Xilimiao Fm
Type Locality and Naming
The type section is located in the Xilimiao area of the Siziwang Banner, Inner Mongolia. It was named by Jiang Haoxian et al., in 1979.
Lithology and Thickness
Volcanics. Composed of yellow-green and grey-white schistose rhyolitic crystal tuff, pink and grey-white rhyolitic tuffaceous lava, tuff, rhyolite and tuffaceous siltstone, intercalated with crystalline limestone, and with a thickness range of 436-2526 m.
Relationships and Distribution
Lower contact
Uncertain lower boundary. Regionally, next older unit is either the Amushan Fm (latest Carboniferous through early Permian) or the local volcanics of the Baoligemiao Fm (late Carboniferous)
Upper contact
Unconformable contact with the overlying Baotege Fm
Regional extent
Exposed in the form of a belt in the Xilimiao, Haraobao and Sumoganaobao areas in the northern part of the Siziwang Banner, Inner Mongolia in an area of 426 km2, extending northerly into the territory of the Mongolian People’s Republic.
GeoJSON
Fossils
The limestone yields coral fossils such as Lytvolasma sp., Tachylasma cf. elongatum, Lophocarinophyllum sp., etc.
Age
Depositional setting
It is interpreted as a marine effusive acidic to intermediate-acidic volcanic-rock and volcaniclastic-rock formation.
Additional Information