Yuanpan Fm
Type Locality and Naming
Western Fujian. The Yuanpan Formation was erected by the Fujian Institute of Geology in 1961. The type locality for the designation is in Yuanpan of the Pucheng County of Fujian. The reference section is from Dalongpeng to Jingshan of the Yongan City of Fujian. Lower formation of the Douling Gr.
Lithology and Thickness
The Yuanpan Formation is represented by a set of purple red and gray white tuffaceous sandy conglomerate and sandstone with silty mudstone. The Yuanpan Formation is 903.40 m thick.
Relationships and Distribution
Lower contact
Its unconformable base marked by purple red and light gray green clayey sandstone, thick-bedded gravel-bearing grit and conglomerate is distinguished from the underlying Indo-Chinese granite. Elsewhere, it is conformable on the Zhangping Fm.
Upper contact
Its unconformable top is bounded by the appearance of purple gray rhyolitic tuff lava of the Xiadu Fm.
Regional extent
The formation occurs in the various basins of west Fujian. It varies considerably both in lithology and thickness. In southwest Fujian, it is represented largely by purple red rocks while in northwest Fujian it is often intercalated with black rocks and marl, ranging from scores of meters to 1000 m or more in thickness, up to 1355.4 m at maximum in Yuejikeng of Chongan.
GeoJSON
Fossils
In Xiejiaping of Guangze and Yuejikeng of Chongan and Huyuan of Shaxian, it yields floras Cupressinocladus elegans; estherias Yanjiestheria cf. sinensis; and bivalves Ferganoconcha sp.
Age
Depositional setting
Additional Information