金川铜镍硫化物矿床硫饱和机制的研究
发布时间：2018-07-16 14:31
【摘要】：金川岩浆型铜镍硫化物矿床是在采的世界第三大铜镍硫化物矿床,金川岩体出露面积仅有1.34km2,矿化率却高达47%。金川岩体主要组分成分为镁铁质岩石,主要造岩矿物为：橄榄石、单斜辉石和斜方辉石。金川岩体中不同岩石类型的橄榄石牌号Fo值变化范围小,橄榄石探针分析表明Fo值集中在80～83,暗示金川岩体成矿环境为开放式的岩浆系统,岩浆到达成矿环境之后还存在多期次新鲜岩浆的补充贯入。不同粒度岩相以及矿石类型之间的接触关系呈突变类型,暗示金川母岩浆上升到现存成矿空间之间即发生了成矿物质的富集作用,即硫化物饱和在侵入就位前就已经实现。硫饱和机制的研究主要包括：岩浆源区的判别、岩浆原始组分的厘定、地幔部分熔融程度的厘定、熔融岩浆中硫的含量、影响岩浆硫溶解能力的因素、不同因素的主导能力、岩浆达到硫化物饱和时硫的含量等。本文研究表明金川母岩浆源于20%部分熔融程度的富集地幔,微量元素分析表明岩浆在上升过程经历了约15%～-40%的地壳物质混染,而硫同位特征显示金川矿区中的硫为幔源流,排除了地壳硫的加入的可能。对岩浆离开源区时岩浆中硫的含量进行估算为1000ppm,根据高镁玄武岩浆SCSS(sulfur content at sulfide saturation,即岩浆达到硫化物饱和状态时硫的含量)与深度的关系,金川母岩浆形成时的SCSS在950ppm-1100ppm,因此金川母岩浆在离开地幔时是接近其SCSS的。基于以上分析结果,本文提出金川岩浆实现硫化物饱和的过程大致如下：金川母岩浆在富集地幔的20%部分熔融作用下形成,形成时硫的含量大约为1000ppm, SCSS为950ppm～1100ppm,在其上升至就位岩浆房途中经历了约15%-40%地壳物质的混染,使得SCSS降至其硫含量之下,进而发生硫化物熔离,并在岩浆房中富集成矿。
[Abstract]:Jinchuan magmatic copper-nickel sulfide deposit is the third largest copper nickel sulfide deposit in the world. The area of Jinchuan rock body is only 1.34 km ~ 2, but the mineralization rate is as high as 47. The main composition of Jinchuan rock body is mafic rock, and the main rock-forming minerals are olivine, clinopyroxene and clinopyroxene. The Fo value of olivine in different rock types in Jinchuan rock mass varies in a small range. The olivine probe analysis shows that the Fo value is concentrated in 80 / 83, suggesting that the metallogenic environment of the Jinchuan rock mass is an open magmatic system. After the magma reaches the metallogenic environment, there are several times fresh magma supplementary penetration. The contact relationship between different granularity lithofacies and ore type is abrupt, suggesting that the enrichment of ore-forming material occurred between Jinchuan magma rising to the existing ore-forming space, that is, sulfide saturation was realized before invading into place. The research on the mechanism of sulfur saturation mainly includes: distinguishing the magmatic source region, determining the original composition of the magma, determining the degree of partial melting of mantle, the content of sulfur in the molten magma, the factors influencing the sulfur dissolution ability of the magma, and the leading ability of different factors. Sulfur content when magma reaches sulphide saturation. This paper shows that Jinchuan mother magma originated from the enriched mantle with 20% partial melting degree. Trace element analysis shows that the magma experienced about 150-40% crustal material mixing in the rising process, while the sulfur isochronal characteristics indicate that the sulfur in Jinchuan mining area is a mantle source. The addition of crustal sulfur is ruled out. The sulfur content in the magma is estimated to be 1000 ppm when the magma leaves the source area. According to the relationship between the sulfur content and the depth of the high magnesium Black Tortoise magma, that is, when the magma reaches the sulphide saturation state, the content of sulfur in the magma is estimated to be 1 000 ppm. The SCSS of Jinchuan mother magma was 950ppm-1100ppm, so the Jinchuan mother magma was close to its SCSS when leaving the mantle. Based on the above analysis results, it is suggested that the process of sulphide saturation of Jinchuan magma is as follows: Jinchuan mother magma is formed by 20% partial melting of enriched mantle. The sulfur content at the time of formation is about 1000 ppmand SCSS is 950ppm-1 100ppm.The sulfur content of SCSS decreases to below its sulfur content during its rise to the in-situ magma chamber, which causes the SCSS to fall below its sulfur content, and then it is enriched in magma chamber for mineralization.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41;P618.63
本文编号：2126684
[Abstract]:Jinchuan magmatic copper-nickel sulfide deposit is the third largest copper nickel sulfide deposit in the world. The area of Jinchuan rock body is only 1.34 km ~ 2, but the mineralization rate is as high as 47. The main composition of Jinchuan rock body is mafic rock, and the main rock-forming minerals are olivine, clinopyroxene and clinopyroxene. The Fo value of olivine in different rock types in Jinchuan rock mass varies in a small range. The olivine probe analysis shows that the Fo value is concentrated in 80 / 83, suggesting that the metallogenic environment of the Jinchuan rock mass is an open magmatic system. After the magma reaches the metallogenic environment, there are several times fresh magma supplementary penetration. The contact relationship between different granularity lithofacies and ore type is abrupt, suggesting that the enrichment of ore-forming material occurred between Jinchuan magma rising to the existing ore-forming space, that is, sulfide saturation was realized before invading into place. The research on the mechanism of sulfur saturation mainly includes: distinguishing the magmatic source region, determining the original composition of the magma, determining the degree of partial melting of mantle, the content of sulfur in the molten magma, the factors influencing the sulfur dissolution ability of the magma, and the leading ability of different factors. Sulfur content when magma reaches sulphide saturation. This paper shows that Jinchuan mother magma originated from the enriched mantle with 20% partial melting degree. Trace element analysis shows that the magma experienced about 150-40% crustal material mixing in the rising process, while the sulfur isochronal characteristics indicate that the sulfur in Jinchuan mining area is a mantle source. The addition of crustal sulfur is ruled out. The sulfur content in the magma is estimated to be 1000 ppm when the magma leaves the source area. According to the relationship between the sulfur content and the depth of the high magnesium Black Tortoise magma, that is, when the magma reaches the sulphide saturation state, the content of sulfur in the magma is estimated to be 1 000 ppm. The SCSS of Jinchuan mother magma was 950ppm-1100ppm, so the Jinchuan mother magma was close to its SCSS when leaving the mantle. Based on the above analysis results, it is suggested that the process of sulphide saturation of Jinchuan magma is as follows: Jinchuan mother magma is formed by 20% partial melting of enriched mantle. The sulfur content at the time of formation is about 1000 ppmand SCSS is 950ppm-1 100ppm.The sulfur content of SCSS decreases to below its sulfur content during its rise to the in-situ magma chamber, which causes the SCSS to fall below its sulfur content, and then it is enriched in magma chamber for mineralization.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41;P618.63
【参考文献】
相关期刊论文 前1条
1 孙赫;唐冬梅;秦克章;范新;肖庆华;苏本勋;;亲铜元素的地球化学行为研究进展及其在岩浆硫化物矿床中的应用[J];地质论评;2009年06期
，本文编号：2126684
本文链接：https://www.wllwen.com/kejilunwen/kuangye/2126684.html
