西天山库茹尔铜金矿床成矿流体特征及矿床成因  

Characteristics of Ore-forming Fluids and Genesis of Kuru’er Cu-Au Deposit in West Tianshan, China

作　　者：赵凯培 顾雪祥[1,2] 章永梅[1,2] 彭义伟[3,4] 王冠南 何宇 郭建平 ZHAO Kai-pei;GU Xue-xiang;ZHANG Yong-mei;PENG Yi-wei;WANG Guan-nan;HE Yu;GUO Jian-ping(School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,Sichuan,China;State Key Laboratory for Mineral Deposits Research,Nanjing University,Nanjing 210046,Jiangsu,China;Aluminum Corporation of China Limited,Beijing 100082,China;No.703 Geological Team,Xinjiang Nonferrous Geoexploration Bureau,Yining 835000,Xinjiang,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [3]成都理工大学地球科学学院,四川成都610059 [4]南京大学内生金属矿床成矿机制研究国家重点实验室,江苏南京210046 [5]中国铝业集团有限公司,北京100082 [6]新疆维吾尔自治区有色地质勘查局七〇三队,新疆伊宁835000

出　　处：《地球科学与环境学报》2019年第6期691-706,共16页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41572062,41702081);国家重点研发计划项目(2018YFC0604003);南京大学内生金属矿床成矿机制研究国家重点实验室开放研究基金项目(2018-LAMD-K07);中央高校基本科研业务费专项资金项目(2652017226)

摘　　要：库茹尔铜金矿床位于新疆西天山晚古生代伊什基里克裂谷带,赋矿围岩为下石炭统大哈拉军山组安山质岩屑凝灰岩,矿体受一系列断裂构造控制。有关该矿床的成矿流体特征研究不足,限制了对矿床成因的认识。以该矿床的地质特征、流体包裹体为主要研究对象,探讨了成矿流体性质、来源及演化规律,初步查明了矿床成因类型。库茹尔铜金矿床热液成矿过程可划分为石英-黄铜矿-黄铁矿-自然金阶段、石英-黄铜矿阶段和石英-绿泥石/绿帘石-方解石阶段。流体包裹体研究表明:主成矿阶段(石英-黄铜矿-黄铁矿-自然金阶段)以气液水两相包裹体为主,含少量CO2-H2O三相包裹体与含石盐子晶多相包裹体,均一温度分别为184℃~359℃、250℃~319℃和229℃~263℃,盐度分别为4.1%~8.5%NaCleq、1.0%~6.0%NaCleq和32.7%~33.9%NaCleq;石英-黄铜矿阶段和石英-绿泥石/绿帘石-方解石阶段均以气液水两相包裹体为主,均一温度分别为144℃~212℃和114℃~163℃,盐度分别为0.2%~6.7%NaCleq和0.1%~3.1%NaCleq。库茹尔铜金矿床的初始成矿流体具中-高温、中-低和高盐度的岩浆热液特征,流体不混溶是导致Au-Cu富集成矿的主要机制,矿床成因类型应属于与斑岩成矿系统相关的次浅成低温热液矿床。Kuru’er Cu-Au deposit is located in Late Paleozoic Yishijilike rift belt of West Tianshan, Xinjiang. The host rock is andesite lithic tuff of Lower Carboniferous Dahalajunshan Formation, and the occurrence of orebodies is controlled by a series of fault structures. Insufficient research on the characteristics of ore-forming fluids limits the understanding of the genesis of Kuru’er Cu-Au deposit. Based on the geological characteristics and fluid inclusions, the properties, sources and evolution of ore-forming fluids were discussed, and the genetic types of deposit were initially identified. The hydrothermal mineralization process of Kuru’er Cu-Au deposit can be divided into quartz-chalcopyrite-pyrite-gold stage, quartz-chalcopyrite stage and quartz-chlorite/epidote-calcite stage. The fluid inclusion shows that the main metallogenic stage(quartz-chalcopyrite-pyrite-gold stage) is mainly composed of gas-liquid-water two-phase inclusions, containing a small amount of CO2-H2O three-phase inclusions and stone salt crystal multiphase inclusions, and the homogenization temperatures are 184 ℃-359 ℃, 250 ℃-319 ℃ and 229 ℃-263 ℃ with the salinities of 4.1%-8.5% NaCleq, 1.0%-6.0% NaCleq and 32.7%-33.9% NaCleq;quartz-chalcopyrite stage and quartz-chlorite/epidote-calcite stage are both gas-liquid-water two-phase inclusions, and the homogenization temperatures are 144 ℃-212 ℃ and 114 ℃-163 ℃, respectively, and the salinities are 0.2%-6.7% NaCleq and 0.1%-3.1% NaCleq. The initial ore-forming fluid of Kuru’er Cu-Au deposit has the characteristics of magmatic water with medium-high temperature, and medium-low and high salinities. The fluid immiscibility is the main mechanism for Au-Cu enrichment and mineralization. The genetic type of deposit belongs to the subepithermal deposit associated with the porphyry metallogenic system.

关 键 词：流体包裹体 成矿流体 流体不混溶 矿床成因 次浅成低温热液矿床 铜金矿床 西天山 新疆 

分 类 号：P611[天文地球—矿床学] P618.2[天文地球—地质学]