贵州安龙戈塘金矿角砾状矿石流体包裹体特征研究及意义

发布时间：2018-06-08 10:39

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

【摘要】：戈塘金矿床位于黔西南地区典型的卡林型金矿集区构造活动带右江造山带内,属贵州安龙县管辖。本文以角砾状矿石中石英包裹体为研究对象,来探讨矿床成矿流体的性质与来源、成矿物质来源、成矿流体特征,从而确定矿床成因模式。戈塘矿区出露的地层以二叠系、三叠系为主,构造发育,以褶皱和北东向断裂为主。矿体多呈层状、似层状、透镜状赋存于龙潭组与茅口组岩溶不整合面上的构造蚀变体中,赋矿岩石为硅化角砾岩,围岩蚀变以硅化为主。矿体的产出受层间滑脱构造控制。矿石类型为原生矿石及氧化矿石。矿石构造主要有角砾状构造、网脉状构造、细脉状构造、浸染状构造和多孔状构造等。矿石结构主要有自形-半自形粒状结构、交代结构、环状结构和包含结构等。矿石中金属矿物以黄铁矿、磁黄铁矿、毒砂、辉锑矿为主。非金属矿物为石英、方解石、萤石、粘土矿物等。最重要的载金矿物是黄铁矿和毒砂,其次是粘土矿物。戈塘矿床流体包裹体类型以水溶液包裹体为主,CO_2包裹体、纯液相包裹体、纯气相包裹体发育较少。矿石中包裹体均一温度波动范围集中在120~150℃与170~200℃范围内,平均均一温度146.82℃,表明戈塘金矿的主成矿期有两个阶段。包裹体冰点温度波动范围在-3.5~-0.1℃之间,平均冰点温度为-1.8℃。包裹体平均盐度2.98wt%,为中低盐度。成矿流体密度均值为0.95g/cm~3,成矿平均压力366.17×10~5 Pa,推测成矿深度0.60~1.91km。成矿流体密度范围为0.86~0.98g/cm~3,平均0.95g/cm~3,具中高密度流体特点,平均成矿深度1.22km。戈塘金矿床表现为中低温浅层热液矿床的特点,主成矿期与燕山晚期构造运动有关。矿床成矿流体与成矿物质来源复杂,表现为多源性和多期性。深部幔源以及含矿建造为主要成矿物质来源。成矿流体来源以深部岩浆热液为主,盆地建造水以及大气降水也参与了成矿流体形成过程。初步建立了矿床成因模式:深部流体沿右江盆地裂解形成的深大断裂与多期次喷发的岩浆形成混合流体向上迁移,到达“大厂层”时沿古风化面进入层滑构造,并与围岩发生交代蚀变作用,成矿后期受引张空间及破碎带低渗透率岩石组合的影响,形成层带型矿化,含矿物质析出富集成矿。
[Abstract]:The Gotang gold deposit is located in the Youjiang orogenic belt of the tectonic active belt in the typical Carlin-type gold concentration area in southwest Guizhou Province, and belongs to the jurisdiction of Anlong County, Guizhou Province. In this paper, quartz inclusions in breccia ore are taken as the research object to discuss the nature and source of ore-forming fluid, the source of ore-forming material and the characteristics of ore-forming fluid, and to determine the genetic model of ore deposit. The strata exposed in Gotang mining area are Permian, Triassic, tectonic development, fold and NE faults. The orebodies are mostly layered, like layered, and lenticular in the structural alteration of karst unconformities of Longtan formation and Maokou formation. The ore-bearing rocks are silicified breccia, and the main alteration of surrounding rock is silicification. The production of ore body is controlled by interlayer slip structure. The ore type is primary ore and oxidized ore. Ore structures mainly include breccia structure, reticular vein structure, veinlike structure, disseminated structure and porous structure. The ore structure mainly consists of granular structure, metasomatic structure, annular structure and inclusion structure. Ore with pyrite, pyrrhotite, arsenopyrite, stibnite. Non-metallic minerals are quartz, calcite, fluorite, clay minerals and so on. The most important gold-bearing minerals are pyrite and arsenopyrite, followed by clay minerals. The fluid inclusions are mainly composed of aqueous solution inclusions, pure liquid inclusions and pure gas inclusions. The range of homogenization temperature of inclusions in ore is concentrated in the range of 120 ~ 150 鈩，

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