Datong Fm
Type Locality and Naming
It was named as “Datong Coal Series” by Zhang Xiti in 1936. The naming locality is situated at Datong, Shanxi Province. In 1995 the Regional Survey Party of Shanxi Province recommended that the Ergou section at Kouquanzhen Temple, Datong City be selected as the type section for the Datong Formation.
Synonym: （大同组）
Lithology and Thickness
Composed of grey-white and light-yellow sandstones (quartz-greywacke, feldspar-quartz sandstone, and lithic greywacke) siltstone, grey-green sandy mudstone, black mudstone, intercalated with rhythmic layering constituted by coal beds and fresh-water limestone concretionary horizons or lenses. It is 230 m in thickness.
Relationships and Distribution
Lower contact
In the Datong Coal Mine this formation is in a conformable contact with the underlying Yongdingzhuang Fm (late-Early Jurassic). In the Guangling and Ningwu Coal Mines the formation is in a disconformable contact with the underlying Ordovician or Triassic System.
Upper contact
In the Guangling and Ningwu Coal Mines the formation is in a disconformable contact with the overlying Yungang Fm (in the Datong and Ningwu Coal Mines).
Regional extent
It is distributed mainly in the Yungang Basin of Datong City and the Ningwu-Zinglo Basin, with a small area of its exposures being found in the Guangling Basin as well. Its lithology is consistent in various places, with its thickness varying in a range from 200 m to 450 m.
GeoJSON
Fossils
It yields plant fossils as presented by Coniopteris tatongensis, C. hymenophylloides, Phoenicopsis speciosa, Baiera gracilis, Hausmannia leeiana, Cladophlebis whitbyensis, C. raciborskii, Elatocladus manchurica, Nilssonia simplex, and Ginkgoites magnifolius; and bivalves as represented by Pseudocardinia sp., Margaritifera isfarensis and Tutuella chachlovi.
Age
Depositional setting
It belongs to fluvo-lacustrine and swamp-facies deposits.
Additional Information