Hongxingyan Fm
Type Locality and Naming
The type section is named in 1978 by the Second District Investigation Team of the Sichuan Geological Bureau, the type section is located on the northern slope of Hongxingyan, Songpan County, Sichuan Province.
Synonym: Hongxing Fm
Lithology and Thickness
It is dominated by limestone dolomite, with dolomite and a small amount of limestone in between, and lava breccia in the middle. The local limestone has an oolitic structure with wave marks on the top. The thickness is 408 m.
Relationships and Distribution
Lower contact
At the bottom, the purple-red iron-bearing sandy limestone is conformable contact with the underlying Fuluorangou Fm (=Luoranggou Fm?)
Upper contact
The top is in false conformable contact with the overlying Qiranggou Fm
Regional extent
The distribution is limited, which is only found in Songpan, Sichuan Province. It is 407.9 m thick in the Hongxingyan area from south to north. The Qirang ditch is 581.9 m thick, and the Zhongcha ditch is 339 m thick, which tends to be thicker in the south and thinner in the north.
GeoJSON
Fossils
Fossils are rare, only gastropods Zygites sp. are seen.
Age
Depositional setting
It is interpreted as shallow sea lagoon deposits.
Additional Information