Linbuzong Fm
Type Locality and Naming
South Lhasa Block - Linzhou Basin. It was named by Luo Zhongshu in 1973, Tibet Geology. The naming section is located at Linbuzong north of Lhasa, Tibet (Wang Naiwen and others, 1983), with its reference section being situated at the Quesang Village, Duilong-Deqing County, Tibet (Tibetan Geological Bureau, 1979).
Synonym: （林布宗组）
Lithology and Thickness
Indicated as mainly dark claystone on regional summary column (Dangpeng Xi, Wan Xiaoqiao, et al., 2019). Lower part of the formation is composed of black concretion-bearing shales intercalated with siltstones, sandstones and sandy conglomerates, intercalated with coal beds and carbonaceous shales, with its basal part yielding ammonites, bivalves and plant fossils. Middle part consists of black concretion-bearing shales intercalated thin-bedded siltstones and sandstones, yielding plant fossils. Upper part is composed of black-grey and black concretion-bearing shales intercalated with siltstones and quartz-sandstones, yielding plant fossils. It is 450-619 m in thickness.
Relationships and Distribution
Lower contact
The concretion-bearing shales, siltstones and sandy conglomerates of its basal part are in a conformable contact with the grey limestones from the top part of the underlying Duodigou Fm.
Upper contact
Its top part is in a conformable contact with the grey-green gritstones from the overlying Chumulong Fm
Regional extent
South Lhasa Block - Linzhou Basin. The formation is distributed extensively in the areas of Quesang, Linbuzong, Yebar Gully of Lhasa region, as well as at Chumulong and Niuma Gully of Linzhou County, with a consistent lithology, representing continental coal-bearing deposits in most regions, and with its lower part being characterized by the occurrence of marine and continental alternating deposits only in the areas of Quesang, Linbuzong and Yebar Gully, with a thickness of 400-3300 m.
GeoJSON
Fossils
In the Quesang section there occur plant fossils as represented by Weichselia reliculata, Zamiophyllum buchianum, Ptilophyllum acutifolium, P. cf. cutchense, Elatide curvifolia, Cycadolepis sp. and Desmiophyllum. In the areas of Quesang and Yebar Gully of Dazi County it yields ammonites such as Virgatosphinctes sp.? Aspidoceras sp., Aulacosphinctoides sp.; bivalves such as Pseudomonotis inornata and P. amoena.
Age
Depositional setting
Additional Information