Named as uppermost formation of Sapulpa group in the southern area of the Sapulpa group; named for the town of Ramona, Washington Co, OK on the Chautauqua platform. Divided into three newly named members (ascending): Dewey limestone member, Ochelata shale member, and Avant limestone member. No type locality given. Shows widest outcrop in extreme northwest corner of the Claremore quad; extends as a narrow band westward to Avant; after crossing Bird Creek, extends southwest to bluffs on either side of the Arkansas River 1 mi west of Wekiwa. Consists of a lower (Dewey) and upper (Avant) limestone and intervening shales and sandstones (Ochelata). Both limestones are fossiliferous. Dewey is 6-8 ft thick; Avant is about 12 ft thick. Intervening Ochelata is 5-12 ft thick. Thickness varies from 6 to 85 ft. Overlies Skiatook formation (new) of Sapulpa group. Stratigraphic chart. Of Pennsylvanian age.

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