PEDIMENT CONCEPT APPLIED TO SHINARUMP AND SIMILAR CONGLOMERATES

The Shinarump and Buckhorn conglomerates and the Dakota sandstone are widespread deposits of Mesozoic age in the western interior. The physical characters indicate a fluvial origin, but the wide areal extent, scarcity of fossils, and exceptional thinness are difficult to explain by current concepts. It is suggested that these and similar continental formations are extensive pediment deposits which originated by processes observable in present-day arid and semiarid regions. These ancient deposits are compared with known pediment deposits, and the implications with regard to stratigraphic terminology and age assignments are briefly discussed.