Cuoguo Fm
Type Locality and Naming
It was named by the Regional Geological Survey Party under the Geological Bureau of Tibet in 1987. The naming section is located on the western side of Cuoguo, Wuma District, Gaize County, Tibet (E 83°10′, N 32°12′).
Synonym: （错果组）
Lithology and Thickness
Composed of limestone and sandstone. Lower part consists of grey medium-bedded sandstone, quartz-sandstone and siltstone, intercalated with a small amount of limestone and chert. Upper part consists of grey and dark-grey medium-bedded limestone, bioclastic limestone, marl and siliceous limestone, commonly being unmetamorphosed. The top part of it being composed of grey and dark-grey limestone, intercalated with bioclastic limestone, with an exposed thickness of over 810 m.
Relationships and Distribution
Lower contact
No basal part of the formation has been found. Regionally, the schematic strat column indicates the next older unit as Longhai Fm.
Upper contact
It is in an unconformable contact with the overlying upper Cretaceous. Regionally, the schematic strat column indicates the next younger units are the Muggarkangri Gr or the Shamuluo Fm.
Regional extent
The formation is distributed in the Cuoguo area, with a consistent lithology; commonly being unmetamorphosed, and with a thickness of 810-1000 m.
GeoJSON
Fossils
In the Cuoguo area the formation yields bivalves: Astarte cf. huralensis, Pseudotrapezium cordiforme.
Age
Depositional setting
Additional Information