Aobaotinghundi Fm
Type Locality and Naming
The type section is located at the west hill of Dong Ujimqin Qi (Banner), Inner Mongolia Autonomous Region. It was named by Inner Mongolia Team of Regional Geological Survey in 1973 during mapping the East Wuchumuqinqi sheet of Geological Map in scale 1:200000 and was published in the Inner Mongolia Volume of The Paleontological Atlas of North China in 1976.
Lithology and Thickness
Siltstone. The formation is mainly characterized by calcareous and clayey siltstone intercalated with minor tuffaceous siltstone and contains abundant fossils. The thickness is about 500 m.
Relationships and Distribution
Lower contact
Conformably contact with the underlying Baruntehua Fm, which differs from Aobaotinghundi Fm by having a more tuffaceous composition.
Upper contact
Conformably overlain by the Wendueraobaote Fm (volcanic-ash-dominated)
Regional extent
It is mainly exposed at Aobaotinghundi in the west hill of Dong Ujimqin Qi, at the southern part of Cailunguoshao and at Muhar Mtn.
GeoJSON
Fossils
The formation yields the following important fossils: brachiopods Coelospira sp., Paraspirifer” gigantean, Rhytistrophia beckii, Leptaenopyxis bouei, Ivanothyris sp., Discomyorthis sp.; coral Siphonophretis yandelli, Metriophyllum sp., Keriophyllum sp.; sponge Receptaculites sp.; bryozoan Fistulipora sp., Leioclema sp.
Age
Depositional setting
Additional Information
The lithological character of the formation is relative uniform along strike