Fangou Fm

The naming section is located in the vicinity of Fangougounao and Xiafangou in the Shimen basin ~15 km north of Luonan County, Shaanxi. Established by Xue Xiangxi and Zhao Jufa in 1983.

Predominantly brownish red and light red sandy mudstone and mudstone with grayish green pebbly and sandy mudstone and muddy sandstone, the lower part of which is a conglomerate bed. Generally, rocks in the middle and lower parts are exposed more widely at the surface and mainly distributed in the central and northern parts of the Shimen basin. The thickness is ~165 m.

The upper and lower fossil horizons are found in the formation now. It mainly yields such mammals as Linnania qinlingensis, Prosarcodon luonanensis, Hukoutherium cf. shimenensis and Bemalambda spp. This fauna closely resembles the early-mid Paleocene Shanghu Fauna in the Nanxiong basin, northern Guangdong with respect to its aspect.

The features of the Paleocene fauna in the Shimen basin, Luonan, Shaanxi, are similar to those in related Paleocene basins of south China. Thus it follows that in the Paleocene there were similar geological structures and paleoclimate and paleoenvironments and existed similar mammal faunas in many areas in the north and south (especially the south) of the Qinling region. From these it may be inferred that by that time the Qinling possibly had not risen high to form a high mountain barrier separating the north and south of China.