Yihewusu Fm
(11), Capitanian Stage (late Guadalupian Epoch; late-Middle Permian)
Type Locality and Naming
The type section is located at the northeastern end of the Zhesi-Aobao area 33 km to the northeast of the Maodula Country, the Maomingan United Banner, Darhan (Darkhan), Inner Mongolia. It was named by Ding Yunjie et al., in 1985.
Lithology and Thickness
Limestone and Clastics. Its basal part is composed of grey thick-bedded massive bio-limestone. Its Lower part is composed of black-grey and light-purple-grey thick-bedded limestone and brecciated and edgewise bio-limestone. Its Upper part is composed of grey-yellow feldspar-coarse-grained sandstone and shale, intercalated with limestone lenses; and its top part is composed of pebbled coarse-grained sandstone. Thickness is over 663 m.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Zhesi Fm
Upper contact
Unknown; no top has been found.
Regional extent
Distributed in the Zhesi-Aobao and Baotege areas.
GeoJSON
Fossils
Yields Brachiopods represented by the Streptorhynchus-Hemiptychina-Richthofenia assemblage; Fusulinids represented by the Schwagerina ulanqabuensis-Codonofusiella pseudoextensa subzone; Corals represented by the Carinoverbeekiella sinensis-Pseudowaagenophyllum vesiculosum-Diphycarinophyllum assemblage in its lower part, and represented by the Waagenophyllum virgatense mongoliense-W. stereoseptatum-Wentzelella assemblage; and Ammonoids represented by Rhiphaeoceras laxum in its upper part.
Age
Depositional setting
It is interpreted as a marine-facies.
Additional Information