地学前缘 ›› 2010, Vol. 17 ›› Issue (2): 359-374.

• 论文 • 上一篇    下一篇

新疆哈腊苏铜矿床I号矿化带流体包裹体和碳氢氧同位素地球化学

杨富全, 闫升好, 屈文俊, 周刚, 刘锋, 耿新霞, 刘国仁, 王祥   

  1. 1中国地质科学院 矿产资源研究所 国土资源部成矿作用与资源评价重点开放实验室, 北京 100037
    2国土资源部中央地质勘查基金管理中心, 北京 100812
    3国家地质实验测试中心, 北京 100037
    4新疆地质矿产勘探开发局 第四地质大队, 新疆 阿尔泰  836500
  • 收稿日期:2009-06-30 修回日期:2010-01-04 出版日期:2010-03-15 发布日期:2010-04-05
  • 作者简介:杨富全(1968—),男,博士,研究员,矿床学专业,从事矿床地质、地球化学研究。E-mail:fuquanyang@163.com
  • 基金资助:

    国家重点基础研究发展计划“973”项目(2007CB411302);国家自然科学基金项目(40972069);国土资源大调查项目(1212010630603,1212010786006,1212010786004)

 The fluid inclusions and C, H and O isotopic geochemistry of the  Mineralized Zone No1 at the Halasu copper deposit, Xinjiang.

 YANG  Fu-Quan, YAN  Sheng-Hao, JUE  Wen-Dun, ZHOU  Gang, LIU  Feng, GENG  Xin-Xia, LIU  Guo-Ren, WANG  Xiang   

  1. 1MRL Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
    2Center Geology and Mineral Exploration Foundation Manage Center, The Ministry of Land and Resources, Beijing 100812, China
    3National Research of Geoanalysis, Beijing 100037, China
    4No4 Geological Party of the Xinjiang Bureau of Geology and Mineral Exploration and Development, Altay  836500, China
  • Received:2009-06-30 Revised:2010-01-04 Online:2010-03-15 Published:2010-04-05

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摘要：

青河县哈腊苏铜矿床I号矿化带位于准噶尔北缘卡拉先格尔斑岩铜矿带,铜矿化主要呈不均匀团块、细脉或细脉浸染状产于花岗闪长斑岩、石英闪长斑岩及玄武岩、辉斑玄武岩围岩中。矿石中石英和方解石流体包裹体划分为H2O-NaCl型和H2O-CO2 (±CH4/N2)-NaCl型。成矿温度主要集中在120～431 ℃,峰值在390、290和190 ℃。成矿流体盐度(w(NaCleqv))变化于0.53％～66.76％,峰值在19.5％、12.5％、9.5％和1.5％。密度为0.55～1.11 g/cm3。矿脉中石英和方解石的δ18OSMOW值为2.9‰~12.3‰,δ18OH2O值为-5.81‰～4.83‰,δDSMOW为-129‰~-80‰,表明成矿流体主要为岩浆水和混合大气降水。方解石的δ13CPDB变化于-2.4‰~-1.4‰,δ18OSMOW为8.3‰~9.2‰,表明流体中的碳来自岩浆。对辉钼矿石英脉中辉钼矿进行了Re-Os同位素测年,获得等时线年龄为（378.3±5.6） Ma,与花岗闪长斑岩锆石SHRIMP U-Pb年龄(381～375 Ma)在误差范围内一致。早期成矿作用发生在中泥盆世,与斑岩有关,晚期叠加成矿作用发生在中、晚三叠世,与构造岩浆热液活动有关。

关键词: Re-Os年龄;流体包裹体;稳定同位素;铜矿床;哈腊苏, 新疆

Abstract:

The  Mineralized Zone NoI at the Halasu copper deposit in Qinghe County is situated in Kalaxiangeer porphyry copper belt. The copperbearing minerals mainly occur in the form of heterogeneous gobbets, veinlets and veinletdisseminated in the granodiorite porphyry, quartz diorite porphyry, basalt and pyroxene phenocrysts basalt. Two types of fluid inclusions, namely H2O-NaCl and H2O-CO2 (±CH4/N2)NaCl types, have been recognized in quartz and calcite from the ore. Homogenization temperatures of fluid inclusions vary from 120 to 431  ℃, with three temperature peaks at 390,290 and 190 ℃. Salinity ranges from 053% to 6676 ％ NaCleqv, with four peaks at 19.5％ NaCleqv, 12.5％ NaCleqv, 9.5％ NaCleqv and 1.5％ NaCleqv. Ore fluid densities range from 055 to 1.11 g/cm3. The δ18OSMOW values of quartz and calcite in the ore vein range from 2.9‰ to 12.3‰ with corresponding δ18Ofluid values of -5.81‰ to 4.83‰ and δD values of fluid inclusions between -129‰ and -80‰. The isotopic data imply that the oreforming fluids of the Halasu copper deposit were mainly derived from magmatic fluids, with some contributions from meteoric water. The δ13CPDB values of calcite define a narrow range of -2.4‰ to -1.4‰ and δ18OSMOW values range from 8.3‰ to 9.2‰ indicating that the carbon in the ore fluids was mainly derived from magma. ReOs dating was performed on molybdenite from molybdenite vein, which yielded isochron ages of (378.3±5.6) Ma. This isochron age is coincident with the age of 381375 Ma from granodiorite porphyry pluton within error range. Early mineralization formed in the Middle Devonian, which was closely related to porphyry systems. The LateMiddle tectonicmagmatichydrothermalmineralization overlapped the early porphyry mineralization in the Halasu copper deposit.

Key words: Re-Os age, fluid inclusions, stable isotopes, copper deposit, Halasu, Xinjiang

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