贵州独山锑矿田石英Rb-Sr定年及矿床地球化学研究

独山锑矿田位于扬子古陆西南缘与雪峰山隆起的嵌接部,是华南锑矿带的重要组成部分.为厘清该矿田锑矿的成因,在总结区域上典型锑矿床地质特征的基础上,开展了石英Rb-Sr定年、流体包裹体和碳、氧同位素分析,并结合前人的氢、氧、硫、铅同位素研究结果,从成矿时代、成矿流体性质及来源、成矿物质来源等方面探讨了成矿作用.分析测试得到石...

The Rb-Sr Dating of Quartz and Geochemistry Studying of the Dushan Antimony Ore-Field,Guizhou,China

The Dushan antimony ore-field, an important part of the south China antimony ore belt, is located in the conjunction of the southwestern margin of Yangtze land block and the Xuefengshan uplift. In order to clarify the genesis of antimony deposits in the ore-field, on the basis of summarizing geological characteristics of typical antimony deposits in the region, in this paper, we have carried out the quartz Rb-Sr dating, fluid inclusion geochemistry, and C and O isotopic composition analysis, combined with the previous H, O, S, Pb isotopic data, and then discussed the metallogenesis of antimony deposits in the Dushan ore-field in aspects of metallogenic epoch, properties and sources of metallogenic fluids, and sources of metallogenic materials. The quartz Rb-Sr isochronal age of(189±3.2) Ma indicates that the Banpo deposit was formed in Yanshanian. The ore-forming fluids of various deposits are characterized with the low temperature, medium to low salinity, medium to low density, weak acidity, and reducd to weak oxidized REDOX condition. They belong to the H₂O-Ca²⁺-Mg²⁺-SO₄^2-(F^-,Cl^-)-CO₂ system. They were mainly sourced from deep magmatic water, with minor mixed meteoric water in late stage. The metallogenic materials have characteristics of the crust-mantle mixed source. The Lower Cambrian and Upper Sinian strata could provide part of ore-forming materials for the mineralization of antimony deposits in the Dushan ore-field. It is believed that the antimony deposits of the Dushan ore-field belong to the magmatic-hydrothermal fluid associated infilled type epithermal deposits.