Bijingtawu Fm
Type Locality and Naming
The type section is located in west slope of Bijingtawu Mt., Kalpin, Xinjiang; the reference section lies south of Kunkelaqitag, Akqi, Xinjiang. It was named by Ma Kulin and Chen Zhefu in 1957, and cited in Regional Stratigraphical Scale of Xinjiang in 1981.
Synonym:
Biegentawu Fm
Lithology and Thickness
Limestone and Sandstone. It can be divided into the upper and lower members. Lower Member is dominated by limestones intercalated with quartzose sandstones, consisting of gray-black micritic bioclastic limestone, micritic limestone, clastic limestone, calcarenite, intercalated with gray quartzose sandstone, sedimentary quartzite and bedded quartzose sandstone. Upper Member is composed completely of limestones, including micritic limestone, clastic limestone, bedded limestone, breccia limestone, bioclastic limestone, etc. On the west slope of Bijingtawu Mt., the bottom of the formation is intercalated with thin coal seams. The formation is 100−1200 m thick, thinning from west to east.
Relationships and Distribution
Lower contact
Unconformable over various strata of the Early Paleozoic at type section; or regionally unconformable on lower Carboniferous Bashisuogong Fm.
Upper contact
Unconformable overlap with the overlying Kangkelin Fm
Regional extent
Distributed in the areas from Kenuo’erjia, Chang’aketashitawu south of Akqi to Bijingtawu and Suogeyantawu
GeoJSON
Fossils
Lower Member contains Fusulinid Pseudostaffella sp. Upper Member contains the Fusulina-Fusulinella zone, as well as Brachiopods Linoproducus sp., Buxtonia sp., Kutorginella sp. and Choristites sp., and Corals Lithostrotionella sp. and Caninia sp.
Age
Depositional setting
It is interpreted as a neritic facies
Additional Information