The birth and termination of the Western Mediterranean subduction systems

The Western Mediterranean realm is characterized by a series of structural arcs that separate contractional from extensional crustal domains. Similarly arched structural arcs are also apparent in the relief of southern Europe, like those forming the Carpathians and Alpine belts, indicating a possible common geodynamic link. The different tectonic elements of the arcs are formed by poorly known basement units and tectonic structure, and their age, evolution and geodynamic origin are still debated: Their origin includes continental delamination, slab break-off, oceanic or/and subduction, collision, etc.. Those uncertainties arise from the lack of deep-penetration modern geophysical data in mot of the regions. In the last ~8 years, 7 marine experiments conducted by the Barcelona Center for Subsurface Imaging and collaborators including Geomar, WHOI, and CNR-Bolognia have produced an extensive new data set across those geological domains, including new seismic reflection images, wide-angle seismic data and MT data. In this seminar I will present new results from the structure of the two youngest and more recently active arc systems: The Gibraltar Arc and the Calabrian Arc systems. We have characterized their different tectonic elements, define the nature of the domains and age of their basement, and interpret their formation process. These results are discussed to interpret the most likely geodynamic origin of the systems, as well as the geodynamic setting of currently active tectonic structures and associated seismicity.