Datouyanggou Fm
Type Locality and Naming
The type section is at Datouyanggou southwest of Da Qaidam, Qinghai. The Datouyanggou Fm is derived from Mu Enzhi's et al. Datouyanggou Series proposed in 1958. Zhang Wentang renamed it the Datouyanggou Fm in 1962.
Synonym: (大头羊沟组）
Lithology and Thickness
The formation is composed of a Lower part of pebbly limestone, and an Upper part of purple siltstone and argillaceous limestone. In Datouyanggou, the Datouyanggou Fm recorded an incomplete thickness of 200-250 m.
Relationships and Distribution
Lower contact
It rests disconformably on the Shihuigou Fm
Upper contact
The upper boundary is covered.
Regional extent
The thickness and lithology of the Datouyanggou Fm vary considerably along the length of its outcrop extending from Datouyanggou on the south slope of Dakendaban to the lower reaches of the Tataling River. On the banks of the Tataling River, it recorded an incomplete thickness of 1829 m, and is characterized by conglomerate, sandstone, siltstone in the lower part and silty dolomite, thick-bedded limestone in the upper. The limestone in the upper part yields brachiopod Evenkina, Rafinesquina, Campylorthis, Sowerbyella, Ptychoglyptus, Aporthophyla and cephalopod Armenocears, Chisiloceras. It rests unconformably on the Lower Proterozoic, with a covered upper boundary (Qinghai Bureau of Geology and Mineral Resources, 1991).
GeoJSON
Fossils
It yields Cephalopod Armenocears tani and gastropod Lophospira sp.
Age
Depositional setting
Additional Information