Xiaoxi Fm
Type Locality and Naming
Eastern Fujian. The Xiaoxi Formation was erected by the Fujian Regional Geological Survey Team in 1977. The section for the designation is at the Xiaoxi Village of the Gutian County of Fujian.
Lithology and Thickness
The Xiaoxi Formation is represented by a set of continental sedimentary-volcanic eruptive rock series, which is roughly divided into two members. The lower member is built up by dark gray and purple red tuffaceous siltstone with tuff and carbonaceous siltstone, while the upper member gray and purple gray rhyolitic crystal tuff and sediment tuff. The Xiaoxi Formation is 782.90 m thick.
Relationships and Distribution
Lower contact
The base of the formation marked by dark gray tuffaceous sandstone with crystal tuff lava and carboniferous siltstone lies disconformably on the underlying Ezhai Fm.
Upper contact
The top is bounded by the appearance of purple red gravel-bearing sandstone of the Huangkeng Fm, showing an unconformable contact with the latter.
Regional extent
The formation is distributed in east Fujian. It varies considerably both in thickness and lithology. The lower member is quite developed in Xiaoxi of Gutian, with a thickness of 782.9 m, while the upper member is most developed in Houcuo of Putian and is dominated by rhyolitic tuff, with a thickness of 911.6 m. The general trend is that the formation becomes more and more extensively exposed from southwest to northeast.
GeoJSON
Fossils
The formation yields estheria Orthestheria intermedia, Yanjiestheria yumenensis, Y. sinensis; and floras Rufffordia goepperti, Onychiopsis sp., Cupressinocladus elegans.
Age
Depositional setting
Additional Information