X-ray fluorescence and X-ray absorption spectroscopy studies of element redistribution processes between carbonates and mantle phases at lower mantle conditions

在这个项目中，我们想要建立对上、下地幔条件下橄榄岩岩性中碳酸盐和地幔硅酸盐之间的元素交换的理解，并估计碳酸盐对地幔微量元素收支和相关性质的影响。将进行现场实验，以确定微量元素在碳酸盐和地幔相之间的分配。此外，我们希望开发用于原位观察硅酸盐-碳酸盐反应的时间分辨XRF测量技术，并在时间分辨率为毫秒或更低的情况下首次深入了解硅酸盐和碳酸盐之间的反应过程。总体而言，该项目旨在更好地理解Brenker等人的研究结果。(2007)，他证明了稀土和锶是形成于下地幔条件下的天然金刚石包裹体中的重要微量元素。到目前为止，由于缺乏关于地幔条件下碳酸盐和硅酸盐之间的微量元素分配的知识，导致所观察到的钻石包裹体相中微量元素模式的成因过程尚不清楚。

In this project we would like to establish an understanding of the exchange of elements between carbonates and mantle silicates in peridotitic lithologies at upper and lower Earth's mantle conditions and estimate the influence of carbonates on the trace element budget of the mantle and related properties. In-situ experiments will be performed to determine the trace-element partitioning between carbonates and mantle phases. Furthermore, we want to develop time-resolved XRF measurement techniques for in situ observation of silicate-carbonate reactions and gain first insight into reaction processes between silicates and carbonates at a time resolution of milliseconds and below. Overall, the project aims at a better understanding of findings by Brenker et al. (2007), who evidenced that REE and Sr are important trace elements in natural diamond inclusions formed at lower mantle conditions. So far, genetic processes leading to the observed trace element patterns in the phases of the diamond inclusions remain unclear due to the lack of knowledge on trace element partitioning between carbonates and silicates at the conditions of the mantle.