Dawokeng Fm
Type Locality and Naming
Central-westernmost Hubei. The Dawokeng Fm was named by the Party of Regional Geological Survey, Hubei Bureau of Geology in 1974.The type section is in Dawokeng of Shennongjia forest Region near the main peak of Shennongjia Mt., Hubei Province. Lowest formation (4 of 11 in Lexicon) of Shennongjia Gr.
Synonym: （大窝坑组）, Huangcaoping Fm and the Jiucaiyazi Fm (upper part).
Lithology and Thickness
In the type section: Lower part of the formation consists of grey thick-bedded dolomite, grey-black, yellow-white stromatolite-bearing, micritic-fine- crystalline dolomite, and black streaky tuffaceous micritic dolomite, muddy dolomite. algal-detritus dolomite, siliceous-banded dolomite intercalated with grey-green volcanic breccia. Upper part is grey thick-bedded massive, stromatolite-bearing reef dolomite. The dolomite has oolitic or banded structure, oblique bedding, ripple mark, with the development of syngenetic clasts. The formation is 103-267 m thick.
Relationships and Distribution
Lower contact
Bottom is not seen. Regionally, the next older unit is the Shuiyuesi Gr. (Luanshigou Fm?)
Upper contact
It is disconformably overlain by the Kuangshishan Fm
Regional extent
Central-westernmost Hubei. The formation is distributed at the main peak of Shennongjia Mountain, Jiuchong, Laojunshan, Tiechanghe and Laohuding.
GeoJSON
Fossils
The stromatolites in the formation are dominated by conic shape, namely, Conophyton garganicum, C. lituum, C. dahonyuense, Gaoyuzhangia f.
the microplants are Trachysphaeridium, Dictyosphaeridium, Trematosphaeridium, Polyorata.
Age
Depositional setting
Additional Information