Ningguo Fm
Type Locality and Naming
The type section is at Lannihu in Hulesi, 60 km south of Ningguo City, Anhui. The Ningguo Fm was named by Xu Jie (S.C. Hsü) in 1934.
Synonym: (宁国组); Ningkou Fm (spelling)
Lithology and Thickness
The Ningguo Formation is composed of grayish green, dark gray and brown shale. In the type area, the Ningguo Fm is 110 m thick. In Changshan, western Zhejiang, Jiangxi and Tongshan, Hubei, the Ningguo Fm is intercalated with limestone lenses.
Relationships and Distribution
Lower contact
It rests conformably on the variegated shale intercalated with lenticular marl at the top of the Yinchupu Fm (Yinzhubu Fm). Fang Yiting (1991) reconsidered the Ningguo Fm as a lithostratigraphic unit, a suggestion followed by the present book. Meanwhile, the lower boundary within T. approximatus zone in Yushan, A. wuecicux zone in Jiangshan or D. deflexus zone in Ningguo, southern Anhui and Lin'an, Zhejiang, indicating a diachronism.
Upper contact
It is conformably overlain by the black siliceous shale and chert at the base of the Hule Fm. Fang Yiting (1991) reconsidered the Ningguo Fm as a lithostratigraphic unit, a suggestion followed by the present book. Meanwhile, the upper boundary of the Ningguo Fm is drawn within Paraglossograptus tentaculatus zone.
Regional extent
The Ningguo Fm is exposed in Zhejiang-Anhui-Jiangxi region south of Hangzhou-Xuancheng-Shitai and north of Yushan-Jingdezhen, westward to Xiushui River in northwestern Jiangxi. In Lin'an, Yuhang, from west to east, limestone occurs in the Ningguo Fm. To Hangzhou, the Ningguo Fm is composed dominantly of carbonate rock (Chen Xu et al., 1981). In Tongshan, Hubei, the Ningguo Fm was previously named the Dageng Fm (Liu Yongyao et al., 1984).
GeoJSON
Fossils
The Ningguo Fm includes nine graptolite zones, Tetra. approximatus zone, Pend. fruticosus zone, D. (Corymograptus) deflexus zone, A. suecicus zone, I. victoriae zone, O. magnus zone, C. (Procardiograptus) cor zone, Undul. austrodentatus zone and a part of Paraglossograptus tentaculatus zone, in ascending order, and five conodont zones, P. gracilis zone, Prioniodus elegans zone, Oepikodus evae zone, Baltoniodus triangularis and Paroistodus originalis zone, in ascending order (Yao Lunqi et al., 1991). Qian Yiyuan et al. (1964) restudied the type section and established four graptolite zones. At the same time, Ge Meiyu (1964), Chen Xu and Han Nairen (1964) studied the Ningguo Fm in western Zhejiang and northeastern Jiangxi, and established the graptolite zones.
Age
Depositional setting
Additional Information