A new perspective on melting in the Earth and the origin of basalts

Melting of the Earth's mantle to produce basaltic magma, the major process that has shaped the Earth, occurs in different tectonic environments, each distinguishable by its basalt chemistry. Are these different chemistries due to different melting processes, or to different mantle source compositions, reflecting prior events in Earth's history This question will be investigated experimentally at high temperatures and pressures, in a program to link the many studies of natural basalts with the fundamentals of melting processes in simplified chemical systems. The outcome will be a comprehensive model for the origin of basalts, on Earth and in other rocky planets, which will establish the framework for the geochemical cycles of the elements.