Changcun Fm
Type Locality and Naming
The type section is located at the west of Yingtang Village of Dale in Xiangzhou County, Guangxi Zhuang Autonomous Region. It was named by Hou Hongfei and Xian Siyuan in 1975.
Lithology and Thickness
Shallow-marine marl. It is composed of a set of grayish green mudstone, shale, siltstone intercalated with shelly clayey limestone with bioturbation and bird-eye structures. In the sandy mudstone at the base contains apatite grains, 0.5-5 mm in size, occasionally reaching 50 mm. The megafossils are rare and reworked with basal wash surface. The formation is about 214 m in thickness..
Relationships and Distribution
Lower contact
Conformable: The base of the formation is separated by the appearance of phosphorite-bearing mudstone from the underlying Guche Fm in a conformable contact.
Upper contact
It is overlain by the Donggangling Fm (Tungkangling Fm), but the contact is not clear.
Regional extent
It is restrictively distributed in the Dale area.
GeoJSON
Fossils
The formation contains rare mega-fossils such as gastropods, bivalve, stromatoporoids, brachiopods and fish fragments.. There are abundant charophyte fossils in the base.
Age
Depositional setting
It is interpreted as a tidal flat to shallow-subtidal facies environment.
Additional Information
The Changcun Fm was often placed within a broadly defined Donggangling Fm (Tungkangling Fm)