Coupling Between Deformation and Melt Distribution in Partially Molten Rocks Abstract

Speaker: David Kohlstedt
A small amount of melt significantly influences the viscosity and deformation behavior of an otherwise crystalline rock. In turn, deformation not only aligns melt pockets but also causes melt to segregate into melt-enriched channels. The kinetics and extent of melt segregation is greatly enhanced if the melt is out of equilibrium with the host rock. In our laboratory, we study stress-driven melt segregation and associated strain localization using high-strain torsion experiments under well-controlled thermomechanical conditions. Our goal is to understand these physical processes with application both to rapid extraction of melt from beneath mid-ocean ridges along the high-permeability melt-enriched channels and to formation of low-viscosity, low velocity layers at the lithosphere-asthenosphere boundary.