Jingangquan Fm
Type Locality and Naming
Gan Kewen and Zhang Jiahuan erected the Jingangquan bed in 1953. The type locality is in Jingangquan of Alxa Youqi of Inner Mongolia. The reference section is from Amugejing to Daxiahe of Alxa Youqi of Inner Mongolia (101°17′; 38°58′).
Lithology and Thickness
The Jingangquan Formation is represented by brown yellow and brown red (with gray white) interbedded conglomerate, sandstone, sandy conglomerate and mudstone. Its base marked by dark red mudstone with gray white granule conglomerate and variegated fine sandstone lies conformably on the underlying Miaogou Fm. Its top is unknown. It is 727.5 m thick.
Relationships and Distribution
Lower contact
The present formation may lie disconformably on the Miaogou Fm or overlaps unconformably the older strata
Upper contact
It is unconformably under the overlying Paleogene Sizikou Fm.
Regional extent
The present formation is only distributed in the Chaoshui basin and Yabrai basin at the juncture of Inner Mongolia and Gansu. In the Yabrai basin, the lower part of the formation is represented by light red and gray white conglomerate, sandy conglomerate and gravel-bearing sandstone; the middle part dark gray silty mudstone with marl; and the upper part light red and light gray gravel-bearing conglomerate and sandy conglomerate with siltstone. The thickness of the formation is from 131 to 570 m. In the western part of the Chaoshui basin, the formation is represented by a set of dark purple red and brick-red gravel-bearing sandstone interbedded with sandstone, with gypsum, ranging from 270 to 750 m in thickness.
GeoJSON
Fossils
In the Yabrai basin of Inner Mongolia, it yields ostracods Candone prona, C. disjuncta, etc. It also contains Reptilia Protoceratops sp. and Chilantaisaurus tashuikouensis and bivalves.
Age
Depositional setting
It is mainly of lacustrine deposition.
Additional Information