Zhada Fm
Type Locality and Naming
The type section is located at the Gongba Gully (E79°47′, N31°29′), Zhada County, western Xizang (Tibet) Autonomous Region (BGMRXTAR, 1997). Zhang et al. (1981) firstly named the Zhada Fm.
Lithology and Thickness
It is a series of thick lacustrine and fluvial sediments. It is divided into two parts: Lower part is mainly formed by grey, greyish-green, greyish-yellow siltstones, coarse to fine sandstones containing gravels; Upper part is characterized by grey, brownish-yellow thick bedded sandstones and conglomerates containing laminar clays and sands. It contains abundant fossil mammals, fishes, plants, ostracods, gastropods, and sporopollens. Its thickness is more than 800 m.
Relationships and Distribution
Lower contact
Upper contact
In the type section, the Zhada Fm disconformably contacts with the overlying middle or late Pleistocene tillites, glaciofluvial deposits or terrace.
Regional extent
The formation is restricted in the Zhada Basin.
GeoJSON
Fossils
Mammals: Aepyocricetus liuae, Nannocricetus qiui, Prosiphneus eriksoni, Mimomys (Aratomys) bilikeensis, Trischziolagus mirificus, Coelodonta thibetana, Panthera blytheae, Sinicuon cf. S. Dubius, Vulpes qiuzhudingi, Chasmaporthetes gansriensis, Hipparion zandaense, Paleotragus microdon, Protovis himalayensis. (Deng et al., 2011; Wang et al., 2013) Plants: Cotoneaster, Spiraea, Caragana, Hippophae, Rhododendron, Potentilla fruticosa, etc. (Huang et al., 2020) Ostrocods: Qinghaicypris suboentanoda, Qinghaicypris medialis, Leucocythere mirabilis, Leucocytherella sinensis, Ilyocypris sp. Gastropods: Velatinopsis, Radix.
Age
Depositional setting
It is interpreted as an intermontane basin environment.
Additional Information