Xintianmen Fm
Type Locality and Naming
It was named by the Coalfield Company of Hunan Province in 1974, and was first cited publicly by Chen Jinhua and others in 1980. The naming section is located in the vicinity of the Xintianmen area, Changche region, Yizhang County, Hunan Province.
Synonym: （心田门组）
Lithology and Thickness
Lower part is composed of an alternating layer of black quartz-sandstone and silty mudstone. Middle part is black siltstone and carbonaceous and siderite-bearing mudstone, containing siderite concretions. Upper part is black mudstone and silty mudstone, containing siderite bands, with a total thickness of 80-207 m.
Relationships and Distribution
Lower contact
It overlies conformably the Tanglong Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Maoxianling Fm
Regional extent
It is distributed essentially in the Xintianmen area of the Changche region, Yizhang County. In the Yanshouyu area of Rucheng County it is also known as the Yanshouyu Formation composed of quartz-sandstone and micaceous sandstone; northerly till the Sandu area of Zixing County the formation is turning to be composed of thin-bedded quartz-sandstone and silty mudstone, with thickness of only about 18 m, while in the Yongxing and Caling counties the formation is pinching out and missing.
GeoJSON
Fossils
It yields bivalve fossils as represented by the Parainoceramus-Tienonuculana assemblage whose important members comprise Parainoceramus, Retroceramus and Tienonuculana; and plant fossils as represented by the Marattiopsis-Otozamites assemblage of the Dictyophyllum-Clathropteris flora.
Age
Depositional setting
The formation represents shallow-sea-littoral or sea-inlet-facies deposits.
Additional Information