Tiaomajian Fm
Type Locality and Naming
The type section is located at Tiaomajian, about 35 km southeast of Changsha, Hunan (near the present Dawuwan reservoir of Tiaomajian Town).
It was named by Tian Qijun in 1928.
Lithology and Thickness
Sandstone. This formation is mainly composed of grayish-white, grayish yellow, purplish-red and grayish-purple feldspathic quartz sandstone, sandy shale, silty mudstone and clayey fine-grained sandstone, and occasionally intercalated with pisolitic hematite beds. At the base is a 7.2-m-thick bed of grayish-white massive quartz conglomerate.
In the type section, the total thickness is 156 m.
Relationships and Distribution
Lower contact
The formation is in an unconformable contact with the underlying sandy slate of Wuqiangxi Fm of the Banxi Group (Cryogenian).
Upper contact
The top is in a conformable contact with the overlying Qiziqiao Fm.
Regional extent
This formation is distributed in central and south Hunan. The lithology is consistent through the entire area.
GeoJSON
Fossils
The main fossils are fish Bothriolepis sinensis, Hunanolepis tieni; plants Sublepidodendron, Taeniocrada?, etc., and bivalves.
In Jinshansi of Zhuzhou, microfossils of spores are recorded from this formation (Zhao Ruxuan et al., 1978).
Age
Depositional setting
Additional Information
ron ore is developed in Jiangshui, Daoxian County, Guiyang, southern Hunan, commonly as 1 to 5 beds, although some areas have more than 6 to 7 beds. In the north, Shaoyang, Shuangfeng, Changsha area, there is no iron ore found.