A synopsis of Paleocene stratigraphy and vertebrate paleontology in the Qianshan Basin, Anhui, China
WANG Yuan-Qing, LI Chuan-Kui, LI Qian, LI Ding-Sheng
Abstract The Mesozoic and Cenozoic redbeds in the Qianshan Basin comprise a set of monocline clastic rocks and are subdivided into the Late Cretaceous Gaohebu Formation, the Paleocene Wanghudun Formation (including the Lower, Middle, and Upper members) and Doumu Formation (including the Lower and Upper members). Continuous investigations in the Qianshan Basin since 1970 have resulted in discovery of a lot of vertebrate specimens. Up to date, 61 species (including 9 unnamed ones) in 45 genera of vertebrates, representing reptiles, birds and mammals, have been reported from the Paleocene of the Qianshan Basin. Among them, mammals are most diverse and have been classified into 46 species (7 unnamed) of 33 genera, representing 16 families in 10 orders. According to their stratigraphic occurrence, seven fossiliferous horizons can be recognized in the Qianshan Paleocene. Based on the evidence of mammalian biostratigraphy, the strata from the Lower Member through the lower part of the Upper Member of Wanghudun Formation could be roughly correlated to the Shanghu Formation of the Nanxiong Basin (Guangdong Province) and the Shizikou Formation of the Chijiang Basin (Jiangxi Province), corresponding to the Shanghuan Asian Land Mammal Age (ALMA). Both the upper part of the Upper Member of Wanghudun Formation and the Doumu Formation could be correlated to the Nongshan Formation of the Nanxiong Basin and the Chijiang Formation of the Chijiang Basin, corresponding to the Nongshanian ALMA. Paleomagnetic results from several Chinese Paleocene basins suggest that the Shanghuan is roughly correlative to the Puercan and Torrejonian North American Land Mammal Ages (NALMA), while the Nongshanian correlative to the early to middle Tiffanian (Ti1–4a). The Shanghuan and the Nongshanian are probably correlated to the Danian and the Selandian of the Global Geologic Time Scale. Therefore, all the fossil vertebrates collected in the Qianshan Basin are the Early and Middle Paleocene in age.
Key words Qianshan, Anhui, Paleocene, vertebrates, stratigraphy, correlation