Yarang Fm
Type Locality and Naming
The type section is located at Chengbei roadside (110°21’E-22°45’N), 3.5 km of Beiliu City of Guangxi Zhuang Autonomous Region. It was named by Wang Yu and others in 1965.
Lithology and Thickness
Limestone. The Formation, about 400 m thick, can be subdivided into two parts. Lower part, about 160 m thick, is characterized by gray, dark gray bioclastic limestone intercalated with bird-eye limestone, fine laminated peloidal limestone, algal limestone and clayey limestone. Upper part, about 220 m thick, mainly consists of bioclastic limestone and dolomitic limestone.
Relationships and Distribution
Lower contact
It rests conformably on the Guitang Fm with a bed of fine-grained quartz sandstone at its base.
Upper contact
Conformable contact with the overlying Tungkangling Fm (Donggonling Fm), but the definite boundary is disputable.
Regional extent
The Formation is distributed in Beiliu area, representing a facies lateral shifting change of Gupa and Gucha Fm at west side of Dayaoshan Mts.
GeoJSON
Fossils
The lower part contains brachiopoda Eospriferina lachrymose-Athyrisina Assemblage Zone and coral Utarauia sinensis, and the upper part has a few coral Dendrostella sp.
Age
Depositional setting
It is interpreted as an open to semi-restricted platform setting.
Additional Information