个旧锡矿锡石成因矿物学及流体包裹体研究

发布时间：2018-03-05 12:12

本文选题：锡石　切入点：成因矿物学　出处：《昆明理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：论文依托国家自然科学基金项目“个旧超大型锡矿床锡石矿物学、矿物化学、矿物U-Pb年代学研究”,对个旧锡矿锡石的成因矿物学和流体包裹体特征进行一个系统研究,为进一步揭示个旧锡矿床的形成环境和成因提供科学依据。本文对个旧锡矿老厂矿田和松树脚矿田的块状硫化物型锡铜矿、电气石细脉型锡钨铋矿、含锡白云岩、层间氧化矿矿床中的锡石进行了分析研究,利用扫描电镜、阴极发光成像技术、X-射线粉晶衍射、电子探针、包裹体测温和激光拉曼技术,锡石单矿物进行了锡石颗粒的大小、锡石晶体锥和柱的发育情况、锡石晶体的内部结构、锡石晶胞参数、锡石中类质同像的元素的含量,锡石均一温度和成矿环境的研究,研究表明：(1)块状硫化物型、电气石细脉型、含锡白云岩型、层间氧化型矿床的锡石颗粒体积依次变小；(2)四种矿床类型中锡石的晶型共有7个类型：A类型：{111}+{110}+{321}+{100}：B类型：{111}+{110}；C类型：{321}+{111}+{221};D类型：{111}+{110}+(102)+(321)；E类型：{111}+{110}+{100}；F类型：{111}+{101}+{110}+{100}；G类型：{111}+{123}+{110},从块状硫化物型到层间氧化型矿床中锡石由锥面较发育逐渐向柱面较发育发展；(3)块状硫化物型矿床中深色锡石晶胞体积大于浅色锡石晶胞体积；(4)块状硫化物型、电气石细脉型、含锡白云岩型矿床类型中锡石的CL亮度差异将锡石分为早、晚两期锡石；(5)块状硫化物型、电气石细脉型、含锡白云岩型矿床中锡石在CL下出现的环带是生长层,而不是由于化学成分的差异形成的生长环带；(6)块状硫化物型、电气石细脉型、含锡白云岩型、层间氧化型矿床类型中锡石成矿流体温度逐渐降低,同时锡石颗粒由大逐渐变小；(7)成矿压力的增大使得晶体的a、c、v变小；(8)结合锡石包裹体温度、盐度、密度、成矿压力深度的研究,认为块状硫化物型、电气石细脉型、含锡白云岩型矿床属于花岗岩浆期后热液叠加改造成因,松树脚层间氧化型矿床属于重泥质沉积形成。
[Abstract]:Based on the National Natural Science Foundation project "cassiterite Mineralogy, Mineral Chemistry, Mineral U-Pb chronology of Gejiu Super large Tin Deposit", this paper makes a systematic study on the genetic mineralogy and fluid inclusion characteristics of cassiterite in Gejiu tin deposit. In order to further reveal the forming environment and genesis of Gejiu tin deposit, this paper deals with the massive sulphide type tin copper deposit, tourmaline thin vein tin tungsten bismuth ore and tin dolomite in the Laochang and Songshujiao ore fields of Gejiu tin mine. The cassiterite in the interlayer oxidized ore deposit has been analyzed and studied. The particle size of cassiterite has been carried out by means of scanning electron microscope, catholuminescence imaging technique, X-ray powder diffraction, electron probe, inclusion temperature measurement and laser Raman technique. The development of cassiterite crystal cone and column, the internal structure of cassiterite crystal, the parameters of cassiterite crystal, the content of cassiter-like elements in cassiterite, the homogenization temperature of cassiterite and the metallogenic environment are studied. Tourmaline vein type, tin dolomite type, The grain volume of cassiterite in the interlayer oxidized deposit has been reduced in turn) among the four deposit types, there are seven types of cassiterite type: type A: type {111} {110} {100}: type B: type {111} {110} {221} D: type {111} {110} (102) E: type {111} {110} {100} F: type {111} {101} {110} {100} G. Type: {111} {123} {110}, from massive sulphide type to interlayer oxidation type deposit, cassiterite develops gradually from cone to cylinder. CL luminance difference of cassiterite in tourmaline thin vein type and tin dolomite type deposit type: cassiterite is divided into early and late cassiterite sulphide type, tourmaline fine vein type, tin dolomite type deposit and cassiterite ring zone under CL is the growth layer. Not because of the difference of chemical composition, the temperature of cassiterite ore-forming fluid decreases gradually in the type of growth ring, such as massive sulphide type, tourmaline vein type, tin dolomite type, and interlayer oxidation type deposit type. At the same time, with the increasing of the mineralizing pressure of cassiterite particles from large to small), the au _ (cv) of the crystals becomes smaller and smaller. (8) in combination with the study of the temperature, salinity, density and ore-forming pressure depth of cassiterite inclusions, it is considered that the massive sulphide type and the tourmaline veinlet type are considered to be massive sulphide type and tourmaline veinlet type. The tin dolomite type deposit belongs to the genesis of post-granitic magmatic superposition reformation, and the Songshujiao interlayer oxidation type deposit belongs to heavy argillaceous deposit.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.44

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