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Bokchito Formation

ARDMORE-SHERMAN- Clay, illitic, kaolinitic, with some tan limestones and sandstones. Subdivided into "Pawpaw Clay" at top, 40 to 60 feet thick; "Quarry Limestone," 13 feet thick; "Weno Clay," 100 to 135 feet thick; and basal "Denton Clay," 50 to 70 feet thick.
State Oklahoma
Name Bokchito Formation
Geologic age Phanerozoic | Mesozoic | Cretaceous-Early
Comments Comments: Lowermost 90 ft is sandy clay shale with some ferruginous limestone segregations and ironstone nodules; above these are 20-30 ft of friable sandstone followed by bluish shell limestones separated by friable shales. Limestone is hard, semicrystalline, and on weathering turns yellowish brown or reddish. At top of formation are 50 ft of sandy and clay shales and, locally, friable sandstone strata; shows cross- bedding in places. Total thickness of formation is 140 ft. Ouachita Mountain uplift; S. OK folded belt province.
Primary rock type claystone
Secondary rock type limestone
Other rock types sandstone
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Map references
Heran, W. D., Green, G. and Stoeser, D. B., 2003, A Digital Geologic Map Database of Oklahoma: U. S. G. S. Open File Report 03-247
Unit references
Heran, W. D., Green, G. and Stoeser, D. B., 2003, A Digital Geologic Map Database of Oklahoma: U. S. G. S. Open File Report 03-247
Hart, D.L., 1974, Reconnaissance of the water resources of the Ardmore and Sherman quadrangles, southern Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 3, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by D.L. Hart, and R.O. Fay, in 1970.)
Cederstrand, J.R., 1996a, Digital geologic map of Ardmore-Sherman quadrangles, south-central Oklahoma: U.S. Geological Survey Open-File Report 96-370, (3 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology
Counties Bryan - Love - Marshall