Highly siderophile element geochemistry of mantle pyroxenites

地幔中高亲铁元素（HSE，包括铼、金和铂族元素）的丰度可能会限制地核形成和晚期吸积过程的影响。然而，这种方法需要很好地了解这些元素在地幔岩浆过程中的分布和行为，如部分熔融、熔体迁移和晶体分馏。辉长岩是地幔中的一种次要岩性，但对地幔演化和玄武岩岩浆的形成具有重要意义。地幔辉石岩中某些HSE丰度的升高表明它们与这些元素在地幔中的再分配有关。为了揭示玄武岩中HSE丰度的控制过程，以及岩浆在地幔中运移过程中HSE的再分布情况，评价不同HSE的相对分配，评价地幔辉石岩形成过程中硫化物在HSE分异中的作用，我们拟研究玄武岩中HSE丰度的分异及放射性成因同位素（187Os、87Sr、143Nd）的组成。

Abundances of highly siderophile elements (HSE, which include rhenium, gold and the plati-num group elements) in the Earth’s mantle may yield constraints on the influence of core formation and late accretion processes. This approach, however, requires a good understanding of the distribution and behaviour of these elements during magmatic processes in the Earth’s mantle such as partial melting, melt migration and crystal fractionation. Pyrox-enites are a minor lithology in the mantle, but may play a key role in understanding mantle evolution and formation of basaltic magmas. Elevated abundances of some HSE in mantle pyroxenites indicate their relevance for redistribution of these elements in the mantle. Here we propose to study the abundance systematics of HSE and the composition of radiogenic isotopes (187Os, 87Sr, 143Nd) in pyroxenites in order to shed light on the processes that control HSE abundances in basalts, how HSE redistribute during magma transport in the mantle, to evaluate the relative partitioning of different HSE, and to assess the role of sulfide in HSE fractionation during the formation of mantle pyroxenites.