomitized facies underlies most of Cass and of the upper 1nember are mapped in the project area Bowie Counties, Tex., and northwestern Miller County, (fig. 6). Ark. (fig. 6). The botmdaries of this facies are indis­ tinct and small amounts of dolomitization are found outside the prescribed facies area. Most of the dolomite consists of fine secondary rhombs in the matrix of oolit­ ic rock. The oolites are generally not dolomitized, but smne samples are entirely dolomitized. Smne of the dolmnitized rock is nonporous and some has a cellular porosity that apparently formed where the calcitic oolites that remained after dolomitization were dis­ solved. The extent of dolomitization in the Smackover Fonnation corresponds approximately to the extent of the thick evaporite deposits of the overlying lower member of the Buckner Formation and may be geneti­ cally related to it (Halbouty, 1966). The thickness of the upper 1nember of the Smackover For1nation in the report area ranges from zero on the north to at least 261 feet in northern Bossier Parish, La., but it is generally less than 100 feet (pl.1A, B, D). The upper mmnber makes up about one-tenth to one­ fourth of the total thickness of the formation in this area, but greater proportions have, been reported else­ where (Swain, 1949, p.1214). In the S1nackover oil-field 0 5 10 15 20 MILES locality the upper 1nember constitutes about one-seventh I,, I I I I EXPLANATION of the total thickness of the formation C\V" eeks, 1938, p. 965). 0 ~ PALEOTECTONIC RELATIONS Light-brown to light-gray Areas in which depositional facies The lithology and the thickness of the Smackover oolitic limestone are wholly or partially obliterated by postdepositional dolomitization Fonnation were affected by local and regional struc­ 0 tural features that formed at the time of deposition. The Light- to medium-brown effect of local features is difficult to detennine because oolitic pisolitic limestone • Facies determined from sample of few closely spaced wells that penetrate the entire and electric logs fonnation, but som.e conclusions can be made. Accord­ ~ 0 ing to Arper (1953) the anticline at Texarkana oil Dark-gray oolitic pisolitic Facies determined from field (fig. 9) began to rise prior to the deposition of the limestone electric logs only Smackover Formation. The formation is apparently 0 thin over anticlines in southern and eastern Bowie Dark-gray oolitic pisolitic limestone County, Tex. (fig. 5). The effect of the ancestral Sabine containing interlensing beds of light-gray to white fine-grained. uplift on the thickness of the Smackover can be seen in sandstone Marion County, Tex., where a total thickness of only FIGURE 6.-Lithofacies map of upper member of Smackover 678 feet was penetrated (pl. 1A). The facies distribu­ Formation. tion was also affected by the uplift. The dark-gray UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E13

I oolitic-pisolitic li1nestone facies and the sandstone facies OKLAHOMA I ARKANSAS do not extend across the uplift (fig. 6). ('-"2-L~L LITTLE RIvER 1 TEXAS0 ~ BUCKNER FORMATION I • ';L-,.~~~~ \. ~---o-- _.....,... 1 "" According to Weeks ( 1938), the Buckner Formation ~o----J~o-7>New Bosto11e j, 1 • ~~-,;-::---, as described frmn the Buckner oil field is composed of V--...... _ PTexarkana c. • •. • --1 , • BOWIE • 1 three parts: a lower part that is predominantly anhy­ • '~ • -~ 4 ....r- ~...... ;;... . tions, and an upper part that is preclmninantly red N "t:._...... _ .• • • • ~.,.---1 oo~--LJ shale. In this report the upper part in general is taken ~;::------V

UPPER MEMBER The upper member of the Buckner Formation con­ sists largely of nodular anhydritic red mudstone at the Buckner oil field in northeastern Lafayette County, as well as in northern Lafayette and Miller Counties, Ark. Southward in the report area in southern Cass County, Tex., and near the Arkansas-Louisiana State line, the member contains various amounts of anhydrite, dolo­ mite, limestone, sandstone, and gray mudstone. It also contains a persistent bed of oolitic limestone, the A zone of local usage. The A zone, which is lithologically some­ what similar to the upper member of the Smackover Formation, is interbedded in the upper member of the Buckner near its downdip limits. This bed, or several lenticular carbonate and sandstone beds at about the same horizon, can be traced northwestward nearly to the northern border of Cas.s County, Tex. (pl. lD). Gray shale and carbonate increase in abundance in the upper member toward the downdip edge of the member. In southern Cass County, Tex., the A zone divides the upper member into an upper gray mudstone part and a EXPLANATION lower red mudstone part; in the southwestern part of • --400-- Cass County the shale in the entire upper member is Control well --ooo-- Isopach gray. B~------B' Main deposi­ Dashed where approximate lntervallOOfeet tional axis Partial section of the lower member of the Buckner Formation C ------C' Less conspicuous and the upper part of the Smackover Formation depositional axis [Logged from cores; Tidewater Oil Co. I. G. Talleywelll, J. S. Herring Survey A-263, Bowie County, Tex. Derrick floor elevation, 291 feet above sea level] FIGURE 8.-Isopach map of upper member o.f Buckner Formation. Thick­ nes~r Depth (feet) (feet) part of the basin where the greatest thickness of sedi­ Buckner Formation-lower member ments is deposited, an anhydrite facies surrounding the (lower part) : Anhydrite, light- to medium-gray and salt facies, and an outer carbonate facies around the pink, very finely crystalline to margins of the basin. microcrystalline, having a felty A maximum thicknes.s of 424 feet is reached by the appearance ______8,954-8,957 3 lower member of the Buckner Formation near a local Shale, reddish-brown, interbedded depositional center in north-central Cass County, Tex. with light-gray dense anhydrite and dolomite ______8,957-8,959 2 (fig. 7) . The depositional axis of the lower member Anhydrite, light-gray, microcrystal- trends generally eastward through northern Cass line, argillaceous, dolomitic ______8,959-8,962 3 County, Tex., and central Miller and northern Lafay­ Anhydrite, light-gray, having dis­ ette Counties, Ark. (fig. 7, A-A'). The northern limit coidal anhydrite nodules separated by thin layers of gray silty shale __ 8,962-8,964 2 apparently extends from west-central Bowie County, Dolomite, light-brown, containing Tex., along the northern border of Miller County and detrital grains(?) and nodules of through southern Hempstead County, Ark. The anhydrite ______8,964-8,965 1 southern limit extends through central Oa.ss County, Mudstone, light-reddish-brown, dolo- Tex., and south-central Miller and Lafayette Counties, mitic ______------8,965-8,966 1 Anhydrite, light-gray to light-brown, Ark. cryptocrystalline, dolomitic, pyrit­ The lower member of the Buckner Formation rests ic, having a waxy luster, partly laminated ______with apparent conformity on the Smackover Forma­ 8,966-8,973 7 Siltstone, gray, hard, dolomitic ____ _ 8,973-8,974 1 tion and is overla:in, as far as is known, by the upper Anhydrite, brownish-gray, microcrys- member of the Buckner. talline, having a waxy luster ______8,974-8,975 1 UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TE;xAS, LOUISIANA, ARKANSAS E15

