Ulansuhai Formation | |
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Stratigraphic range: Turonian ~ | |
Type | Geological formation |
Unit of | Dashuigou Group |
Lithology | |
Primary | Claystone, siltstone |
Location | |
Coordinates | 40°18′N 105°54′E / 40.3°N 105.9°E |
Approximate paleocoordinates | 41°30′N 97°12′E / 41.5°N 97.2°E |
Region | Inner Mongolia |
Country | China |
The Ulansuhai Formation (simplified Chinese: 乌兰苏海组; traditional Chinese: 烏蘭蘇海組; pinyin: Wūlánsūhǎi Zǔ) is a geological formation in Inner Mongolia, north China. Dinosaur remains are among the fossils that have been recovered from the formation.[1]
The Ulansuhai Formation has traditionally been considered to date to the Aptian-Albian stages of the Lower Cretaceous, due to similarities between the Ulansuhai fauna and known Aptian formations.[1] However, radiometric dating done on underlying formations has shown this to be incorrect. Due to the age of underlying rocks, the Ulansuhai Formation cannot be older than the Turonian stage of the Late Cretaceous, about 92 Ma.[2][3]