Evolution of Melt Distribution During Deformation of Partially Molten Mantle Rocks: Implications for Geodynamical Processes

部分熔融岩石中熔体的连通性和粒度分布控制渗透性、流变性、电导率、地震速度和地震衰减。 这项研究的目的是量化的熔体拓扑结构的演化过程中变形的部分熔融地幔岩石。 迄今为止，大多数研究的熔体分布集中在样品暴露于流体静力学条件下，很少有特征的熔体拓扑结构在部分熔融的材料进行非流体静力学状态的应力。 PI最近的实验表明，变形对熔体几何形状，因此，对物理性能有显着的影响。 为了将实验室条件下获得的关于变形对熔体连通性和分布的影响的观测结果应用于地幔长度和时间尺度上发生的对流和熔体迁移等过程，必须理解熔体再分布发生的机制。 为了解决这个问题，PI设计了一系列实验来量化控制变形诱导熔体分布的发生和性质的物理参数。 这些实验的一个重要目标是确定变形条件（如应力和应变速率）与熔体分布之间的定量关系。 这些结果是必不可少的发展理论框架，将允许可靠的实验室结果外推到地幔环境，并利用实验结果来开发地球内部的动态行为模型。

9815039 Kohlstedt Connectivity and grain-scale distribution of melt in a partially molten rock control permeability, rheology, electrical conductivity, seismic velocitie and seismic attenuation. This research is designed to quantify the evolution of melt topology during deformation of partially molten mantle rocks. To date, most studies of melt distribution have concentrated on samples exposed only to a hydrostatic conditions; few have characterized melt topology in partially molten materials subjected to a non-hydrostatic state of stress. The PI's recent experiments demonstrate that deformation has a dramatic effect on melt geometry and, consequently, on physical properties. To apply observations concerning the influence of deformation on melt connectivity and distribution obtained under laboratory conditions to processes such as convection and melt migration occurring at mantle length and time scales, the mechanism by which melt redistribution takes place must be understood. To address this issue, the PI has designed a series of experiments to quantify the physical parameters that govern the occurrence and nature of a deformation-induced melt distribution. An important goal of these experiments is to determine quantitative relationships between deformation conditions, such as stress and strain rate, and melt distribution. These results are essential for developing a theoretical framework that will permit reliable extrapolation of laboratory results to mantle environment and for utilizing experimental results to develop models of the dynamic behavior of Earth's interior.