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）观测进行比较，我们才能将地球深部的热状态与其化学性质分开。传统上，作为一级近似，地球地幔被认为是由均匀的地幔岩组成。洋中脊玄武岩和洋岛玄武岩的微量元素特征反映了地幔的不均一性。虽然不均匀性的规模是未知的，它很可能是大面积的地幔是由一个亏损的哈兹伯拉和富集地壳部分。我们对高压下这些俯冲壳中矿物相的热力学和物理性质的了解有限，在本提案中，PI打算使用第一原理计算来研究化学如何影响可能在深俯冲洋壳和陆壳中稳定的铝质矿物相的晶体结构、能量学和弹性。他还将研究这些铝相内氢结合的能量学。其结果将与地球物理学、矿物物理学、地球动力学、岩石学和地球化学子学科有关。PI还将培训固体地球科学/矿物物理学的本科生。