Zhewang Fm
Type Locality and Naming
The type section is located at Zhewang Village, 7 km south of Mochong Town of Duyun County, Guizhou Province (107o23’E-26o03’N). The lectostratotype is located at eastern slope of Baihupo Hill, 3 km northwest Dushan City. It was named by Deng F.L. in a manuscript and introduced by Dong W.P. of Guizhou Geological Survey Team in 1967.
Lithology and Thickness
Limestone. The Zhewang Formation is characterized by a number of stromatoporid-bearing limestone in the type locality with varied thickness from 2 to 100 m. According to the Baihupo section in the west suburban of Dushan, it consists of black gray medium-thick bedded micritic limestone with a few cherty nodules yielding abundant stromatoporoids associated with tabulate rugose and bivalves, which may construct biostroms or reef limestone, 30.3 m thick. In the upper part of the formation it is marked by the shale intercalations, 13.5 m thick.
Relationships and Distribution
Lower contact
The Formation rests conformably on ostracod-bearing dolostone of the Yaosuo Fm at Dushan, and on the Gaopochang Fm at Guiyang.
Upper contact
Conformable contact with the overlying Gelaohe Fm at Dushan; hiatus overlain by Quaternary at Guiyang.
Regional extent
The distribution of Zhewang Fm is extensive in southern Guizhou, and also in northern Guangxi and southern Hunan. Throughout these regions, the formation is characterized by a large number of stromatoporoid-bearing limestones.
GeoJSON
Fossils
It contains abundant stromatoporoids: Stromatocerium sinense, S. guichowensis, Stylostroma sinense, S. Huangjiangensis, Labechia sp., Pennastroma sp.;
Tabulata corals: Chia cystosa, Aulocystella kueichowensis and Syringopora spp.; and
Foraminifera: Septaglomospiranella sp., Septalournayella sp., Septabrunsina sp., Quasiendothyra sp.
Age
Depositional setting
It is interpreted as a shallow-water platform setting.
Additional Information