Lingmaigou Fm

The type section is located at Lingmaigou, Tongba, Muli County, Sichuan. It was named by Mao Junyi in 1971 and it was firstly used for publication by the third district survey group of Sichuan Geological Bureau in 1977. The Lingmaigou Fm has been rarely cited since the creation of the Cigang Fm (representing the Early Triassic marine deposits in Baiyu and Yidun, Sichuan) by the Sichuan Geology and Mineral Bureau District Investigation Team and Nanjing Institute of Geology and Palaeontology in 1982. In 1992, the Chengdu Institute of Geology and Mineral Resources of the Chinese Academy of Geological Sciences and the Sichuan Geology and Mineral Bureau District Diao Brigade thought that the Lower Triassic in Muli is dominated by gray sand and shale and it is different from the oolitic limestone and the bioclastic limestone in the Derong Guxue Cigang area. So they used the Lingmaigou Fm to represent the Early Triassic deposits in the Muli area. This lexicon follows this usage and age assignment..

Synonym:

It is mainly dominated by gray sandstones and shales and can be divided into upper and lower members. Lower Member is gray sandstone, silty slate intercalated with thin limestone, with a thickness of 159 m. The lower and upper part of the Upper Member are composed of the gray silty slate interbedded with feldspar quartz sandstone and thin limestone, and the middle part of the Upper Member is light gray medium-thick limestone and argillaceous limestone interbedded with bioclastic limestone, 221 m thick. In Dangbagou, Tongweng, Muli, its thickness can be up to 714 m.

Bivalves: Claraia wangi Assemblage Zone and Claraia stachei-C. Aurita Assemblage. Ammonoids: Ophiceras Zone and Owenites Zone.

It is interpreted as shallow marine.