Qiuzhuang Fm
Type Locality and Naming
Heifei Basin, north zone. The Qiuzhuang formation was designated by the Anhui Regional Geological Survey Team in 1978. The section for the designation is in Qiuzhuang about 12 km southeast of the Wuhe County, Anhui.
Synonym: Xiangdaopu Fm. It is equivalent to the Xiangdaopu Fm designated by the No.108 Geological Team of the East China Petroleum Exploration Brigade in 1961.
Lithology and Thickness
The Qiuzhuang Formation is represented by a set of brown red sandy mudstone, which is divided into two members. Lower member is represented by brownish red occasionally with grayish green medium and fine-grained lithic sandstone with siltstone and calcareous mudstone. Upper member is brown red siltstone and fine sandstone with marl. It is 2190 m thick.
Relationships and Distribution
Lower contact
The base of the formation marked by sandy conglomerate is distinguished from sandy mudstone of the underlying XinzhuangAnhui Fm. The contact is disconformable.
Upper contact
The top marked by sandstone is distinguished from calcareous sandy conglomerate of the overlying Zhangqiao Fm. The contact is disconformable.
Regional extent
The formation occurs in Bangbu on the southern bank of the Huaihe River. In the Hefei basin, it is overlain by the Quaternary except on the margin of the basin where sporadic outcrops are observed. In the north Huaiyang area, the strata equivalent to the formation is called the Xiafuqiao Fm.
GeoJSON
Fossils
The formation bears Bivalves Sphaerium shuangtungense, Floras Manica cf. tholistoma, Suturovagina sp., and Elatocladus sp., Brachyphyllum sp.
Age
Depositional setting
It belongs to lacustrine deposition.
Additional Information