Kangnan Fm
Type Locality and Naming
Wen Shixuan named it in 1979. The named section is located in the south of Kanglu Mountain, Shuanghu County, Tibet, about 1.5 km northeast of Shuanghu Office.
Synonym:
Lithology and Thickness
It is a set of sandstone interbedded with sandy limestone and thin-bedded limestone formations. Lower part consists of gray-black thin to intermediate limestone. Upper part is interbedded with gray-green sandstone, sandy shale and thin argillaceous limestone, interbedded with coarse sandstone and conglomerate. The thickness is 256 m.
Relationships and Distribution
Lower contact
The grey-green sandstone at the bottom overlies the Xishuanghu Fm
Upper contact
The sandstone at the top is conformably overlain by the Xiaochaka Gr limestone.
Regional extent
It is mainly distributed in the area from Rejue Chaka to Kangru Chaka near Shuanghu Office, Shuanghu County, northern Xizang.
GeoJSON
Fossils
There are ammonoids Arthaberites alexandrae, Acrochordiceras cf. carolinae, Haydenites hatscheki, Cuccoceras yoga, C. taramellii, Balatonites tibeticus, Procladiscites crassus, P. cf. brancoi, Gymnites incultus, Ptychites rugifer, P. arcestoides, Aristoptychites sp. and brachiopods Mentzelia cf. subspherica, Lepismatina cf. hsuei, Nudirostralina griesbachi in the lower part. There is bivalve Daonella bulongensis bifurcata in the upper part.
Age
Depositional setting
This formation is a shallow sea deposit.
Additional Information
Rao Rongbiao et al. (1987) doubted whether the Kangnan Formation in northern Tibet included the Latina deposition. There is no specific place name for Kangnan, so it is suggested to create a new name.