Babaoshan Gr
Type Locality and Naming
Team 632 of Northwest Geological Bureau named it in 1964, and first quoted by Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and Qinghai Institute of Geology and Palaeontology in 1979. The named section is located in the upper reaches of Nuomuhong River in Babaoshan area, Dulan County, Qinghai Province. Schematic stratigraphic section divided it into a lower Caomuce Fm (Carnian) and an upper Kelubo Fm (Norian-Rhaetian)
Synonym:
Lithology and Thickness
The main lithology is yellowish-gray, brown-yellow, gray-black thin-thick lithic feldspar sandstone, feldspar lithic sandstone, clay shale, and mudstone. The bottom is a thin layer of black iron-bearing clay shale, anisometric quartz sandstone, medium-grained feldspar sandstone. 1323 m thick.
Relationships and Distribution
Lower contact
It is in unconformable contact with the underlying Indosinian early gray medium grain rich plagioclase granite. Or, a pseudo-conformable contact onto the underlying Naocangjiangou Fm of Anisian (with Ladinian absent?).
Upper contact
It was a false conformable contact with the overlying Lower Jurassic (a Xiaomeigou Fm is indicated on schematic stratigraphic section for column TJ21 of north Qaidam basin). [In south Qilian Mts, column TJ23, the next younger unit is shown as the middle Jurassic Yangkyi Fm.; and in Qinghai/Sichuan border (TJ75a), the next younger regional unit is the mid-Cenozoic Maladun Fm.]
Regional extent
The group is distributed in the south slope of the east Kunlun Mountains and the west Qinling Mountains.
GeoJSON
Fossils
Contains plant fossils: Danaeopsis fecunda, Glossophyllum shensiense, Lepidopteris ottonis, Asterotheca cottoni, Todites goeppertianus, etc.; Palynology: Leiopsora, Phosphaera, Micrhystridium, Discisporites et al; Bivalve Utschamiella.
Age
Depositional setting
In the Caomu Ce area, the lower part is a set of sea-land inter-deposition. There is a set of continental volcanic rocks, conglomerates and sandstones in the upper part of Haidawula, Kelubo and Babaoshan.
Additional Information