Jiange Fm
Type Locality and Naming
Sichuan Basin – north and NW. Chen Chuzhen et al erected the Jiange Formation in 1964. The section for the designation is near the Jiange County on the northwest margin of the Sichuan basin. Upper formation in the Chengqiangyan Gr in northern Sichuan Basin.
Synonym: Jian'ge Fm
Lithology and Thickness
The Jiange Formation is mainly represented by purple red and pink sandstone and siltstone interbedded with mudstone, intercalated with conglomerate and sandy conglomerate. It is about 300 m thick.
Relationships and Distribution
Lower contact
Its base marked by the occurrence of conglomerate shows a gradational relationship with the underlying Hanyangpu Fm built up by purple red fine sandstone with mudstone.
Upper contact
Its top is unknown. Major erosion or non-deposition through the rest of the Cretaceous.
Regional extent
The formation is near the Jiange County on the northwest margin of the Sichuan basin. The basal conglomerate varies slightly to the east of Xinchang, which changes gradually in facies into sandstone and conglomerate and from fine to coarse grain size, and up to 300 m at maximum in the Mumasi area.
GeoJSON
Fossils
The formation yields ostracods Pinnocypridea sp., Jingguella ovata, J. elliptica, Cypridea sichuanensis and Deyangia deyangensis.
Age
Depositional setting
It is of piedmont alluvial fan facies.
Additional Information