投稿时间：2012-08-12
修订日期：2012-08-20
中文摘要:玉勒肯哈腊苏中型斑岩型铜(钼)矿主要赋存在闪长玢岩中,有少量矿化产在北塔山组火山岩及似斑状黑云母石英二长岩中。矿化呈细脉状、细脉-浸染状和浸染状。围岩蚀变主要为钾化、硅化、绢云母化、石膏化、磁铁矿化、绿泥石化、绿帘石化。矿床的形成经历了斑岩期、剪切变形期和表生期,铜和钼矿化主要形成于斑岩期的硫化物-钾硅酸盐阶段和辉钼矿阶段。石英和方解石中的流体包裹体可划分为H2O-NaCl型和H2O-CO2(±CH4/N2)-NaCl型。硫化物-钾硅酸盐阶段的成矿温度为141~500℃,主要集中在200~340℃;流体的w(NaCleq) 为2.96%~14.97%;流体的密度为0.60~0.98 g/cm3。碳酸盐阶段的流体以中-低温度(140~320℃)和低盐度〔w(NaCleq) 为2.74%~10.61%〕为特征。硫化物的δ34S值集中于-4.5‰~-0.1‰,峰值为-3.5‰,表明硫来自深源岩浆。石英和方解石的δ18OSMOW值为9.1‰~13.2‰,δ18OH2O值为2.05‰~6.28‰,δD值为-120‰~-97‰,表明主成矿阶段的成矿流体主要是岩浆水,混合有大气降水;碳酸盐阶段的流体主要为大气降水,混合有岩浆水。成矿时代为中泥盆世〔(373.9±2.2 Ma)〕,成矿作用与闪长玢岩的侵入有关。温度和压力的降低导致流体沸腾,同时,水-岩交换反应、流体成分的改变等在铜钼成矿过程中起着主导作用。
Abstract:The Yulekenhalasu medium-size porphyry copper-(molybdenum) deposit occurs in the diorite porphyry, with some mineralization also observed in the porphyroid biotite quartz monzonite and volcanic rocks of the Beitashan Formation. Mineralization occurs as veinlets, veinlet-disseminations and stockworks. Wall-rock alteration is well developed, and mainly comprises K-feldspathization, biotitization, quartzification, sericitization, magnetitization, gypsification, chloritization, and epidotization. According to cutting relationships of the ore veins, mineral assemblages, paragenetic sequence and ore fabrics, the ore-forming process can be divided into three metallogenic periods: porphyry, shear deformation and supergene periods. The sulfides-K-silicate stage and the molybdenite stage in the porphyry period constituted the main stages for copper mineralization and molybdenum mineralization, respectively. Two types of fluid inclusions, namely H2O-NaCl and H2O-CO2(±CH4/N2)-NaCl types, have been recognized in quartz and calcite. Homogenization temperatures of fluid inclusions in the sulfides-K-silicate stage vary from 141℃ to 500℃, concentrated from 200℃ to 340℃. Salinity w(NaCleq) ranges from 2.96% to 14.97%. Ore fluid densities range from 0.60 to 0.98 g/cm3. Fluids of the carbonate stage are characterized by medium-low temperatures (140℃ to 320℃) and low salinities (2.74% to 10.61%). δ34S values of sulfides associated with mineralization range from -4.5‰ to -0.1‰, with the peak being -3.5‰, indicating that sulfur was derived from deep-seated magma. δ18OSMOW values of quartz and calcite range from 9.1‰ to 13.2‰, with the corresponding δ18OH2O values between -2.05‰ and 6.28‰, and δD values of fluid inclusions vary between -120‰ and -97‰. The combined isotopic data imply that the ore-forming fluids of the sulfides-K-silicate stage in the Yulekenhalasu Cu-(Mo) deposit were mainly derived from magmatic fluids, with a minor part from the meteoric water, and the fluids of the carbonate stage were mainly derived from the meteoric water, with a minor part from magmatic fluids. Cu-(Mo) mineralization in Yulekenhalasu took place in Middle Devonian 〔(373.9±2.2) Ma〕, related to the diorite porphyry. The decrease of temperature and pressure, the boiling of local ore-forming fluid, the water-rock exchange, and the compositional variation of ore fluids played important roles in ore-forming processes of the Cu-(Mo) ore bodies.
keywords:geochemistry porphyry copper-(molybdenum) deposit fluid inclusion sulfur-oxygen-hydrogen stable isotopes metallogenesis Yulekenhalasu northern margin of Junggar Xinjiang
文章编号：
中图分类号：P618.41;P618.65
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基金项目:本文得到国家自然科学基金项目(编号: 40972069)和国家重点基础研究发展计划项目(编号: 2007CB411302)联合资助
引用文本：
杨富全,刘国仁,秦纪华,张志欣,刘振江,张立武,魏广智,刘锋,耿新霞.2012.新疆准噶尔北缘玉勒肯哈腊苏铜(钼)矿床流体包裹体和稳定同位素研究[J].矿床地质,31(5):965~982YANG FuQuan,LIU GuoRen,QIN JiHua,ZHANG ZhiXin,LIU ZhenJiang,ZHANG LiWu,WEI GuangZhi,LIU Feng,GENG XinXia.2012.Fluid inclusion and stable isotope study of Yulekenhalasu copper-(molybdenum) deposit in northern margin of Junggar, Xinjiang[J].Mineral Deposits31(5):965~982
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