粗粒与剪切结构橄榄岩捕虏体及其单斜辉石微量元素对比  

Comparison of the trace element of clinopyroxenes and xenoliths with coarse-grained and shear peridotites.

作　　者：郑建平[1] 路凤香[1] Suzanne Y O'REILLY 余淳梅[1] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]澳大利亚曼魁里大学地球与行星科学系

出　　处：《岩石学报》2001年第2期263-268,共6页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(40072021;49733110);中国科学院项目(KZCX1-07)

摘　　要：对山东栖霞具不同结构的“干”尖晶石相橄榄岩进行了全岩化学、微量元素 ,矿物成分和单斜辉石微量元素分析和对比。表明在橄榄岩从粗粒结构向剪切结构的转化中 ,随着变质变形作用的增强存在着复杂的熔 /流体的加入富集和熔体的提取亏损作用 ;交代介质属具强渗透性的 Si O2 不饱和的硅酸盐碳酸岩熔体。同时发现不同结构橄榄岩中单斜辉石的 REE与其全岩的 REE程度有如下的关系 :粗粒结构橄榄岩中矿物与岩石的差别最大 ,但 REE的配分形式可以反映全岩的情况 ;剪切结构橄榄岩中两者的差别较小。其它高度不相容微量元素可能主要赋存在粒间组分或The mineral chemistry, petrochemistry and the trace element of 'dry' spinel-facies peridotitic xenoliths with different microstructure and their clinopyroxenes are compared and discussed in this paper. With the increasing metamorphism and deformation of peridotites in the transform from the coarse-grained to the shear microstructure, the complex processes on enrichment and depiction existed. The metasomatism agent was the SiO(2)-undersaturation silicate-carbonatite melt with strong infiltration. The results also show that the REE relationship between 'dry' spinel-facies peridotitic xenoliths with different microstructure and their clinopyroxenes are following: there are obvious differences between coarse-grained peridotite and its clinopyroxene, on the other hand, the REE pattern of clinopyroxene can totally represent its host peridotite; there is only a little difference between shear peridotite and its clinopyroxene. The other high incompatible elements most probably existed as the inter-grain constituents or in fluid inclusions.

关 键 词：微量元素 橄榄岩 单斜辉石 剪切结构 捕虏体 矿物组成 流体包裹体 

分 类 号：P588.125[天文地球—岩石学] P595[天文地球—地质学]