内蒙古黄岗矽卡岩型铁锡矿床S-Pb-O同位素组成及对成矿物质来源的指示  

SULFUR-LEAD-OXYGEN ISOTOPE COMPOSITIONS OF THE HUANGGANG SKARN Fe-Sn DEPOSIT,INNER MONGOLIA:IMPLICATIONS FOR THE SOURCES OF ORE-FORMING MATERIALS

作　　者：刘智[1] 吕新彪[1] 梅微[1] 

机构地区：[1]中国地质大学(武汉)资源学院,湖北武汉430074

出　　处：《矿物岩石》2013年第3期30-37,共8页Mineralogy and Petrology

摘　　要：内蒙古黄岗矿床是大兴安岭南段多金属成矿带一个重要的大型铁锡矿床。笔者在详细分析该矿床成矿地质条件的基础上,系统地研究矿床硫、铅、氧同位素组成特征,探讨了成矿物质来源。矿石硫化物的硫同位素组成变化范围较宽,δ34S值分布范围为-9.5‰～4.5‰,显示了硫具混合来源及多阶段成矿的特征;矿石硫化物铅同位素组成稳定,206Pb/204Pb值为18.252～18.344,207Pb/204Pb值为15.511～15.607,208Pb/204Pb值为38.071～38.388,矿石铅与钾长花岗岩钾长石铅同位素相似,且与矿区钾长花岗岩铅同位素具有较一致的范围而与其他花岗岩相差较大,表明矿石铅同位素与钾长花岗岩可能具有同源关系;磁铁矿δ18 O值为-2.3‰～3.9‰,结合矿床地质特征,认为铁质来源于大石寨组安山岩地层。The Huanggang deposit in the South Daxinganling metallogenic belt is a large Fe-Sn deposit. Based on analysis of geological data, this paper systematically studies the compositions of S,Pb,O isotopes from the ores and discusses the source of ore-forming materials. It is shown that the composition of S isotope in ore sulfides has a wide variation range. The 334S values vary from -9.5‰ to 4. 5‰, with several peaks, showing mixed-source and multi-stage mineralization. The Pb isotopic composition is stable, characterized by 206Pb/204Pb, 207Pb/204 Pb, 208Pb/204 Pb ratios for sulfur varying in range of 18. 252- 18. 344,15. 511 - 15. 607,38. 071 - 38. 388, respectively. The Pb isotopes for sulfide and K-feldspar of K-feldspar granite are similar,and the Pb isotope compo- sition for Sulfide is linear correlation with that for K-feldspar granite rather than other granite, suggesting that the Pb isotope of sulfide and K-feldspar granite have the same source. The δ18O values of magnetite vary from --2.3‰ to 3.9‰,indicating that the iron comes from the andesite of Dashizhai Formation.

关 键 词：同位素组成 成矿物质来源 黄岗矽卡岩矿床 内蒙古 

分 类 号：P597.2[天文地球—地球化学]