Qiuwu Fm
Type Locality and Naming
Named the Qiuwu coal measures by Li Pu in 1955 and was originally assigned to a Triassic age. In 1964, the Tibet Bureau of Industrial Geology renamed it the Qiuwu Formation and assigned its age to Late Cretaceous. In 1983 the Tibet Regional Geological Party re-assigned its age to Eocene. The reference section is located at Qiabulin (Dongga Village) 10 km northwest of Xigazê, Tibet.
Lithology and Thickness
A sequence of sandy shale, coal-bearing clastic rocks and basal conglomerate. It is divided into the upper and lower members: Lower member is the sandy conglomerate member; Upper member is coal-bearing sandstone-shale member with thin coal beds. The thickness ranges from 100 to 500 m.
Relationships and Distribution
Lower contact
It has an unconformable contact with the underlying early Himalayan granite. However, regionally, the next older unit (on China Lexicon strat chart) is the Zhepure Fm
Upper contact
It has an unconformable contact with the overlying Oligocene–Miocene Dazhuka Fm.
Regional extent
The formation is distributed between Ngamring and Xigazê, Tibet, extending for 400 km.
GeoJSON
Fossils
The upper member yields the plants Ficus, Populus etc. and sporopollen.
Age
Depositional setting
Additional Information