HIMU型洋岛玄武岩的地球化学特征  

Geochemical Characteristics of HIMU-Type Oceanic Island Basalts

作　　者：王小均[1] 刘建强[1] 陈立辉[1] 

机构地区：[1]南京大学地球科学与工程学院、内生金属矿床成矿机制研究国家重点实验室,南京210023

出　　处：《高校地质学报》2014年第3期353-367,共15页Geological Journal of China Universities

基　　金：国家自然科学基金(41372064;41172060)资助

摘　　要：洋岛玄武岩的元素和同位素地球化学特征可以示踪深部地幔的化学结构和化学演化过程。HIMU(Highμ,μ=238U/204Pbt=0)型玄武岩是一类元素和同位素组成特殊的洋岛玄武岩,被认为与地幔柱中再循环的洋壳物质直接相关,因此,HIMU型玄武岩的成因是地幔柱(热点)研究中长期关注的话题。本文概述了HIMU型玄武岩的地球化学定义,对HIMU洋岛的分布、火山演化阶段以及岩性变化做了综合阐述,并在对比经典HIMU型玄武岩与其他板内玄武岩元素地球化学特征、放射成因同位素组成以及惰性气体同位素组成特征的基础上,简要探讨其源区组成和成因上的不同。The elemental and isotope geochemical characteristics of oceanic island basalts can be used to trace chemical structure and chemical evolution of the deep mantle. HIMU（Highμ,μ=（238）~U/（204）~Pb_t=0） -type basalt is a kind of oceanic island basalts which has unique elemental and isotopic composition and is thought to be directly associated with recycled oceanic erust in the mantle plume. Therefore, the genesis of HIMU basahs is a long-term topic of the mantle plume （hot spot） researches. This paper summarizes the geochemical definition, distribution, stages of volcanic evolution and changes in lithology of HIMU-type ocean island basalts.Furthermore, we discuss the differenees of the source compositions and genesis between classical HIMU basalts and other intraplate basahs against their elemental, radiogenic isotopic compositions and noble gas isotonic compositions.

关 键 词：HIMU 空间分布 同位素 成因模式 

分 类 号：P588.12[天文地球—岩石学]