贵州省册亨县丫他金矿流体包裹体特征研究及意义

发布时间：2018-05-01 22:55

  本文选题：流体包裹体 + 成矿流体　； 参考：《成都理工大学》2017年硕士论文

【摘要】：丫他金矿床位于我国黔西南卡林型金矿成矿区内,而黔西南金矿成矿区又是我国滇黔桂“金三角”卡林型金矿的矿集区,是我国重要的Au、Hg、Sb、As、Pb-Zn、Ag和多种分散元素产地。黔西南卡林型金矿成矿区大地构造位置处于扬子陆块西南缘和右江造山带的交汇部位,两个大地构造单元的地质、构造成岩—成矿作用的演化历程决定了该金矿成矿带的形成。自上世纪70年代来在黔西南发现我国最早的卡林型金矿(微细浸染型金矿)以来,相继在该区发现金矿床(点)50多个;截止目前,已探明金矿资源储量超过500多吨,从该区的地质、构造、地球物理、地球化学、遥感地质特征反映该区仍有寻找大型金矿资源的潜力。前人对丫他金矿的矿床地质特征、控矿条件、地球化学特征、金的赋存形式及选矿试验、矿床成因都有过一定的研究,而对丫他金矿床成矿流体方面的研究却不够完善,成矿流体又与矿床成因密切相关。因此,本论文以丫他金矿床的流体包裹体作为研究对象,通过对包裹体进行实验数据的测试、计算和分析,来进一步判断丫他金矿床的成矿热液类型及矿床的成因类型。本论文通过对丫他金矿床野外地质调查,进一步了解了该矿床的成矿地质背景和矿床地质特征。论文中从微观方面入手,对所采样品磨制的包裹体薄片进行显微岩相学观察和研究、均一法测温,获取包裹体中流体的均一温度和冰点温度,通过计算进一步得出流体的盐度、密度、压力等相关参数,结合前人对该矿床的研究资料,对丫他金矿床的成矿流体性质、流体来源、流体迁移和金的沉淀机制等方面进行了讨论,进而判断丫他金矿的矿床成因类型。本论文主要得出以下几点认识:丫他金矿床的包裹体有三种类型,主要为气液两相包裹体,次为纯液相包裹体,三相包裹体最少;包裹体的形态以不规则状、次椭圆状、椭圆状及负晶形为主,包裹体大小普遍为3~20μm,纯液相包裹体较多为不易观察的小包裹体。论文中主要选取气液两相包裹体进行数据的测试,得到包裹体的均一温度(101.7~293.3℃)、盐度(0.35~13.61wt%)、密度(0.75~1.06g/cm~3)、成矿压力(26.5~73.2MPa)、成矿深度(小于3km)等信息,由此推断,成矿流体介质水主要来源于沉积建造水(油田水)或大气降水,该矿床具有浅成中低温热液矿床流体的特点,因此,本论文认为丫他金矿其矿床类型为浅成中低温热液金矿床。
[Abstract]:The Yata gold deposit is located in the Carlin type gold deposit in southwest Guizhou, and the gold deposit in southwest Guizhou is the ore accumulation area of the "golden triangle" Carlin type gold deposit in Yunnan, Guizhou and Guangxi in China. The tectonic position of the Carlin type gold deposit in southwest Guizhou is located at the junction of the southwestern margin of the Yangtze block and the Youjiang orogenic belt. The evolution of the two tectonic units determines the formation of the metallogenic belt. Since the discovery of the earliest Carlin type gold deposits (micro-disseminated gold deposits) in southwest Guizhou in the 1970s, more than 50 gold deposits have been discovered in this area. Up to now, more than 500 tons of gold resources have been proved. From the geological, tectonic, geophysical, geochemical and remote sensing geological features of the area, there is still potential for prospecting for large gold resources in this area. The ore deposit geological characteristics, ore-controlling conditions, geochemical characteristics, gold occurrence forms and ore dressing tests, ore genesis of Yata gold deposit have been studied by predecessors, but the study on ore-forming fluid of Yata gold deposit is not perfect. The ore-forming fluid is closely related to the genesis of the deposit. Therefore, in this paper, the fluid inclusions of Yata gold deposit are taken as the object of study. By testing, calculating and analyzing the experimental data of inclusions, we can further judge the metallogenic hydrothermal types and the genetic types of Yata gold deposits. Based on the field geological investigation of Yata gold deposit, the metallogenic geological background and geological characteristics of the deposit are further understood in this paper. In this paper, from the micro aspect, the microlithofacies observation and study are carried out on the thin sections of the inclusions, the homogeneous method is used to measure the temperature, the homogeneous temperature and the freezing point temperature of the fluid in the inclusion are obtained, and the salinity of the fluid is further obtained by calculating the salinity of the fluid. The related parameters such as density and pressure, combined with the previous research data, discussed the ore-forming fluid properties, fluid source, fluid migration and gold precipitation mechanism of the Yata gold deposit. Then the genetic type of the Yata gold deposit is judged. The main conclusions of this paper are as follows: there are three types of inclusions in Yata gold deposit, mainly gas-liquid two-phase inclusions, secondary pure liquid inclusions, three-phase inclusions are the least, the shape of inclusions is irregular and subellipsoidal, The inclusions are mainly ellipsoidal and negative. The size of inclusions is generally 3 ~ 20 渭 m, and the pure liquid inclusions are mostly small inclusions which are difficult to observe. In this paper, the data of gas-liquid two-phase inclusions are tested, and the homogenization temperature of inclusions is 101.7 ~ 293.3 鈩，

本文编号：1831358