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

高压下的铝相

• 批准号: 1520726
• 负责人: Mainak Mookherjee
• 金额: $ 32万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1520726&HistoricalAwards=false
• 关键词: Aluminous; phase; pressures; & temperatures

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.

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见解。但是，只有通过将矿物物理数据（物理特性）与地球物理（地震学）观察进行比较，我们才能将深地球的热状态脱离化学。通常，作为一阶近似，地球的地幔被认为是由同质的黄铁矿组成的。但是，海洋山脊和海洋岛玄武岩中的独特痕量元素签名揭示了地球地幔的异质性。尽管异质性的尺度尚不清楚，但地幔的大区域可能是由耗尽的哈尔兹堡和富集的地壳组成的。我们对在高压下这些俯冲的地壳中对矿物相的热力学和物理性质的了解有限。在这项建议中，PI打算使用第一原理计算来研究化学如何影响晶体结构，能量和铝矿物相的弹性，这些相位可能会稳定在深层的海洋和大型collusterals crolstertals crolsters anteraltals crolosts crolosts crolosts crolosts crolust。他还将研究这些铝相阶段中氢化的能量学。结果将与地球物理学，矿物质物质，地球动力学，岩石学和地球化学子学科有关。 PI还将在固体地球科学/矿物质物理学中训练本科生。