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

地山西栖霞具不同结构的“干”灾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SiO2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;粗粒结构橄榄岩石中矿物与岩石的差别量大,但REE的配合分形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粒间组分或／和矿物流体包裹体中。

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

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 depletion 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.