南太行山平顺铁矿床成矿物质来源示踪:微量元素、S和Pb同位素  

Ore-Forming Material Sources of the Pingshun Iron Deposits in the Southern Taihang Mountains:Constraints from Trace Elements and S and Pb Isotopes

作　　者：张海东[1,2] 刘建朝[1,2] 彭淑霞[1] 张苏楠[1] 门文辉[1] 王瑞美[1] 吴继莲[1] 黄水文[1] 

机构地区：[1]长安大学资源学院,陕西西安100541 [2]长安大学成矿作用及其动力学国土资源部开放研究实验室,陕西西安710054

出　　处：《地质与勘探》2013年第6期1088-1097,共10页Geology and Exploration

基　　金：中国地质调查局项目(编号1212011121076);国家自然科学基金(编号41040020);中央高校基金(编号CHD2011ZY005;CHD2011JC168)联合资助

摘　　要：平顺地区矽卡岩型铁矿位于太行山南段山西省境内，主要产于燕山期中性侵入岩与中奥陶统碳酸盐岩地层接触带及其附近。不同类型铁矿石与平顺岩体的微量元素、稀土元素组成特征表明，矿体与岩体具有一定的继承性，说明二者成因关系密切。矿石s同位素（δ^34S=12．5‰～17．4％。，平均值为15．0％e）显示具有地壳硫的特征；Pb同位素（^206Pb／^204Pb=17．365～19．032，平均值为18．121；^207Pb／^204Pb=15．417-15．689。平均值为15．543；^208Pb／^204Pb=37．433～39．762，平均值为38．379；p=9．21～9．28，w=34．6～39．33，）显示铀铅富集，钍铅亏损的特征。平顺铁矿石微量元素、稀土元素、S、Pb同位素组成特征表明，较早期闪长岩是主要的成矿母岩，但晚期辉长岩可能通过交代作用，间接提供了物质来源和热源。在成矿过程分析的基础上，建立了本区矽卡岩型铁矿床的成矿模式。The Pingshun skam iron deposits, located in the southern Taihang Mountains of Shanxi Province, mainly occur along the contact zone between the Yanshanian intermediate rocks and Middle Ordovician carbonate rocks and vicinity. Composition features of trace elements, rare earth elements of different types of iron ores and rocks in Pingshun indicate that the orebodies may inherit from rock masses, and there is a close relationship of genesis between them. Sulfur isotope analysis shows that δ^34S values of iron ores vary in the range of 12.5‰ - 17.4‰ （average 15.0‰）, which is the character of crust sulfur. Pb isotope analysis reveals that ^206pb/^204pb, ^207pb/^204pb and ^208pb/^204pb ratios of ore lead are 17. 365 - 19. 032 （ average 18. 121 ）, 15. 417 - 15. 689 （ average 15. 543 ） , 37. 433 - 39. 762 （ average 38. 379 ） , respectively, and u varies from 9.21 to 9.28, to varies from 34.6 to 39.33, which show the character of enrichment of uranium and lead, and depletion of thorium and lead. Composition characters of trace elements, rare earth ele- ments and sulfur and lead isotopes in the Pingshun iron ore imply that earlier diorites are main metallogenic mother rocks, while later gabbros may provide some ore-forming materials and the heat source during the metasomatism. Based on the above-mentioned analysis, an ore-forming model of skarn iron de- posits in this area has been constructed.

关 键 词：平顺铁矿床微量元素 S、Pb同位素 成矿物质来源 

分 类 号：P621[天文地球—地质矿产勘探]