安徽狮子山矿田硅酸盐和硫化物熔浆演化与金属元素矿化关系研究

Due to their economic significance, Intermediate-acidic magma-related hydrothermal ore deposits have been intensely investigated worldwide. Most of the metals that form Intermediate-acidic magma-related hydrothermal ore deposits are probably derived from magmas, but the controlling processes in the magmatic evolution prior to large-scale volatile exsolution are little understood. The study of silicate and sulfide melt inclusion offers the potential to better understand the early evolution of magmatic-hydrothermal ore-forming systems. Therefore, the project is planned to investigate the mechanism of immiscible separation of sulfide melt from silicate magma during Intermediate-acidic magma evolution, the evolution of sulfide melts during the evolution of mafic to siliceous magmas from the upper mantle to the upper crust, and the behavior of Cu and Fe during silicate and sulfide melt evolution, based on the detailed analysis of silicate and sulfide melt inclusions trapped within the minerals of the ultramafic clots, cumulates, microgranular mafic enclaves, and intermediate-acidic magmatic rocks in the Shizishan ore-field, Tongling, Anhui Province. The major achievements obtained in this study would improve our understanding of the sulfide melt evolution in upper mantle to upper crust magmas, and provide new insight into the formation of Cu-Fe polymetallic deposits associated with Intermediate-acidic magmatism.

岩浆作用过程是中酸性岩浆-热液成矿过程的重要组成部分。然而，国内外地质工作者对中酸性岩浆作用过程与金属元素成矿的关系，特别是中酸性岩浆作用过程中金属元素迁移与富集机制的研究相对薄弱。利用硅酸盐和硫化物熔融包裹体资料分析岩浆演化过程中元素的迁移与富集机制已成为岩浆作用与成矿作用研究的一种重要手段和趋势。因此，本项研究拟通过对狮子山矿田内的硅酸盐、硫化物熔融包裹体的详细研究，并结合已有的地质与地球化学资料，来分析中酸性岩浆演化过程中硫化物熔浆的出熔与分解机制，探索从上地幔到上地壳范围内，镁铁质到长英质岩浆演化过程中硫化物熔浆的演化模型，并在此模型的基础上探讨Cu、Fe等元素的迁移富集机制。其成果有望在岩浆-热液成矿作用，特别是中酸性岩浆演化与铜、铁矿化关系方面获得一些新的进展，为丰富岩浆-热液成矿理论补充新的科学依据。

中酸性岩浆作用过程与金属元素成矿的关系是当前矿床学研究的热点问题。本项目通过对狮子山矿田内的硅酸盐、硫化物熔融包裹体和流体包裹体的详细研究，并结合已有的地质与地球化学资料，基本查明了狮子山矿田内中酸性岩浆岩及岩石包体中硅酸盐、硫化物熔融包裹体特征；揭示了中酸性岩浆演化过程中硫化物熔体的出熔和分解机制；初步建立从上地幔到上地壳范围内，镁铁质到长英质岩浆演化过程中硫化物熔浆的演化模型，为正确认识中酸性岩浆演化过程中 Cu、Fe 等元素的迁移富集机制提供了重要信息，为丰富岩浆-热液成矿理论和进一步勘查该类矿床补充了新的科学依据。此外，在项目研究成果的基础上，发表SCI检索学术论文6篇，中文核心论文2篇。