Petrogenesis of Diamondiferous Eclogites from the Siberian Platform

9505930泰勒这是一项对西伯利亚地台榴辉岩捕虏体进行的全面的岩石学和地球化学研究，由一组科学家组成，以确定西伯利亚榴辉岩捕虏体的成分和岩石学变化。主要元素和微量元素数据将通过电子和离子微探针收集在矿物上。将收集由X射线荧光和仪器中子活化分析确定的块状岩石成分，以及关于矿物分离物和块状岩石的稳定同位素数据(碳和氧)(仅关于钻石的碳同位素成分)。将收集超纯矿物分离物和块状岩石的放射性成因同位素数据(Sr-Nd-Os)，以评估这些样品的来源(例如，地壳或地幔)和这些来源的年龄。来自地幔包体的Sm-ND等时线，其年龄比其主岩更古老。最后，一个独特的机会以五对石榴石-单斜辉石包裹体的形式出现，这些包裹体以钻石为宿主，而这些包裹体又以来自和平号和乌达克纳亚管道的榴辉岩模块为宿主。对这些配对包裹体进行微量元素和主量元素研究，并将其与寄主榴辉岩进行比较，对于我们理解榴辉岩和钻石的形成以及可能的寄主后期交代作用是至关重要的。这项研究将是首次对来自北半球太古代地壳段的榴辉岩包体进行全面、详细的研究。

9505930 Taylor This is a comprehensive petrographic and geochemical study of eclogite xenoliths from the Siberian platform using a consortium of scientists, to establish the compositional and petrographical variation of eclogite xenoliths from Siberia. Major- and trace-element data will be collected on minerals by electron and ion microprobe. Bulk-rock compositions determined by x-ray fluorescence and instrumental neutron-activation analysis, and stable isotopic data (C and O) will be collected on mineral separates and bulk rocks (C isotopic compositions only on diamond). Radiogenic isotopic data (Sr-Nd-Os) will be collected on ultra-pure mineral separates and bulk rocks to evaluate the sources from which these samples were derived (e.g., crustal or mantle) and the age of these sources by model ages. Samarium-Nd isochrons from mantle xenoliths that are older than their host rock. Finally, a unique opportunity has presented itself in the form of five pairs of garnet-clinopyroxene inclusions which are hosted by diamonds and which, in turn, are hosted by eclogite modules from the Mir and Udachnaya pipes. A trace- and major -element study involving these paired inclusions and comparing them to the host eclogites is paramount to our understanding of eclogite and diamond formation and possible later metasomatism of the host. This study will be the first comprehensive detailed study of eclogite xenoliths from a northern hemisphere Archean-aged crustal segment.