扬子地块西南缘拉拉IOCG矿床矿化蚀变元素地球化学研究

发布时间：2018-04-12 11:38

本文选题：拉拉IOCG矿床 + 围岩蚀变　；参考：《大地构造与成矿学》2016年05期

【摘要】：拉拉IOCG矿床是我国西南地区著名的大型铁铜矿床,矿床中与铜(钼)矿化密切相关的钠长石化、碳酸盐化、钾长石化、黑云母化、萤石化等蚀变作用广泛发育。本文在对该矿床中黑云母片岩系列和钠长石变粒岩系列大量赋矿岩石样品进行岩相学研究的基础上,选取典型蚀变与矿化样品进行主、微量元素分析测试,通过质量比簇判别法和等浓度公式元素定量迁移计算研究矿床中蚀变元素特征及其与矿化的关系。质量比簇判别法和等浓度图解法确定了两个系列岩石共有的主量元素不活动组分为SiO_2,微量元素不活动组分为Yb。主量元素定量迁移计算表明黑云母片岩系列铜矿化与钠长石化和碳酸盐化成正相关关系,钠长石变粒岩系列铜矿化与钾长石化和碳酸盐化成正相关关系,且变粒岩系列碳酸盐化程度较片岩系列更强。稀土元素和金属元素定量迁移计算发现拉拉IOCG矿床中U、Co、Mo、Ni等成矿金属元素在蚀变过程中随Cu矿化大量带入,说明热液蚀变是拉拉Fe-Cu-Au-U-Mo-REE多金属矿床形成的主要原因。蚀变与矿化关系分析表明二者基本是同步发生,蚀变的过程也是矿化的过程,即蚀变的标志也是找矿的标志。拉拉IOCG矿床中蚀变元素地球化学特征及其与矿化关系的研究,对于矿床成矿理论的丰富及矿区进一步找矿勘探工作都具有重要意义。
[Abstract]:Lala IOCG deposit is a famous large iron copper deposit in southwest China. Albite carbonization potassium feldspar biotite and fireflitization are widely developed in the deposit which are closely related to copper (molybdenum) mineralization.Based on the petrographic study of a large number of ore-bearing rock samples of biotite schist series and albite granulite series in the deposit, typical alteration and mineralization samples are selected for the analysis and testing of main and trace elements.The characteristics of altered elements in ore deposits and their relationship with mineralization are studied by means of mass ratio cluster discrimination method and quantitative element migration calculation with equal concentration formula.The mass ratio cluster discrimination method and the equal concentration diagram method have determined that the inactivity components of the principal elements shared by the two series of rocks are SiO-2, and the trace element inactive components are Yb.The quantitative migration calculation of major elements shows that the copper mineralization of biotite schist series is positively correlated with albite and carbonization, and that of albite granulite series is positively correlated with potassium feldspar and carbonization.The carbonization degree of granulite series is stronger than that of schist series.The quantitative migration calculation of rare earth elements and metal elements shows that the ore-forming metal elements such as U _ (Co _ (Co) Mo _ (Mo) Ni) in Lala IOCG deposit are brought in with Cu mineralization in large quantities during the alteration process, indicating that hydrothermal alteration is the main reason for the formation of Lala Fe-Cu-Au-U-Mo-REE polymetallic deposit.The analysis of the relationship between alteration and mineralization shows that the process of alteration occurs simultaneously and the process of alteration is also a process of mineralization, that is, the mark of alteration is also the mark of prospecting.The study of geochemical characteristics of altered elements and its relationship with mineralization in Lala IOCG deposit is of great significance for the enrichment of ore forming theory and the further exploration of ore deposits.
【作者单位】：成都理工大学地球科学学院;中国科学院地球化学研究所;
【基金】：国家自然科学基金项目(41072065) 教育部博士点基金(20105122110001) 西南地区主要成矿带铜铁金多金属找矿模型与勘查方法技术研究(12120113095500) 矿床地球化学国家重点实验室(200808) 四川省教育厅重点项目(07ZA005)联合资助
【分类号】：P618.41;P618.31

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