Aluminous phase at high-pressures & temperatures: Elasticity and Energetics of hydrogen incorporation

地球物理和地球化学观测提供了对地球内部物理和化学状态的深入了解。然而，只有将矿物物理数据（物理性质）与地球物理（地震学）观测结果进行比较，我们才能将地球深部的热状态与其化学成分区分开来。传统上，作为一阶近似，地幔被认为是由均质软锰矿组成的。然而，洋中脊和洋岛玄武岩中明显的微量元素特征揭示了地幔的非均质性。虽然不均匀性的规模是未知的，但很可能地幔的大部分是由枯竭的辉锌矿和富集的地壳组分组成的。我们对这些高压俯冲地壳中矿物相的热力学和物理性质了解有限。在这项建议中，PI打算使用第一性原理计算来研究化学如何影响铝矿物相的晶体结构，能量学和弹性，这些矿物相可能在深俯冲的海洋和大陆地壳中稳定下来。他还将研究氢与这些铝相结合的能量学。研究结果将与地球物理学、矿物物理学、地球动力学、岩石学和地球化学等分支学科相关。该项目还将培养固体地球科学/矿物物理学的本科生。

Geophysical and geochemical observations provide insights into the physical and chemical states of the Earth's interior. However, only by comparing mineral physics data (physical properties) with geophysical (seismological) observations can we disentangle the thermal state of the deep Earth from its chemistry. Conventionally, as a first order approximation, the Earth's mantle is thought to be composed of a homogenous pyrolite. However, the distinct trace element signatures in mid ocean ridge and ocean island basalts reveal the heterogeneity in the Earth's mantle. Although the scale of the heterogeneity is unknown, it is likely that large regions of the mantle are composed of a depleted harzburgite and enriched crustal fractions. We have limited knowledge of the thermodynamics and physical properties of mineral phases in these subducted crusts at high pressures.In this proposal, the PI intends to use first principles calculations to investigate how chemistry influences crystal structure, energetics, and elasticity of aluminous mineral phases which are likely to be stabilized in deeply subducted oceanic and continental crusts. He will also investigate the energetics of hydrogen incorporation within these aluminous phases. The results will be relevant for geophysics, mineral-physics, geodynamics, petrology, and geochemistry sub disciplines. The PI will also train undergraduate student/s in Solid Earth Geosciences/Mineral Physics.