山西繁峙县辛庄金矿床矿物学和流体包裹体特征研究

发布时间：2018-04-30 17:18

  本文选题：辛庄金矿 + 成因矿物学　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：山西繁峙县辛庄金矿床位于华北克拉通中间带北部,燕山沉降带西南缘与山西陆台五台隆起西北侧两大构造单元相互嵌接的中生代构造岩浆活动带上。本文系统总结了辛庄金矿床的区域地质背景、矿床地质特征,尤其对矿石特征进行了比较细致的研究,在此基础上,以金矿床成因理论为依据,划分了辛庄金矿的成矿期次与成矿阶段,开展了电子探针分析测试、流体包裹体测温以及激光拉曼测试等工作,探讨了矿床成因,并对典型的金属硫化物矿物矿物学特征进行了分析。辛庄金矿床划分为2个成矿期:ⅰ是岩浆热液期;ⅱ是表生期,其中岩浆热液期可以进一步划分为五个成矿阶段:依次是Ⅰ氧化阶段、Ⅱ1黄铁矿-石英阶段、Ⅱ2石英-黄铁矿阶段、Ⅲ石英-多金属硫化物阶段和Ⅳ碳酸盐阶段。黄铁矿电子探针分析:Fe、S亏损却富Co、Ni,且对Co/Ni、Au/Ag、S/Se比值计算;综合Fe、S特点与三个特殊元素比值对特点均表明黄铁矿属于岩浆热液成因。本区黄铁矿中富含As元素,As在黄铁矿中的含量及Fe/S+As值具有很重要的标型性,本区黄铁矿Fe/S+As均值为0.867。据此可知,辛庄矿区的黄铁矿形成于中偏浅成环境。对Co、Ni、As投点,从Co顶点区到As顶点区均有分布,暗示了成矿早期岩浆水占主要地位而成矿晚期有大气水的加入。黄铁矿、黄铜矿、石英是Au的主要载体,且金赋存状态有包体金、粒间金、裂隙金三种。根据包裹体在室温下的相态可以将其分为5类:包括Ⅰ富液相包裹体、Ⅱ富气相包裹体、Ⅲ含子晶包裹体、Ⅳ纯气相包裹体、ⅤCO2三相包裹体,流体包裹体气相成分为CO2,子矿物镜下特点呈无色透明、立方体形态,极可能是石盐。包裹体均一温度介于127.2℃~407.5℃,温度、盐度直方图中可以得出,温度范围260℃~280℃、200℃~240℃,盐度7%~8%、3%~5%,分别对应Ⅱ2石英-黄铁阶段、Ⅲ石英-多金属阶段这两大主成矿阶段。碳酸盐阶段的均一温度127.2℃~190.3℃、盐度介于0.3%~4.2%,总体而言属于中低温、低盐度成矿流体,整个岩浆热液期流体密度范围0.568g/cm3~0.963g/cm3,均值0.818g/cm3,属于中等密度流体,成矿压力范围28.73MPa~201.89MPa,主成矿阶段成矿深度集中于3.1Km~5.3Km,属于浅成成矿环境。综述,山西繁峙县辛庄金矿为一中等密度、低盐度、浅成中低温岩浆热液石英脉型金矿床。
[Abstract]:The Xinzhuang gold deposit in Fanshi County Shanxi Province is located in the northern part of the North China Craton intermediate belt the southwestern margin of the Yanshanian subsidence belt and the Mesozoic tectonic magmatic active belt interwoven with the two tectonic units in the west and north of the Wutai uplift of Shanxi Lutai. In this paper, the regional geological background and geological characteristics of the Xinzhuang gold deposit, especially the ore characteristics, are systematically summarized. On this basis, the genetic theory of the gold deposit is taken as the basis. The metallogenic epoch and metallogenic stage of Xinzhuang gold deposit are divided. The authors have carried out the work of electron probe analysis, fluid inclusion temperature measurement and laser Raman measurement, and discussed the genesis of the deposit. The mineralogical characteristics of typical metallic sulphide minerals are also analyzed. The Xinzhuang gold deposit can be divided into two metallogenic periods: I is the magmatic hydrothermal period, II is the epigenetic period, among which the magmatic hydrothermal period can be further divided into five metallogenic stages: I oxidation stage, 鈪，

本文编号：1825456