Huizhou Fm
Type Locality and Naming
Huangshan Basin. The Huizhou Formation was named by Zhang Wentang et al. (1976) in Guilin of the Shexian County, Anhui. The formation was also called as the Guilin Formation by the No 332 Geological Team of Anhui in 1971. The type locality of the Huizhou Formation is at the Guilin section in Shexian of Anhui (29º57', 118º29').
Lithology and Thickness
The Huizhou Formation is a group of brownish red thick-bedded calcareous sandstone and mudstone, with conglomerate interbeds locally. It is 1291 to 2520 m in thickness. Lower part is coeval with the granite and rhyolite of the Huangjian Fm (126 Ma for the famous granite GeoPark; ca. 133 Ma for the rhyolite)
Relationships and Distribution
Lower contact
The Huizhou Formation conformably contacts with the underlying Yantang Fm.
Upper contact
The Huizhou Formation unconformably contacts with the overlying Qiyunshan Fm.
Regional extent
It is distributed in the area of Shexian, Xiuning and Qimen.
GeoJSON
Fossils
The formation yields bivalves Sphaerium shantungense, S. yanbianensis, S. dayaoense, Nakamuranaia chingshanensis, Nippononaia sp., Plicatounio (Plicatounio) naktongensis, Trigonioides (Trigonioides) kodairai, T. (T.）sinensis; conchostracans Sinoestheria shexianensis, Halysestheria guangtagensis; ostracods Monosulcocypris contracta, M. oblonga, Cypridea (Cypridea) shexianensis, C. (C.) paranitidula, C. (C.) anhuiensis, Cypridea (Bisulcopridea) sp.; charophytes Atopochara trivolvis, Euaclistochara mundula, Mesochara symmetrica, Obtusochara cylindrical. Those fossils belong to the bivalve Trigonioides - Plicatounio – Nippononaia Assemblage; ostracod Cypridea (Cypridea) - C. (Bisulcocypridea) - Monosulcocypris Assemblage; conchostracan Sinoestheria Assemblage; and charophyte Euaclistochara mundula - Mesochara cymmetrica Assemblage. The assemblages indicate an Early Cretaceous age.
Age
Depositional setting
The formation belongs to the lacustrine facies.
Additional Information