塔里木陆块西北缘萨热克砂岩型铜矿床构造-流体演化对成矿的制约  

Constraints on tectonic, fluid and metallogenic system evolution for the formation of Sareke sandstone copper deposit in northwestern Tarim block

作　　者：王伟 李文渊[1,2] 高满新[2] 熊中乙 李天虎[2] 宿晓虹[2] 郭周平[2] 孟勇[2] 全守村[2] 刘增仁[3] 叶雷[3] 陈传庆[4] 唐小东 WANG Wei;LI Wenyuan;GAO Manxin;XIONG Zhongyi;LI Tianhu;SU Xiaohong;GUO Zhouping;MENG Yong;QUAN Shoucun;LIU Zengren;YE Lei;CHEN Chuanqing;TANG Xiaodong(Faculty of Earth Science and Resources,Chang＇an University,Xi＇an 710054,Shaanxi,China;Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits,MLR/Xi＇an Center of Geological Survey,CGS,Xi＇an 710054,Shaanxi,China;Xinjiang Geological Survey Institute of China Non-ferrrous Metals Resource Geological Survey,Urumqi 830011,Xinjiang,China;Xinjiang Institute of China Geological Exploration and Engineering Bureau,Urumqi 830000,Xinjiang,China)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]国土资源部岩浆作用成矿与找矿重点实验室/中国地质调查局西安地质调查中心,陕西西安710054 [3]有色金属矿产地质调查中心新疆地质调查所,新疆乌鲁木齐830011 [4]中国冶金地质勘查工程总局新疆地质勘查院,新疆乌鲁木齐830000

出　　处：《地质通报》2018年第7期1315-1324,共10页Geological Bulletin of China

基　　金：中国地质调查局项目《天山-北山成矿带那拉提-营毛沱地区地质矿产调查》(编号：DD20160009)、《西昆仑铁铅锌资源基地调查与勘查示范》(编号：DD20160015)和《新疆西南天山萨瓦甫齐地区矿产地质调查》(编号：12120113043700)

摘　　要：塔里木陆块西北缘萨热克砂岩型铜矿床构造演化、流体演化与成矿之间具有密切关系,处于一个统一系统中。矿床成岩期方解石中包裹体水的δD值为-65.3‰^-99.2‰,改造成矿期石英包裹体水的δD值为-77.7‰^-96.3‰,成岩成矿期成矿流体δ^(18)OH_2O变化范围为-3.22‰~1.84‰,改造成矿期成矿流体δ^(18)OH_2O变化范围为-4.26‰~5.14‰,指示萨热克铜矿成岩期、改造期成矿流体主要为中生代大气降水及其经水岩作用而成的盆地卤水。矿石中辉铜矿δ^(34)S值为-24.7‰^-15.4‰,指示硫主要源自硫酸盐细菌与有机质还原,部分源于有机硫。构造与成矿流体演化对砂岩铜矿成矿起关键制约作用。盆地发展早期强烈的抬升运动使盆地周缘基底与古生界剥蚀,为富铜矿源层的形成提供了丰富物源,至晚侏罗世盆地发展晚期,长期演化积聚的巨量含矿流体在库孜贡苏组砾岩胶结物及裂隙中富集,在萨热克巴依盆地内形成具有经济意义的砂岩型铜矿床。There exist close relationships between tectonics, fluid evolution and formation of copper ore in the Sareke sandstone deposit in northwestern Tarim block, which constitute an integrated system. The δD values of inclusion water in the calcite of diagenetic stage are in the range of -65.3‰^-99.2‰, and the δD values of inclusion water in the quartz of metallogenic epoch are in the range of -65.3‰^-99.2‰, the δ18OH2O values of the ore-forming fluid in the diagenetic stage are in the range of -3.22‰~1.84‰, and the δ18OH2O values of the ore-forming fluid in the metallogenic epoch are in the range of-4.26‰~5.14‰, suggesting that the ore-forming fluid in the diagenetic stage and transformation period of the Sareke copper deposit mainly originated from the atmospheric water in the Mesozoic period and basin brine evolved from the water-rock interaction of the rainfall. The δ34S values of the chalcocite in the ore are in the range of-15.4‰^-24.7‰, suggesting that most of the sulfur originated from the bacteria and reduced organic carbon in the strata, with the addition of minor organic sulfur. The evolution of the tectonics and ore-forming fluid controlled the formation of sandstone copper deposits. In the early period of the basin development, the strong uplift movement caused the erosion of the basement and Paleozoic strata in the periphery of Sareke basin, which offered abundant provenance to the formation of copper-rich source layer. Toward the late period, i.e., Late Jurassic epoch, large amounts of ore-forming fluid after long-term evolution was concentrated in the agglutinate and fissures of conglomerate in Kuzigongsu Formation, forming sandstone copper deposits with economic value in Sareke basin.

关 键 词：塔里木陆块 萨热克 砂岩型铜矿 构造 流体 成矿体系 

分 类 号：P618.41[天文地球—矿床学]