Partial section of the lower member of the Buckner Formation and Section of the upper member of the Buckner Formation and part the upper part of the Smackover Formation-Continued of adjacent formations Thick­ [Logged from cores; Arkansas-Louisiana Oil Co. M. Pitts well 6, sec. 11, T. 23 N., neu Depth (feet) (feet) R. 16 W., Caddo Parish, La. Derrick floor elevation, 287 feet above sea level] Thick­ Buckner Formation-lower member {lower neal part) -Continued Depth (feet) (feet) Dolomite, light-gray, dense, contain­ Schuler Formation-P tongue (lower ing fine detrital(?) grains of anhy- part): drite ______8,975-8,977 2 Sandstone, medium- to light-gray, Anhydrite, medium-gray, microcrys- noncalcareous, somewhat anhy­ talline to cryptocrystalline, dolo- dritic; dark-greenish-gray and red mitic, silty______8, 977-8, 986 9 shale ______10,563-10,568 5 Buckner Formation-upper member: Total described______32 Shale, reddish-brown and dark­ greenish-gray, noncalcareous, Smackover Formation-upper member hard, containing a few thin layers (upper part): of anhydrite and dense gray dolo- Limestone, light-brown, oolitic, por­ mite, bearing Cyzicus sp______10, 568-10, 619 51 ous, containing much secondary Shale, grayish-red, containing nod­ dolomite and anhydrite in the up- ules of white to pink anhydrite per part______8, 986-9, 027 41 and small amounts of dense gray- The upper member of the Buclmer Formation reaches ish-brown hard dolomite______10, 619-10, 680 61 a thickne&S of 692 feet near an apparent local deposi­ Limestone, brown, partly oolitic, tional center in west-central Cass County, Tex., a few I containing some fine rhombs of miles southwest of the main depositional center of the dolomite; medium-gray, very lower member (figs. 7, 8). It reportedly is more than calcareous, nonporous siltstone containing scattered oolites______10, 68Q-10, 693 13 714 feet thick in Teneco and Barnhart Barker well 1, Shale, dark-grayish-red, green, and sec. 4, T. 20 S., R. 25 W., Lafayette County, Ark., but gray, containinganhydritenodules_ 10,693-10,702 9 this thickness is apparently found only in a narrow gra­ Siltstone, medium-gray, containing ben and is not plotted on figure 8. The unit thins north­ interbedded layers of white an- ward to an edge that trends northeast through north­ hydrite and dense gray dolomite_ 10, 702-10, 708 6 western Bowie County, Tex. The main depositional axis Shale, dark-grayish-red and green to gray mottled, containing nod­ of the upper member (fig. 8, B-B') is south of that of dules or beds of anhydrite as the lower member and trends east from west-central much as 1 inch thick______10, 708-10, 800 92 Cass County, Tex., through south-c~ntral Miller and Shale, dark-gray; gray, hard, very Lafayette Counties, Ark. Another less conspicuous dep­ slightly calcareous mudstone containing a few dark nodules of ositional axis (fig. 8, 0-0') is north of the main deposi­ pyrite ______10,80Q-10,818 18 tional axis and more closely coincides with the deposi­ tional axis of the lower member. The upper member Total, upper member (lower mem- extends 12-15 miles farther downdip than the lower ber absent) ______------250 member. Near the updip edge the upper member is very uniform in thickness (pl.10). Smackover Formation (upper part): The upper member is coexten.sive with the lower Limestone, medium-dark-gray, member except along the downdip margins where the slightly porous, finely oolitic_____ 10, 818-10, 822 4 upper member lies directly on the Smackover Forma­ area is in an extension of the ancestral east Texas basin tion. The contact with the Smackover may be uncon­ north of the ancestral Sabine uplift in W(\stern Cass formable along this narrow belt, but evidence to support County, Tex. The formation also is found around the a widespread unconformity is lacking. The member is margins of the ancestral north Louisiana basin where probably conformable with the overlying Schuler its distribution is apparently related to the locations Formation. of salt-cored anticlines.

