Niqiuhe Fm

The type section is located in Jinshui and Handaqi area of Nenjiang County, Heilongjiang Province. There are two measured sections: the section at Erzhigou of Wudaogou in Heihe City and the Xigulanhe section, both listed in the Regional Report of “Woduhe Geological Map”(1:2,000,000) in 1976, with a thickness difference about 300 m. The Xigulanhe section is directly overlain by the Jinshui Fm, without the overlying volcanic rock. Hereby we would suggest accepting the Wudaogou section as stratotype for the Niqiuhe Fm. It was named by Zhao Guisan et al. in 1957.

Slate, siltstone. In the Erzhigou section of Wudaogou, the formation is dominated by gray clayey or sandy slate intercalated with siltstone and greywacke, and also intercalated with limestone lenses in its upper part. The outcropped thickness of the formation is 389.3 m.

Westwards from Handaqi, the Niqiuhe Fm in the middle reaches of Guanniaohe River directly underlies the Huolongmen Fm without the volcanics of the Handaqi Fm; the thickness is up to 1000 m; and the lithology is dominated by siltstone and clayey slate, intercalated with pebble-bearing sandstone and a few crystalline limestone lenses, which may represent both the Niqiuhe Fm and the Jinshui Fm.

It yields brachiopods: Coelospira pseudocamilla, Leptococlia sinica, Merista sp., Aulacella sp.; corals: Pleurodictyum sp., ?Syringaxon sp.; and trilobites: Phacops sp., Odontochile sp.