岗讲铜矿床中低温低盐度流体包裹体及其成因意义  

Low Temperature and Low Salinity Fluid Inclusions in Gangjiang Copper Deposit and its Genetic Significance

作　　者：赵向东 坚润堂 吕晓宏 吴俊 王岩梅 余璨 ZHAO Xiangdong;JIAN Runtang;LYU Xiaohong;WU Jun;WANG Yanmei;YU Can(Kunming Prospecting Design Institute of China Nonferrous Metals Industry;Baise University;Yunnan Geological Survey Institute;Yunnan Province Institute of Land Resources Planning and Design)

机构地区：[1]中国有色金属工业昆明勘察设计研究院有限公司 [2]百色学院 [3]云南省地质调查院 [4]云南省国土资源规划设计研究院

出　　处：《现代矿业》2023年第10期33-38,共6页Modern Mining

基　　金：云南省科技惠民计划(应用研究开发)(编号:2013CA019);云南省对外科技合作计划(省院省校科技合作)(编号:2014IB001)。

摘　　要：岗讲斑岩型铜矿床是西藏冈斯成矿带一个大型铜矿床,为进一步查明矿床成因,在野外调查、取样测试的基础上,对流体包裹体开展分析。结果表明:矿床中流体包裹体分为富液相包裹体(Ⅰ)、富气相包裹体(Ⅱ)和含子矿物多相包裹体(Ⅲ)3类;黄铜矿-黄铁矿化阶段流体包裹体主要为Ⅰ、Ⅱ和Ⅲ类包裹体,均一温度在173.2~493.2℃,盐度为1.74%~36.2%NaCleqv;辉钼矿-黄铜矿化阶段的流体包裹体主要为Ⅰ、Ⅱ和Ⅲ类包裹体,均一温度介于179.8~390℃,盐度为7.13%~35.2%NaCleqv;成矿流体总体表现为中温、低盐度的NaCl-H_(2)O体系,可能与青藏高原快速隆升过程中大量大气降水参与成矿活动有关;流体包裹体液相成分主要为H_(2)O,气相成分含有CO_(2),子矿物含少量黄铜矿。该矿床品位总体偏低,规模有限,可能是原始岩浆流体“先天不足”造成。The Kanggangjiang porphyry copper deposit is a large copper deposit in the Gangsi metallogenic belt of Tibet.In order to further identify the genesis of the deposit,fluid inclusions were analyzed on the basis of field investigation and sampling test.The results show that the fluid inclusions in the deposit are divided into three types:liquid-rich inclusions(Ⅰ),gas-rich inclusions(Ⅱ) and daughter mineral-bearing multiphase inclusions(Ⅲ).The fluid inclusions in the chalcopyrite-pyritization stage are mainly type Ⅰ,Ⅱ and Ⅲ inclusions.The homogenization temperature is 173.2~493.2℃,and the salinity is 1.74%~36.2%NaCleqv.The fluid inclusions in molybdenite-chalcopyrite mineralization stage are mainly type Ⅰ,Ⅱ and Ⅲ inclusions,with homogenization temperature of 179.8~390℃ and salinity of 7.13%~35.2% NaCleqv.The ore-forming fluid is a medium-temperature and low-salinity NaCl-H_(2)O system,which may be related to the large amount of meteoric water participating in the metallogenic activities during the rapid uplift of the Qinghai-Tibet Plateau.The liquid phase composition of fluid inclusions is mainly H_(2)O,the gas phase composition contains CO_(2),and the daughter minerals contain a small amount of chalcopyrite.The grade of the deposit is generally low and the scale is limited,which may be caused by the ' congenital deficiency ' of the original magmatic fluid.

关 键 词：流体包裹体 流体演化 成矿过程 岗讲矿床 

分 类 号：P618.41[天文地球—矿床学]