Ziniquanzi Fm
Type Locality and Naming
Junggar Basin. The naming section is located near Ziniquanzi, Manas County on the southern margin of the Junggar basin, Xinjiang. Named by the Compilation Team of the “Regional Stratigraphic Table of the Xinjiang Uygur Autonomous Region” in 1981.
Lithology and Thickness
The boundary between its base and the Cretaceous Donggou Fm is marked by a bed of calcareous conglomerate or pebbly limestone. Lower part consists of alternating beds of red mudstone, sandstone and conglomerate. Middle part is red, sandy mudstone with green conglomerate, marlstone and calcareous concretions. Upper part is red mudstone alternating with sandstone and siltstone, intercalated with conglomerate lenses. The total thickness is 461 m. This formation is also called the red bed. The upper part is distinguished from the Anjihaihe Formation by purple or brownish purple or grayish green mudstone and siltstone.
Relationships and Distribution
Lower contact
It is in conformable contact with the underlying Late Cretaceous Donggou Fm.
Upper contact
It is in conformable contact with the overlying Eocene Anjihaihe Fm.
Regional extent
It is distributed from the Toutun River to Tuotuo River and best developed from the Changji River to Manas River, with a thickness of 854 m. West of Ziniquanzi, the formation becomes thin and fine in grain size, represented by brown sandy mudstone, with a thickness of 15–78 m. In the east the formation becomes thick and coarse in grain size, marked by red and reddish brown sandy mudstone and grayish red or grayish brown conglomerate and sandstone. West of Ulan Bulak, it directly covers the Tugulu Group or metamorphic rocks.
GeoJSON
Fossils
The fossils contained are the ostracods Limnocythere, Eucypris, etc.
Age
Depositional setting
Lithologically the formation belongs to fluvio-lacustrine clastic rocks.
Additional Information