Tangshang Fm
Type Locality and Naming
Eastern Zhejiang The Tangshang Formation was erected by the Zhejiang Regional Geological Survey Team in 1978. The section for the designation is at the Tangshang Village 3 km southwest of the Tiantai County town of Zhejiang.
Lithology and Thickness
The Tangshang Formation is represented by a set of purple gray, purple red and gray white acidic pyroclastic rocks, intercalated with acidic and intermediate lava and purple red sandstone, siltstone and sandy conglomerate. The Tangshang Formation is 1129.90 m thick in average, but 2359.3 m at maximum (at Xianyanpu) and 68.8 m of minimum (at Zhengkengkou)..
Relationships and Distribution
Lower contact
Its base marked by gray purple and purple red massive sediment tuff breccia with purple red and gray yellow tuffaceous feldspar fine sandstone is distinguished from light gray green analcitized breccia sediment tuff of the Xitoushan Fm of the Moshishan Gr, showing an unconformable contact with the latter.
Upper contact
Its top is bounded by the appearance of purple red thin- moderately thick-bedded calcareous siltstone of the Liangtoutang Fm, showing a conformable contact with the latter.
Regional extent
The formation mainly occurs in the Lishui-Xiaoxiong area of southeast Zhejiang. It decreases in the number of sedimentary partings and increases in the amount of volcanic rocks. The lithology of volcanic rocks is varied as follows: dominated by acidic pyroclastic rocks in the Lishui basin of west Zhejiang; acidic lava developed in Jinyun of central Zhejiang; slightly alkaline lava appearing in the caldera at Xiaoxiong of east Zhejiang.
GeoJSON
Fossils
The formation yields floras Pseudofrenelopsis papillosa, P. sp., Pagiophyllum sp., abundant Classopollis and small amounts of Exesipollenites, Sphaeripollenites, Schizaeoisporites, and Cicatricosisporites.
Age
Depositional setting
It mainly belongs to volcanic eruptive accumulation.
Additional Information