Woronggou Fm
Type Locality and Naming
It was named by the Comprehensive Searching and Prospecting Party under the Tibetan Geological Bureau in 1979. The naming section is located in the Ri’arlongba area of Pengqu⎯Takaxiageiqu, Lajiangshan Township, Deqing Region, Bange County, Tibet (E 90°10′, N 30°30′).
Synonym: （卧荣沟组）; Wuoronggou Fm (spelling)
Lithology and Thickness
It is composed of violet-grey and grey tuffaceous conglomerates, sandstones, pebble-bearing sandstones, andesite, dacite, basalt, tuff and volcanic agglomerate, intercalated with a small amount of mudstones, marls and black shales. Its thickness is of over 1900 m.
Relationships and Distribution
Lower contact
The basal tuffaceous conglomerate is in an unconformable contact with the underlying Pangduo Gr of the Carboniferous-Permian System. [But, the Panduo Gr is mainly elsewhere in Lhasa region of Tibet with other overlying Perm-Tri strata – needs clarification.]
Upper contact
Its top part is in an unconformable contact with the basal dark-violet and purple conglomerate and sandstone of the overlying Lajiangshan Fm (mid-Early Cretaceous). Regionally, the next younger unit (Tithonian-Berriasian) is the sandy claystone of the Qusumpo Fm.
Regional extent
The formation is exposed essentially in the Namuco area of Bange County, as well as in the Baoji region, and with a consistent lithology.
GeoJSON
Fossils
In the Deqing-Lajiangshan area the formation yields Ostracod fossils as represented by Lycopterocypsis cf. grandis, L. fabaria, Cypridea cf. pusilla, Damonella sp., Schuleridea sp. and Darwinula sp.
Age
Depositional setting
Additional Information