Suhongtu Fm
Type Locality and Naming
The Suhongtu Formation was erected by the Ningxia Regional Geological Survey Team in 1980. The section for the designation is in Sumusuhongtu of Uliji of Alxa Zuoqi of Inner Mongolia (104°13′E; 41°11′N).
Lithology and Thickness
Lower part of the Suhongtu Formation is represented by gray black and gray green andesite and basalt with sandy conglomerate. Upper part is yellow green silty mudstone and brown red clayey siltstone interbedded with dark purple gray basalt with thin-bedded marl. The Suhongtu Formation is in excess of 450 m in thickness.
Relationships and Distribution
Lower contact
The base of the formation is not observed in the type sections. On the Balongwula mountain of Urad Houqi, it lies conformably on the underlying Bayingebi Fm.
Upper contact
The top marked by dark purple and gray yellow basalt lies unconformably under the Wulansuhai Fm.
Regional extent
The present formation mainly occurs in Suhongtu, Ludeng-Hukoueligen of the Suhong basin of Urad Houqi. It is less than 50 m thick at minimum and up to 946.1 m at maximum.
GeoJSON
Fossils
It yields bivalves Sphaerium jeholense, S. selonginense; ostracods Cypridea globra, C. kansuensis, C. yabulaiensis, etc. About 15 km southwest of Suhongtu, it yields Reptilia Psittacosaurus; estheria Eosestheria sp. In Tulugaihuduge, it also yields sporopollen grains represented by the Classopollis-Tricolpites assemblage.
Age
Depositional setting
Additional Information