Maer Fm
Type Locality and Naming
It was named by the Northwest Sichuan Geological Party in 1984 and published by the Sichuan Bureau of Geology and Mineral Resources in 1991. The type section is located at Maer Village, Zhanwa Township, Ruoergai County, Sichuan Province. The reference section is at Xiaolianggou, Zhigou, Miaogou in Zhouqu County, Gansu Province.
Synonym: (马尔组) . The Miaogou Fm was named by Fu Lipu et al (1983) with the type section locating at Xiaolianggou, Zhigou, Miaogou in Zhouqu County, Gansu Province. The name Miaogou had been occupied by the Miaogou Limestone for the rocks in the Taiyuan Fm of late Carbonaceous. Therefore, the Miaogou Fm was abandoned by Lin Baoyu and Zhu Xiufeng in 1998.
Lithology and Thickness
The formation, 643-684 m in thickness, consists of dark gray medium-to-thick-bedded medium-to-coarse-grained lithic arkosic quartzose sandstone, lithic sandstone, fine-grained quartzose sandstone, siltstone, slate, intercalated with clastic limestone.
Relationships and Distribution
Lower contact
It is conformably contacted with the underlying Xiaolianggou Fm
Upper contact
It is conformably contacted with the overlying Hongshuigoukou Fm
Regional extent
The Maer Fm belongs to neritic flysch deposits, eastwards becoming finer-grained with thickness decreasing down to merely 178 m at Zhouqu County, Gansu Province. It is mainly exposed in the border area between Sichuan and Gansu provinces.
GeoJSON
Fossils
It yields corals Mesofavosites sp., Tryplasma subflexuosum, Holmophyllia cyathiformis; brachiopods Xinanospirifer vergouensis, Stegospira nucleota, S. uniformis, Ferganella Borealis, etc.; trilobite Proetus sp.; cephalopods Michelinoceras sp., Virgoceras sp.; graptolite Monograptus sp.
Age
Depositional setting
Additional Information