Geochemistry, Petrology and Volcanology

Origin of mantle plumes, flux of sediments in subduction zones,  the origin of the Andes Mountains,  creation and evolution of the continental crust, composition of seawater, and the flux of elements to the oceans, origin of metaliferrous sediments, erosion rates of the Himalayas, evolution of the atmosphere and climate cycling, workings of continental, oceanic island, and mid-ocean ridge volcanoes.