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

高压下的铝相

基本信息

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 &amp temperatures

项目摘要

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，只有通过将矿物物理数据（物理性质）与地球物理（地震学）观测结果进行比较，我们才能将地球深处的热状态与其化学成分分开。传统上，作为一阶近似，地球的地幔被认为是由均质的火山岩组成。然而，大洋中脊和洋岛玄武岩中独特的微量元素特征揭示了地幔的异质性。尽管异质性的规模尚不清楚，但地幔的大部分区域很可能由贫化的方辉橄榄岩和富集的地壳部分组成。我们对这些高压下俯冲地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，很可能在深俯冲的海洋和大陆地壳中稳定下来。他还将研究这些铝相中氢结合的能量学。研究结果将与地球物理学、矿物物理学、地球动力学、岩石学和地球化学子学科相关。 PI 还将培训固体地球地球科学/矿物物理学方面的本科生。