Paotaishan Fm
Type Locality and Naming
The type section of Paotaishan Formation is located at highway side on the Mufushan Hill, Nanjing, Jiangsu Province (118°49’E, 32°08’ N), about 8 km north of the seat of Nanjing City. The section is measured by Yu et al. in 1962. It is the upper portion of the same section shared by the underlying Mufushan Fm. The Paotaishan Formation was named by Yu et al. (1962). The name is derived from Paotaishan on the Mufushan Hill, in the north of Nanjing City, southwestern Jiangsu Province.
Synonym: （炮台山组）
Lithology and Thickness
The Paotaishan Formation is a carbonate (dolomite) sequence. The formation can be divided into two lithological parts. Lower part is dominated by grey, dark grey dolomite with some of thin-bedded, lamination-bearing argillaceous limestone. Upper part consists of light red, grey, dark grey, thin-bedded argillaceous dolomite, intercalated with limestone and marlstone. In the type section, the Paotaishan Formation is 94.53 m thick.
Relationships and Distribution
Lower contact
The Paotaishan Fm is in conformable contact with the underlying Mufushan Fm. The lower boundary of the formation is defined by disappearance of underlying purplish red argillaceous limestone at the top of the Mufushan Fm. In southern Jiangsu, the Paotaishan Fm is in conformable contact with the overlying Yangliugang Fm
Upper contact
The Paotaishan Fm is in conformable contact with the overlying Guanyintai Fm in southwestern Jiangsu and south-central Anhui provinces. The upper boundary is defined by the appearance of reddish grey-white massive dolomitic limestone at the base of the Guanyintai Fm, which contains relatively large amount of cherty nodules, and overlies on the light grey and black, thin-bedded dolomitic limestone at the top of the Paotaishan Fm, which bears small amount of chert nodules. In southern Jiangsu, the Paotaishan Fm is in conformable contact with the underlying Mufushan Fm
Regional extent
The Paotaishan Formation is exposed in the Yangtze Area of South China Region, including the Nanjing-Zhenjiang Hills in southwestern Jiangsu Province (Nanjing City and Jurong County of Zhenjiang City), and Chaohu City, southern Anhui Province. It is also known under the surface, by drill hole, in the South Slope Area of South China Region, i.e. in Kunshan, southern Jiangsu Province. Thickness of the formation is variable. It is about 95 m in Nanjing, about 40 m in Jurong, and about 250 m in Kunshan.
GeoJSON
Fossils
In the type section, the basal part of the Paotaishan Formation yields Mufushania changi, and M. nankingensis. In other locality, the formation also yields trilobites Redlichia, Probowmania, and Kumingaspis.
Age
Depositional setting
Additional Information