Zhengyang Fm
Type Locality and Naming
Sichuan Basin – east. The Zhengyang Formation was named by the 107 Geological Team of Sichuan Geological Bureau in 1974. The type section is in Zhengyang of the Qianjiang County, Sichuan Province (108º49'18″, 29 º26'1″). It is also called as the Donghu Fm in western Hubei. Before the nomination, the formation was described as the “Maotai Conglomerate” (Li Siguang, 1924).
Lithology and Thickness
Lower part of the Zhengyang Formation is mostly a group of conglomerates, and 35~50 m in thickness. Upper part of the formation is composed of interbeds of sandstone and conglomerates of the characters of coarser in the lower part and thinner upwards. The total thickness is about 120 m.
Relationships and Distribution
Lower contact
The formation contacts unconformably with the underlying Triassic Jialingjiang Fm; or the late Jurassic Penglaizhen Fm. In western Hubei, there is an underlying Shimen Fm of earliest Cretaceous.
Upper contact
The top is covered unconformably by the strata of different ages.
Regional extent
It is distributed in Qianjiang County, Sichuan Province. It also occurs in Hubei, Guizhou, and Hunan provinces.
GeoJSON
Fossils
Fossils are rear found in this formation. Some dinosaur fossils belong to Hadrosauridae and Titanosauridae yields in the type section at Zhengyang of Qianjiang County.
Age
Depositional setting
Additional Information