Huang’ai Fm
Type Locality and Naming
The type section is at Village Huang'ai 50 km northwest of Xing'an County, Guangxi. The Huang'ai Fm is derived from Huang'ai Shale of Zhao Jinke (Chao Kingkoo) and Zhang Wenyou (Chang W.Y.) (1959). Following the naming of Chao and Chang's Huang'ai Shale, Li Zhicai (1965) defined the strata bearing abundant graptolite in the upper part of the Huang'ai Shale the Shengping Fm, and the lower part the Huang'ai Fm. Chen Xu et al. (1981) restudied the type section of the Huang'ai Fm, and established the graptolite zone sequence. Considering the similar lithology of the Shengping Fm and the Huang'ai Fm proposed by Li (1965), the present book includes the Shengping Fm in the Huang'ai Fm, and does not use the former term.
Synonym: (黄隘组）
Lithology and Thickness
The Huang’ai Formation consists of a sequence of gray, grayish green and grayish purple banded siltstone and siliceous shale. In the type area, the Huang'ai Fm is 200 m thick.
Relationships and Distribution
Lower contact
The type section is cut by fault at the base. In Songjiangkou and Shengpingxu, Xing'an, the Hunag'ai Fm rests conformably on the limestone of the Baidong Fm
Upper contact
In Songjiangkou and Shengpingxu, Xing'an, the Hunag'ai Fm, it is conformably overlain by the fine-grained sandstone intercalated with shale of the Tianlingkou Fm
Regional extent
In Liuchen, the Huang'ai Fm recorded a thickness of over 200 m, and its base is at the base of T. approximatus zone (Chen et al., 1981).
GeoJSON
Fossils
It includes six graptolite zones, in ascending order, D. (Corymbograptus) balticus zone, D. (Expansograptus) abnormis zone, “C. amplus" zone, Undul. austrodentatus zone, Paraglossograptus zone and Nicholsonograptus zone.
Age
Depositional setting
Additional Information