UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director Bulletin 874 B GEOLOGY AND FUEL RESOURCES OF THE SOUTHERN PART OF THE OKLAHOMA COAL FIELD PART 2. THE LEHIGH DISTRICT COAL, ATOKA, AND PITTSBURG COUNTIES BY M. M. KNECHTEL UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1937 Forsaleby the Superintendent of Documents, Washington, D. C. -------- Price 20 cents NOTE The Geological Survey, in 1930, 1931, 1933, and 1934, conducted an investiga­ tion of the geology and coal resources of the portion of the southeastern Okla­ homa coal field extending northeastward from Coalga,te to McAlester and thence eastward through Wilburton and Howe to the Oklahoma-Arkansas State line. The geologists have prepared separate reports on the areas for which they were responsible. However, as these areas are adjacent and form a real unit both geographically and geologically, the four reports are issued as parts of a single bulletin covering this portion of the southeastern Oklahoma coal field. No edition of the consolidated volume will be published, but the four parts can be bound together if desired, ii CONTENTS Paw Abstract-----.. _-_-_____-_---_-__-___--_---_--___----_--..- 91 Introduction_________________________-______--_.----__--_-_--_-_ 92 Location_________-_-_____--___-- --_-------_----_--_-------- . 92 Routes of travel-___-_---_________--_------__---_-_----------- 92 Industry .-._..__.____________.__-------- ._-._ 93 Land forms and drainage.-.------------------------------------ 93 Vegetation._______________________-_____---___---_-_-______-- 94 Climate__________.____._______.-__-___-_-___-_--____---_-_- 94 Present investigation.________.._.___-____---___-__---_-__----- 94 Previous publications._____.__________-_______-_-___---_____-_- 95 Stratigraphy....____.._____.___._____._-_---__-_--_-_--_-_-.-_-_-. 96 Exposed rocks_____________--_____--_-_-___-_____-_-__-__--__- 96 Character. ___________________-__---_---_----____-----__-- 96 Carboniferous system..--__-___-__-------_-_-_--__--_-----_ 98 Pennsylvanian series...-------------------------------- 98 Formations of Pottsville age--___-_____-_-_-_-__-.__ 98 Springer formation_____-_-__----_-_-_____-_--. 98 Wapanucka limestone.________________________ 99 Atoka formation.____--___--___-_-_-__________ 100 Formations of Allegheny age.______--_______._-_-__ 101 Hartshorne sandstone.-----------.------------- 102 McAlester shale._-_.-__-_-__--_--_-_-.___--_ 103 Savanna sandstone.-___-_---------_---__--_--- 105 Boggy shale-.-----------------------------.-- 106 Thurman sandstone---_---_-_---_-_---------__ 107 Quaternary (?) system____._____-_-_----__-_-___-_-_---____ 108 Gerty sand (Pleistocene?)..---.------..-.-.----_----- 108 Quaternary system.-_-___-_-_-_-_-_-_--__---_-_---_---_-__ 108 Recent alluvium_______._.___________-________-_-----_ 108 Unexposed rocks._____________________________________________ 108 Cambrian to Carboniferous systems-_____-__-._____--__--.__ 108 Pre-Pennsylvanian rocks.__-_-__-_-_--_---__-__------_- 108 Pennsylvanian rocks._______--__-___-___-_____-_-______ 124 Origin of the Pennsylvanian rocks--__-----------_---_-_---_--___ 124 Structure-_______________________________________________________ 126 General features.____-_______-_____-_____-___-_-___________--. 126 Centrahoma dome..___________________----_----_______-__-_-__ 128 Ashland anticline.___________-____---_-_----_-_-_-_-___.__-_-- 128 Savanna anticline_-__-_-_-____-____-_-------_-__-----_____-___ 129 Coalgate anticline.._____-__________-_-_--____-_-___-__-_______ 129 Hunton anticline.._________________-_-_-_-_-_-____-___-__.____ 129 Wardville syncline_______---_-_____-_-___-_-_-________-_-_____ 129 Lehigh syncline.--_-_____-__--__.__---_-_-_____-___-_-_____-_- 130 PhiUips fault.___.._._....__...___.-_._____-.____._._. _._._. 130 Olney and Clarita faults. ______________________________________ 130 Minor faults__-_____________.___.-_--__-___-__-______.__.__. 131 Origin of the faults and folds__.._._______-____-_.___-__________ 131 ill IV CONTENTS Page Economic geology.________________________________________________ 134 Coal. __-__-____-__-__-__________________-.-_.-_._____ 134 Occurrence _______________________________________________ 134 Quality...._______.____. ___...____.._______.__._.__.____ 136 Mining.__.___._.._______________________________________ 139 Oil possibilities_______________________________________________ 140 Natural gas__________________________________________________ 144 Index._________________________________________________________ 147 ILLUSTRATIONS Page PLATE 11. Geologic map of the Lehigh district, Coal, Atoka, and Pitts- burg Counties, Okla____-___--__--__---_--_----__-_-_Inpocket FIGURE 6. Diagram showing relation of Lehigh district to six 30-minute quadrangles in southern Oklahoma ______________________ 95 7. Map showing areal distribution of rock exposures in portions of Oklahoma, Arkansas, and Texas.-----_-------__-_--_. 