Study on the Genesis and Tectonic Significance of the Volcanic Rocks of the Sanwan Formation in the Hannan Area

3rd International Symposium on Resource Exploration and Environmental Science

生态环境科学

Wang, Dequan^1 ; Wang, Jianguo^2 ; Deng, Shengbo^2 ; Wang, Yizhong^2

Sino Shaanxi Nuclear Industry Group, Shaanxi province, China^1

Sino Shaanxi Nuclear Industry Group 214 Brigade Co. Ltd., China^2

关键词: High field strength elements;    Island arc;    Large ion lithophile elements;    Major elements;    Partial melting;    Tectonic activity;    Trace element analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/300/2/022054/pdf
DOI  :  10.1088/1755-1315/300/2/022054

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The Sanwan Formation is distributed in Baimianxia, Bailongtang, Xixiang County, north margin of Yangtze Platform. It is mainly composed of a set of metamorphic volcanic sedimentary rocks.The Sanwan Formation experienced multi-phase tectonic activities and produced long strips of faults. Four representative volcanic rocks of the Sanwan Formation were collected. According to the analysis results of major elements, they are andesite-basalt andesite.According to trace element analysis, large ion lithophile elements (Sr, Ba, Rb, Th) are enriched, while high field strength elements (Ta, Nb, Zr, Hf, Ti) are relatively deficient. They have the characteristics of island arc volcanic rocks.According to trace element geochemical diagrams, we believe that fluid is involved in the formation of primitive magma, and magma shows strong partial melting trend and weak crystallization differentiation trend.