Jiudingshan Fm

North Anhui. The Jiudingshan Fm was named by the Jiangsu and Anhui Parties of Regional Geological Survey in 1976 and was formally published on the Guidebook of 1: 200000 Scale Geological Map of Xuzhou Sheet in 1978. The typical section is situated at the Longshan section near the Jiuding village in Lingbi County, Anhui Province.

Synonym: （九顶山组）

The Jiudingshan Formation is dominated by dolomite intercalated with limestone. Lower part is composed of gray to dark gray massive limestone and white gray massive dolomite intercalated with minor pelitic limestone and edgewise limestone. Lower part is only 177 m thick in Laoshankou area, north of Suzhou City. Upper consists of gray medium-bedded dolomite bearing cherty bandings interbedded with medium-to thick-bedded limestone. With a persistent lithology, the upper part is about 370 m thick in the typical section and westward becoming more dolomitic and the thickness somewhat decreases.

It yields abundant stromatolites: Kussiella cf. engmatica, Conophyton lijiadunensis, Inzeria intia, Jurusania cf. nisvensis, Tunggussia cf. inna, Eleonora cf. Japonica, Baicalia dubyi, B. Formosa, Gymnosolen f. etc. Microplants: Lophominuscula sp., Laminarites cf. antiquissimus, Quadratimorpha sp., Siphonophycus sp., Eoentophysalis yudomatica, Myxococcoidesstophylidion, Bigeminococcus lamellosus, Asperatopsophosphaera sp., Leiofusa sp. etc.