Collisional processes and links to episodic changes in subduction zones

Continental collision is commonly accompanied by a sequence of several plate-mantle interactions, including accretion of buoyant features, pulses of slab rollback, slab break-off, formation of slab windows, and lithosphere delamination. Using the combined insight from seismic and dynamical modelling studies, we illustrate how these processes and their characteristic rates and timescales played an important role in shaping the Mediterranean and how they dominated the closure of the Tethyan oceans. Older collisions, such as the one that formed the Norwegian Caledonites, probably experienced similarly complex plate-mantle interaction, even though direct evidence of the associated mantle dynamics is absent.