Bastawu Fm

The type section is at Jiabosar on the northern bank of the Ertaiwulungu River in Fuyun County, northern Xinjiang. The Bastawu Formation was named by Xinjiang Party of Regional Geological Survey and Institute of Geology and Mineral Resources of Chinese Academy of Geological Sciences (1974), and was published by Xinjiang Compiling Group for Regional Stratigraphic Scale (1981).

Synonym: (巴斯他乌组)The strata equivalent to the Bastawu Formation was first named the Bastawukuduk Fm by Hou et al. (1979). Wu et al. (1976) renamed it the Bastawu Formation, which was followed by Xinjiang Compiling Group for Regional Stratigraphic Scale (1981) and Xiao (1990). Xinjiang Bureau of Geology and Mineral Resources (1999) divided this formation into three of Wuliegai Fm, Daliugou Fm and Miaoergou Fm from lower to upper for regional comparison and geological mapping with the Huangcaopo Group. It is not followed in this paper through lithology comparison of these formations.

The formation is represented by purple thick bedded to massive limestone, calcareous conglomerate, variegated tuffaceous sandstone, dark purple andesitic volcanic breccia, intercalated with limestone and magnetite lenses. In the type section, the formation records a thickness of 1240 m.

The limestone yields corals Rhabdotetradium densum, Paratetradium tollinoides, trilobites Calliops taimyricus, Remopleurides qiakuertaensis and brachiopod Wulungguia wulungguensis.