Element Partitioning at Earth's Deep Chemical Boundaries

地核-地幔边界(CMB)和内核边界(ICB)是决定地球内部动力学和控制地球磁场产生的最重要的深部化学边界。晶界通过金属-硅酸盐的分异和内部结晶重新调整了元素的重新分布。这项研究的目的是利用新开发的高压和温度技术以及最先进的分析工具来了解这些边界上的元素分配行为，这些分析工具允许模拟边界条件并分析回收样品中共存相的化学成分。这项工作将极大地促进我们对地球深部过程的了解，以及研究深部化学边界元素再分布的实验技术。拟议的研究重点是高压和高温下地幔和地核之间的硅(Si)和氧(O)分配，适用于核-地幔分异和核中硅和氧的并入。具体项目包括(1)确定液态地幔硅酸盐和熔融核铁合金之间的Si和O分配，直至CMB压力；(2)确定压力对Si，O和S在固态和液态铁合金之间分配系数的影响，并研究它们在ICB条件下的分配行为。这项研究将在极端条件下产生高质量的数据，这是理解地核化学和洞察地球吸积环境和地球内部演化所必需的。它将在岩石学、矿物物理、地球化学和地球物理的界面上开辟新的研究机会。

The Earth's core-mantle boundary (CMB) and inner core boundary (ICB) are the most important deep chemical boundaries that define the dynamics of the interior and control the generation of Earth magnetic field. The boundaries reset the element redistribution through metal-silicate differentiation and inner crystallization. The goal of this study is to understand the behavior of element partitioning at these boundaries using newly developed high-pressure and temperature techniques and state-of-the-art analytical tools that allow simulating the conditions of the boundaries and analyzing the chemical compositions of the coexisting phases in the recovered samples. The proposed work will significantly advance our knowledge of Earth's deep processes and experimental techniques to investigate element redistribution at deep chemical boundaries.The focus of the proposed research is on the silicon (Si) and oxygen (O) partitioning between mantle and core at high pressure and temperature, applicable to core-mantle differentiation and the incorporation of Si and O in the core. Specific projects include (1) determining the Si and O partitioning between liquid mantle silicate and molten core iron alloy up to CMB pressure, and (2) determining the effect of pressure on the Si, O, and S partitioning coefficients between solid and liquid iron alloy and examining their partitioning behavior at ICB conditions. The research will produce high-quality data under extreme conditions that are necessary for understanding the chemistry of Earth's core and providing insight into the Earth accretion environment and the evolution of Earth's interior. It will open new research opportunities at the interface of petrology, mineral physics, geochemistry, and geophysics.