Aertash Fm
Type Locality and Naming
Kashi-Yarkand region (NW Tarim). The naming section is located near Aertash (Alatax) Village, Shache County, in the piedmont zone of the Kunlun Mountains. Named by the Xinjiang Petroleum Administration in 1975.
Synonym: Alatax Fm
Lithology and Thickness
The formation is lithologically uniform in the area, composed dominantly of a white, very thick, cryptocrystalline gypsum bed, with a <10 m thick, quite persistent and rich mollusk-bearing dolomitic limestone bed at the top and a conglomerate or sandy conglomerate bed at the base. It grades facially into white coquina locally at the foot of the eastern and southern Kunlun Mountains, belonging to lagoonal sediments. Its thickness varies from place to place and may reach a maximum of over 300 m.
Relationships and Distribution
Lower contact
It has a disconformable or conformable contact with the underlying Paleocene Tuyiluoke Fm
Upper contact
Conformable contact with the overlying Paleocene-Eocene Qimugen Fm
Regional extent
This formation is widespread, extending from the national borderline eastward roughly to east of the Hotan River. Outcrops are mostly concentrated in Shache, Yengisar and Yecheng in the piedmont zones of the Tianshan and Kunlun Mountains.
GeoJSON
Fossils
The bivalves Brachidontes jexemejewi, Corbula (Cuneocorbula) asiatica and C. (C.) angulata, the gastropods Potamides (?) romanovskyi and the foraminifera Miliolina, etc.
Age
Depositional setting
Mainly marine sediment, and grades into lagoonal sediments at the foot of the eastern and southern Kunlun Mountains.
Additional Information