Yijiawan Fm
Type Locality and Naming
The type section is located at Yijiawan of Xiangtan City, Hunan Province. It was named by Tian Qijun (=Tien C. C.) in 1938.
Lithology and Thickness
Shale, limestone. The Formation is mainly characterized by shale, siltstone and mudstone with a few clayey limestone layers or lenses of limestone in the Lower part, and clayey limestone in the Upper. The thickness of the Formation varies from tens meters to 200 m in Shaodong, Leiminqiao of Lianyuan, Xiangxian, Ningxiang, Taojinag and Liuyang; and more than 200 m to 537 m in Maotang of Lianyuan, Tiaomajian of Changsha.
Relationships and Distribution
Lower contact
Upper contact
The upper part may consist of more interbeds of clayey limestone and bioclastic limestone when it is overlain by Qiziqizo Limestone or Huanggongtang Dolomite.
Regional extent
The thickness of the Formation varies from tens meters to 200 m in Shaodong, Leiminqiao of Lianyuan, Xiangxian, Ningxiang, Taojinag and Liuyang; and more than 200 m to 537 m in Maotang of Lianyuan, Tiaomajian of Changsha.
GeoJSON
Fossils
It contains abundant fossils such as
brachiopoda Chonetes supragibbosa Assemblage Zone and Strigocephalus Assemblage Zone, and
coral Endophyllum-Stringophyllum Assemblage Zone,
as well as bivalves, stromatoporoids, and crinoids.
Age
Depositional setting
Additional Information