印度尼西亚苏门答腊岛唐塞斑岩铜钼矿床成矿流体及成矿物质来源--来自氢、氧、硫和铅同位素证据  

Sources of Ore-Forming Fluids and Materials of the Tangse Porphyry Cu-Mo Deposit in Sumatra,Indonesia: Constraints from H,O,S and Pb Isotopic Gechemistry

作　　者：胡鹏[1] 曹亮[1,2] Tampubolon Armin 张海坤[1] 刘阿睢 程湘[1] HU Peng;CAO Liang;Tampubolon ARMIN;ZHANG Hai-kun;LIU A-sui;CHENG Xiang(Wuhan Center of Geology Survey,CGS,Wuhan,Hubei 430205;Research Center of Granitic Diagenesis and Mineralization,China Geological Survey,Wuhan,Hubei 430205;Geological Survey of Indonesia,Bandung 40254,Indonesia)

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205 [2]中国地质调查局花岗岩成岩成矿地质研究中心,湖北武汉430205 [3]印度尼西亚地质局,印度尼西亚万隆40254

出　　处：《地质与勘探》2018年第6期1202-1214,共13页Geology and Exploration

基　　金：中国地质调查局印度尼西亚苏门答腊岛铜多金属资源潜力评价(编号DD20160114);湘西-鄂西成矿带神农架-花垣地区地质矿产调查二级项目(编号DD20160029)资助。

摘　　要：唐塞斑岩铜钼矿床位于苏门答腊岛北部,是岛上规模最大的矿床。本文在系统野外观察及室内岩相学观察的基础上,通过开展系统的流体包裹体岩相学、显微测温及H、O、S、Pb同位素测试分析,查明该矿床的成矿流体特征,分析探讨其成矿物质来源。研究表明,含矿石英脉中主要发育气液两相包裹体,主成矿阶段流体为中高温(280～386℃)、中等盐度(11. 46～15. 27) wt%Na Cleqv、中等密度(0. 73～1. 11g/cm3)的流体,成矿深度为1. 64～7. 72km,平均为4. 68km,矿床形成于中等深度环境。矿石石英脉中石英的δ18OH2O值范围为4. 6‰～6. 3‰,含矿石英脉中石英的δ18DV-SMOW值范围为-64. 9‰～-73. 5‰,成矿流体主要为岩浆水,有一定量的大气降水混入。矿石中硫化物组成变化范围窄,为1. 32‰～2. 23‰,多数集中在1‰左右,且具有呈塔式分布特点,表明主要为岩浆硫源;矿石硫化物的206Pb/204Pb、207Pb/204Pb、208Pb/204Pb比值分别为18. 767～19. 032、15. 689～15. 899和38. 683～39. 159,具有显著的上地壳和地幔混合性质,表明成矿物质可能与大洋沉积物和洋壳的部分熔融有关。以上研究证明,唐塞矿床属于中-高温中等深度斑岩型铜钼矿床。The Tangse porphyry copper-molybdenum deposit is located in the northern part of Sumatra island and the northern part of Sumatra fault system,which is the largest deposit on the Sumatra island.Based on systematic geologic,petrographic and H-O-S-Pb isotope geochemical studies on hydrothermal minerals,this work discussed the origin of ore-forming fluid and materials and genesis of the Tangse deposit.The result shows that the ore-bearing quartz veins are dominated by gas-liquid two-phase inclusions.The fluids in the main mineralization stage are characterized by medium-high temperature(280~386℃),medium salinity(11.46~15.27)wt%NaCleqv and medium density(0.73~1.11 g/cm 3).The mineralization depth is 1.64~7.72 km(4.68 km on average),indicating that the deposit was formed in a medium-depth environment.Hydrogen and oxygen isotope analyses indicate thatδ18 O H 2O of quartz from quartz vein of ores range from 4.6‰to 6.3‰,andδ18 D V-SMOW of quartz ranges from-64.9‰to-64.9‰,suggesting that the ore-forming fluid is mainly granite magmatic water,with certain amounts of meteoric water.Theδ34 S values of sulfide minerals range from 1.32‰to 2.23‰.S isotopic histogram shows single peak distribution,indicating an origin of magma sulphur.Lead isotopic compositions of ore are basically constant,with 206 Pb/204 Pb,207 Pb/204 Pb,208 Pb/204 Pb ratios of sulfide ores of 18.767~19.032,15.689~15.899 and 38.683~39.159,respectively,which shows that the ore-forming materials may be related to the partial melting of ocean sediments and ocean shells.This study proves that the Tangse deposit belongs to medium-high temperature and medium-depth porphyry copper-molybdenum deposit.

关 键 词：流体包裹体 同位素 成矿流体 成矿物质 唐塞 苏门答腊岛 

分 类 号：P618.41[天文地球—矿床学] P597.2[天文地球—地质学]