锡矿山超大型锑矿床U-Th/He年代学和He-Ar同位素示踪研究

锡矿山超大型锑矿床是全球最大的锑矿床，是全球很具特色的华南大面积低温成矿域的重要组成部分。由于低温矿床矿物组成的固有特点和研究方法的局限性，包括锡矿山锑矿床在内的华南低温成矿域的成矿时代、以及成矿作用是否有深源（地幔或岩浆）流体的贡献而受深部过程驱动，是以往未解决的重要科学问题。锆石U-Th/He同位素定年方法，以及对辨析地幔信息极为敏感的He-Ar同位素示踪方法，是近年拓展到矿床学研究的新方法，是解决上述问题的可靠选择。本项目以锡矿山超大型锑矿床为对象，系统研究其蚀变围岩中受成矿热事件影响而发生了U-Th/He重置的继承锆石的U-Th/He年代学，以及成矿阶段形成的热液成因矿物中流体包裹体的He-Ar同位素地球化学，以确定该矿床的成矿时代以及成矿流体的成因和驱动机制。这些研究不仅对深入认识这一国际著名超大型矿床的形成机制具有重要意义，而且也是发展华南大面积低温成矿理论的重要基础。

The Xikuangshan is the largest Sb deposit in the world, being an important part of the unique large-scale low-temperature metallogenic domain in South China. The chronology and contribution of deep-derived fluids (mantle or magma) to these deposits including the Xikuangshan in this domain, have not yet been well constrained due to the intrinsic characteristics of ore composition of these deposits and the limits of research methods. U-Th/He isotopic dating and He-Ar isotopic tracing have been successfully applied in studying ore deposits in recent years, providing a reliable solution to above-mentioned issues. This project takes the Xikuangshan giant Sb deposit as the studying objective, and carries out systematic researches on U-Th/He isotopic dating of zircon grains from altered wall rocks impacted by mineralization thermal event, as well as He-Ar isotopic geochemistry of fluid inclusions within hydrothermal sulfides. We attempt to determine the mineralization age and origin and driving mechanism of ore-forming fluids of Xikuangshan giant Sb deposit. Our study will show some new insights into the metallogenic mechanism of this world-famous giant deposit, as well as the development of theoretical system on the large-scale low-temperature metallogeny in South China.