Olivier Beyssac, Marie Edmonds, Jörg Hermann and Timm John (contact: olivier.beyssac@upmc.fr)

Subduction zones are active geodynamic environments enabling crustal recycing into the mantle and generating new continental crust. Of particular importance is the slab-mantle wedge system at 40-200 km depth. It is increasingly recognized that subduction materials are modified in this region by metamorphism, metasomatism and mechanical mixing with vast implications for the physico-chemical state of subduction zones.
Complexation in C-O-H-S fluids and mineral transformations involving hydrous silicates, carbonates, sulfides, graphitic carbon and/or diamond govern mass transfer in the fore- and sub-arc region of slab-mantle interface. Dissolution, oxidation/reduction, melting, and reactive percolation account for the variety of metasomatized rocks forming in the slab and in the mantle wedge, source for the magmatism.
Fluids, melts and rocks derived from subducting lithosphere interact with depleted mantle in a region of strong chemical and physical gradients. These interactions mediate planetary-scale volatile cycling, produce arc magmas and continental crust and yield modified subducted lithosphere and mantle-wedge peridotites whose chemical signals may persist in the deep Earth for billions of years.

The Keynote speakers will be Rajdeep Dasgupta (Rice University, USA) and Oliver Plümper  (University of Utrecht, The Netherlands)