金宝山铂-钯矿和力马河镍矿的硫同位素组成特征及地质意义  

The Sulfur Isotopic Characteristics and Geological Significance of Jinbaoshan Pt-Pd Deposit and Limahe Nickel Deposit

作　　者：马言胜[1,2] 陶琰[1] 朱飞霖[1,2] 王兴阵[3] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550002 [2]中国科学院研究生院,北京100049 [3]安徽理工大学,安徽淮南232001

出　　处：《矿物岩石地球化学通报》2009年第2期123-127,共5页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(40573020;40773033);中国科学院重要方向项目(KZCX3-SW-111)

摘　　要：金宝山铂钯矿和四川力马河镍矿是峨眉山大火成岩省内两个重要的Ni-Cu-PGE硫化物矿床,但二者矿化特征明显不同,前者贫铜、镍,富铂、钯,硫化物含量低,呈浸染状;后者贫铂族元素,富含硫化物,矿石以陨铁状或块状为主。本文以两矿床成矿元素组成的变化和矿石结构类型的显著差异为出发点,系统分析了硫化物的硫同位素,发现金宝山铂-钯矿的硫化物δ34S值（0.6‰~2.8‰）略高于地幔硫（0±2‰）,显示有微弱的地壳物质混染,而力马河镍矿的硫化物δ34S值（2.4‰~5.4‰）显著高于金宝山铂-钯矿,反映受地壳混染程度较高;指出成矿岩浆演化过程中地壳混染程度上的差异,可能是造成峨眉山大火成岩省岩浆Ni-Cu-PGE矿床矿化类型不同的重要原因。The Jinbaoshan Pt-Pd deposit and Limahe nickel deposit are two important Ni-Cu-PGE sulfide deposits in the Emeishan Large Igneous Province （ELIP）, SW China. The two deposits have very distinctive mineralization characteristics that the Jinbaoshan deposit enriched Pt and Pd but depleted Cu and Ni, and contained low content of disseminated sulfides; while the Limahe deposit depleted PGE and enriched troilite-like or massive sulfide ores. The objective of this study is to explore the large variations of ore-forming elements and texture types of ores by the means of analyzing S isotopic compositions of the sulfide ores. The sulfide ores in Jinbaoshan have a restricted range of δ34S values from ＋0.6‰ to ＋ 2.8‰ slightly higher than the range of 0-± 2‰, which is considered to be normal for sulfur of mantle derivation. These values indicate that the ore-forming magma experienced a weak contamination of crustal material. Compared with the Jinbaoshan deposit, the Limahe deposit has higher δ34S values from ＋2.4‰ to＋5.4‰which are significantly higher than the corresponding values of Jinbaoshan deposit. It indicates that the ore-forming magma of Limahe experienced a larger degree of contamination from the crustal material. As a result, the difference degrees of crustal material contamination during the evolution of ore-forming magma may be one important reason for the variations of mineralization types of magmatic Ni-Cu-PGE deposits in the ELIP.

关 键 词：硫同位素 岩浆Ni-Cu-PGE矿床 地壳混染 金宝山铂钯矿 力马河镍矿 

分 类 号：P618.53[天文地球—矿床学]