Accurate information on the deformation mechanisms, microstructures and flow laws of the lithospheric mantle is crucial for appropriate interpretations of seismic anisotropy as well as accurate predictions of lithospheric strength. Laboratory experiments are critical for identifying the deformation mechanisms operative over the range of upper mantle conditions, and quantifying the flow laws, lattice preferred orientations (LPOs) and microstructural piezometer relations. The investigators' preliminary high pressure general shear experiments on olivine aggregates, using a molten salt cell, do not agree with observations from previous studies in several important ways. In the SGER grant, they will perform additional experiments and analyses to try to resolve the discrepancies in the strength of high pressure samples and LPOs and recrystallized grain size piezometer relations. The Broader Impacts of the work include support for a post-doc who will be able to work with researchers at University of Wisconsin-Madison and Brown University. The results of this study are of great importance to researchers in seismology, geodynamics and tectonics, in addition to the rock deformation community.
