Aoertu Fm
Type Locality and Naming
The type section lies north of the Qijiagou Lime Plant 20 km southeast of Ürümqi, Xinjiang. It was named in 1977 by the Xinjiang Party of Regional Geological Survey, the Institute of Geology of Chinese Academy of Geological Sciences and the United Team on Stratigraphy of Xinjiang Institute of Technology, and formally adopted by the Earth Science Division of the Chinese Academy of Sciences, etc. in 1989.
Synonym: Ao'ertu Fm; Aortu Fm
Lithology and Thickness
Siltstone. A suite of terrigenous clastic rocks, dominated in Qijiagou by gray-black to gray-green siltstone, silty fine-grained sandstone, calcareous sandstone intercalated with minor thin-bedded sandy limestone and lenticular limestone. Exposed thickness 227 m.
Relationships and Distribution
Lower contact
Conformably with the underlying Qijiagou Fm
Upper contact
Minor disconformity to the overlying Shirenzi Fm (Shirenzhigou Fm) in Urumqi; or a major disconformity to the overlying Daheyan Fm in Turpan region (but continuity implied by stratigraphic column of Shuzhong Shen et al. (2019, Permian integrated stratigraphy and timescale of China).
Regional extent
Distributed on the west edge of Bogda Mountain, Xinjiang = same as that of the Qijiagou Fm.
GeoJSON
Fossils
Containing Corals Protomichelinia sp., Pseudosyrigaxon sp., Metriophyllum sp., Lophophyllidium pendulum and Allotropiophyllum sp.; Brachiopods Echonoconchus sp. and Marginifera pusilla, Ammonoids Glaphyrites parangulatus, G. gijiajingensis, Eoasianites sp., Neopronorites carboniferus, Somoholites glomerosus and Proudenites sp.; Plant Calamites sp., as well as gastropods, bivalves, bryozoans, etc.
Age
Depositional setting
It is interpreted as a neritic shelf facies.
Additional Information