Physical Properties of Partially Molten Rocks from Microtomography Experiments and Digital Rock Physics

显微断层摄影实验和数字岩石物理中部分熔融岩石的物理性质

• 批准号: 1551300
• 负责人: Wen-Lu Zhu
• 金额: $ 29.91万
• 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: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1551300&HistoricalAwards=false
• 关键词: Physical; Properties; Partially; Molten; Rocks

Melt generated in the interior of the Earth at plate boundaries plays an important role in the transfer of heat and mass and eventually feeds the volcanic activity of our planet. It is important to better constrain how much melt is present at depth and where it is present. Seismic and electromagnetic measurements provide data to constrain melt distribution but how to convert these data into melt fraction estimates remains a subject of contention. This project will analyze three-dimensional images of the distribution of melt in experimentally produced partially molten rocks and simulate several physical properties of these samples. Results from this study will make it possible to link seismic and electromagnetic data with models of melt transport in the interior of the Earth, which ultimately helps understand how plate tectonics works and the link between mantle processes and volcanic activity.This study will use synchrotron microtomography to image partially molten mantle rocks in three-dimensions. The samples will be hydrostatically-annealed aggregates that consist of olivine and orthopyroxene in different proportions, and contain melt fractions of 0.005 to 0.20. Digital rock physics simulations will be performed to obtain permeability, electrical conductivity and elastic moduli of both hydrostatically annealed olivine + orthopyroxene-basaltic melt and sheared partially molten olivine rocks. Variation of melt content with distance in the sample will be analyzed to constrain the bulk viscosity of the sample. This project will quantify the effects of lithological partitioning due to the presence of orthopyroxene on melt distribution and show how deformation affects melt distribution, and induces permeability anisotropy.

在地球内部产生的熔体在板边界上产生的熔体在热量和质量的转移中起着重要作用，并最终喂养我们行星的火山活性。重要的是要更好地限制在深度和存在何处的熔体存在多少。地震和电磁测量可提供数据以限制熔体分布，但是如何将这些数据转换为熔体分数估计值仍然是争论的主题。该项目将分析在实验产生的部分熔融岩石中熔体分布的三维图像，并模拟这些样品的几种物理特性。这项研究的结果将使可以将地震和电磁数据与地球内部的熔体传输模型联系起来，这最终有助于了解板块构造的工作原理以及地幔过程与火山活动之间的联系。这项研究将使用同步微动力学来形象图像在三维三维中层压层状地幔岩石。样品将是由橄榄石和邻苯二苯甲油组成的静水骨料，并以不同的比例组成，并包含0.005至0.20的熔体级分。将进行数字岩石物理模拟，以获得两种液压退火的橄榄石 +正pypyroxene-basaltic熔体和剪切的部分熔融橄榄石岩石的渗透率，电导率和弹性模量。熔体含量与样品中距离的变化将进行分析，以限制样品的块状粘度。该项目将量化岩性分配的影响，这是由于存在异耐氧烯对熔体分布的影响，并显示变形如何影响熔体分布并诱导渗透率各向异性。

项目成果

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