Sanhekou Gr
Type Locality and Naming
The type section is located at the area from Sanhekou of Wudu to Kanxian, Gansu Province.
It was named by Geological Team of West Qinling in 1963 and was published in 1976 by Qinfeng and Ganyan.
Lithology and Thickness
Sandy claystone (metamorphic), volcanic rocks. The Sanhekou Group was subdivided by Yang Zhucai (1991) into three formations:
Lower formation is characterized by sericitic phyllite intercalated with thin-bedded nodular limestone.
Middle formation consists of medium-acidic tuff rocks.
Upper formation is composed of thin- to medium-bedded limestone intercalated with phyllite.
In the area from east of Kanxian to Jinjiahe of Nuoyang, all three formations of the Group contain basic- to intermediate-acidic volcanics and tuff rocks.
Incomplete outcrops range from about 4501 to an amazing 11,237 m thick!
Relationships and Distribution
Lower contact
The Group is unconformably underlain by the Silurian Bikou Gr.
Upper contact
The Group is unconformably overlain by the Carboniferous.
Regional extent
GeoJSON
Fossils
The fossils recorded are Favosites regularissimus, F. diformis, Squameofavosites obliquespinus, Pachyfavosites regularis, Emmonsia sp., Caliapora sp., Lyrielasma sp., Euryspirifer sp., Paramphipora sp., Anostylostroma sp.
Age
Depositional setting
Additional Information