Renewal-Experimental Studies of Elasticity, Rheology, Volume, and Texture of Materials at Pressure-Temperature Conditions of the Earth's Mantle and Core

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 对地幔和地核的地球物理观测为我们提供了大量尚未完全理解的大尺度过程和现象。构成深层内部大部分的矿物受到巨大压力和温度的影响，这些压力和温度极大地改变了矿物的性质。该奖项将支持研究人员将其实验室模拟的压力-温度能力扩展到内核的极端条件。他们将利用国家X射线设施开发新技术，以调查压缩矿物的变化特性，并将利用新数据帮助解释地球物理观测结果。拟议中的实验还将揭示在地球形成期间液态铁核是如何从岩石地幔中分离出来的。除了使用该团队在先前的支持下开发的一组新的同步加速器分析探测器继续采集外核P-T范围的数据外，他们建议将矿物物理学研究扩展到内核P-T条件（330-360 GPa，5000-6000 K），并且为了能够测量亚微米单晶的弹性和变形，非晶体材料的直接体积测定，以及岩石复杂粒间结构的研究。 这些新功能将通过将金刚石砧单元与最先进的纳米聚焦硬X射线束、具有全场纳米物镜的3D X射线断层扫描以及由NSF-MRI资助的新一代激光加热系统相结合来实现。 利用新的和现有的技术，研究人员建议研究弹性，流变学，体积，地幔硅酸盐，氧化物和硫化物，以及核心金属和合金沿着地热P-T条件的纹理。 研究结果将用于解决主要的地球物理问题，包括岩浆海洋以外的地幔-核分离，地幔中硅酸盐和氧化物晶界的液态铁的排出或捕获，流体的质量输送，深地幔和核中的地震剖面和异常，外核中铁和合金的液体密度，内核矿物学，生长和流变学，和提议的最里面的内核的性质。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Geophysical observations of the Earth's mantle and core present us with a rich array of large-scale processes and phenomena that are not yet fully understood. Minerals that make up the bulk of the deep interior are subject to enormous pressures and temperatures that drastically altered the minerals properties. This award will support the investigators to extend their pressure-temperature capability of in-laboratory simulations to the extreme conditions of the inner core. They will develop new techniques using national x-ray facilities to investigate the altered properties of the compressed minerals, and will use the new data to help interpreting the geophysical observations. The proposed experiments will also shed light on how the liquid iron core separated from the rocky mantle during the Earth's formation.In addition to the continuation of data acquisition up to the P-T range of the outer core using a battery of newly available synchrotron analytical probes that the team has developed with prior support, they propose to extend mineral physics investigations to inner core P-T conditions (330-360 GPa, 5000-6000 K), and to enable elasticity and deformation measurements of sub-micron single crystals, direct volume determinations of non-crystalline materials, and investigations of complex intergranular textures of rocks. These new capabilities will be accomplished by integration of diamond-anvil cells with the state-of-the-art nano-focusing hard x-ray beam, 3D x-ray tomography with full-field nanoscope objective, and a new-generation, laser-heating system supported by a NSF-MRI grant. Using the new and existing techniques, the investigators propose to study elasticity, rheology, volume, and texture of the mantle silicates, oxides, and sulfides, and core metals and alloys along the geotherm P-T conditions. The results will be used to address major geophysical issues, including mantle-core separation beyond the magma ocean, drainage or trapping of liquid iron from silicate and oxide grain boundaries in the mantle, mass transport of fluids, seismic profiles and anomalies in the deep mantle and core, liquid density of Fe and alloys in the outer core, inner core mineralogy, growth, and rheology, and nature of the proposed innermost inner core.