Caijiachong Fm

The naming section is located to the north of Caijiachong ~20 km southeast of the seat of Qujing County, Yunnan Province. Named by Pei Wenzhong in 1963.

According to the section across the Yuchuan basin from SE to NW north of Caijiachong measured by Wang Banyue et al. (1983), this formation may be divided into five beds; ascending they are: (1) grayish green mudstone; (2) light gray marlstone with variegated (grayish green, grayish yellow and yellowish red) mudstone and calcareous mudstone with clayey sandstone ad siltstone; (3) alternating light grayish green, thick-bedded siltstone and grayish green and grayish yellow mudstone and calcareous mudstone; (4) grayish green, thick-bedded marlstone and calcareous mudstone with gray green mudstone and light gray siltstone and fine sandstone, showing a nodular shape after weathered; and (5) light gray, siliceous siltstone and mudstone, which are light and show a grayish brown color when weathered, called locally “sheep-wool stone”. The total thickness is more than 200 m.

Fossils mainly occur in beds 2 and 4 of the above-mentioned section. Charophytes include Amblyochara subeiensis, Maedlerisphaera chinensis, Harrisichara vesifomis and Sphaerochara inconpicua; gastropods mainly include Bithynia largicirca and Assiminea pressoopercura; vertebrates include mammals in addition to fishes such as Cyprinidae and reptiles such crocodiles and turtles, of which mammals include Cadurcodon ardynensis, Gigantamynodon giganteus, Indricotherium qujingensis, Bothriodon chowi, Eucricetodon meridionalis, Sinosminthus inapetus and Lophiomeryx sp..

It is interpreted to lacustrine deposits