Longdongchuan Fm
Type Locality and Naming
The type section is located at Longdongchuan of the Xikou region, Zhenan County, Shaanxi Province. It was named by the 3rd Division of the Chinese Academy of Geological Sciences in 1963.
Lithology and Thickness
Limestone. Composed chiefly of grey and grey-white massive limestone, intercalated with purplish-red clayey limestone or pure limestone. Thickness is 789.5 m.
Relationships and Distribution
Lower contact
Conformable contact with the light-red limestone at the top of the underlying Yundoutan Fm
Upper contact
Conformable contact with the purplish-red and light-yellow clayey limestone, intercalated with shale of the overlying Jinjiling Fm of the Lower Triassic Series
Regional extent
Distributed in the Xikou-Yundoutan areas of the Zhenan County, Shaanxi Province, and it is found to occur in the Yunxi County of Hubei Province (with its thickness being of 386 m).
GeoJSON
Fossils
In the Xikou region it yields Fusulinida such as Palaeofusulina sinensis, P. nana, etc.; Foraminifera represented by Colaniella cylindrica, Paracolaniella inflata; and Corals such as Waagenophyllum simplex, Liangshanophyllum sinensis, etc., belonging to the Changhsingian Stage.
Age
Depositional setting
It is interpreted as a reef-facies deposits with the sponges and blue algae being dominant.
Additional Information