9526660 van Keken The PI proposes numerical studies of the rheological and thermodynamic properties of the lower mantle and the role of the 400- and 670- km phase transitions in lower mantle viscosity models. The goal of this research is to further our current understanding of the importance of the lower mantle in governing the dynamics and long term chemical and thermal evolution of the mantle. This work may help to better understand the fate of subducted slabs, the source of hotspot volcanism, the geochemical record explained by upper/lower mantle mixing, and will aid the interpretation of tomographic seismic images by applying dynamical considerations. ***
