内蒙古乌拉特后旗查干德尔斯钼矿Re-Os同位素测年及地球化学特征

发布时间：2018-05-27 10:29

本文选题：查干德尔斯 + 钼矿床　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：查干德尔斯钼矿床是近几年新发现的一个大型的隐伏矿床,其位于内蒙古西部,中蒙边界地区。矿区内花岗岩极其发育,主要包括浅肉红色的正长花岗岩以及中细粒二长花岗岩。花岗岩体内部有无数石英脉穿插,而钼矿化与其关系十分的紧密。含钼矿石矿化主要以细脉浸染状以及团块状为主。文中较为系统地研究了辉钼矿的岩石化学特征以及微量、稀土元素的特征,并分析了矿石成因以及构造环境等方面的特征。分析表明二长花岗岩和钾长花岗岩具有相同的源区、构造背景以及形成演化过程,其源区是受到早期陆缘弧俯冲作用改造及地壳混染的岩石,再经过部分熔融作用所形成。通过辉钼矿铼-锇同位素年龄测定,得出辉钼矿的成矿时间距今243Ma左右,历时大约10Ma。根据相关资料显示,该矿体的辉钼矿的成矿时代非常接近早三叠世正长花岗岩的成岩时代,正长花岗岩形成于印支期早期,从而可以判断出查干德尔斯矿区钼矿也形成于为印支期早期。矿区内大部分钼矿受到石英脉的控制,因此钼矿的形成与NW向的石英脉之间密切相关。综上所述,查干德尔斯钼矿的成矿物质来源主要是在早三叠世后碰撞作用过程中由地幔岩浆与地壳重熔岩浆经过结晶分异作用形成的。由于该矿区的构造运动活跃,矿区内裂隙发育较好,随着成矿后期富含成矿元素的岩浆热液由地幔相地壳运移,并充填在这些石英脉中,由此逐渐形成钼矿床。
[Abstract]:Chagandels molybdenum deposit is a large concealed deposit discovered in recent years. It is located in the western part of Inner Mongolia and the border area between China and Mongolia. The granites in the mining area are extremely developed, mainly including reddish syenite and medium-fine-grained monzomorphic granites. There are numerous quartz veins interspersed in the granite body, and molybdenum mineralization is closely related to it. The mineralization of molybdenum-bearing ore is mainly vein-disseminated and lump-shaped. In this paper, the petrochemical characteristics, trace and rare earth elements of molybdenum ore are systematically studied, and the characteristics of ore genesis and tectonic environment are analyzed. The analysis shows that the bifeldite and the potash feldspar have the same source region, tectonic setting and evolution process. The source area is the rock transformed by early continental margin arc subduction and crustal mixing, and then formed by partial melting. Based on the determination of rhenium and osmium isotopic age of molybdenum ore, the metallogenic time of molybdenum ore is about 243Ma, which lasts about 10 Ma. According to the relevant data, the metallogenic age of the molybdenum deposit is very close to that of the early Triassic syenite, and the syenite formed in the early Indosinian period. It can be concluded that the molybdenum deposit of Chagandels deposit was also formed in the early Indosinian period. Most molybdenum deposits are controlled by quartz veins, so the formation of molybdenum ore is closely related to the NW direction quartz veins. To sum up, the source of metallogenic material of Chagandels molybdenum deposit is mainly formed by the crystallization differentiation between mantle magma and crustal remelting magma during the early Triassic collision. Because of the active tectonic movement in the ore area, the cracks in the ore area are well developed. With the magmatic hydrothermal fluid rich in ore-forming elements migrating from the mantle facies crust and filling in these quartz veins, molybdenum deposits are gradually formed during the late metallogenic period.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.65;P597

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