Shiyewan Fm
Type Locality and Naming
The type section is located to the east of the Tongshengmao Village, Shiguai District, Baotou City, Inner Mongolia (110°26′, 40°38′). It was named by Li Xingxu et al., in 1953, and was issued publicly in 1954.
Lithology and Thickness
Clastics. Composed of dark-purple, yellow-green sandy shale, shale, sandstone and coarse-grained sandstone, intercalated with conglomerate. Its basal part is composed of yellow-green conglomerate and pebbled sandstone.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Zahuaigou Fm.
Upper contact
Conformable contact with the overlying Naobaogou Fm.
Regional extent
Distributed only in the areas of Naobaogou, Tongshengmao and Shuiquangou till the central Bugesu to the east of the Shiguaizi District, Baotou City. In the area of the Beiyaozi Village of the Naobaogou Trench the formation is composed mainly of grey and dark-purple clastic rocks, with a thickness of 182 m. In the Tongshengmao and central Bugesu areas it is composed of dark-purple and yellow-green clastic rocks, with a thickness of 93 m, and getting smaller in a direction from north to south.
GeoJSON
Fossils
In the boreholes drilled in the area of central Bugesu the grey-yellow conglomerate and pebbled sandy coarse-grained sandstone from the base of the formation yield such Plant fossils (phytolites) as Pecopteris sp., Cordaites principalis, Calamites sp., Sphenophyllum sp., etc.
Age
Depositional setting
It is interpreted as a intermontane-basin deposits which are characterized predominantly by its purple color.
Additional Information