This 10-chapter volume encompasses contributions from a wide spectrum of Earth science disciplines, including geophysics, geodynamics, geochemistry, and petrology, to provide an overview of the nature and evolution of the crust-mantle and lithosphere-asthenosphere boundaries in different tectonic settings, combining studies that exploit different types of data and interpretative approaches. The integration of geochemical, geophysical, and geodynamic data sets and their interpretation provides a state-of-the-art summary of current understanding, and will serve as a blueprint for future research activities.