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

根据该奖项，PI将继续进行实验研究，调查部分熔融橄榄岩在排水和不排水条件下的物理特性。本工作的目标是约束部分熔融镁铁质岩中变形与熔体迁移之间的关系，并了解在不同温度、应力、岩石静压力、岩浆压力、应变率和时间条件下这些岩石中熔体迁移的物理机制。 PI的初步实验表明，固体基质和熔体形成一个系统，其机械性能强烈依赖于排水条件和外部载荷，和丰富多样的机械行为是可能的。将使用的实验技术的组合，包括提取的熔体在均衡加载，排水和不排水条件下的常规三轴力学实验，和渗透率测量使用的脉冲衰减和振荡孔隙压力技术。实验将有两个固相：辉石和橄榄石和熔体含量下降到5%。将使用光学显微镜、SEM和TEM进行观察。 本研究涉及研究生的参与，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.