Suotoushan Fm
Type Locality and Naming
The type section is located at a gully of Bianqinggou, Qingmen of County, Chaotong City (103o48’E-27 o 23’N), Yunnan Province. It was named by Xian Shiyuan and Zhou Xiyun in 1974 and published in 1978.
Lithology and Thickness
Sandstone. The formation is characterized by grayish-white and yellow medium- to thick-bedded well-sorted, pure quartz sandstone. Few siltstone and sandy mudstone are observed. Maximum thickness is up to 440 m.
Relationships and Distribution
Lower contact
It rests conformably on the Qingmen Fm in the type section and is disconformable with underlying Pojiao Fm or Cambrian rocks in Qiaojia and Ninglang. At the Ningiang section, it rests on the Dacaozi Fm.
Upper contact
It is conformable contact with overlying Haikou Fm, the contact being placed at the change from sandstone below to limestone or dolostone above. In Ninglang section, it is overlain by Lanniqing Fm.
Regional extent
The Formation is widely distributed in northeastern Yunnan forming step cliffs in landscape.
GeoJSON
Fossils
The formation yields plant Hostimella sp. and fish fossil fragments.
Age
Depositional setting
It is interpreted as a backshore littoral environment.
Additional Information