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

高压下的铝相

• 批准号: 1634422
• 负责人: Mainak Mookherjee
• 金额: $ 32万
• 依托单位: Florida State 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: 2015-12-23 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1634422&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洞察。然而，只有将矿物物理数据(物理性质)与地球物理(地震)观测相比较，才能将地球深处的热状态与化学物质分开。传统上，作为一级近似，地幔被认为是由均质地幔组成的。然而，大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不均一性。尽管这种不均一性的规模尚不清楚，但很可能是地幔的大片区域由亏损的方辉橄榄岩和浓缩的地壳部分组成。我们对这些俯冲地壳中矿物相在高压下的热力学和物理性质的了解有限。在这项提议中，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、能量和弹性，这些矿物相很可能在深俯冲的海洋和大陆地壳中稳定下来。他还将研究氢在这些铝相中掺入的能量学。这些结果将与地球物理、矿物物理、地球动力学、岩石学和地球化学子学科相关。国际和平研究所还将培训本科生/S固体地球科学/矿物物理。

项目成果

Structure and Properties of Albite Melt at High Pressures

• DOI: 10.1021/acsearthspacechem.9b00187
• 发表时间: 2020-01-01
• 期刊: ACS EARTH AND SPACE CHEMISTRY
• 影响因子: 3.4
• 作者: Bajgain, Suraj K.;Mookherjee, Mainak
• 通讯作者: Mookherjee, Mainak

Anomalous elastic behavior of phase egg, AlSiO3(OH), at high pressures

• DOI: 10.2138/am-2019-6694
• 发表时间: 2019-01
• 期刊: American Mineralogist
• 影响因子: 3.1
• 作者: M. Mookherjee;W. R. Panero;B. Wunder;S. Jahn

Nitrogen Content in the Earth's Outer Core

• DOI: 10.1029/2018gl080555
• 发表时间: 2019-01
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: S. Bajgain;M. Mookherjee;R. Dasgupta;D. Ghosh;B. Karki