康滇地轴中段西缘黎溪式铜矿床流体包裹体研究  

Fluid inclusion study of the Lixi-type copper deposits on the western margin of the middle section of Kang-Dian geological axis

作　　者：胡杰[1,2] 王兆成 周福篯[1,2] 史少飞 余旭辉 Hu Jie;Wang Zhaocheng;Zhou Fujian;Shi Shaofei;Yu Xuhui(Regional Geological Survey Brigade of Sichuan Bureau of Geology&Mineral Resources;Sichuan Rongda Mining Group Co.,Ltd.)

机构地区：[1]四川省地质矿产勘查开发局区域地质调查队 [2]四川省容大矿业集团有限公司

出　　处：《黄金》2023年第12期64-70,共7页Gold

基　　金：四川省地质勘查基金项目(DZ202203);四川省容大矿业集团有限公司科研项目(容大科技科字〔2023〕02号)。

摘　　要：为研究黎溪式铜矿床成因,选取了3处典型黎溪式铜矿床的流体包裹体进行岩相学、显微测温及激光拉曼成分测试研究。流体包裹体岩相学及显微测温结果显示,主成矿期包裹体中发育气液两相、含子矿物、含液体CO_(2)、纯液体和纯气体等5类包裹体;气液两相包裹体完全均一温度(平均值191.42℃)和含子矿物包裹体完全均一温度(平均值170.33℃)基本一致,但盐度差异较大,说明成矿流体发生过沸腾作用,该作用对成矿起到了重要作用。成矿后期流体包裹体完全均一温度为319.00℃~425.00℃,明显高于主成矿期完全均一温度,显示出后期热液对成矿流体的改造作用。激光拉曼成分测试结果显示,成矿流体中气相成分以CH_(4)和H 2O为主,其次为CO_(2),偶见N 2和纯气相CO_(2),成矿流体属于具有还原性的H 2O-NaCl-CH_(4)-CO_(2)±N 2体系。根据黎溪式铜矿床产出地质条件、矿化蚀变特征,并综合流体包裹体研究,认为黎溪式铜矿床属于沉积-改造型矿床。In order to study the genesis of Lixi-type copper deposits,fluid inclusions from 3 typical Lixi-type copper deposits were selected for petrographic,microthermometric,and laser Raman compositional analysis.The petrographic and microthermometric results revealed 5 types of inclusions in the mineralizing stage,including gas-liquid two-phase inclusions,daughter mineral-bearing inclusions,liquid CO_(2)-bearing inclusions,pure liquid inclusions,and pure gas inclusions;the gas-liquid two-phase inclusions and daughter mineral-bearing inclusions showed consistent fully homogeneous temperatures(average 191.42℃and 170.33℃,respectively),but with significant salinity variations,indicating boiling of the ore-forming fluids and its importance in mineralization;the fully homogeneous temperatures of the late-stage fluid inclusions ranged from 319.00℃to 425.00℃,significantly higher than those of the main mineralizing stage,indicating the modification of the mineralizing fluids by late-stage hydrothermal activity.Laser Raman compositional analysis results showed that the gas phase composition in the mineralizing fluids is dominated by CH_(4) and H 2O,followed by CO_(2),with occasional presence of N 2 and pure gas-phase CO_(2),suggesting a reducing H 2O-NaCl-CH_(4)-CO_(2)±N 2 system.Based on the geological conditions and mineralization alteration characteristics of the Lixi-type copper deposits,as well as the study of fluid inclusions,the Lixi-type copper deposits are classified as sedimentary-reformed deposits.

关 键 词：流体包裹体 黎溪式铜矿床 显微测温 激光拉曼 完全均一温度 矿床成因类型 

分 类 号：TD11[矿业工程—矿山地质测量]