Xiangbai Fm
Type Locality and Naming
The type section is located in the Xiangbai lumbering area of Baijin, Huishui County, Guizhou. It was named by the No. 108 Geological Party of Guizhou in 1976.
Lithology and Thickness
Clayey sandstone. Composed mainly of gray, gray-yellow and gray-white thin- to moderately thick-bedded quartz sandstone interbedded with gray-black, black and yellow-brown sandy shale and carbonaceous shale, intercalated with 1−4 coal seams or streaks, yielding bedded and nodular siderite. In the Dushan, Pingtang, Libo, Huishui and Heishi River areas, the sedimentation is thick, generally about 200 m; reaching the greatest thickness at Xiajiajie of Libo, 806 m; and thinning along Changshun and Anshun. Northeastward from the above two sedimentation centers, it is only several to over ten meters around Congjiang and Liping.
Relationships and Distribution
Lower contact
Disconformable overlying the Sinian System and Xiajiang Gr in the areas east of Liping and Congjiang; and overlying the Yaosuo Fm, Gaopochang Fm, Gelaohe Fm and Tangbagou Fm at Hezhang, Nayong, Huishui, Guiyang, Changshun, Longli et al.
Upper contact
Regional extent
GeoJSON
Fossils
The sandy shale, marl and shale contain Bivalves Nuculopsis sp., Aviculopecten sp., Parallelodon sp., etc.; the black shale yields Plants Lepidodendron sp. and ?Sublepidodendron sp.; the limestone in the upper part yields Brachiopods Delepinea sp. and Megachonetes sp.
Age
Depositional setting
It is interpreted as littoral clastic and littoral swamp deposits
Additional Information