Maonong Fm
Type Locality and Naming
It was named by Wu Zhizhun, Zhan Xikun, Zhu Fuwu as the “Maonong Coal-bearing Member” in 1961. The naming section is located at the Maonong Coal Mine, Jingjukou area, Songyang County, Zhejiang Province.
Synonym: （毛弄组）
Lithology and Thickness
Lower member represents dacitic pebble-bearing crystal vitric tuffs, intercalated with a small amount of thin-bedded pebble-bearing sandstones, with its lower part containing occasionally lenticular coal beds, with a thickness of over 400 m. Upper member represents an alternating layer of sandy conglomerates in association with sandstones, siltstones, shales and carbonaceous shales, intercalated with coal beds, with a thickness of about 460 m.
Relationships and Distribution
Lower contact
The relationship between its basal part and the underlying Longpu Fm is unknown (with no base having been found).
Upper contact
Regionally, the schematic strat column indicates the next younger unit is a volcanic-sedimentary unit of Baiyancun Fm of late Jurassic. However, it may be disconformably overlain by the early Cretaceous Moshishan Gr (Dashuang Fm).
Regional extent
The formation is distributed largely in the Maonong and Xiaocha areas of Songyang County, the Yangjia Mt of Yunhe County, and the Zhucun and Yangcun Villages of Lishui County.
GeoJSON
Fossils
It yields bivalve fossils such as Ferganoconcha aff. estheriaeformis and F. cf. subcentralis; and plant fossils as represented by a middle-stage assemblage of the Coniopteris-Phoenicopsis flora, whose important members are Neocalamites carrerei, Coniopteris hymenophylloides, Eboracia lobifolia, Baiera furcata and Phoenicopsis spp.
Age
Depositional setting
The formation belongs to deposits of volcanic-eruption facies and intermontane lacustrine-swamp facies.
Additional Information