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The grodynnmical evolution of thc Medllerranean region is pcncrally considered in the contcxt of the interactian (cclni-ergencel of thc Eurasian plate and thc African plate.In analyses of fhis interaction the distrihution of earthquakc hypocentres and the focal mechan~sms of earthquakesin parilcular rhose occurring in subduction 7.oneshave been an important source of data.Rcccntly.new information runcernrnE tbc nature ofthis interaction has been obtained by thc application of seismic lornography Iechnlques.Thc rcsultinp three-dimensional seismic velocity structure provides insight into thc historq. of plate convcrgencc in the region on a lime wale much hcyond thai contained in the distribution oS present-day scicmic activity.1-rom the seismic velocity structure ol' the subducted lithosphere we infer that deeper parts of subducred slabs have hccome de~ached from lithosphcrc near the surfacc.Thiq deiachment procccs has interesting gcodynamical lrnplications on a rcgional scale.Using this prvcess as a key clcment we propose 3 hypothesis for the first-order geodynamic evolution which includes a dynamic basis Tor the observed kinematic patterns involving rotalion of cuntincntal blmk5.migration o f island arcs and opcning of hack-arc basins. TNTRODUCTIONOver the )cars the abundant data available on the structure and tectonics of thc Mediterranean region have been compiled into regional paleogeographic and tectonic reconstructions.Among these arc those by Dewey el al. (1973).Biju-Duval et al. (1977), Dercourt et a].(1986) and Le Pichon et al. (1988).for the entire Mcditerranean regiun, and those by Channel1 et al. (1979).Dewcy et aI.(1 989).and Mantovani et al. ( I 990) for the western and central parts (see also Smith and Woodcock 1 982).Probably the most fundamental obscrvation made for the Mediterranean is the non-uniformity in age of the deep basins.A variety ol' data sets {paleomagnetic data, see VandenBerg and Zijdervcld.1932; heatflow