Collaborative Research: Melt Transport and Mechanical Properties in Partially Molten Peridotites

根据这一奖项，PIS将继续进行实验研究，调查在排水和不排水条件下部分熔融橄榄岩的物理性质。这项工作的目的是约束部分熔融的镁铁质岩石变形和熔体迁移之间的关系，并了解在不同的温度、应力、静岩压、岩浆压力、应变率和时间条件下熔体在这些岩石中迁移的物理机制。PI的初步实验表明，固体基质和熔体形成了一个系统，其力学性能强烈地依赖于排水条件和外部载荷，并且可能有丰富多样的力学行为。实验技术将结合使用，包括在均衡加载期间提取熔体，在排水和不排水条件下的常规三轴力学实验，以及使用脉冲衰减和振荡孔压技术测量渗透率。实验将有两个固相：辉石和橄榄石，熔体含量降至5%。将用光学显微镜、扫描电子显微镜和透射电子显微镜进行观察。这项研究需要研究生的参与，其结果将广泛应用于地球科学的许多子领域。

Under this award, the PIs will continue an experimental study investigating the physical properties of partially molten peridotite under drained and undrained conditions. The goals of this work are to constrain the relation between deformation and melt migration in partially molten mafic rocks and to understand the physical mechanisms of the migration of melt in those rocks under varying conditions of temperature, stress, lithostatic pressure, magma pressure, strain rate and time. Initial experiments by the PIs indicate that the solid matrix and melt form a system whose mechanical properties strongly depend on the drainage conditions and external loading, and a rich variety of mechanical behavior is possible. A combination of experimental techniques will be used, including extraction of melt during isostatic loading, conventional triaxial mechanical experiments under drained and undrained conditions, and permeability measurements using the pulse decay and oscillating pore pressure techniques. The experiments will have two solid phases: pyroxene and olivine and melt contents down to 5%. Observations will be made with optical microscopes, SEM, and TEM. The study entailes graduate student involvement, and the results will be widely applicable in many sub fields of geoscience.