Yunnanyi Fm
Type Locality and Naming
Xie Jiarong named "Yunnan Yi Layer" in 1941. The named section is located in Yunanyi, Xiangyun County, Yunnan Province.
Lithology and Thickness
Mainly clastic rocks. From bottom to top, it can be divided into three parts: Lower shale is dominated by yellow-green and yellow shale, intercalated with argillaceous siltstone, with a thickness of 956 m. Middle limestone segment is composed of argillaceous limestone and dolomitic limestone with yellow-green sand shale with a thickness of 400-600 m. Upper shale section is dominated by yellow-green shale interlaced with siltstone and mudstone lens.
Relationships and Distribution
Lower contact
The bottom is in unconformable contact with the underlying Paleoproterozoic Dahongshan Gr.
Upper contact
The top is in conformable contact with the overlying Luojiadashan Fm or Xiangyun Fm.
Regional extent
GeoJSON
Fossils
Bivalves: Halobia pluriradiata, H. yunnanensis, H. rugosa, Angustella angusta, Halobia yunnanensis. Ammonoids: Indojuvarites sp.
Age
Depositional setting
Additional Information