新疆哈密白石泉含铜镍镁铁-超镁铁质岩体铂族元素特征  

Platinum Group Elements Geochemistry of Baishiquan Mafic-Ultramafic Intrusives in Central Tianshan Block, Xinjiang

作　　者：柴凤梅[1] 张招崇[1] 毛景文[1] 董连慧[2] 叶会寿 吴华[3] 莫新华[3] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室 [2]新疆维吾尔自治区地质矿产勘查开发局,乌鲁木齐830000 [3]新疆维吾尔自治区地质矿产勘查开发局第六地质大队,新疆哈密839000

出　　处：《地球学报》2006年第2期123-128,共6页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:40402012);国家305项目(编号:2001BA609A0702)资助。

摘　　要：新疆哈密白石泉镁铁超镁铁质岩体的铂族元素研究表明,岩体的铂族元素总含量较低,原始地幔标准化模式具镁铁质岩石的特征,并具Pt正异常,且铂族元素的分异主要受结晶分异作用的影响。岩体的Cu/Pd、Se/S、Ti/Pd值表明其发生过硫化物的熔离作用。Pd/Ir、Ni/Cu特征表明了岩体系高镁玄武岩岩浆的产物。铂族元素特征揭示了白石泉岩体硫化物的熔离作用是由原始岩浆结晶分异导致的,岩体的形成是原始岩浆发生橄榄石等的结晶,导致硫化物的熔离作用后,其残余岩浆演化的结果。Peridotite, pyroxenite, hornblendite, troctolite and gabbro in Baishiquan intrusion were chosen for platinum-group elements analysis. The results show that their total PGE contents are low, and their primitive mantle-normalized PGE patterns are similar to those of mafic rocks in other areas with positive Pt anomalies and from PGE nonfractionation (Pd/Ir=1.35～5.36) to mild fractionation (Pd/Ir=12～81.54), mainly affected by crystallization differentiation. The Cu/Pd, Ti/Pd and Se/S ratios of these rocks suggest that segregation of sulfide melt must have occurred. The fractionation of olivine and chromite triggered the immiscibility of the sulfide melt from the silicate-melt. The intrusions were generated from the magma that had undergone crystallization differentiation of olivine and segregation of sulfides.

关 键 词：铂族元素 镁铁-超镁铁质岩 新疆白石泉 

分 类 号：P5[天文地球—地质学]