赣南狮吼山硫铁-钨多金属矿床H-O-S同位素组成特征  

Hydrogen-Oxygen-Sulfur Isotope Composition of Shihoushan Pyrite and Tungsten Polymetallic Deposit,Southern Jiangxi

作　　者：李伟[1] 于长琦 曾载淋[1] 刘翠辉 贺根文 陈伟[1] 邬思涛 LI Wei;YU Chang-qi;ZENG Zai-lin;LIU Cui-hui;HE Gen-wen;CHEN Wei;WU Si-tao(Geological Survey Team of Gannan,Bureau of Geology and Mineral Exploration&Development of Jiangxi Province,Ganzhou 341000,China)

机构地区：[1]江西省地质矿产勘查开发局赣南地质调查大队,江西赣州341000

出　　处：《岩矿测试》2018年第6期713-720,共8页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查工作项目"江西于都银坑-宁都青塘地区金银多金属矿整装勘查区矿产调查与找矿预测"(121201004000150017-14;121201004000160901-13;121201004000160901-14)

摘　　要：狮吼山硫铁-钨多金属矿床位于银坑-青塘整装勘查区北部,是赣南地区唯一大型硫铁矿床。磁黄铁矿-黄铁矿(-黄铜矿-白钨矿)矿体赋存于石炭系梓山组上段地层中含铁、含钙层位,主要形成于石英-硫化物阶段。本文通过分析原生矿石矿物中H-O-S同位素组成特征,结合Pb同位素和成矿年代测试结果,探讨成矿流体来源及成矿演化过程。矿石硫化物中δ^(34)S组成特征(-5. 50‰～-0. 20‰,集中于-3. 0‰～0. 0‰)显示,硫源以岩浆硫为主,较宽的变化范围预示成矿流体遭受了叠加和改造作用。δD-δ^(18)O同位素组成主要集中于岩浆水与变质水重叠区域(δD=-74. 4‰～-48. 0‰,δ^(18)O_(H_2O)=3. 76‰～10. 86‰),说明成矿流体以岩浆水和变质水为主,后期有少量的天水混入。综合分析认为,该矿床成矿流体主要来自深部岩浆水,岩浆热液与含钙地层的接触交代作用形成大规模变质流体,再加上少量的天水混入,流体间的不混溶作用使成矿物质在岩体与含钙层位接触部位富集沉淀,形成热液充填交代型矿床。BACKGROUND:Shihoushan Pyrite and Tungsten polymetallic deposit,located in the northern of Yinkeng-Qingtang Au-Ag polymetallic integrated exploration area,is the only large pyrite deposit in southern Jiangxi.The pyrrhotite-pyrite(-chalcopyrite-scheelite)orebody hosts in calciferous sandstone in the Zishan Formation of Carboniferous System,mainly formed in the quartz-sulfide stage.OBJECTIVES:In order to better understand the ore-forming material source and the evolution processes of Shihoushan deposit,the primary ores were selected as laboratory raw materials for stable isotope testing.METHODS:H-O-S isotope composition of primary ore minerals was analyzed combined with the Pb isotope and metallogenic age results.The ore-forming fluid source and ore-forming evolution process are discussed.RESULTS:Theδ^34 S values range from-5.50‰to-0.20‰,which are mainly concentrated at-3.0‰-0.0‰(n=11),show the typical signature of mantle S.The wide range of variation indicates that the ore-forming fluid has been subjected to superposition and modification.H-O isotope analyses show thatδD=-74.4‰--48.0‰(n=9),δ^18 O H 2O=3.76‰-10.86‰(n=9),indicating that the ore-forming fluid is composed mainly of magmatic water and metamorphic water,with minor meteoric water.CONCLUSIONS:According to the comprehensive analysis,the ore-forming fluid of this deposit mainly comes from deep magmatic water.The contact between magmatic hydrothermal fluid and calcium-bearing strata forms a large-scale metamorphic fluid,mixed with a small amount of meteoric water.The fluid immiscibility makes the ore-forming materials precipitate in the contact between the rock mass and the calcium-bearing strata,forming a hydrothermal filling and metasomatic deposit.

关 键 词：硫铁-钨多金属矿床 H-O-S同位素 成矿流体演化 岩浆期后热液充填交代型矿床 赣南 

分 类 号：P618.1[天文地球—矿床学]