新疆红十井金矿床特征及成因  

Characteristics and Genesis of Hongshijing Gold Deposit, Xinjiang

作　　者：肖惠良[1] 周济元[2] 王鹤年[1] 崔炳芳[2] 陈世忠[2] 

机构地区：[1]南京大学地球科学系 [2]南京地质矿产研究所,江苏南京210016

出　　处：《矿床地质》2003年第1期32-40,共9页Mineral Deposits

基　　金：国家 30 5项目 (编号 96-915-0 5-0 5 );南京大学内生金属矿床成矿机制研究实验室基金和南京大学现代分析中心基金资助项目

摘　　要：文章通过K_Ar同位素年龄 ,氢、氧、硫、铅等同位素测试和流体包裹研究 ,结合红十井金矿床的地质、矿区岩石化学、微量元素及稀土元素地球化学特征 ,探讨了红十井金矿床含金建造与金矿关系及矿床成因。研究表明红十井金矿床为晚古生代裂谷带火山岩区受韧性剪切带控制的中_低温热液矿床 ,矿体赋存于中石炭统玄武 (玢 )岩及凝灰质砂岩组成的含金建造内 ,成矿物质主要来源于含金建造 ,矿化以蚀变岩型和石英脉型为主。成矿年龄为2 0 9～ 2 6 7Ma。成矿流体为岩浆水、玄武 (玢 )岩和凝灰质砂岩的变质水、建造水和大气降水的混合溶液 ,δD为 - 114.6‰～ - 6 8.8‰ ,δ18OH2 O变化为 - 2 .47‰～ 5 .91‰。成矿温度为 115～ 381℃ ,成矿压力为 471.8× 10 5～ 6 75 .9× 10 5Pa ;流体盐度w(NaCleq)为 2 .18%～ 16 .77% ,平均 7.79% ,流体属中_低盐度、H2 O_CO2 体系。The Hongshijing gold ore deposit, which occurs in the volcanic rock and pyroclastic rock of the middle and late Carboniferous Period, is of brittle-ductile shear zone type controlled by the rift belt. There are altered-rock type and quartz type orebodies, which are contained in gold-bearing formation consisting of basalt and tuffaceous-sandstone. The gold content of the gold-bearing formation is 2.4×10 -9. The major ore-forming stage is 267～261 Ma and the superimposition ore-forming stage is 220～209 Ma.The ore minerals include pyrite, magnetite, copper, bornite, ferrohydrite and native gold, whereas the gangue minerals include quartz, sercite, calcite, Fe-dolomite, leucoxene, anorthose, biotite, cajuelite, agustite etc. The wall rock alteration associated with gold mineralization comprises silicification, carbonization, pyritization, sericitization and chloritization. Geochemical investigation reveals that the mineralizing material came from the basalt and tuffaceous-sandstone in the gold-bearing formation. Under the action of ductile brittle shear structure, the gold-bearing formation was metamorphosed and altered, and the ore-forming material underwent activation, migration and mineralization. The ore-forming fluid shows characteristics of mantle fluid and has middle to low temperature (381～115℃) and middle to low mass fraction of NaCl (2.18%～16.77%) and H 2O-CO 2 system. According to the data of hydrogen and oxygen isotopic compositions (δD=-114.6‰～-68.8‰,δ 18O H 2O=-2.47‰～5.91‰), the conclusion can be reached that the ore-forming fluid of the Hongshijing gold deposit was a kind of mixed hydrothermal solution mainly composed of meteroric water, magmatic water and formation water in basalt and tuffaceous-sandstone or metamorphic water. Under the action of brittle shear, the gold-bearing formation was metamorphosed and altered, and the ore-forming material activated, migrated and mineralized with the change of the physical and chemical conditions at the depth of 1.57～2.25 km be

关 键 词：地球化学 金矿床 成因 新疆 同位素 成矿流体 赋存条件 

分 类 号：P618.51[天文地球—矿床学]