铜陵地区岩浆系统中硫化物饱和与铜金分离：铂族元素和硫化物包裹体研究

Metallogenic difference among the intermediate-acidic magmatic systems is one of important research issues in mineral deposit. The metals separation in the magmatic evolution is an important factor that leads to metallogenic difference among magmatic systems, especially for homogeneous magmas. However, the separation mechanism of metals in the magmatic evolution is little understood. Investigation of saturation and segregation degree of the sulfide in evolving magmas will provides important and critical information for understanding the separation mechanism of the metals in the magmatic evolution. Platinum group elements geochemistry and sulfide melt inclusions can be used to trace the sulfide saturation history and segregation degree in evolving magmas. Tongling ore district is an ideal natural laboratory in which to examine the sulfide saturation history and segregation degree in evolving magmas and the magmatic processes that lead to the separation of copper and gold. Therefore, the project is planned to investigate the sulfide saturation history and segregation degree in evolving magmas and its effect on the separation of copper and gold, and the magmatic processes that lead to the separation of copper and gold, based on the detailed analysis of the platinum group elements geochemistry and sulfide melt inclusions trapped within the minerals of the magmatic rocks and xenoliths in the Tongling ore district, Anhui Province. The major achievements obtained in this study would improve our understanding of the nature of the metallogenic difference among the intermediate-acidic magmatic systems, and provide new insight into the formation of copper and gold deposits associated with intermediate-acidic magmatism.

中酸性岩浆系统成矿差异性是当前矿床学研究的重要课题。岩浆演化过程中金属元素的分离是造成岩浆系统，特别是具有相同源区的岩浆系统成矿差异性的一个重要因素。然而，目前对于岩浆演化过程中金属元素分离机制的研究相对薄弱。岩浆演化过程中硫化物的饱和与分异可能是控制岩浆系统中铜金等亲硫元素分离的一个重要甚至关键因素。铂族元素和硫化物熔融包裹体的联合研究是分析岩浆演化过程中硫化物的饱和与分异程度及其与铜金等亲硫元素分离关系的一种有效手段。而铜陵地区是开展岩浆演化过程中硫化物饱和与分异程度和铜金分离机制研究的理想基地。因此，本项目拟通过铜陵地区中生代岩浆岩及其岩石包体铂族元素地球化学和硫化物熔融包裹体的详细研究，来分析岩浆演化过程中硫化物的饱和与分异程度及其与铜金分离的关系，探索岩浆演化过程中铜金的分离机制，以期在中酸性岩浆系统成矿差异性研究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。

岩浆演化过程金属元素的分离机制是当前矿床学研究的重要课题。硫化物的饱和与分异可能是控制岩浆系统中铜金等亲硫元素分离的一个重要甚至关键因素。铂族元素和硫化物熔融包裹体的联合研究是分析岩浆演化过程中硫化物的饱和与分异程度及其与铜金等亲硫元素分离关系的一种有效手段。铜陵地区是开展岩浆演化过程中硫化物饱和与分异程度和铜金分离机制研究的理想基地。基于以上考虑，本项目对铜陵地区中生代岩浆岩及岩石包体开展了铂族元素地球化学和硫化物熔融包裹体研究，取得了以下主要认识：基本查明了铜陵地区中生代岩浆岩及其岩包体的铂族元素地球化学特征；初步查清了铜陵地区中生代岩浆岩及其岩石包体中硫化物熔融包裹体的微区成分特征；分析了与斑岩-矽卡岩型矿床相关岩浆系统演化过程中硫化物出熔与分异过程；探讨了与斑岩-矽卡岩型矿床相关岩浆系统演化过程中硫化物饱和与分异程度对岩浆系统铜金分离的影响，为正确认识岩浆演化过程中铜金的分离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，项目组成员发表学术论文3篇，完成硕士学位论文3篇。