Duwa Fm
Type Locality and Naming
The type section is located at Duwa about 100 km to the southeast of Pishan County, Xinjiang. It was named by the Compiling Group on the Regional Stratigraphic Chart of Xinjiang Uygur Autonomous Region in 1977.
Lithology and Thickness
Conglomerate. Composed of brown, grey-green and grey-brown conglomerates, intercalated with grey-white and green-grey coarse-grained sandstone lenses, brown-red siltstone, grey-green siltstone and thin-bedded limestone. The basal part of the formation consists of red-brown conglomerate strata. Thickness is 418 m
Relationships and Distribution
Lower contact
Conformable contact with the underlying Pusige Fm.
Upper contact
Conformable contact with the overlying Wuzunsayi Fm of the Lower Triassic Series
Regional extent
Distributed in the Duwa, Piaman and Arqike areas. In the area of Keziliqiman it is composed mainly of sandy conglomerate and sandstone, with the siltstone increasing in amount, with a thickness of 1268 m.
GeoJSON
Fossils
Estheria represented by Lioestheria evenkiensis, Cyclotunguzites tungussensis, Polygrapta chatangensis; bivalves as represented by Anthraconauta duwaensis; Ostracoda represented by Panxiania-Volganella-Darwinuloides assemblage; Spore-pollen represented by Piceaepollenites-Gardenasporites assemblage (Fang Zhongjie et al., 1996),
Age
Depositional setting
It is interpreted as river- and pediment-alluvial deposits.
Additional Information