Zhusileng Fm

The type section is located at western Zhusilenghaierhan, north margin of Badanjilin Desert in western Inner Mongolia Autonomous Region. It was named by the Cooperative Research Group of Xian Institute of Geology and Mineral Resources and Ningxia Geological Team in 1979, and published by Zhang Yan in 1981.

Sandstone. Lower part of the Formation is characterized by grayish sericite calcareous sandstone intercalated with thin-bedded fine-pebble conglomerate, with a 3-m-thick bed of thick-bedded conglomerate at base. Upper part of the Formation is composed of gray, grayish-brown and purplish-red thin-bedded medium- and fine-grained calcareous sandstone with sandy limestone interbeds.

The Formation is 405.89 m thick,

The ammonoid Anarcestes plebejus, and corals, brachiopods and trilobites had been described by Zhang (1981,1983) and Li and Zhou (1987), respectively.