Yigenhe Fm
Type Locality and Naming
The type section is lies south of the Yiligen pasture, Ergun Right Banner, Inner Mongolia. It was named by the No. 2 Heilongjiang Party of Regional Geological Survey in 1981.
Lithology and Thickness
Conglomerate and Siltstone. A suite of continental clastic rocks. Lower part consists of variegated fine-grained to medium-grained conglomerates interbedded with black siltstone. Upper part is of gray-black siltstone and clayey siltstone intercalated with gray-black clayey rock. Exposed thickness 450 m. At Galacheng, it is similar to the type section in lithology, except that the former is intercalated with thin-bedded dacite, 518 m thick.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Xiertala Fm (or with Jiogaoshan Fm)
Upper contact
Known: The upper boundary is unclear. In western extent, Permian Lexicon chart indicates that next higher unit is the mid-Permian Gaojiawopeng Fm.
Regional extent
Distributed in the southern part of the newly-built team of Yiligen pasture of Ergun Right Banner and around Galacheng of Zhalantun City.
GeoJSON
Fossils
Lower part is dominated by Brachiopods, including Tangshanella sp., Neospirifer cf. orientalis, Mesolobus cf. indistinotus and Chonetinella alata. Upper part is characterized by the early Angara Flora, dominantly Angaropteridium cardiopteroides, Noeggerathiopsis sp., Paracalamites sp., Tingia? sp. and Neuropteris plicata;
Age
Depositional setting
It is interpreted as continental clastics.
Additional Information