Wangjiazhai Fm
Type Locality and Naming
The type section is located in the Wangjiazhai area about 20 km to the north of Liupan City, Guizhou Province. It was named by Tian Baolin et al. in 1980.
Lithology and Thickness
Siltstone and Coal. Composed of black-grey calcareous fine siltstone, siltstone, grey fine-grained sandstone, grey-brown claystone, thin-bedded marl and bioclastic limestone, containing 4-5 layers of minable coal, with a thickness of 78 m.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Xuanwei Fm (Hsuanwei Fm)
Upper contact
Conformable contact with the overlying Feixianguan Fm of the lower Triassic Series
Regional extent
In a Memoir of the《Regional Geology of Guizhou Province》(1987) the Wangjiazhai Fm is regarded as a part of westerly extension of the Longtan Fm, and its underlying continental coal-bearing strata are known as the Xuanwei Fm (Hsuanwei Fm). By taking the Wangjiazhai (78 m) of the Shuicheng County of Guizhou Province as its center and in its extension northerly through the Zhengxiong and Weixin Counties of Yunnan Province to the Yunlian County (35 m) and the Xingwen County (40 m) of Sichuan Province the formation is characterized by an increase of limestone in amount and a shrinkage of its thickness, with the marine strata being decreasing in amount westward, and also with its stratigraphic horizon being gradually uprising to transition into the Xuanwei (Hsuanwei) Fm up to the Laowuji and Weining areas of the Panxian County.
GeoJSON
Fossils
It yields ammonoids such as Pseudotirolites acutus, Pleuronodoceras anshunense, Rotodiscoceras longilobatum, River torulosum; such Fusulinids as Palaeofusulina guizhouensis; brachiopods such as Waagenites soochowensis, Oldhamina decipiens; and plant fossils (phytolites) such as Ullmannia cf. bronnii, whose stratigraphic horizon is corresponding to that of the Changxing Fm (Changhsing Fm)
Age
Depositional setting
Additional Information