Shanghu Fm

The naming section is located near Shanghedong and Wutoujiang, Hukou Township, in Luofozai, 12 km northeast of Nanxiong County, Guangdong (114º26', 25º06'), and the reference section is located in the vicinity of Pingling and Gucheng 25 km northeast of Nanxiong County. In 1973 Zhou Mingzhen et al. named the lower member of the Luofozhai Formation the Shanghu Member (published in 1977); in 1976 Tong Yongsheng et al. renamed the member the Shanghu Formation.

Purplish red or brownish red sandy mudstone and mudstone with sandstone, intercalated with thin-bedded gravel-bearing sandstone or lenses, containing abundant ginger-shaped calcareous concretions, 450–600 m thick.

The formation yields dinosaur egg Oolithes sp., mammals Anagalidae and Bemalambdidae, and ostracods, charophyte fossils. The formation contains abundant fossils of various groups, mainly including ostracods, gastropods, Estheria, reptiles, mammals, charophytes and sporopollen. At present at least fossils of 5 orders (Anagalida, Tillodonta, Nudibranchia, Pantodonta and Carnivora), 13 genera and 18 species of mammals have been found; they come from three fossils beds. The main species are Astigale nanxiongensis, Linnania lofoensis, Pappictidops acies, Yantanglestes feiganensis, Lofochaius brachyodus, Bemalambda nanshiungensis B. crassa, etc. In the sporopollen there appear large quantities of Quercoidites, Cupuliferoidaepollenites and Ulmoideipites, as well as arid elements such as Schizaeoisporites and Ephedra. This suggests that the flora in neighboring areas has deciduous broadleaf and evergreen broadleaf forests formed in a tropical-subtropical climate, below which various types of pteridophytes were prosperous. Furthermore, data of mammal fossils found in the Nanxiong basin and other areas of southern China in the last three decades indicate that the most distinct and important feature of Early Paleocene in Asia is that endemic groups (e.g. Anagalida etc.) characteristic of Asia predominate while groups that are close to or common with those on other continents are rare. Therefore, on the whole, in the Early Paleocene commonly no pronounced, direct exchange phenomenon is found between the Asian continent and Europe and America. The region may be an isolated one in zoogeography, and at least no corridor-style passageway such as “Bering land bridge” existed between these continents.

According to an analysis of clay minerals, during the deposition of the formation, the degree of salinization was high and evaporation was strong. The formation was deposited in a hot, lakeshore environment.