PALEOTECTONIC RELATIONS The lower member is found only on ~the north or The thickness and distribution of the Buckner shoreward side of a seri(\s of salt-cored anticlines. These Form~tion are closely related to local and regional anticlines formed concurrently with desposition and structural features. The formation is absent on the were probably largely responsible for restricting the ancestral Sabine uplift and in the ancestral north outflow of hypersaline water from marginal basins and Louisiana basin. Its greatest thickness in the report for the deposition of evaporites within. This series of E16 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

ESSON

BOWIE

I

UTH SAREPTA' I

CADDO BOSSIER c!,} WEBSTER II CLAIBORNE I L, HARRISON I I l N 0 5 10 15 20 25 MILES EXPLANATION

~ .-.::::;;:)!HfU:· 1 Oil fields located on anticlines that were forming during deposition of the Buckner Formation Solid pattern shows anticlines limit­ ing downdip edge of member; stippled pattern slwws others A········· .. ·········A' B····················B' C····················C' Depositional axis of the lower Main depositional axis of the Secondary depositional axis of the member upper member upper member

///(///// Approximate southern (downdip) Approximate""""""""" southern (downdip) edge of the lower member edge of the upper member

Area where Buckner Formation is absent FIGURE 9.-Map showing relations of anticlines to southern ( downdip) edges and depositional axes of lower and upper members of Buckner Formation. anticlines extends eastwa.rd from central Miller County, series of anticlines (fig. 9). The A zone expands south­ through Lafayette, Colrunbia, and Union Counties, ward into a carbonate facies of the upper member and Ark. Several oil fields that are located on these anti­ extends for some distance south of this second anti­ clines include McKamie oil field in Lafayette County; clinal trend, but the evaporite-red shale facies is largely Dorcheat, Macedonia, Calhom1, Atlanta, and West restricted to the north or shoreward side. Oil fields Atlanta oil fields in Columbia County; and Schuler, found along this trend are the Lassater in Marion East Schuler, and Cairo oil fields in Union County, County, Tex. ; the Rodessa in Marion and Cass Counties, Ark. (fig. 9). Tex., Miller County, Ark., and Caddo Parish,. La.; the The upper member of the Buckner Formation thins Kiblah in Miller County, Ark.; the South Sarepta in or is absent over the series of the anticlines mentioned Bossier Parish, La. ; the Shongaloo in Webster Parish, in the preceding paragraph but extends farther south, La.; and the Haynesville, East Haynesville, Colquitt, and its downdip limit seems to be related to another and Mount Sinai in Claiborne Parish, La. UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TE~AS, LOUISIANA, ARKANSAS E17

Other anticlines such as the Antioch in Claiborne the ancestral North Louisiana basin. A reference section Parish, La., and the Mcl{amie-Patton in Lafayette of the Bossier from the ancestral Sabine uplift follows. County, Ark., were forming concurrently with the dep­ osition of the Buckner and probably also affected to Reference section of the Bossier Formation and partial sections of some extent the circulation of water and hence the dis­ adjacent formations [Logged from cuttings; Chicago Corp. Allison Brothers well1, James Hughes Survey tribution of the eva porites. A-278, Panola County, Tex. (pl. 1A). Derrick floor elevation, 297 feet above sea level] COTTON VALLEY GROUP Depth (feet) Thickness (feet) The Cotton Valley Group, as used here, consists of the Schuler Formation (lower part): Bossier and Schuler Formations. Sandstone, light-grayish-brown, fine-grained, noncalcareous___ _ _ 9, 446-9, 510 64 BOSSIER FORMATION Bossier Formation: The Bossier Formation is predominantly dark-gray Shale, dark-gray, calcareous to noncalcareous, fossiliferous, fossiliferous calcareous marine shale. It also contains chloritic, very fi~ely micaceous, small amounts of limestone, particularly in updip areas silty, having splintery to blocky (pl. 1A, B). A reference section of the Bossier for the fracture and a few thin interbeds ancestral North Louisiana basin follows. of dark-brown argillaceous limestone______9, 510-10, 614 1, 104 Shale, dark-gray to brown, very Reference section of the Bossier Formation and partial sections of adjacent formations calcareous, very finely micace­ ous, chloritic, having blocky {Logged from cores except as indicated by asterisk (logged from cuttings); Union fracture; gray, dense, non­ Producing Co. Section 13 Unit well1, sec. 13, T. 17 N., R. 12 W., Bossier Parish, La. (pl. 1B). Derrick floor elevation, approximately 200 feet above sea level] porous, argillaceous limestone, Depth Thickness containing a little oolitic lime- (feet) (feet) stone ______10,614-10,754 140 Schuler Formation (lower part): Shale, dark-gray, chloritic, non- Siltstone, dark-gray, mottled, cal­ calcareous to calcareous, very careous, fossiliferous; gray, non­ finely micaceous______10, 754-10, 928 17 4 porous sandstone; dark-gray to black shale ______9,015-9,200 185 Total, Bossier Formation______1, 418 Bossier Formation: Shale, dark-gray, flaky, fossilifer­ Smackover Formation-lower member: ous, calcareous, partly inter­ Limestone, light-gray to dark­ bedded with thin layers of cal- gray or dark-brown, dense, careous dark-gray siltstone ____ _ 9, 200-9,468 268 silty to arenaceous, partly No record of samples ______9,468-9,514 46 laminated______10, 928-11,001 73 Shale, dark-gray, calcareous ______9, 514-9, 614 100 Shale, dark-gray, silty, platy to THICKNE,SS AND DISTRIBUTION blocky fracture, very finely The Bossier Formation is thickest in the ancestral micaceous, calcareous, fossil­ iferous, interbedded vvith a few north Louisiana basin; it thins somewhat over the ances­ thin layers of dark-gray fossil- tral Sabine uplift to the west and thins abruptly north­ iferous limestone* ______9, 614-9, 800 186 ward because of facies change into other formations Shale, dark-gray, calcareous to (figs. 3, 10; pl.1A, B). A thin tongue of the Bossier, the noncalcareous, somewhat silty, ,Q tongue, extends northward into the updip shelf area splintery to blocky fracture, fossiliferous, pyritic, containing a;S far as north-central Cass County, Tex., and south­ white calcite in veins near base, central Miller and Lafayette Counties, Ark. The forma­ and pyritized spores*------9,800-10,800 1, 000 tion reaches a thickness of as much as 2,352 feet in east­ Shale, dark-gray, calcareous, part­ central Bossier Parish, La. The recorded thicknesses ly laminated; unit contains a over the ancestral Sabine uplift range from 1,204 feet in few thin interbeds of dark-gray limestone* ______10,80Q-11,018 218 the central part to 1,475 feet on the flanks. The forma­ tion apparently continues downdip into the deeper parts Total, Bossier Formation ______1, 818 of the gulf coast embayment to the south, but it has not been penetrated in this part of the embayment south Smackover Formation-lower member: Limestone, dark-brown, dense, of Shelby County, Tex. silty, pyritic, partly laminated*_ 10, 974-11, 390 416 STRAITIGRAPHIC RELATIONS The lithology of the Bossier Formation on the an­ The Bossier Formation conformably overlies the cestral Sabine uplift is substantially the same as it is in lower member of the Smackover Formation offshore in E18 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY the gulf coast embayment in Marion, Harrison, and The Bossier Formation is overlain conformably by Panola Counties, Tex., and in Caddo and Bossier Par­ and intertongues with the Schuler Formation (pl. 1A, ishes, La. The Q tongue of the Bossier Formation lies B). directly on the upper member of the Smackover Forma­ Q TONGUE tion in a narrow belt along the near-shore margins of the north Louisiana basin and the ancestral Sabine up­ The Q tongue is largely dark-gray marine fossilifer­ lift in southern Marion County, Tex., and northern ous shale. The lower part of the tongue is more cal­ Caddo and Bossier Parishes, La. North of this narrow careous than the m·ain part, and in southern Cass Coun­ belt, the Q tongue lies directly and with apparent con­ ty, Tex., it contains oolitic limestone. The tongue ranges formity on the P tongue of the Schuler Formation. in thickness from 400 feet along the north edge of the ancestral north Louisiana basin to a featheredge north of the basin.

