Changhangou Fm
Type Locality and Naming
It was named as the “Changhangou System” by Tian Benyu in 1950. The naming section is located at Changhangou of Guchengta, Shiguai District, Baotou City, Inner Mongolia.
Synonym: （长汉沟组）
Lithology and Thickness
This formation is composed essentially of dark-green sandy conglomerate and sandy shale, intercalated with marl and a good many of freshwater limestone and calcareous shale. It is of 181-404 m in thickness.
Relationships and Distribution
Lower contact
It is in a conformable contact with the underlying Zhaogou Fm
Upper contact
It is in an unconformable contact with the overlying Daqingshan Fm
Regional extent
The formation has a limited distribution, and is found to occur only at Changhangou, Shiguai District, Baotou City, as well as Gongshanwan and Dagou areas to the east of Changhangou, with its intermittent exposures being found from place to place, and being characterized as a whole by a tendency of a smaller thickness in the west, and a greater thickness in the east.
GeoJSON
Fossils
It yields fish fossils in the shale of its lower part: Lepidotus rugosus, L. notopterus, Eugnathus orthostomus.
Age
Depositional setting
Additional Information