Summary: The main purpose of geodynamical models is to provide a set of testable hypothesis which can be compared to observations (e.g., geophysical, geological, geochemical, and petrological data). Surface manifestations of intraplate volcanism result from the interaction of deep mantle plumes with the lithosphere/crust. Therefore their interpretation requires the understanding of the solid state dynamics in the Earth's mantle and of the physics/chemistry of the petrological processes leading to partial melting and volcanism. I propose to investigate intraplate volcanism using a geodynamical model coupled to a thermodynamically based petrological model that includes the complexity of petrological processes, such as fractional melting and fractionation-assimilation processes. The proposed research will increase our ability to interpret surface observations and to estimate the global role of mantle plumes for the Earth's evolution. I propose to conduct this research at ENS-Paris and to collaborate with Prof. U. Christensen in Goettingen.