Section of the Q tongue of the Bossier Formation and parts of the Schuler Formation

[Logged from cores; Arkansas-Louisiana Oil Co. M. Pitts well 5, sec. 11, T. 23 N.~ R. 16 W., Caddo Parish, La. Derrick :floor elevation, 287 feet above sea level] Thick­ neB~~ Depth (feet) (feet) Schuler Formation (main body, lower part): Sandstone, light-gray to white, well-sorted, fine-grained, some­ what calcareous, containing car­ bonized wood and shale frag- ments______10, 164-10, 185 21 Bossier Formation-Q tongue: Shale, dark-gray, slightly calcar­ eous, containing carbonized plant remains and small pelecypods; medium-gray, slightly calcare­ ous mudstone having irregular fracture______10, 185-10, 210 25 Sandstone, medium-light-gray, very fine grained, hard, thinly bedded, nonporous, dolomitic______10, 210-10, 216 6 Shale, medium- to dark-gray, cal­ careous to noncalcareous; some parts very fossiliferous, contain­ ing mollusks; in the upper part, a few thin beds of brown, hard, somewhat argillaceous limestone, containing mollusks; one thin bed of gray, calcareous mudstone near the bottom, containing "oysters" and some solid hydro- carbon ______10,216-10,402 186 Shale, dark-gray, fossiliferous, silty, very calcareous, having blocky fracture ______10,402-10,453 51

Total, Q tongue of Bossier For- mation______268 Schuler Formation- P tongue (upper EXPLANATION part): D--·······-·--··---D' • Sandstone, medium-gray, fine- --500-­ Depositionat·axis Control well grained, calcareous, silty, con­ Isopach taining solid hydrocarbon; tan, Dashed where approximate IntervallOO and 500jee~ fossiliferous limestone; dark-gray, partly laminated, noncalcareous FIGURE 10.-Isopach map of Bossier Formation. shalecontainingafewfossils _____ 10,453-10,478 25 UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E19

