Toutunhe Fm
Type Locality and Naming
Junggar and Turfan-Hami Basins. It was named by Fan Chenglong and others as the Toutunhe Horizon in 1956. Its naming section is located at the Toutun River west of Urumqi City, Xinjiang, with the section at the Manasi River serving as its reference section.
Synonym: （头屯河组）
Lithology and Thickness
The formation is composed of yellow-green, grey-green and violet mudstones and grey-green sandstone, intercalated with tuffs and carbonaceous shales, with a thickness of 400-500 m.
Relationships and Distribution
Lower contact
It is in a conformable contact with the underlying Xishanyao Fm
Upper contact
It is in a conformable contact with the overlying Qigu Fm
Regional extent
The formation is distributed in the Junggar Basin and the eastern and western Junggar mountainous regions, as well as in the Tulufan-Hami Basin. The lithology of it is consistent in various regions, but with a great variation in its thickness, being of 28-440 m on the northwestern margin of the Junggar Basin; of 400-500 m on the southern margin of the Junggar Basin, with the greatest thickness of about 640 m being seen in the area of the Manass River, and with the thickness getting smaller westerly.
GeoJSON
Fossils
It yields the Coniopteris-Phoenicopsis flora, bivalve fossils such as Ferganoconcha minor, Pseudocardinia gansuensis, P. yumenensis, Margaritifera isfarensis, Psilunio ovalis, P. jingyuanesis, P. manasensis and P. globitriangularis; and Ostracoda fossils as represented by Darwinula impudica and D. sarytirmenensis.
Age
Depositional setting
It is interpreted as a fluvial-lacustrine environment.
Additional Information