9315935 Wanamaker The PI will perform an experimental laboratory investigation of the electrical conductivity of polycrystalline olivine plus silicate melt rocks to elucidate the variables important in controlling conductivity in partially molten rocks and to constrain extrapolation of conductivity measurements to the deep earth. Synthetic analogues of simplified partially molten mantle rocks will be used to study systematically the dependence of electrical conductivity on melt distribution as a function of temperature, oxygen fugacity, and a.c. frequency. The sensitivity of melt distribution, and thus conductivity, to changes in volume of melt and the interfacial energies of the melt-solid system will be assessed by independently varying both the melt fraction and melt composition at fixed temperature and oxygen activity. By subsequently investigating the effect of changes in temperature and oxygen fugacity on the frequency response, electrical conductivity will also be used to measure the kinetics of melt migration, equilibration, and ionic diffusion. Electron microscopy observations will link the electrical results with structural changes in the samples. ****