PALEOTECTONIC RELATIONS pastel varicolored shale or mudstone. The sandstone is The Bossier Formation is about 500 feet thinner over commonly white to light gray or pink except in the the ancestral Srubine uplift than in the ancestral north lower part of the formation in sectors A and B where it Louisiana basin (fig. 10). Tlus thinning is apparently is reddish brown. In sector A the sandstone is conglom­ due to differential deposition because no evidence of eratic especially near the bottom of the formation but it erosion has been found. The Q tongue of the Bossier is nonconglomeratic in sector B. The shale or mudstone Formation is of uniform thickness over the anticline at is characterized by various pastel colors, by a waxy to East Haynesville oil field, Claiborne Parish, La. crinkly texture, and by the presence of siderite spheru­ (Shreveport Geological Society, 1953b, p. 63). In this lites (pl. 1A, B). A reference section from sector A and possibly other places the salt-cored anticlines, follows. which had such a pronounced effoot on sedimentation during the deposition of the Buckner Formation and Reference section of the Schuler Formation and partial sections part of the P tongue of the Schuler Formation, had of adjacent formations little effect during the deposition of the Q tongue. [Logged from cuttings; McAlester Fuel Co. S. Hervey well A-1, sec. 1, T. 15 8., R. 26 W., Miller County, Ark. Derrick floor elevation, 252 feet above sea level] SCHULER FORMATION Depth Thtckne&l Hosston Formation (lower part): (feet) (feet) In updip areas marginal to the gulf coast embayment Sandstone, white, pink, or reddish­ the Schuler Formation is composed in general of lentic­ brown, fine- to medium-grained, angular, silty, containing thin in- ular fine-grained, red, pink, or light-gray sandstone terbeds of red and gray shale ___ -- 4,954-5,035 81 and of shale or mudstone of various colors. According Schuler Formation: to several geologists (Imlay, 1943; Swain, 1944; Forgot­ Sandstone, pink and tan, fine­ son, 1954) , the rocks of the Schuler Formation were grained; gray, calcareous silt­ deposited in a near-shore or nonmarine environment in stone; dark-reddish-brown, splin- tery shale______- ___ --- -- 5,035-5,080 45 updip areas. Although a discussion of the evidence is be­ Shale, light-gray to pink with some yond ,the scope of this report, the updip unfossiliferous yellow-brown mottling, noncal- part of the Schuler will be referred to as the near-shore careous, pyritic ______5,08o-5, 110 30 or nonmarine facies and the downdip part, which con­ Sandstone, pink to light-gray, fine­ tains marine fossils, will be referred to as the normal grained, argillaceous, noncalcar- eous------5, 11o-5, 152 42 marine facies. In the downdip offshore part of the em­ Shale, light-gray to pink, noncalcar- bayment the rock is predominantly light-gray, fine­ eous, silty, containing a trace of grained sandstone and dark-gray fissile fossiliferous sideritic spherulites------_----­ 5,152-5,218 66 shale. Sandstone, pink, medium-grained, noncalcareous, well-sorted ______5,218-5,246 28 For the purpose of describing in greater detail the Shale, pink to light-gray ______- _- 5, 246-5, 260 14: lithofacies of the Schuler Formation, the report area Sandstone, pink, medium-grained, has been divided into seven sectors as shown in figure 11. noncalcareous, well-sorted ______5, 26Q-5,278 18 Sectors A and B are parallel updip marginal areas; Shale, light-gray to pink, containing sideritic spherulites ___ - __ - __ ---- 5,278-5,310 32 sector Cis transitional between the updip basin-margin Sandstone, pink, medium-grained, areas and the downdip basinal areas and extends south­ noncalcareous, well-sorted ______5,3lo-5,333 23 ward partly over the ancestral Sabine uplift; sector D Shale, pastel varicolored, red, sid- eritic ______- _------5,333-5,366 33 is an extension of the ancestral east Texas basin; sec­ Sandstone, white, very fine to fine- tor E is coincident with the west end of the ancestral grained, noncalcareous ______5,366-5,408 42 north Louisiana basin; sector F is transitional between Shale, light-gray to pink, waxy­ the ancestral north Louisiana basin and the main body textured, containing sideritic spher- ulites ______5,408-5,430 22 of the gulf coast embayment; and sector G is apparently Sandstone, light-gray, medium to within the main body of the embayment. fine-grained, argillaceous, non- The near-shore or nonmarine facies includes nearly calcareous ______------5,43Q-5,480 50 the whole Schuler Formation in sectors A and B and S an d s t on e , fine-grained, white, slightly porous; pastel varicolored, approximately the upper half of the formation in sec­ waxy-textured shale______- 5,48Q-5,550 70 tors C and D. The near-shore or nonmarine rocks gen­ No record ______-- _- 5,55Q-5,580 30 erally consist of light-colored fine-grained calcareous to Sandstone, tan to pink, fine-grained, noncalcareous, porous, containing noncalcareous sandstone that contains some carbonized a few thin interbeds of reddish- wood or other carbonaceous material and red, gray, or brown shale______5, 58Q-5, 698 118 E20 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

EXPLANATION

Near-shore or nonmarine facies 0 .A upper part is largely sideritic pastel shale, red and • BOWIE green shale, and light-gray, tan, or pink fine-grained sandstone; lower part is mainly red shale, light-gray, pink, or redjine-grained sandstone, and reddish­ brown conglomeratic sandstone. Unit generally un­ jossiliferous 8 similar to unit A except that lower part contains little or no red conglomeratic sandstone I

! o cAss • o "'l o ~. • ~ o' Linden • ~ -~~~~S-'.S~ 0 • • • LO;?JSIA!!. 0 ~· ~: T Near-shore or nonmarine and m~rine facies , •• c ,~ ' \ C upper part is light-gray sandstone, red and green \--'------, OCO\ shale, and sideritic pastel shale; lower part is dark­ ~ gray shale and conglomeratic sandstone containing I' J3i 1. R I<() N • II I I o o• ( abundant marine fossils. Upper part is in near-shore "-.. I Jefferson • B 0 S S ieE a> or nonmarine facies, and lower part is in marine 0 0 ·i ! '''1..._ /.._ .;- AN ctfiYSTRAL l facies 1 Benton D similar to unit C except tkat the lower part also •/ .... _ _, ~ 0 1 contains abundant dark-gray partly ofillitic fossilif­ I J •o / C A D D 0 '2. I erous limestone. '/ _,./ o~eNORTH LOUISIANAo / d o1 I f Marshall 0 / I I 1 ,~ ihrevepo~0~ ~ HARRIS 0 N 1 • BASIN 1 l ,, I 0 .,0 L ~ANCESTRAL o3 • · -- N ... ,SAB~N_£;..- o ~ ) -o-oJ• Marine facies / UPLIFT 1 )'"'.....__, <.. r 0 E upper part consists of gray to brown dense lime­ / 0 • 1 ~ '~Jz._) stone, dark-gray splintery shale, persistent beds of light-gray fine-grained sandstone (blanket sands of I 0 / \ Forgotson,1954); the lower part is largely calcareous j F F ' conglomeratic sandstone and dark-gray shale. Marine fossils abundant I DESOTO 1: F upper part consists of gray to brown limestone, dark­ { I 0 Mansfield \ gray shale, and somewhat conglomeratic sandstone I o ~ (massive sandstone· of Forgotson, 1954); lower part L.l _____o ---~, ''\ is dark-gray calcareous shale and a jew interbeds of light-gray sandstone. Marine fossils abundant ' ' ~J .G dark-gray shaly limestone \ ,-~--- l \ oCen;er/ ~-~-{o~s-;Q" MILES Facies boundary ~ . H E];{B Y G • \ 1 , " 1 i 1 , 8 Da·shed where approximate l______{ • Facies determined from sample ----.... ( and electric logs '..../'/~ r.. Facies determined from sample log

