Named for the lowest bench of massive cliff-making sandstone about 75 ft above the valley floor at Torpedo, Osage Co, OK on the Chautauqua platform. Forms the top member of the division described by Shannon and Trout (1915) as the Wilson formation. Rims valley of Sand Creek and is typically exposed 1 mi northwest of Torpedo, on north side of the creek; here it consists of massive medium-grained sandstone about 30 ft thick which breaks into large ripple-marked blocks. This sandstone ranges from 30 to 60 ft thick in T25N, R12E, where it is exposed in valleys along north township line. Forms resistant bed near top of prominent escarpment along east side of the township and rims the valley of Candy Creek and its tributaries in southern part. Immediately underlain by shale and overlain by a bed of hard gray limestone 2-3 ft thick, which is loaded with crinoid stems and weathers cinnamon-brown. Stratigraphic sections. Geologic maps. Of middle Pennsylvanian age.

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