Wolonggang Fm
Type Locality and Naming
In 1985, the First regional geological survey of Xinjiang named this formation, and in 1993, Regional Geological Records of Xinjiang Uygur Autonomous Region officially cited. The named section is located in the Wolonggang area of Muzitage, southeast of Qiemo County, Xinjiang Uygur Autonomous Region.
Lithology and Thickness
Characterized by a set of continental clastic rocks. Lower part is grey, grey black, yellow green, brown grey with dark purple siltstone, sandstone, coarse sandstone mainly with conglomerate, about 1227 m thick; Upper part is mainly gray black, brown gray and yellow brown siltstone, sandstone and mudstone interbedded with coal, about 1268 m thick. The total thickness observed in this formation was about 2500 m.
Relationships and Distribution
Lower contact
The bottom part composed of gravel bearing sandstone is in an unconformable contact onto lower Permian Huangyangling Fm (but China Geol Names (Springer) assigned Huangyangling Fm as Paleoproterozoic.); Regionally, the next older unit is the Middle Permian sandy limestone of the Karwa Fm or the coeval and similar upper Yesanggang Fm.
Upper contact
The contact relationship with the overlying strata is unknown, but the contact with the overlying Lower Jurassic is disconformable in the region.
Regional extent
Wolonggang Fm is exposed sporadically in the area, and its thickness is obviously thinned to the east and north.
GeoJSON
Fossils
Bearing plants: Neocalamites carrei, Drepanozamites sp., Sinozamites leeiana, Glossophyllum shansiensis.
Age
Depositional setting
This formation is lacustrine facies
Additional Information