Xindu Fm
Type Locality and Naming
The type section is located at Hongfan-Shankou area of Renyi Town, 4 km away from Xindu Town, Hexian County, Guangxi Zhuang Autonomous Region. It was named by Guangxi Regional Geological Survey in 1974.
Synonym (translation option): Xingdu Fm
Lithology and Thickness
Sandstone. The Xindu Formation is characterized by three parts: Lower part is siltstone and fine-grained sandstone with shale and dolomitic limestone; Middle part is fine-grained sandstone with a few limestone and oolitic hematite; Upper part is sandstone, siltstone and shale with limestone and 1-3 beds of oolitic hematite. It is 220 m thick at the type section, and ranges from 50 to 865 m thickness in the region.
[Figure - Outcrop of Xindu Fm showing the oblique bedding structures.]
Relationships and Distribution
Lower contact
It rests disconformably on the Lianhuashan Fm (although Hexian Fm is indicated on the regional strat column), and overlaps on the margin of Pre-Devonian Old Land at Quanzhou, Xinon, Rongon Rongshui and Luocheng.
Upper contact
The Formation is distributed in the northeast and north Guangxi.
Regional extent
With gradual transition the formation is conformable contact with overlying Donggangling Fm (Tungkangling Fm); or the overlying Tangjiawan Fm, depending on locality.
GeoJSON
Fossils
The fossils are: Brachiopods Eospiriferina lachrymose, Xenospirifer fungi, Athyrisina squamosa, Indospirifer quadriplicata, I. maoerchuanensis; Fish Hohsienolepis hsintuensis; Plants Protolepidodendron scharyanum, Philophyton sp.; and ostracods and bivalves.
Age
Depositional setting
It is interpreted as tidal flat, intertidal and subtidal depositional environments and partial lagoon conditions.
Additional Information