Yierdingmanha Fm
Type Locality and Naming
Central-Eastern Inner Mongolia. The naming section is located on the Irdin Manha steep slope southeast of Erenhot City, Inner Mongolia, and the reference section is located at Erden Obo, Siziwang Banner, Inner Mongolia. Named by W. Granger and C.P. Berkey in 1922.
Synonym: Irdin Manha Fm
Lithology and Thickness
Mainly unequal-thickness alternating beds of grayish white or grayish green glutenite, grayish white fine sandstone and grayish green mudstone. It consists of gray sandy mudstone, sandstone and conglomerate on the Irdin Manha steep slope. The thickness is ~20 m.
Relationships and Distribution
Lower contact
The formation is disconformably underlain by the Late to Early Eocene Paleocene Naomugen Fm (or, China Lexicon chart shows next older regional unit is a Arshanto Fm).
Upper contact
The formation is disconformably overlain by the Middle Eocene Shara Murun Fm (Shalamulun Fm)
Regional extent
This formation is mainly distributed in the vicinity of Naomugen, Siziwang Banner, southeast of Erenhot City, Nariyin Obo (Irdin Obo), Fu Usu, Ashantou and Kundeleng north, and in addition it is also exposed near northeast of Mubatu to Sonid Right Banner.
GeoJSON
Fossils
Abundant fossil mammals are found in this formation, mainly including more than 30 species such as Sarkastodon mongoliensis, Propterodon irdinensis, Miacis invictus, Hapalodectes serus, Andrewsarchus mongoliensis, Eudinoceras mongoliensis, Metatelmatherium parvum, Protitan grangeri, Lophialetes expeditus, Breviodon minutus, Teleolophus medius, Helaletes mongoliensis, Forstercooperia totadentata and Gobiohyus orientalis.
Age
Depositional setting
Additional Information