A provenance study of the triassic deposits of Northwestern Texas

Continental deposits of the Upper Triassic Dockum Group are exposed along the eastern escarpment of the Southern High Plains in northwestern Texas. Three formations are present: the Tecovas, the Trujillo, and the Chinle, generally representing the floodplain, stream channel, and floodplain environments respectively. Analyses of the sedimentary structures were made to determine the direction of the source of these beds. Mineralogical studies were conducted in an effort to establish the litho logic character of the source rocks. Results indicate that the provenance consisted chiefly of a terrene of sedimentary rooks to the east and southeast. Specific source areas are proposed and some pale geographic reconstructions are suggested.