Songziyuan Fm
Type Locality and Naming
Central-westernmost Hubei. The Songziyuan Fm was named by the Party of Regional Geological Survey, Hubei Bureau of Geology in 1974. The type section is in Songziyuan, Lianghek-ou, Badong County, Hubei Province. Upper formation (10 of 11 in Lexicon) of Shennongjia Gr.
Synonym: （送子园组）, Lijiaziu Fm of the Dagushi Gr in the Dahong Mountain area is considered to be a synonym of the Songziyuan Fm
Lithology and Thickness
Lower part of the formation is composed of black thin-bedded siliceous siltstone, laminated siliceous dolomitic siltstone, fine-grained sandstone, chert, muddy dolomite and thin-bedded hematite. Upper part is monotonous siltstone intercalated with carbonaceous, siliceous quartz sandstone and dolomite bands or lenses. It is 350 m thick.
Relationships and Distribution
Lower contact
The base of the Songziyuan Fm is in disconformable or unconformable contact with the underlying Shicaohe Fm.
Upper contact
It has a conformable contact with Wanganxi Fm.
Regional extent
Central-westernmost Hubei. It is distributed at Wujiaya, Shennongjia Forest District and along bank of Jiemeichong of Songhe River, Dahong Mt. area, and around Lianghekou, Badong County.
GeoJSON
Fossils
The dolomite bed near the top of the formation bears stromatolites, the main taxa are Cryptozoon f.; and the siltstone bears microplants, such as: Trematosphaeridium, Polyporata obsoleta.
Age
Depositional setting
Additional Information