长江中下游地区含矿埃达克质岩的成因——以丰山洞岩体为例的开题报告

精品文档---下载后可任意编辑长江中下游地区含矿埃达克质岩的成因——以丰山洞岩体为例的开题报告【摘要】含矿埃达克质岩在长江中下游地区普遍分布，其中丰山洞岩体是一个典型例子。本文以丰山洞岩体为讨论对象，通过对其岩石学、地球化学和同位素地球化学的综合分析，探讨了含矿埃达克质岩的成因。讨论结果表明，丰山洞岩体为埃达克质岩-角闪岩系列，主要组成为二长花岗岩和闪长岩。岩石中富含 Cu、Mo、Ag 等金属元素，与含矿埃达克质岩的特征相符。地球化学分析结果显示，丰山洞岩体富集了大量的亏损地幔元素，与玄武岩质地壳物质混染的模式一致。同位素地球化学讨论表明，丰山洞岩体形成时的岩石圈环境为亏损地幔环境，与含矿埃达克质岩的成因机制相符。综上所述，丰山洞岩体的成因是在玄武岩质地壳物质混染的基础上，受到亏损地幔物质的参加，形成了含矿埃达克质岩。本讨论对于深化了解长江中下游地区含矿埃达克质岩的成因机制，具有一定的理论指导意义。【关键词】含矿埃达克质岩；丰山洞岩体；岩石学；地球化学；同位素地球化学；成因【Abstract】Mineral-bearing adakite rocks are widely distributed in the middle and lower reaches of the Yangtze River, among which the Fengshan Cave Rock Mass is a typical example. In this paper, taking the Fengshan Cave Rock Mass as the research object, through the comprehensive analysis of petrology, geochemistry and isotope geochemistry, the genesis of mineral-bearing adakite rocks is explored.The results show that the Fengshan Cave Rock Mass is an adakitic-granodiorite–diorite series, mainly composed of biotite granite and diorite. The rock is rich in metal elements such as Cu, Mo and Ag, which is consistent with the characteristics of mineral-bearing adakite rocks. Geochemical analysis shows that the Fengshan Cave Rock Mass is enriched in a large number of depleted mantle elements, which is consistent with the mixing pattern of basaltic crustal material. Isotope geochemical studies show that the lithospheric environment 精品文档---下载后可任意编辑during the formation of the Fengshan Cave Rock Mass was a depleted mantle environment, which is consistent with the genesis mechanism of mineral-bearing adakite rocks.In summary, the genesis of the Fengshan Cave Rock Mass is based on the mixing of basaltic crustal material, and it was formed with the involvement of depleted mantle material, forming a mineral-bearing adakite rock. This study has a certain theoretical guiding significance for an in-depth understanding of the genesis mechanism of mineral-bearing adakite rocks in the middle and lower reaches of the Yangtze River.【Keywords】mineral-bearing adakite rocks; Fengshan Cave Rock Mass; petrology; geochemistry; isotope geochemistry; genesis