华北地幔捕虏体Fe-Mg-Ca同位素研究进展

近年来，得益于同位素分析技术和质谱仪器性能的提高，使得铁（Fe）、镁（Mg）和钙（Ca）等非传统稳定同位素的高精度测量成为可能，并很快在地球化学、天体化学和生物地球化学等研究领域取得了丰硕的成果。本文通过对比分析来自华北克拉通不同地区不同类型地幔捕虏体的Fe、Mg和Ca位素组成特征，揭示华北克拉通岩石圈地幔Fe、Mg和Ca同位素组成不均一性的成因，并在此基础上，探讨华北大陆岩石圈地幔演化过程如部分熔融、橄榄岩-熔体反应过程、熔体的性质和来源等科学问题，为华北克拉通岩石圈的演化过程提供新证据。

Progress in Fe,Ca and Mg isotopes of mantle xenoliths from the North China Craton

With rapid improvements in analytical techniques and growing interest in non-traditional isotopic geochemistry over the past decade, high-precision isotopic measurements of Fe, Mg and Ca become reality and have proven to be especially useful tracers in fields of geochemistry, cosmochemistry and biogeochemistry. In this paper, we first give a brief introduction of Fe, Mg and Ca isotopic systems, and then present a systematic overview of available Fe, Mg and Ca isotopic data in mantle xenoliths from the North China Craton. The statistic results show that the sub-continental lithospheric mantle beneath the North China Craton has distinguishable and heterogeneous Fe, Mg and Ca isotopic variations at mantle xenolith scale. Peridotite-melt interaction is the most likely cause for the Fe, Mg and Ca isotopic variations in mantle xenoliths from the North China Craton. It has become increasingly clear that Fe, Mg and Ca isotopic signatures can be used to trace a wide variety of high-temperature processes in the Earth's upper mantle such as partial melting, melt percolation or metasomatism. The combined study of Fe, Mg and Ca isotope systems is expect to be very helpful to evaluate the effect of peridotite-melt on Fe, Ca and Mg isotope fractionation, as well as the nature and origin of the melts involved in the modification of the subcontinental lithospheric mantl beneath the North China Craton in the future.