0 Facies determined from electric log

FIGURE H.-Lithofacies map of Schuler Formation. UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E21

Reference section of the Schuler Formation and partial sections able over the ancestral Sabine uplift, and they are not of adjacent formations-Continued in the updip near-shore or nonmarine facies. According Depth Thickness have been informally named in northern Louisiana, but Schuler Formation-Continued (feet) (feet) Mudstone, reddish-brown, finely mi- to Mann and Thomas ( 1964) 22 blanket sandstone units caceous______5,698-5,715 17 many of them do not extend into the report area. The Sandstone, tan to pink, fine-grained, names are generally well known because of the great noncalcareous______5, 715-5, 768 53 economic importance of the sands as oil or gas pro­ Mudstone, reddish-brown, finely mi- caceous, containing some interbeds ducers. In the north part of sector E the lower half of of fine-grained sandstone______5, 768-5, 800 32 the Schuler is mostly fine-grained light-gray calcareous Sandstone, fine- to medium-grained, to noncalcareous somewhat fossiliferous sandstone to­ white, silty, noncalcareous, partly gether with lesser amounts of dark-gray shale, lime­ conglomeratic; containing a few thin interbeds of pastel varicolored stone, and very calcareous conglomeratic sandstone. shale, gray fissile shale, and red- Some of these beds are correlatable over wide areas, but dish-brown mudstone______5, 800-6, 105 305 1nost are lenticular. Farther south in sector E and in Sandstone, reddish-brown, silty, cal­ sector F, the lower part of the Schuler is mostly dark­ careous to noncalcareous, some­ what conglomeratic, containing gray calcareous shale, but it also contains a few non­ thin interbeds of reddish-brown conglomeratic sandstone beds there. The entire Schuler mudstone and gray fossiliferous Formation is dark-gray shaly limestone in sector G, as shale______6, 105-6, 320 215 represented by one well, Humble Oil & Refining Co. Total, Schuler Formation______1, 285 Pickering Lumber Co. well 1. A reference section from the ancestral north Louisiana basin (sector E) follows. Buckner Formation-upper member: Shale, reddish-brown, silty, finely Reference section of the Schuler Formation and partial sections micaceous, noncalcareous ______6, 320-6, 360 40 of adjacent formations

