Coffeyville or Francis Formation (restricted)

ARDMORE-SHERMAN- Shale, dark-blue, 20 to 70 feet thick, with "DeNay Limestone," yellow, massive, 2 to 6 feet thick at base, and 20 feet or more of buff fine- to coarse-grained sandstone and chert conglomerate at top. (Upper Franks Conglomerate).
State Oklahoma
Name Coffeyville or Francis Formation (restricted)
Geologic age Middle Pennsylvanian
Lithologic constituents
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Conglomerate (Bed)
Comments Named for Francis, Stonewall quad, Pontotoc Co, OK, westward from which outcrop extends. Type area is that portion of outcrop which extends 3 mi north and south of Canadian River, Pontotoc and Seminole Cos, OK, Arkoma basin and Chautauqua platform. Includes (ascending): DeNay limestone; dark-blue and black shales, about 30 ft; these grade upward into sandstones which (on creek bluff west of Sasakwa) are 20 ft thick; a series of thick, dark, sometimes calcareous shales, average thickness 250 ft (slightly more to north, slightly less to south). Lower part of this shale much darker and more calcareous than upper part--contains limestone concretions, often fossiliferous; 100 ft of coarse brown sandstones and chert conglomerates, with only occasional fossils; 100 ft of shale with a few thin sandstones and one persistent conglomeratic limestone (often very fossiliferous). (Morgan, 1924).
NGMDB product
Counties Pontotoc - Seminole