Sedimentary facies of the Lower Permian Ngangze Formation in the Coqen Basin, Xizang

The sedimentary facies analysis is an important basic research in the petroleum exploration and assessment. The present paper presents a description of lithology, sedimentary facies , vertical evolution and regional deposition on the basis of the data obtained from the Lajiadang section in Gyungcang, Nyima, Xizang. The formation is dominated by a suite of dark clastic rock series consisting of sandstones and mudstones which are ascribed to the Carboniferous Permian glacial marginal sea sediments on Gondwana land, and characteristic of both continental stable sediments and littoral low energy sediments. The depositional environments are related to short period small scale nearshore glacial activity.