Loc. 268. Cut in the north bank Grand River about one mile ESE of Highway 65 bridge in E1/2, NW1/4, NE1/4, SW1/4, sec. 20, T. 20 N, R23E, Black Horse NE quadrangle, Corson Co, So. Dak. Following adapted from Reiskind notes. Base of section on a .5 [illegible] layer overlying th gray thinly interbedded silt and shale (distance above river not noted) (1) 32.4 Interbedded & laminated silty clay and fine sand scattered burrows; thin (.01) [illegible] layer at 17.5. laminated with obvious burrows (2) 19.9 "Clay and shale with sand-lined 1/4 inch burrows" Fossils: loose in matrix (JR says "Meztra and ?Protocruzia") At top is thin (.06) concr. layer. (3) 13.1 {S*} Sand and silt, mottled, overlain by more dominantly sandy, bedded, zone which is capped by 2.0 concr layer consisting of gray sandy jackets with rusty to rb sandy cores. (4) 27.8 Sand, tan to yellow, massive but with feint appearance of bedding on weathered surfaces. At top is conc layer 1. to 3.0 in diam. ("ironstones") (5) 6.8 Sand, with faint layering (scale?),massive lyeas 1-2" (6) 7.14 Sand, tan, faint layering, with interbedds of dk gray fissile shale with limonitic concs in lower 1/2 and upper 1/3 *unit apparently bridges change from massive to bedded sand 8.