Yujiabeigou Fm
Type Locality and Naming
The type section is located in the Yujiabeigou area, Guangxing Country, Keshiketeng Banner, Inner Mongolia. It was named by Gu Feng et al. in 1983.
Lithology and Thickness
Volcaniclastics. Lower part is composed essentially of grey-green pebbled tuffaceous sandstone, intercalated with andesitic breccia, with a thickness of 275.9 m. The basal part of the formation consisting of pebbled medium- and coarse-grained sandstone. The lower stratum of its Upper part is composed of grey-green tuffaceous sandy conglomerate, siltstone and slate, yielding plant fossils (phytolites); while the upper stratum of its upper part consists of interbeds of grey-white and grey-green tuffaceous sandstone, conglomerate and siltstone, yielding Fusulinids, brachiopods and bivalves, etc., with a thickness of 29.5 m. Total thickness is 570 m.
Relationships and Distribution
Lower contact
Conformable contact with the acidic tuff of the underlying Qingfengshan Fm
Upper contact
Conformable contact with the overlying Tieyingzi Fm
Regional extent
Distributed in the region to the south of the Xilamulun River to the west of the Balin Bridge of Inner Mongolia, as well as in the area extending from the Zhengxiang White Banner to the Wengniute Banner.
GeoJSON
Fossils
Yields Fusulinids represented by Pseudodoliolina; Brachiopods such as Yakovlevia, Permundaria, Leptodus; and Plant fossils (phytolites) such as Sphenophyllum, Pecopteris, Gigantonoclea, Taeniopteris and Calamites.
Age
Depositional setting
It is interpreted as chiefly of marine deposits, intercalated with a small amount of continental strata.
Additional Information