Chapu Gr
Type Locality and Naming
The type section is at Baimuxia north of Laji Mountain, Qinghai. The Chapu Gr was named by Qinghai Team of Regional Geological Survey in 1960-1962, and was published by Qinghai Compiling Group for Regional Stratigraphic Scale (1980).
Synonym: (茶铺组); Chafu Gr (spelling)
Lithology and Thickness
The group is dominated by slate, intermediate basic volcanic rock intercalated with conglomerate. In the type area, the Chapu Gr is 3342.5 m thick.
Relationships and Distribution
Lower contact
It rests disconformably on the volcanic rock intercalated with limestone lenses at the top of the Ayishan Fm. In 1975, Qinghai Party of Regional Geological Survey drew the lower boundary at the disappearance of the volcanic rock, and the appearance of the polymictic conglomerate (Qinghai Bureau of Geology and Mineral Resources, 1991).
Upper contact
It is disconformably overlain by the basal conglomerate, pebbly arkosic sandstone intercalated with crystalline limestone lenses in the lower part of the Yaoshuiquan Fm. In 1975, Qinghai Party of Regional Geological Survey drew the upper boundary at the base of the conglomerate at the bottom of the Yaoshuiquan Fm (Qinghai Bureau of Geology and Mineral Resources, 1991).
Regional extent
It is exposed only at Caimaojixia area.
GeoJSON
Fossils
The slate in the lower part yields graptolites Dicranograptus cf. irregularis, Climacograptus cf. uniformis, Glyptograptus sp., Didymograptus sp., Orthograptus sp., Amplexograptus sp., Glossograptus cf. gracilis and cephalopods Endocears, Protocylocears.
Age
Depositional setting
Additional Information