One of the most important and least understood processes operating at ocean ridges is the decomposition melting and melt extraction from upwelling mantle peridotite. This project will determine the mechanisms of deformation in partially molten Iherzolites at conditions appropriate to melting under mid-ocean ridge systems, and will determine the distribution melt generation during deformation. These experiments will be done in a high-pressure deformation apparatus utilizing an improved drive system and molten salt cell that allows differential stresses as low as 3-5 MPa to be measured at any confining pressure. A suite of synthetic Iherzolites of progressively less basaltic constituents will be synthesized in order to simulate the progressive melting and melt extraction that occurs in ridge environments. The effects of pressure on partially molten Iherzolite rheology and the effects of melt chemistry and viscosity will be investigated.
