9418941 Ganguly The research supported by this award represents a continuing effort to determine the energetic properties of ferromagnesian silicates and to use these data to constrain the thermal and dynamic histories of terrestrial rocks and meteorites. The research will (1) extend previous work on multicomponent diffusion in (Fe, Mg, Ca, Mn) garnet to lower temperatures and into previously unexplored compositional space, (2) investigate the edfect of H2O on the diffusion of divalent cations in garnet, (3) determine Sm3+ tracer diffusion in garnet, and (4) continue collaborative experimental and modelling work on Fe2+-Mg interdiffusion in clinopyroxene.