Kuangshishan Fm
Type Locality and Naming
Central-westernmost Hubei. The Kuangshishan Fm was named by the Party of Regional Geological Survey, Hubei Bureau of Geology in 1974.The type section is at the main peak of Shennongjia Mt., Hubei Province. Middle formation (5 of 11 in Lexicon) of Shennongjia Gr.
Synonym: （矿石山组）
Lithology and Thickness
The formation is subdivided into lower, middle and upper parts. Lower part is mainly of ferruginous rock series, dark grey to grey-black thin-bedded dolomitic siltstone (= sugary dolomite?) intercalated with argillaceous and ferruginous siltstone and hematite bed. Middle part is grey to dark-grey stromatolites reef-bearing and oolitic dolomite. Upper part consists of grey stromatolite-bearing micritic dolomite, massive dolomite with chert lumps, thick-bedded dolomite intercalated with quartz sandstone. The top is composed of stromatolite-bearing and siliceous macro-crystalline dolomite and dolomitic breccia. Scouring surfaces and syngenetic pebbles are seen in the dolomite. The thickness varies from 12 m to 442 m.
Relationships and Distribution
Lower contact
The base of the formation is in disconformable contact with underlying Dawokeng Fm
Upper contact
The top of the upper part is in disconformable contact with the overlying Taizi Fm (because of a paleo-weathering crust present below the sandstone conglomerate).
Regional extent
Central-westernmost Hubei. The Kuangshishan Fm is especially developed around the main peak of Shennongjia Mountain, Kuangshishan and Heishui River drainage area of Hubei Province.
GeoJSON
Fossils
The stromatolites are mostly stratified and stratocolumn type, the main taxa are Stratifera f., Colonnella f., Conophyton garganicum. The main microplants in the lower part are Trematosphaeridium, Polyporata.
Age
Depositional setting
Additional Information