Menkoushan Fm
Type Locality and Naming
It was named by Li Yingjian, Wu Rongnan as the “Menkoushan Series” in 1959. The naming section is located at Menkou Mt in the Huagushan mining region of Xinyu City, Jiangxi Province, with its reference section being situated in the area of Tushan Village of Huagushan region, Xinyu City.
Synonym: （门口山组）
Lithology and Thickness
Lower member is composed mainly of grey-white feldspar-quartz gritstones, greywacke-quartz medium-, and fine-grained sandstones, intercalated yellow-brown poststones (= fine-grained sandstone), siltstones, carbonaceous shales and thin coal beds, with a thickness of about 606 m. Upper member is composed largely of grey-green, yellow-green and purple siltstones, intercalated with gritstones and a small amount of thin-bedded siltstones, occasionally with carbonaceous mudstone and coal seams, with a thickness of 1075 m.
Relationships and Distribution
Lower contact
Its basal part is in a conformable or a disconformable contact with the underlying upper Triassic Anyuan Fm
Upper contact
Not given. [Linshan Fm in this same west-Jiangxi region is partly coeval, or perhaps may also be the next younger regional unit? Menkoushan Fm was not shown on schematic stratigraphic column for this region.]
Regional extent
It is distributed mainly in the Duojiang area of Wanzai County, the Huagu Mt of Xinyu County, the Caoxi area of Geyang County, as well as in the Caoxi area of Geyang County, and the Cangwulong area of Qianshan County. Except for the development of tuff in the Cangwulong area, the lithology of the particular formation is basically consistent in various regions. In the Xishanwu area of Puqian region, Hengfeng County there are distributed coal-bearing clastic sediments corresponding to the lower member of the particular formation, with a thickness of about 400 m, used to be known as the “Xishanwu Formation”. The thickness of the strata of the particular formation varies greatly, being of 1350 m in the Cangwulong area of Qianshan County; being of only 512 m in the Caoxi area of Geyang County; and being of about 1024 m in the Duojiang area of Wanzai County.
GeoJSON
Fossils
It yields bivalves as represented by the Lilingella-Hunanella-Qiyangia assemblage, in addition to such species as Pseudocardinia, Tutuella and Sibireconcha, with the plant fossils belonging to the Marattiopsis-Otozamites assemblage.
Age
Depositional setting
The particular formation belongs to freshwater lagoon and sea-marsh coal-bearing clastic sediments.
Additional Information