Creation of this volume of the EMU Notes in Mineralogy Series was motivated by at least two important factors. Firstly, the editors wished to celebrate the success of the two editions of
the International winter school 'MElting and fluid/melt-rock REactions in the MAntle -MEREMA'. Despite the great uncertainties due to the global pandemic (2020-2021),
the school attracted many young researchers from all over the world thanks to the stimulating scientific program. The excellent intellectual milieu led a group of top-level lecturers
to accept the invitation to publish their cutting-edge research in this volume. Although finalizing the chapters took longer than expected, the editors have ultimately compiled an outstanding selection of contributions that provides readers who have broad interests with information on how petrology and geochemistry, combined with geophysics, can shed light on mantle dynamics. Secondly, the editors aimed to present the current debated questions concerning mantle dynamics with key studies, which trace an ideal path from the bulk Earth composition (chapter 1) to mantle heterogeneity (chapters 2 and 3), and how these aspects are reflected in the shallow portion of the mantle and derived melts (chapters 4-7).