Stratigraphy of the Lower and Middle Triassic Union Wash Formation, East-Central California

摘要

In the report the authors describe the lithology, stratigraphy, and contact relations of the Union Wash Formation at its type locality and at two additional localities: (1) the Cerro Gordo area near the crest of the Inyo Mountains, 25 km southeast of Union Wash, and (2) the Darwin area, another 35 km to the southeast. The descriptions given herein are largely based on recent work and are intended to supersede previous descriptions of the formation by them and their coworkers (Lewis and others, 1983; Stone, 1984; Stone and Stevens, 1986). In addition, they list new conodont identifications that, together with ammonoids identified by previous workers, constrain the age of the Union Wash Formation in these three areas to Early and Middle Triassic.