Hajier Fm
Type Locality and Naming
The type section is located at about 55 km to the northwest of Yangkang Country, Tianjun County, Qinghai Province. It was named by Liu Guangcai in 1980, and was issued officially in 1984. Lower formation in the Nuoyinhe Gr.
Lithology and Thickness
Sandstone to Shale. Lower part is composed of purple very thick-bedded fine-grained feldspar-rich sandstone intercalated with siltstone. Upper part consists of grey-black shale, intercalated with grey cherty-banded limestone and biolithite. Thickness is 269 m.
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Caodigou Fm.
Upper contact
Conformable contact with the overlying Zhongshigong Fm.
Regional extent
Distributed in an area to the south of Harla Lake and Great Gangca Temple and to the north of Delinghar-Gangcha County extending in a E-W-trend for 160 km, with a width of about 75 km.
GeoJSON
Fossils
Brachiopods: Composita yangkangensis- Spinomarginifera lopingensis-Leptodus assemblage. Bryozoa: Dybowskiella sinensis-Synocladia irregularis-Stenopora linoporalineata assemblage Plus bivalve, coral and plant fossils (phytolites).
Age
Depositional setting
It is interpreted as dry littoral-shallow sea deposits. The Nuoyinhe Gr in the southern marine-facies region is composed mainly of limestone, less of feldspar and quartz, with a thickness of 11.7-269.6 m, yielding abundant brachiopods. In the northern part of the area, it represents a paralic deposit region.
Additional Information