Miboshan Fm
Type Locality and Naming
The type section is at Zhangdajing in Tongxin County, Ningxia. The Miboshan Fm was named by Ningxia Party of Regional Geological Survey in 1963, and was published by Ningxia Compiling Group for Regional Stratigraphic Scale (1980).
Synonym: (米钵山组）
Lithology and Thickness
The formation is dominated by limestone, slate and calcirudite; with sandstone in the upper part, representing flysch sedimentation. In the type area, the Miboshan Fm recorded an incomplete thickness of 265 m.
Relationships and Distribution
Lower contact
It rests conformably on the thick-bedded limestone of the Tianjingshan Fm
Upper contact
It is unconformably or disconformably overlain by the Middle Carboniferous. Regionally, the next younger unit is the Yinchuan Fm of upper Ordovician.
Regional extent
The lithology and thickness of the Miboshan Fm vary considerably along the length of its outcrop. In Tianjing Hill, Mibo Hill and Zhongliangzi-Yingtaogou in Helan Mountain, the Miboshan Fm is composed of limestone, slate and conglomerate, and is 141-541 m thick. In Niushou Hill, Luoshan Hill, it is represented by sandstone and slate in the lower part, and carbonate rock in the upper, and is 1788-6800 m thick. At Dashizigou, Hujiatai in Yinchuan and Alxa Youqi of Inner Mongolia, it is dominated by slate and siltstone intercalated with sandstone, and recorded an incomplete thickness of 1000 m.
The Yingtaogou Fm (Ningxia Bureau of Geology and Mineral Resources, 1990) in Helan Mountain and the Qingshan Fm (Ge et al., 1990) in Tongxin County are equivalent to the Miboshan Fm.
GeoJSON
Fossils
The Miboshan Fm yields graptolite Pseudamplexograptus confertus, and is equivalent to Didymograptus artus zone to D. murchisoni zone.
Age
Depositional setting
Flysch sedimentation in the upper part
Additional Information