GNGTS 2016 - Atti del 35° Convegno Nazionale

224 GNGTS 2016 S essione 1.2 active. These transfer zones were affected by uplifts and inversion structures. In the Late Middle Pleistocene to Present extensional basins and transfer zone formed. Intense volcanism and eastwards migration of the extension was recorded in the northern Campania Margin. NNE-trending normal faults developed in the ETM and Apennines and this extensional pattern is coherent with the migration of the Calabrian accretionary prism toward E-SE. During this tectonic stage, a NW-SE transfer zone, featuring restraining and releasing bends, formed at the SW border of the ETM. The deformation features of the upper plate in correspondance of the ETM are not consistent with the current rifting models. We hypothesize a link between the evolution of upper plate and subducting slab. The proposed geodynamic scenario is characterized by the formation of extensional basins in the upper plate and onset and development of a STEP (Subduction- Transform-Edge-Propagator) fault along the northern margin of the Ionian slab. References Catalano, S., Monaco, C., Tortorici, L., 2004. Neogene-Quaternary tectonic evolution of the southern Apennines. Tectonics 23, TC2003, doi:10.1029/2003TC001512. Koulakov, I., Kaban, M.K., Tesauro M., Cloetingh, S.A.P.L., 2009. P and S velocity anomalies in the upper mantle beneath Europe from tomographic inversion of ISC data. Geophysical Journal International 179, 345-366. Govers, R., Wortel, M.J.R., 2005. Lithosphere tearing at STEP faults: response to edges of subduction zones. Earth Planet. Scie. Lett. 236, 505–523. Marani, M., Gamberi, G., Bortoluzzi, G., Carrarra, G., Ligi, M., Penitenti, D., 2004. Seafloor morphology of the Tyrrhenian Sea. Scale 1:1,000,000. Included to: Mem. Descr. Carta Geol. Ital., LXIV. Rome. Martin, A.K., 2006. Oppositely directed pairs of propagating rifts in back arc basins: double saloon door seafloor spreading during subduction rollback. Tectonics 25, TC3008. http://dx.doi.org/10.1029/2005TC001885. Mattei, M., Petrocelli, V., Lacava, D., Schiattarella, M., 2004. Geodynamic implication of Pleistocene ultrarapid vertical – axis rotation in the Southern Apennines, Italy. Geology,789-792, doi:10.1130/G20552.1. Milia, A., Torrente, M.M., Massa, B., Iannace, P., 2013. Progressive changes in rifting directions in the Campania margin (Italy): new constrains for the Tyrrhenian Sea opening. Glob. Planet. Change 109, 3-17, http://dx.doi. org/10.1016/j.gloplacha.2013.07.003. Milia, A., Torrente, M.M., 2015. Tectono-stratigraphic signature of a rapid multistage subsiding rift basin in the Tyrrhenian-Apennine hinge zone (Italy): A possible interaction of upper plate with subducting slab. J. Geodyn. 86, 42–60, http://dx.doi.org/10.1016/j.jog.2015.02.005. Milia, A., Iannace, P., Tesauro, M., Torrente, M.M., 2016. Upper plate deformation as marker for the Northern STEP fault of the Ionian slab (Tyrrhenian Sea, central Mediterranean). Tectonophysics, in press, http://dx.doi . org/10.1016/j.tecto.2016.08.017 Patacca, E., Sartori, R., Scandone, P., 1990. Tyrrhenian basin and Apenninic arcs: kinematic relations since late Tortonian times. Memorie Società Geologica Italiana 45, 425–451. Schiatterella, M., Beneduce, P., Di Leo, P., Giano, S.I., Giannandrea, P., Principe, P., 2005. Assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del Monte Vulture (Appennino lucano). Boll. Soc. Geol. Ital. 124, 543-562. Wortel, M.J.R., Spakman, W., 2000. Subduction and slab detachment in the Mediterranean-Carpathian Region. Science 290, 1910–1917, http://dx.doi.org/10.1126/science.290.5498.1910. What drives Alpine Tethys opening: suggestions from numerical modelling M. Roda, A. Regorda, A. M. Marotta, M. I. Spalla Dipartimento di Scienze della Terra “A. Desio”, Università degli Studi di Milano, Italy Introduction. Continental crustal slices, preserving pre-Alpine metamorphism, are widely described in Alps and Apennine realms (Fig. 1). Variscan-age eclogites (430-326 Ma) generated from continental, oceanic and mantle rocks occur within these slices and suggest