Named as a member (1 of 6 named members) of Atoka formation. Term Atoka is 1 of 5 formations that replace use of Winslow formation in report area. [Preferred status of Winslow as a result of this study not clearly stated.] Named from exposure in secs 10 and 15, T12N, R20E, about 2 mi west of Webbers Falls, Muskogee Co, OK on the Chautauqua platform. No type locality designated. Area of this report is in Muskogee Co. Consists of impure bluish calcareous sandstone containing angular quartz grains and argillaceous and carbonaceous matter; fossiliferous. In southern part of county, lower portion of member crops out as thin-bedded, blocky, impure sandstone having a fine-grained texture and is dark blue on fresh surfaces; weathers to alternating bands of light blue and brown. Is 35 ft thick. Separated from underlying Dirty Creek sandstone member (new) of Atoka formation by 40 ft of fissile shale of Atoka. Separated from overlying Blackjack School sandstone member (new) of Atoka by 150-350 ft of usually concealed shale of Atoka. Stratigraphic table. Columnar section. Of Early Pennsylvanian age.

Source: GNU records (USGS DDS-6; Denver GNULEX).