The Neogene-Quaternary geodynamic evolution of the centralCalabrian Arc: A case study from the western Catanzaro Trough basin

The Catanzaro Trough is a Neogene-Quaternary basin developed in the central Calabrian Arc, between the Serre and the Sila Massifs, and filled by up to 2000 m of continental to marine deposits. It extendsfrom the Sant’Eufemia Basin (SE Tyrrhenian Sea), offshore, to the Catanzaro Basin, onshore. Here, onshorestructural data have been integrated with structural features interpreted using marine geophysical datato infer the main tectonic processes that have controlled the geodynamic evolution of the western portionof the Catanzaro Trough, since Upper Miocene to present.The data show a complex tectonostratigraphic architecture of the basin, which is mainly controlled bythe activity of NW–SE and NE–SW trending fault systems. In particular, during late Miocene, the NW-SEoriented faults system was characterized by left lateral kinematics. The same structural regime producessecondary fault systems represented by E-W and NE-SW oriented faults. The ca. E-W lineaments showextensional kinematics, which may have played an important role during the opening of the WNW–ESEpaleo-strait; whereas the NE-SW oriented system represents the conjugate faults of the NW-SE orientedstructural system, showing a right lateral component of motion. During the Piacenzian-Lower Pleistocene,structural field and geophysical data show a switch from left-lateral to right-lateral kinematics of theNW-SE oriented faults, due to a change of the stress field. This new structural regime influenced thekinematics of the NE-SW faults system, which registered left lateral movement. Since Middle Pleistocene,the study area experienced an extensional phase, WNW-ESE oriented, controlled mainly by NE-SW and,subordinately, N-S oriented normal faults. This type of faulting splits obliquely the western CatanzaroTrough, producing up-faulted and down-faulted blocks, arranged as graben-type system (i.e LameziaBasin).The multidisciplinary approach adopted, allowed us to constrain the structural setting of the centralCalabria segment. The joined onshore with offshore structural data analysis allowed us to image a morefaithful geodynamic evolution of the Calabrian Arc, included in the wider geodynamic framework of theMediterranean regionMoreover, our results show the close correlation between the NE-SW and N-S normal fault systems andevidence of deformed Quaternary deposits. These findings are relevant to seismic hazard understandingin an area which is historically considered at the highest risk of earthquake and tsunami and where are present important infrastructures and cities.