Phase Relations and Equations of State of the Earth's Lower Mantle

9903014 Duffy对最近地球下地幔地震观测的解释依赖于对这些极端条件下物质的物理和化学性质的详细了解。了解地球的下地幔对于回答有关地球起源、演化和结构的基本问题也至关重要。 这项工作将通过在地球深部存在的压力（25-135 GPa）和温度（1000-4000 K）条件下直接进行的实验测量来研究下地幔矿物和矿物组合的晶体结构、相关系和状态方程。 该实验技术将联合收割机与金刚石对顶砧中的双面激光加热原位同步X射线衍射相结合。 实验计划将包括研究与下地幔有关的单相以及复杂的矿物组合。 对于后者，将开发使用区域探测器的新技术。 这些研究的结果将用于解决有关下地幔性质的基本问题。 具体而言，将通过实验结果与地震数据相结合，探索下地幔的矿物学和整体成分。

9903014DuffyInterpretation of recent seismic observations for the Earth's lower mantle is dependent upon a detailed understanding of the physical and chemical properties of materials under these extreme conditions. Understanding the Earth's lower mantle is also crucial to answering fundamental questions about the Earth's origin, evolution, and structure. This work will examine crystal structures, phase relations, and equations of state of lower mantle minerals and mineral assemblages through experimental measurements conducted directly under the pressure (25-135 GPa) and temperature (1000-4000 K) conditions that exist within the deep Earth. The experimental technique will combine in situ synchrotron x-ray diffraction with double-sided laser heating in the diamond anvil cell. The experimental program will include study of single phases relevant to the lower mantle, as well as complex mineral assemblages. For the latter, new techniques using area detectors will be developed. The results of these studies will be used to address fundamental questions regarding the nature of the lower mantle. Specifically, the mineralogy and bulk composition of the lower mantle will be explored through combination of experimental results with seismic data.