Changyanwo Fm
Type Locality and Naming
The type section is located at Shilamam, Jintang District, Kangding, Sichuan. It was named by the Western Sichuan Team, Chinese Academy of Geological Sciences in 1966.
Lithology and Thickness
The Lower part is composed of gray and gray-black carbonaceous slates intercalated with clastic limestone, siliceous rock, gray thin−thick-bedded crystalline limestone, carbonaceous shale, bioclastic limestone. The Middle part is gray and dark-gray moderately thick-bedded crystalline limestone, and bioclastic limestone, often with siliceous nodules. The formation is 246.2 m thick at Shilama.
Relationships and Distribution
Lower contact
Disconformable contact with the Middle and Upper Devonian (regionally, Weiguan Gr is next older unit)
Upper contact
Conformable contact with the Late Carboniferous Luanshijiao Fm
Regional extent
Distributed in the northwestern Baoxing area, Tongliangzi, Dayu, Kangding on the west side of the Kang-Dian uplift et al.
GeoJSON
Fossils
The Middle part yields Corals Clisiophyllum grossinum, Gangamophyllum sp., Carcinophyllum sp. and Palaeosmilia sp., Fusulinids Millerella sp. and Eostaffella sp., Brachiopods Productus sp. and Chonetes sp.; the Upper part: Fusulinids Eostaffella quasiampla and Millerella minutas, and Coral Dibunophyllum sp.
Age
Depositional setting
It is interpreted as neritic sediments.
Additional Information