阜新中生代火山岩的铂族元素特征——以碱锅和乌拉哈达为例  

The distribution of platinum-group elements in Mesozoic volcanic lavas from Fuxin: A case study of Jianguo and Wulahada

作　　者：刘庆[1] 侯泉林[1] 周新华[2] 张宏福[2] 谢烈文[2] 

机构地区：[1]中国科学院研究生院,北京100049 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《岩石矿物学杂志》2006年第1期33-39,共7页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(40334043;40234050);国家自然科学基金委员会杰出青年科学基金资助项目(40225009)

摘　　要：采用镍锍火试金法结合ICP_MS分析了碱锅玄武岩和乌拉哈达高镁安山岩样品中的Ir、Ru、Rh、Pt和Pd的含量。原始地幔标准化后的PGE分布模式呈正斜率型,Pd/Ir值高于相应的地幔比值,表明铂族元素发生了分异,这是由于在部分熔融过程中,Ir存在于地幔矿物相尖晶石和合金中,而Pd赋存于硫化物中造成的,乌拉哈达高镁安山岩中的铂族元素还可能在结晶分异过程中受到先期结晶的矿物相和合金的影响。阜新火山岩Pt的负异常可能是包含Pt的金属合金残留在地幔中造成。The contents of such platinum-group elements as Ir, Ru, Rh, Pt and Pd in Jianguo basalts and Wulahada Mg-high andesites were determined using ICP-MS after a nickel sulfide fire assay preconcentration. They display positive slope in the mantle-normalized pattern. The Pd/Ir values higher than those of the primitive mantle suggest the fractionation of PGE in Fuxin volcanic rocks. PGE fractionation in the basalts is attributed to the fact that Ir can be potentially fractionated in spinel and alloys but Pd resides in sulfides during partial melting. The PGE in Wulahada Mg-high andesites might be affected by the phases separated from earlier melts during fractionation. The negative Pt anomaly in Fuxin volcanic rocks probably results from Fe-Pt alloys residing in the mantle.

关 键 词：铂族元素 玄武岩 高镁安山岩 部分熔融 结晶分异 

分 类 号：P588.14[天文地球—岩石学] P595[天文地球—地质学]