Subduction zones, where oceanic crust is subducted back into the mantle, are among the scientifically most intriguing areas of the planet because their complex internal processes play a crucial role in the evolution of our planet. This session aims to evaluate the geochemical budgets of subduction zones, particularly the transfer of fluids, melts and geochemical components from slab to mantle wedge and thence to the island arc or convergent margin. This research benefits from new geochemical (trace elements, radiogenic and stable isotopes) and experimental data emerging through the application of cutting-edge research techniques. Our specific goal is to address the petrological processes and associated fluxes at all levels of these systems – slab, mantle wedge, and arc or convergent margin – that ultimately lead to the formation of new continental crust.

We welcome contributions focused on (a) the chemical and isotopic budget of the oceanic crust that is being subducted (sedimentary piles and oceanic basalts), (b) the composition of the volcanic arcs, back-arcs and fore-arc basins, (c) the petrological fractionation occurring during dehydration and melting of the subducted material and (d) the characteristics of the mantle wedge. Confrontation of these different approaches will improve our understanding of the complex processes occurring in one of the key systems of our planet. We invite contributions from a wide range of field, experimental, analytical and theoretical discipline focusing on, but not limited to, geochemical and petrological studies.