[Logged from cores except as indicated by asterisk (logged from cuttings) and by The normal marine facies includes approxin1ately dagger (logged from cuttings and cores); Carter Oil Co. Crystal-Whited well 1, the lower half of the Schuler Formation in sectors C sec. 26, T. 21 N., R.12 W., Bossier Parish, La. Derrick floor elevation, 241 feet and D and the entire formation in sectors E, F, and G. above sea level] A thin marine tongue, the Wesson Tongue of Swain Hosston Formation (lower part) : Depth (feet) Thickness (1944), that consists of fossiliferous medium-gray shale Sandstone, white and pink, fine- (feet) grained, hard ______8,281-8,307 26 and limestone, also extends into the upper otherwise Schuler Formation: near-shore or non1narine facies of the fonnatim1 Shale, light-gray to pink, waxy­ throughout most of sector C. The normal marine facies textured, containing siderite consists mostly of fine-grained light-gray sandstone spherulites ______8,307-8,345 38 that is cmnmonly calcareous and conglmneratic and is Sandstone, light-gray, fine-grained, noncalcareous, containing in- interbedded with fossiliferous medium-gray to black clusions of carbonized wood ___ _ 8, 345-8, 371 26 shale and gray limestone. In sector E several thin per­ Shale, medium-gray, splintery, sistent light-gray fine-grained sandstone beds, such as slightly calcareous, fossiliferous_ 8, 371-8,495 124 the Bodcaw sand of Sloane (1958) and the D sand, are Sandstone, light-gray, fine-grained, calcareous ______8,495-8,511 16 corTelatable in the upper part of the Schuler Forma­ Shale, medium-gray, splintery, tion over n1uch of north Louisiana (fig. 3, pl. 1B). slightly calcareous, fossilifer- These sandstone bodies maintain a thickness of about ous ______8, 511-8, 570 59 No record of samples ______40 to 50 feet over wide areas and are generally called 8, 570-8, 765 195 Shale, medium-gray, laminated blanket sandstones. They are separated by dark-gray with siltstone near base ______8, 765-8, 791 26 splintery fossiliferous shale. To the south and west in Sandstone (D sand), light-tan, sector F, the sandstone bodies thicken and coalesce to medium-grained, very calcareous_ 8, 791-8,814 23 No record of samples* ______8,814-8,850 36 fonn a somewhat n1assive partly conglomeratic sand­ Shale, medium-gray, calcareous, stone, which according to several geologists was de­ fossiliferous* ______8,85Q-8,881 31 posited in the form of barrier beaches or islands (For­ Shale, gray, slightly calcareous, gotson, 1954, p. 2496 ; Sloane, 1958, p. 22; Thomas and containing ostracodes and pe­ lecypods, partly laminated, Mann, 1966). They do not extend or are not recogniz- arenaceous in lower 2 feet ______8,881-8,900 19 E22 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Reference section of the Schuler Formation and partial sections Reference section of the Schuler Formation and partial sections of adjacent formations-Continued of adjacent formations-Continued Depth Thicknell Depth Thicknell (feet) (feet) (feet) (feet) Schuler Formation-Continued Schuler Formation-Continued Sandstone (Bodcaw sand of Sloane Sandstone, light- to medium-gray, (1958)), light-gray, mottled with fine-grained, very calcareous, dark-gray, fine-grained, angular, partly conglomeratic, contain­ argillaceous, crossbedded; con­ ing interbeds of limestone and taining a few quartz over­ conglomerate______9, 436-9, 480 44 growths, magnetite, carbonized Shale, dark-gray, calcareous, very wood fragments, and pelecy- fossiliferous, partly laminated; pods______8,90Q-8,950 50 brown, hard, arenaceous, con­ Shale, dark-gray splintery to fissile; glomeratic limestone containing containing ostracodes, gastro- some sparry cement and mol- pods, and pelecypods t ______8, 95Q-9, 160 210 lusks______9,48Q-9, 504 24 Limestone, dark-gray, coquinoid, Sandstone, light-gray, fine-grained, very argillaceous, consisting of very calcareous, micaceous, fos­ pelecypod shells in a rna trix of siliferous, irregularly bedded, clayey material; dark-gray, cal­ partly conglomeratic; dark-gray, careous, arenaceous, fossiliferous micaceous, noncalcareous shale; shale______9, 160-9, 174 14 conglomerate having pebbles of Sandstone (Davis sand), light-gray clear quartz, milky quartz, and with darker beds, fine-grained igneous rock and sparry calcite somewhat calcareous, containing cement______9, 504-9, 580 76 thin dark-brown shale beds______9, 174-9, 210 36 Limestone, gray, fossiliferous, Shale, dark-brown, fossiliferous, dense; gray, fossiliferous, con­ calcareous, silty, partly lami- glomeratic limestone, having nated______9, 21Q-9, 267 57 sparry calcite cement______9, 58Q-9, 594 14 Sandstone, light- to medium-gray Sandstone, light-gray, slightly or pink, fine-grained, very cal­ calcareous, conglomeratic, fos- careous, well-bedded, fossiliferous, siliferous; dark-grayish-brown, containing shale partings______9, 26 7-9, 305 38 hard, micaceous, fossiliferous Limestone, dark-gray, fissile, argil- shale______9,594-9,608 14 laceous, coquinoid, having a Conglomerate, having pebbles of matrix of dark-gray clay______9, 305-9, 313 8 smoky and milky quartz and a Sandstone, gray and reddish-gray, matrix of fine-grained calcareous calcareous, fine-grained, having sandstone______9,608-9,620 12 red shale partings and irregular Sandstone, light-gray, very fine bedding______9,313-9,324 11 grained, irregularly bedded, cal­ Shale, gray, arenaceous, containing careous, containing worm bur- a few small fossils______9, 324-9, 328 4 rows, interbedded with a few Sandstone, light-gray to pink, fine­ thin layers of arenaceous clastic grained, slightly calcareous with limestone and d'ark-gray fissile some reddish-brown shale part­ shale______9,62Q-9,645 25 ings; conglomerate containing Limestone, light-grayish-brown, pebbles of yellowish-brown chert conglomeratic, fossiliferous, hav- and soft reddish-brown shale and ing solution porosity __ -______9, 645-9, 658 13 having a matrix of very calcare- Sandstone, light-gray to dark- ous fine-grained sandstone_____ 9, 328-9, 395 67 brownish-gray, fine-grained, con­ Limestone, light-gray mottled with taining some argillaceous part­ medium-gray, very silty, dolo- ings; dark-brownish-gray argil- mitic______9, 395-9, 401 6 laceous, arenaceous siltstone_____ 9, 658-9, 683 25 Shale, dark-gray, soft, fissile, fos­ Sandstone, light-gray to dark­ siliferous and arenaceous at in­ brownish-gray and pink, very tervals, containing a few thin fine to fine-grained, calcareous, interbeds of dark-gray fossilifer- partly laminated; dark-gray to ous limestone______9, 401-9, 436 35 brownish-gray, somewhat fissile, fossiliferous, calcareous shale____ 9, 683-9, 866 183 UPPER JURASSIC STRATIGRAPHY, ADJACENT PARTS OF TEXAS, LOUISIANA, ARKANSAS E23

Reference section of the Schuler Formation and partial sections The contact between the Schuler Formation and the of adjacent formations-Continued overlying Hosston Formation of Early Gretaceous age JJepth Thickne11 is generally thought to be conformable in downdip areas (feet) (feet) Schuler Formation-Continued and disconformable in updip areas (Forgotson, 1954; Sandstone, light-gray, fine-grained, Swain, 1944). slightly calcareous to calcareous, P TONGUE fossiliferous, irregularly bedded, The P tongue consists predominantly of light-colored partly conglomeratic, containing shale partings and a few thin fine-grained sandstone and subordinate amounts of in­ interbeds of shale; light- to terbedded gray shale. It ·contains some red sandstone dark-gray, clastic, conglomer­ and shale ne.ar the base and it grades laterally into red atic, fossiliferous limestone, hav­ sandstone and shale in updip areas where it joins the ing scattered shale partings and sparry cement ______9,866-9,966 100

