Bailongmiao Fm

The type section is on the banks of the Bailongmiao River 1 km northeast of the Shuitian River in Xichuan County, Henan, and the reference section is on the Niuweiba Hill 2 km east of the Zhechuan City (Pei Fang and Cai Shuhua 1987). The Bailongmiao Fm was named by the Beijing College of Geology in 1960-1965, and was published by Liu Yinhuan et al. (1991).

Pei and Cai (1987) suggested that the place name “Bailongmiao" is not existent,and so the Bailongmiao Fm should be not maintained. At the same time, they established the type section on Niuweiba Hill, and divided the section into the Longquan Fm in the lower part and the Niuweibashan Fm in the upper part, and also described in detail the conodont sequences in the section. The boundary, however, between the Longquan and Niuweibashan formations in the type section is not clear. Liu et al. (1991) replaced the Longquan Fm with the Bailongmiao Fm, and correlated the Bailongmaio and Niuweibashan formations with the Diaochuanggou Fm in Shaanxi.

Synonym: (白龙庙组）

The formation is composed of gray, light gray thick-bedded dolomite, with banded cherts in the lower part, and with micritic limestone and bioclastic limestone in the upper part. In the type area, the Bailongmiao Fm is 577 m thick.

The conodonts found in Xichuan includes “Acodus" oneotensis-Chosonodina herfurthi assemblage, Scolopodus barbatus assemblage and Serratognathus diversus assemblage in ascending order (Pei and Cai, 1987).