Wudanggou Fm
Type Locality and Naming
It was named by Li Xingxue as the Wudanggou Series in 1954. The naming section is located in the area extending from the Toudaogou Gully to the Erdaogou Gully of the Gucheng Pagoda, Shiguaizi District, Baotou City, Inner Mongolia.
Synonym: （五当沟组）
Lithology and Thickness
It is composed mainly of grey-white and grey-yellow gritstones and pebble-bearing sandstones, intercalated with grey sandy shales, brown and grey-black oil-bearing shales, carbonaceous shales, yellow-green poststones (= fine-grained sandstone) and coal beds, with its basal part being composed of pebble-bearing sandstones and conglomerates, with a thickness of 684-2250 m.
Relationships and Distribution
Lower contact
It is in an unconformable contact with the underlying Archean Wulashan Gr
Upper contact
It is in a conformable contact with the overlying Zhaogou Fm
Regional extent
The formation is distributed essentially in the Shiguaizi District of Baotou City, Yingpanwan of the Wulate Front Banner, Anggen of the Wulate central Banner, and Sulatu of central Banner, Cahar Right Wing. Both the lithology and thickness of the formation are changeable from region to region. As in the Shiguaizi District the formation is composed of arkose and shale, intercalated with coal beds, with a thickness of 684 m; while in the Yingpanwan area the amount of conglomerate in the formation is increasing remarkably, with a thickness of 2250 m; and in the Anggen area the formation is composed of quartz-sandstone, poststone and coarse-grained arkose, intercalated with mineable coal beds, with a thickness of only 83 m.
GeoJSON
Fossils
The formation is rich in plant fossils, whose major members comprise Equisetites grosphodon, E. koreanicus, E. sarani, Neocalamites carrerei, Marattiopsis naglica, N. muenateri, M. asiatica, Osmundopsis plectrophra, Todites recurvatus, T. williamsoni, Klukia exilis, Phlebopteris polypodioides, Clathropteris meniscioides, Coniopteris hymenophylloides, Haosmannia sp., Cladophlebis fukiensis, C. hsiehiana, Pterophyllum angustum, Nilssonia brevis, N. orientalis, N. undulata, Sphenobaiera czekanowskiana, Phoenicopsis augustifolia, Podozamites lanceolatus and Anomozamites sp., as well as in bivalve fossils as represented by Ferganoconcha
Age
Depositional setting
Additional Information