Collaborative Research: Experimental Investigation of the Effects of Lithology and Melt Composition on Permeability and 3-D Melt Distribution in Partially Molten Rocks

合作研究：岩性和熔体成分对部分熔融岩石渗透率和 3-D 熔体分布影响的实验研究

• 批准号: 1250338
• 负责人: Wen-Lu Zhu
• 金额: $ 24.87万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1250338&HistoricalAwards=false
• 关键词: Collaborative; Research; Experimental; Investigation; Effects

Beneath ocean ridges, the divergence of lithospheric plates causes hot mantle peridotite to ascend and induces partial melting. The buoyant melt formed by this process rises through the mantle, is focused towards the ridge axis, and forms new oceanic crust. Because the chemical and physical properties of the upper mantle and lower crust are strongly influenced by the amount of melt present, better understanding of permeability of partially molten rocks is crucial. The goal of this project is to place better constraints on rates of melt migration and melt extraction within the partially molten regions at depth. An approach that integrates state-of-the-art micro-tomography, FIB/SEM CrossBeam imaging techniques, high temperature and pressure laboratory experiments, and numerical models will be used to quantify three-dimensional (3-D) melt distribution in partially molten mantle peridotite. With the experimentally determined 3-D melt distributions as input data, permeability of partially molten rocks with different compositions and melt fractions will be determined. Empirical relations between permeability, melt fraction, and pyroxene content will be derived. Permeability anisotropy for sheared samples with stress-driven melt bands will also be calculated. This study will produce the most reliable results to date on melt distribution and permeability of partially molten rocks. These results will lead to a better understanding of the geochemical and geophysical processes at mid-ocean ridges.

在海脊下，岩石圈板的差异会导致热地幔橄榄岩升起并引起部分熔化。该过程形成的浮力熔体通过地幔升起，集中在山脊轴上，并形成新的海洋壳。由于上地幔和下地壳的化学和物理性质受到熔体量的强烈影响，因此对部分熔融岩石的渗透性的更好理解至关重要。该项目的目的是在深度部分熔融区域内对熔体迁移和熔体提取的速率进行更好的限制。一种整合最先进的微型摄影，FIB/SEM横梁成像技术，高温和压力实验室实验以及数值模型的方法，将用于量化部分熔融地幔橄榄石中的三维（3-D）熔体分布。通过实验确定的3-D熔体分布作为输入数据，将确定具有不同组成和熔体级分的部分熔融岩石的渗透性。将得出渗透性，熔体部分和辉石含量之间的经验关系。还将计算具有应力驱动熔体带的剪切样品的渗透性各向异性。这项研究将在部分熔融岩石的熔体分布和渗透性上产生最可靠的结果。这些结果将使人们对中山脊的地球化学和地球物理过程有更好的了解。

项目成果

Experimental quantification of permeability of partially molten mantle rock

• DOI: 10.1016/j.epsl.2013.12.003
• 发表时间: 2014-02-15
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Miller, Kevin J.;Zhu, Wen-lu;Gaetani, Glenn A.
• 通讯作者: Gaetani, Glenn A.

Estimates of olivine–basaltic melt electrical conductivity using a digital rock physics approach

使用数字岩石物理方法估计橄榄石玄武岩熔体电导率

• DOI: 10.1016/j.epsl.2015.10.004
• 发表时间: 2015
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Miller, Kevin J.;Montési, Laurent G.J.;Zhu, Wen-lu
• 通讯作者: Zhu, Wen-lu

Experimental evidence for melt partitioning between olivine and orthopyroxene in partially molten harzburgite: MELT PARTITIONING IN HARZBURGITE

部分熔融方辉橄榄石中橄榄石和斜方辉石熔体分配的实验证据：方辉橄榄石中的熔体分配

• DOI: 10.1002/2016jb013122
• 发表时间: 2016
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Miller, Kevin J.;Zhu, Wen-lu;Montési, Laurent G.;Gaetani, Glenn A.;Le Roux, Véronique;Xiao, Xianghui
• 通讯作者: Xiao, Xianghui