Fankeng Fm
Type Locality and Naming
The type section is located at Xiacun Village south of the Tangbao region, Yongding County, Fujian Province; with its reference section being situated in the vicinity of the Fankeng Pit 1.5 km north of Xiacun Village. It was named by the Regional Survey Party of Fujian Province and Cao Baosen in 1978-1981.
Synonym:（藩坑组）, Pankeng Fm (spelling)
Lithology and Thickness
The formation is composed mainly of basalt, andesite, dacitic brecciated tuff and crystal-lithic tuff, intercalated with littoral and shallow-sea mudstones, siltstone, fine-grained quartz-sandstone and continental clastics. Thickness is about 1240 m.
Relationships and Distribution
Lower contact
Its basal part is in an unconformable contact with the underlying Xiacun Fm
Upper contact
Regionally, the next younger unit is the sandstone of the Zhangping Fm
Regional extent
The formation is distributed essentially in the areas of Tangbao of Yongding County, Luxi Stream of Pinghe County, Wushi Mt of Nanzing County, Jitou of Shanghang County, Yuanfeng of Wuping County and Neiliao of Changtai County. Since the areas of Datian and Dacai of Yongtai County and Nanyang of Zhangping County are more likely to be close to the land-source area, most of the sediments represent continental clastic deposits, intercalated with parts of tuffaceous sandstone and siltstone.
GeoJSON
Fossils
The lower part of the particular formation yields bivalves as presented by the Parainoceramus-Camptonectes (Hunannonectes) assemblage, while its upper part yields the Qiyangia fauna, ammonites as represented by Coroniceras sp., and Arietites sp., as well as Brachiopoda and Crinoidea stems; conchostraca fossils as represented by the Eosolimnadiopsis-Asiolimnadiopsis assemblage; and Ostracoda as represented by Gomphocythere? Rhomboidalis, G.? yubacuensis, Darwinula megacontracta and Eolimnicythere sp. From among the plant fossils there are found Neocalamites sp., Clathropteris sp., Coniopteris sp., Nilssonia orientalis, Sagenopteris sp., and Ginkgoites cf. marginatus.
Age
Depositional setting
The formation is predominated by deposits of volcano-eruption facies, intercalated with deposits of littoral-shallow-sea, and fluvial-lacustrine facies.
Additional Information