新疆库尔尕生铅锌矿床地质、流体包裹体和同位素地球化学  

Geology,fluid inclusions and isotopic geochemistry of Kuergasheng lead-zinc deposit in western Tianshan,Xinjiang

作　　者：段士刚[1] 薛春纪[2] 李野[2] 石海岗[3] 贾志业[4] 

机构地区：[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实验室,北京100037 [2]地质过程与矿产资源国家重点实验室,中国地质大学,北京100083 [3]核工业航测遥感中心,河北石家庄050002 [4]中国国土资源航空物探遥感中心,北京100083

出　　处：《矿床地质》2012年第5期1014-1024,共11页Mineral Deposits

基　　金：中央科研院所基本科研业务费项目(编号:K1202);中央高校基本科研业务费项目(编号:2009PY04)资助

摘　　要：新疆西天山赛里木地块中部的库尔尕生铅锌矿床受NW向断裂构造的控制;矿体呈脉状、透镜状;矿石呈网脉状、块状、浸染状、角砾状和斑杂状构造;矿石的矿物组成简单,金属矿物主要有方铅矿、闪锌矿、黄铁矿,脉石矿物主要为石英和方解石。脉石石英中发育纯液体包裹体和气液两相包裹体,均一温度为135.4~158.8℃。脉石石英和方解石的H、O、C同位素研究显示,成矿流体的δD值主要为-96.8‰^-84.3‰,δ18O值为-10.92‰^-6.11‰,反映出成矿流体来自岩浆水与大气水的混合水;方铅矿的δ34S值为4.1‰~8.4‰,与区域上晚石炭世的斑岩体来源硫范围(如达巴特流纹斑岩体硫化物的δ34S值为4.9‰~7.9‰,平均6.3‰)相似,揭示其硫可能为斑岩来源;方铅矿的铅同位素组成为206Pb/204Pb=18.207~18.291,207Pb/204Pb=15.595~15.654,208Pb/204Pb=38.085~38.291,在Δβ-Δγ成因分类图解上投影于"化学沉积型铅"与"海底热水作用铅"界线附近,可能反映出有相当一部分成矿金属物质来源于围岩。综合分析认为,库尔尕生铅锌矿床可能是与斑岩有关的远源低温热液型矿床。The Kuergasheng lead-zinc deposit, which is located in the middle of the Sailimu massif within western Tianshan of Xinjiang, is hosted in NW-trending faults and has veinlike and lentieular ore bodies. The ores are of stockwork, massive, disseminated, brecciated and taxitic structure and cosist of rather simple mineral composi- tion comprising metallic minerals of galena, sphalerite and pyrite as well as gangue minerals of quartz and calcite. The primary fluid inclusions trapped in quartz include pure liquid inclusions and gas-liquid two-phase inclusions. Thermometry of two-phase inclusions gives a range of homogenization temperatures between 135.412 and 158. 812. δDv-sMow values of fluid inclusion water in gangue mineral quartz vary from - 96.8‰to - 84.3‰,and calculated 3180 values of ore-forming water using homogenization temperature method vary from - 10.92‰ to -6.11‰, indicating that the ore-forming fluid is a mixture of magmatic water and meteoric water. 834S values of galena vary from 4.1‰ to 8.4‰, very close to the values of sulfides from the porphyry type copper- molybdenum deposits in this region （834S of sulfides from the Dabate copper-molybdenum porphyry deposit are from 4.9%0 to 7.9‰）, implying a magmatic sulfur origin. These galena samples also have 206pb/204pb ratios from 18. 207 to 18.291, 207pb/204pb ratios from 15. 595 to 15. 654, 208Pb/204Pb ratios from 38. 085 to 38. 291, and are projected near the boundaries of ＂chemical deposit lead＂ and ＂submarine hydrothermal lead＂ in the △β- △γdiagram. It is thus inferred that these data may suggest that a considerable part of the ore-forming metals might have come from the surrounding rocks. In summary, the Kuergasheng lead-zinc deposit may be a distal epithermal ore deposit related to porphyry.

关 键 词：地球化学 流体包裹体 H、O、C、S、Pb同位素 库尔尕生铅锌矿床 新疆 

分 类 号：P618[天文地球—矿床学] P618.43[天文地球—地质学]