西藏多不杂铜矿床脉石矿物稀土元素地球化学示踪

探讨多不杂铜矿床成矿流体的演化规律,分析花岗闪长斑岩壳幔混染的过程。选择多不杂铜矿床内相关脉石矿物,测试其稀土元素组成。结果表明,各个成矿阶段脉石矿物的稀土元素均具有轻稀土富集的特征,这是地幔流体作用成矿的标志;斑晶石英和黑云母样品具有明显的正铕异常,脉石英样品具有弱的负铕异常,硬石膏的稀土总量最高,并呈现出明显的负铕异常;随着成矿过程的进行,稀土元素表现为由正铕异常→无铕异常→负铕异常演变,这正是地幔流体作用导致流体性质变化进而混染成矿的证据。

Gangue mineral REE geochemical tracer of the Duobuza Copper Deposit,Tibet

Discussion on metallogenic fluid evolution of the Duobuza copper deposit, Analysis of crust mantle mixing process in granodiorite porphyry. Select the relevant gangue minerals in the Duobuza copper deposit, and test the composition of rare earth elements. Research shows that the rare earth elements of each metallogenic stage of gangue minerals are light REE enrichment, this is a sign of mantle fluid mineralization. The samples of phenocrysts quartz and biotite have obvious positive Eu anomalies, and the quartz samples have weak negative Eu anomaly. The total amount of rare earth in anhydrite is the highest and shows obvious negative Eu anomaly. In the mineralization process, rare earth elements on the characteristics of positive Eu anomaly to negative Eu anomaly evolution, it records the mantle magma and fluid in diagenesis and mineralization process, accompanied by magmatic crystallization diagenetic metasomatic rock and its evolution process of fluid properties, causing mantle matter contamination and superposition mineralization.