Shuhe Fm

The type section is located at Niuchang, Shuhe Country, Yanyuan County. It was named by the Sichuan Regional Geological Survey Party in 1982.

Limestone and Clastics. Composed of dark-grey pebbled limestone, intercalated with sandstone and shale, with its basal part consisting of sandstone. It is 30- to 80-m thick.

In the Gangou section of the Niuchang area, Shuhe Country, this formation yields such Fusulinids as Misellina sp., Schwagerina sp., Triticites sp., T. paramontiparus mesopachus, T. variabilis, Pseudofusulina sp.; corals such as Caninia sp., Lophocarinophyllum yakovlevi, Wentzellophyllum aff. volzi. In the area extending from the Kuangshanliangzi to the Niuchang Village, it yields the following fossils as well: Fusulinids represented by Armenina sp., Verbeekina sp., Brevaxina sp., Ozawainella sp., Pseudoschwagerina sp., Triticites chui, T. parvulus, T. shikhunensis compactus, Rugosofusulina sp., Quasifusulina sp.; corals represented by Polythecalis sp., Chusenophyllum sp., Szechuanophyllum shuheense, etc. Among the above-mentioned Fusulinid fossils, except for the Schwagerina and Pseudofusulina which represent its common elements for the Early and Middle Permian Epochs, the other elements such as Pseudoschwagerina, Triticites, Rugosofusulina, Quasifusulina, etc. are peculiar to the Chuanshanian Epoch, of which the Pseudoschwagerina, Triticites are zonal fossils for the Chuanshanian Series in the country, and the Misellina coexisting with them is the zonal fossil for the Luodianian Stage of the country. The Shuhe Fm represents pebbled limestone, the fossils of the Chuanshanian Epoch represent products of redeposition, and the age of the Shuhe Fm seems to be of the early Luodianian Stage.