Qiranggou Fm
Type Locality and Naming
The second area survey team of Sichuan Geological Bureau was named in 1978. The named section is located in Qilanggou, Hongxing Township, Songpan County, Sichuan Province.
Synonym: Qilanggou Fm
Lithology and Thickness
They are mainly gray dolomitic limestone, dolomite sandy limestone and bioclastic limestone, with yellow-green shale at the bottom and spherical, kidney-like and giant oolitic structures.
Relationships and Distribution
Lower contact
The contact with the Hongxingyan Fm is pseudo-conformable and has not peaked.
Upper contact
'There is parallel unconformity between the strata of Zoige and the overlying metamorphic sand slate with limestone."(?). Schematic stratigraphic column implies a hiatus below the overlying Tazang Gr.
Regional extent
GeoJSON
Fossils
It contains bivalve fossils Asoella illyrica, A. subillyrica, brachiopod fossils Mentzelina sp. and gastropod fossils.
Age
Depositional setting
It is interpreted as littoral and shallow sea deposits.
Additional Information
Taking Awenggou-Sandaopan as the boundary, the southern part is mainly light gray, gray and white compact massive limestone, while the northern part is dolomitic limestone and dolomite. The thickness of the outcrop varies from place to place. The thickness of the Hongxingyan area is more than 400-600 m, the Qilanggou area is 351 m, and the Zhongchagou area is only 200 m.