【摘要】 在简要介绍Fe同位素体系的基础上,对Fe同位素在地幔地球化学研究中的应用进行了较为系统的评述。根据华北克拉通新生代玄武岩及其携带的地幔捕虏体Fe同位素研究最新进展和国际上已发表的有关数据,总结了Fe同位素在大洋玄武岩,地幔捕虏体及其单矿物中的分布特征。统计结果表明,来自世界不同地区的大洋玄武岩的Fe同位素组成比较均一,并且相对地幔橄榄岩Fe同位素组成总体偏重,表明地幔部分熔融过程导致Fe同位素分馏。而地幔捕虏体及其单矿物的Fe同位素组成明显不均一。没有受到地幔交代作用影响的橄榄岩,Fe同素组成变化范围小,而经受不同类型地幔交代作用影响的地幔橄榄岩,Fe同位素组成存在明显的差异,这说明地幔交代作用是导致地幔Fe同位素组成不均一的重要机制。更多还原

【Abstract】 Following a brief introduction of the Fe isotopic system,this paper has reviewed the achievements of its applications in the mantle geochemical researches obtained in recent years. Based on the iron isotopic data of Neozoic basalts and their coexited mantle xenoliths from the North China Craton and worldwide published in recent years,a review on distribution characteristics of iron isotopes of ocenic basalts,mantle xenoliths and their rock-forming minerals has been given in this paper. The result shows that oceanic basalts from various areas worldwide have relatively consistent iron isotopic compositions with their δ57Fe values relatively higher than that of the peridotite,indicating that there is iron isotope fractionation in the mantle partial melting process. In contrast,mantle xenoliths and their ore-forming minerals obviously have heterogeneous iron isotopic compositions. The un-metasomatised peridotites have relatively homogeneous Fe isotopic compositions,whereas various kinds of metasomatised peridotites display obviously different Fe isotopic compositions. These characteristics suggest that the mantle metasomatism could be significantly resulted in the the heterogeneity of Fe isotopes of various metasomatised lithospheric mantle.更多还原