123 GEOLOGY AND FUEL RESOURCES OF THE SOUTHERN PART OF THE OKLAHOMA COAL FIELD PART 2. THE LEHIGH DISTRICT, COAL, ATOKA, AND PITTSBURG COUNTIES By M. M. KNECHTEL ABSTRACT The rocks exposed in the Lehigh district, in the Arkansas-Oklahoma coal basin, aggregate at least 5,000 feet in thickness. All are of Pennsylvanian age, except scattered thin Pleistocene (?) and Recent deposits. Rocks of Pottsville age crop out extensively in the southwestern part of the district and include the Springer formation, Wapanucka limestone, and Atoka forma­ tion. The Pottsville rocks are overlain in the northeastern part by formations of Allegheny age, including the Hartshorne sandstone, McAlester shale, Savanna sandstone, Boggy shale, and Thin-man sandstone. All the Pennsylvania!! for­ mations younger than the Wapanucka limestone are composed chiefly of shale containing rather widely spaced beds of sandstone that is generally fine grained in the western part of the area but contains varying quantities of chert pebbles in the eastern part. The pebbles were apparently derived from a land mass that lay to the east or southeast in late Pottsville and Allegheny time, and this land mass is believed to have been the source of much of the sediment that was deposited in this part of the coal basin in post-Pottsville Pennsylvanian time. Two wells within the area mapped have penetrated rocks of Mississip- pian, Devonian, Silurian, and Ordoviciau age. It is inferred from the records of these wells and from the geology of neighboring areas that the Arbuckle Mountain sequence of pre-Pennsylvanian rocks underlies the Pennsylvania!! formations in all parts of the Lehigh district, though exposures of the dissimi­ lar pre-Pennsylvauian rock sequence of the Ouachita Mountains occur in Black Knob Ridge of the Ouachita Mountains, a few nn'les to the east. The Lehigh district lies in a belt of folded Paleozoic rocks extending from the Arbuckle Mountains northeastward adjacent to the northwestern frontal margin of the Ouachita Mountains. The structural axes within this belt trend northeastward, and the folding is therefore believed to be due to the same forces, directed northwestward, that caused extensive overthrustiiig in the Ouachita region in late Pennsylvanian time. The effects of forces acting from the direction of the Arbuckle Mountains, however, are apparent in the southwestern part of the district, where the oldest exposed rocks crop out, having been tilted northeastward in Pennsylvania)! time. Folds related to the northwestward thrusting are the Ashland, Savanna, and Coalgate anticlines. The origin of the Centrahorna dome is less clear. The structure of the Hunton anticline, which is faulted on both flanks, is similar in many respects to that of the other anticlines of the area, which are flat-topped and steep-sided. It may be essentially an anticline of their general type that has been more deeply eroded than the others. 91 92 SOUTHERN PART OF OKLAHOMA COAL FIELD An unconformity probably exists at the base of the Hartshorne sandstone, and one of less extent has been observed at the base of the Savanna sandstone. An unconformity within the Boggy shale has been reported immediately to the west but has not been recognized in the Lehigh district. Two valuable coal beds, the Lower Hartshorne and Lehigh beds, occur in the Lehigh district in the Hartshorne sandstone and McAlester shale, respec­ tively. Both beds have been mined, but the Lehigh bed has yielded much more coal than the Lower Hartshorne bed. These coal beds are separated by about 1,200 feet of beds and range in thickness from about 3 feet 4 inches to about 5 feet. The coal of the Lehigh bed is classified as high-volatile bituminous. Wells have been drilled for oil and gas in several parts of the district, and gas has been struck, but not marketed, in the Ashland, Coalgate, and Centra- homa anticlines. Nearly all the wells penetrate only the Atoka and younger formations, reaching depths ranging from 3,300 to 3,380 feet. One dry hole on the Coalgate anticline, however, finished in the Atoka beds at a depth of 7,890 feet, and two dry holes in the western part of the district were completed in the Simpson formation (Ordovician) at depths of 5,146 and 7,126 feet. Most of the gas that has been found issues from the Hartshorne sandstone, but some was found in sandy layers in the McAlester shale and a little in the Savanna sandstone. No oil has been discovered to date, but the pre-Pennsyl- vanian rocks underlying the area have not been adequately tested by the drill. INTRODUCTION Location. The area covered by this report (pi. 11, in pocket) com­ prises about 400 square miles in Atoka, Coal, and Pittsburg Coun­ ties, in southeastern Oklahoma. For convenience it is referred to as the Lehigh district, from the town of Lehigh, in the southern part of the district, which has a population of about 500. The largest town in the district is Coalgate, which has a population of about 2,000. The district was formerly a part of the Government reservation set aside for the Choctaw Nation, one of the Five Civilized Tribes, which in 1907 became part of the newly established State of Okla­ homa.