Atoka Formation, undivided (ARPAa;0)

State	Arkansas
Name	Atoka Formation, undivided
Geologic age	Phanerozoic \| Paleozoic \| Carboniferous Pennsylvanian-Middle [Atokan]
Original map label	&a
Comments	Upper, Middle and Lower parts. Terrigenous clastic basin sequence of six or more sandstone members each separated by black clay shale with occasional ferruginous concretions. Approximately 15000 ft. thick. Clastic basin sequence within the Arkoma Basin, ranging from deltaic, shallow-shelf, to deep ocean enviroments. Natural gas production from sandstones, a few thin coal beds
Primary rock type	sandstone
Secondary rock type	shale
Other rock types	coal
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed) Sedimentary > Clastic > Sandstone (Bed) Incidental Sedimentary > Coal (Bed)
Map references	Haley, B. R., Glick, E. E., Bush, W. V.; Clardy, B. F.; Stone, C. G.; Woodward, M. B., Zachry, D.L., 1993, Geologic Map of Arkansas: U.S.Geological Survey Special Geologic Map. Scale 1:500K
Unit references	Taff, J.A., 1901, A comparison of the Ouachita and Arbuckle Mountain sections, Indiana Terr.: Science, pp.271-272. Wilson, C. W., 1935, Age and correlation of Pennsylvanian surface formations and of oil and gas sands of Muskogee County, Oklahoma: AAPG Bull. 19, no. 4, pp 503-520. Sutherland, P. K., and Henry, T,.1977, Carbonate platform facies and new stratigraphic nomenclature of the Morrowan Series (lower and middle Pennsylvanian), northeastern Oklahoma: Geo. Soc.of Amer. Bull., vol.88, no.3, pp.425-440. Ferguson, J.G., 1920. Outlines of the geology, soils, and minerals of the State of Arkansas: Arkansas State Bureau of Mines, Manufactures and Agriculture,192 pp.
Geographic coverage	Cleburne - Conway - Crawford - Faulkner - Franklin - Johnson - Madison - Newton - Pope - Searcy - Sebastian - Van Buren - Washington - White