Bagongshan Fm
Type Locality and Naming
North-central Anhui. The name of the Bagongshan Fm comes from the Bagongshan Group named by Xu Jiawei in 1958 and formally quoted in 1978 (in the Regional Geological Scale of East China, Fascicle of Anhui). The typical section is located in Bagong Mountain in Shouxian County, Anhui Province. The reference section is at Songji in Fengyang County, Anhui Province.
Synonym: （八公山组）
Lithology and Thickness
In the typical area, the Bagongshan Fm is dominated by grayish, milky white medium- to thick-bedded glauconitic sandstone, quartzose sandstone, pebbly sandstone and the lowermost part is quartzose conglomerate. In Huainan region, the thickness varies from 11 to 192 m or more, and in south Shandong, Xuzhou and Huaibei areas, the thickness varies from 78 to 536 m from north to south.
Relationships and Distribution
Lower contact
Conformably or disconformably contact with the Caodian Fm. Unconformably overlapping on the phyllite of the Fengyang Gr or older schist if the Caodian Fm is lacking.
Upper contact
Conformably overlain by the Liulaobei Fm.
Regional extent
North Anhui-southern Shandong. With a limited distribution, it is dominantly exposed in Fengyang and Huainan area, also in Huaibei, Xuzhou and southern Shandong Province.
GeoJSON
Fossils
Age
Depositional setting
The Bagongshan Fm, generally with a persistent single lithology, locally has cross-bedded, ripple marks, and is considered to be a littoral to neritic quartzose sand stone deposit.
Additional Information
The Bagongshan quartzose sandstone was called as the Wushan quartzite on a stratigraphic table on the book Geology of China (English by Li Siguang (J. S. Lee) in 1939, Chinese translation by Zhang Wenyou in 1952), which was renamed as the Wushan Fm by Yang Zhijian in 1960, and it was quoted on some literature. However, as the name and the exact locality of the typical section are both not clearly known, the author proposes to use the name of the Bagongshan Fm.