金红石:重要的地球化学“信息库”

Rutile:An important "reservoir" for geochemical information

金红石是各种岩石特别是地壳组成岩石中重要的副矿物,它在成岩、风化和各种不同程度的变质过程中均能保持极大的稳定性。同时,除主要成分TiO2外,金红石还含有为数众多的其它微量元素(例如:Nb,Ta,Zr,Hf,Sn,Mo,Sb,Cr,V,W,U和Pb等),这些微量元素的变化特征,对于包含金红石的主体岩石所经历的地质过程具有非常重要的指示意义。近二十年特别是近十年来,金红石已成为地球化学研究领域的一个热点。对各种元素和同位素在金红石中变化特征的调查,被广泛地应用于对各种地质过程的了解,其研究应用的范围涉及到了整体地球的元素平衡、大陆地壳的形成机制、含金红石岩石的形成源区、变质岩石的温压条件和形成时代的研究等多个方面,同时其所包含的各种同位素体系也被广泛用于各种地质过程的示踪。本文综合近年来金红石研究的最新进展,系统表述了金红石作为一个近年来发展起来的重要地质信息储库,在地球化学研究中各个方面的应用。

Rutile is an important accessory mineral phase in crust-forming rocks.It remains in great stability during various geological processes such as rock forming,weathering and low to high grade metamorphism.In addition to its main component TiO2,rutile also contains numerous other trace elements（metal ions）.Geochemical features of these trace elements are important tracers for understanding geological processes experienced by the rutile-hosting rocks.In the past two decades,in particular over the last decade,studies of rutile have been a hot and front field in geochemical researches.The trace elemental and isotopic characteristics in rutiles are widely used on the understanding of a variety of geological processes,including the overall mass balance of the Earth＇s elements,the formation mechanism of the continental crust,source tracking of protolith of rutile-bearing rocks,P-T condition estimates of metamorphic rocks,U-Pb geochronology,etc.In this paper we try to summarize the latest developments in the field of rutile studies in recent years,aiming to introduce the newly developed important geochemical information reservoir to Chinese geochemists.