Total, Schuler Formation______1, 659

Bossier Formation (upper part) : Shale, dark-gray and dark-brown­ ish-gray, slightly calcareous to noncalcareous, finely micaceous, fossiliferous, silty to arenaceous, containing a few interbeds of siltstone______10, 076-10, 147 71

THICKNESS AND DISTRIBUTION The Schuler Formation ranges in thickness £rom zero I e north of the project area to more than 2,000 feet in its 1 • I e thickest part in southern Lafayette and Miller Counties, Ark., and in northern Caddo and Bossier Parishes, La. ~--;-----·---~ ,2:::~ (fig. 12). The updip edge probably strikes northeast­ /' M A R I~ N • I • t, :;.1 t--.... efferson ) B 0 S S I E'\1• ward across northwestern Bowie County, Tex., and 0 _/._)., J' I -'0-00 1I .... , l ... _./'_.,- r...... J \J {1 Benton -.....J north of Miller and Lafayette Counties, Ark. No deposi­ 41 0 tional axis was plotted £or the Schuler Formation be­ I lCADDO\ ·I I ( I cause the P tongue was mapped separately £rom the 1 1 I Shreveport0~ l main body, but the general location o£ a depositional I HARRISON I \ • I axis can be seen by comparing the maps of the tongue '\. I ~ L __ ...._ .... """-- f(loo ~vt ..: and the main body of the £ormation (figs. 12, 13). N I ... '\______I ~--"--:3-v. ) / e I ,; ' STRATIGRAPHIC RELATIONS I I ~ ~~1. I e e L_/ \ The Schuler Formation intertongues with and over­ • Carthage• 1 J 0 ~ \ lies the Bossier Formation in downdip areas and over­ ' PAN~1400: DESOT-O £ f lies the Buckner or Smackover Formation in updip ( • 2qo- 0 Mansfield\ I e I! ' areas. The basal contact of the Schuler Formation in the L_l ______--~ ~ updip areas has generally been thought to be discon­ ' ~ ', ~I formable (Swain, 1944; Forgotson, 1954). However, \ ~~------1 \ 0Center ~ ~ 10 \5 MILES conformity in most places is indicated by the uniform 't ... 1 2p thickness of the upper member o£ the underlying Buck­ 1 SHELBY • \ ner For1nation in places where erosion would most ~------...., I r likely have occurred and by the fact that at some places '-.../' ...... ~ the Schuler appears to grade downward into underly­ ing rocks (fig. 7, pl. 10). The contact may be discon­ EXPLANATION • --1600-­ formable over most anticlines, especially along the Control well lsopach structural trend (fig. 9) where the Buckner Formation Interval 200/eet Area where P tongue is either thin or absent, although much of this thinning is present is thought to be a result of differential deposition ( Goe­ FIGURE 12.-Isopach map of Schuler Formation except P tongue bel, 1950, p. 1975). at base. E24 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

I Section of the P tongue of the Schuler Formation and parts of OKLAHOMA I ARKANSAS adjacent formatt"ons-Continued r~..-"2- I L~~LITTLE RIVER Depth Thickness 1l TEXAS;. _,/-. (feet) (feet) I ?""l__,...r-{'--~'11'.\ \. Schuler Formation-P tongue-Continued I I \.? Shale, dark-gray, unfossiliferous; New Boston I ~ I 0 bTexarkana t.~------,_-1 reddish-brown, mudstone con­ I BOWIE J taining nodules or subangular l / r:il Lewisvill7 fragments of pink anhydrite___ 10,478-10, 512 34 l r ~ ~ o J Sandstone, medium-gray, hard, very ~\_ ./"-~ ~J-J M I L L E R r> 1:"£1 j _,..r '"~J I ;>I r- fine grained, noncalcareous, con- N I I t.; ~ I taining dark shale partings______10, 512-10, 520 8 1 I ~· BODY !jERE~ Mudstone, reddish-brown, silty COALESCES WITf!....J~~

northeast Texas and \Yest-central Mississippi: Lawrence, Imlay, R. W., 1952, Correlation of the Jurassic formations of Kansas Univ., Ph.D. thesis, 74 p. North America, exclusive of Canada: Geol. Soc. America Ballard, W. W., 1964, Paleoenvironmental approach to oil ex­ Bull., v. 63, no. 9, p. 953-992. ploration, i.n 'Yilliston Basin Symposium, 3d International, Mann, C. J., and Thomas, W. A., 1964, Cotton Valley Group Regina, Sa~katchewan, 1964: Billings, North Dakota, and (Jurassic) nomenclature, Louisiana and Arkansas: Gulf Saskatchewan Geol. Socs., p. 247-262. Coast Assoc. Geol. Socs. Trans., v. 14, p. 143-152. Bingham, D. H., 1937, Developments in Arkansas-Louisiana­ Martin, J. L., Hough, L. W., Raggio, D. L., and Sandberg, A. E., Texas area, 1936-37: Am. Assoc. Petroleum Geologists 1954, Geology of ·webster Parish: Louisiana Dept. Con­ Bull., v. 21, no. 8, p. 1068-1073. serv., Geol. Survey Bull., no. 29, 252 p. Bornhauser, Max, 1958, Gulf Coast tectonics: Am. Assoc. Pe­ Murray, G. 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U.S. GOVERNMENT PRINTING OFFICE: 1968