【作者】 周凤；

【导师】 赖健清；

【作者基本信息】 中南大学 ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 果洛龙洼金矿是产于东昆仑造山带的一个与华力西-印支-燕山中酸性岩浆活动有关的中温热液石英脉型金矿床。论文以果洛龙洼金矿区为研究对象,运用流体包裹体岩相学、温度测试及成分分析等方法,讨论了果洛龙洼金矿区成矿流体的特征,研究成矿作用条件。研究表明,果洛龙洼金矿成矿过程可以划分为3个阶段：乳白色石英脉阶段(Ⅰ)、含金石英黄铁矿阶段(Ⅱ)、石英硫化物阶段(Ⅲ)。不同阶段的石英中发现了各种类型的流体包裹体。流体包裹体个体一般较小,以4-8μm为主,最大15μm。包裹体的形态以椭圆形为主,少数为条形、板状,不规则状。根据包裹体的特征,将其划分为液相水溶液包裹体,水溶液-二氧化碳包裹体,富CO2包裹体纯二氧化碳包裹体和甲烷包裹体5种类型。该矿床流体包裹体气相成分主要为H2O和CO2,还有含有一定量的CH4和少量H2。液相成分中,阳离子以Na+和k+为主,阴离子以SO42-、Cl-为主。所有样品中,Na+＞K+含量,Cl->SO42-含量。成矿溶液属于CO2-Na+(K+,Ca+)-Cl-(SO42-,F-)-H2O体系.第Ⅱ～Ⅲ阶段成矿流体均一温度主要集中在280～350℃；第Ⅱ阶段(含金石英黄铁矿阶段)对应高盐度群,盐度一般为15～22(wt％NaCl equiv),第Ⅲ阶段对应中盐度群为4～10(wt％NaCl equiv)；成矿压力为2962～3562bar,相当于大约10.5km的深度。成矿流体特征表明金的成矿作用与岩浆热液关系密切,属于中温岩浆热液矿床。后期的热液活动存在明显的H2O和CO2的分离作用,对金矿成矿起到了改造富集作用。更多还原

【Abstract】 The Guoluolongwa gold deposit, located in the Eastern Kunlun orogenic belt, is a mesothermal quartz-vein type gold deposit related to Variscan-Indosinian-Yanshanian intermediate-felsic magmatism. In this paper, the characteristics of ore-forming fluids of the Guoluolongwa gold deposit were discussed, and the conditions of mineralization were studied by means of fluid-inclusion petrography, microthermometry, and component analysis.The metallogenesis of Guoluolongwa gold deposit can be divided into three stages:(Ⅰ) milky white quartz veins stage; (Ⅱ) gold-bearing quartz-pyrite stage; (Ⅲ) quartz-sulfide re-enrichment stage. There are various types of inclusions in the quartz at different stages. The size of inclusions mainly varied from 4 to 8μm, with maximum size of 15 um. Most of inclusions are rounded to irregular in shape, with occasionale presence of ribbon or platy shapes. Five types of fluid inclusions were found in quartz, namely aqueous, aqueous-CO2, CO2-rich, pure CO2, and methane inclusions.The gas component of fluid inclusions are dominantly H2O and CO2, with minor CH4 and H2. The cation ions in fluid inclusions are mainly Na+and K+, and the main anion ions are SO42- and Cl". That is to say, the ore-forming fluids are generally characterized by Cl->SO42- and Na+>K+,which belong to CO2-Na+(K+,Ca+)-Cl-(SO42-,F)-H2O type fluids.The homogenization temperatures of the inclusions fromⅡandⅢstages concentrate between 280℃and 350℃, corresponding to the high salinity groups of 15-22 wt% NaCl equiv. and the middle salinity groups of 4-10 wt% NaCl equiv., respectively. The metallogenic pressure estimated by fluid inclusions is 2962 bars to 3562 bars, equivalent to a depth of 10.5 km.The characteristics of ore-forming fluids show that mineralization is closely related to magmatic hydrothermal, indicating that the deposit is a medium temperature magmatic hydrothermal deposit. Subsequence, phase separation of H2O and CO2 in hydrothermal fluids caused gold transformation and enrichment.更多还原