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马厂箐钼铜金多金属矿床是滇西地区金沙江—哀牢山构造带内与新生代富碱斑岩有关的典型矿床之一。根据赋矿斑状花岗岩中锆石的阴极发光图像、LA-ICP-MS微量元素分析和U-Pb定年以及辉钼矿Re-Os法测年研究等,结合前人研究成果,应用透岩浆流体成矿理论,进一步讨论了马厂箐矿床的成因机制。研究表明:该矿床的多金属成矿与赋矿斑状花岗岩的成岩基本同时,其成岩成矿过程统一受制于与该区大规模活动的新生代富碱岩浆和深部地壳重熔的花岗质岩浆同步运移的成矿流体作用。这种成矿流体是包含于岩浆并与其互不混溶的含矿地幔流体。但在上侵运移过程中,伴随岩浆的成岩作用,流体与岩浆发生不同程度分离,表现为:产于富碱斑状花岗岩体内,形成正岩浆成矿的斑岩型钼矿;产于岩体与围岩接触带,形成接触交代成矿的矽卡岩型铜(钼)矿;产于地层围岩中则形成构造破碎蚀变岩型金矿。在这一成岩成矿过程中,地幔流体可以运载和沿途活化成矿物质至适宜容矿部位集中,并随其对地壳岩石的交代蚀变以及深度和环境变化引起的物理化学条件变化,其流体属性由熔浆流体→超临界流体→热液流体转化,促使壳幔物质相互作用而叠加成矿,导致在不同部位形成不同矿种和不同类型的系列成矿效应。
Ma Cheong molybdenum copper-gold polymetallic deposit is one of the typical deposits related to Cenozoic alkali-rich porphyries in the Jinshajiang-Ailaoshan structural belt in western Yunnan. According to the cathodoluminescence images of zircons in the porphyritic granites, the LA-ICP-MS trace element analysis and the U-Pb dating and the Re-Os dating of the molybdenite, with the previous research results, Mineral theory, to further discuss the genetic mechanism of the Moutan 箐 deposit. The results show that the metallogenic process of the deposit and the porphyry granite are basically diagenetic. At the same time, the diagenesis and mineralization processes are controlled by the large-scale Cenozoic alkali-rich magma and the remelted granitic magma Synchronous migration of the role of ore-forming fluid. This ore-forming fluid is an ore-bearing mantle fluid that is contained in the magma and immiscible with it. However, during the process of the upwelling and translocation, the fluid and magma separated with different degrees due to diagenesis of magma: the porphyry-type molybdenum deposit was formed in the alkali-rich porphyritic granite and was formed in the porphyry And contact with the surrounding rock to form contact with the metallogenic skarn copper (molybdenum) ore; produced in the formation of rock in the formation of structural alteration rock type gold deposit. In this diagenetic mineralization process, the mantle fluid can carry and activate the ore-forming materials along the way to the suitable ore-hosting sites. With the alteration of the crustal rocks and the changes of the physico-chemical conditions caused by the depth and the environmental changes, the fluids The properties are transformed from the melt fluid → supercritical fluid → hydrothermal fluid to promote the interaction of the crust and mantle material to superpose the mineralization, resulting in the formation of different mineralization and different types of metallogenic effects in different parts.