Jinta Fm
(9), mid-Guadalupian Epoch (mid-Middle Permian)
Type Locality and Naming
The type section is located at Dameiyao to the north of the Jiata County, Gansu Province. It was named by the 2nd Regional Geological Survey Party of Gansu Province in 1976.
Lithology and Thickness
Volcaniclastics and Mixed marine facies. Composed of grey-green, yellow and green tuff, volcanic breccia and basalt, intercalated with limestone, black shale, siliceous rocks and a small amount of sandstone. The basal part of the formation is yellow-green tuffaceous breccia. Thickness is 1414 m.
Relationships and Distribution
Lower contact
Conformable contact (but diachronous) with the underlying Jushitan Fm claystone
Upper contact
Unconformable contact with the overlying Jurassic System. But regionally, the next younger unit is Fangshankou Fm or Hongyanjing Gr of upper Permian.
Regional extent
Distributed in eastern part of Beishan Mt. and in the area of Heishan Mt. of Jinta County, Gansu Province, and is composed of basalt, sandstone and siltstone, with a thickness of 2260 m, meanwhile in the areas of Shuangjingzi and Biyunquan it is composed of a suite clastic rocks, with a thickness of 500-1500 m.
GeoJSON
Age
Depositional setting
It is interpreted as marine eruptive-rock deposits.
Additional Information