Neogene-Quaternary structural evolution of the western Catanzaro Trough (Calabria, South Italy)

The Catanzaro Trough is a Neogene-Quaternary basin developed between the Serre and the Sila Massif, filled by up to 2000 m of Messinian to Holocene sedimentary succession, belonging to the central Calabrian Arc and extended from off-shore, Sant'Eufemia Basin (SE Tyrrhenian Sea), to the on-shore, Catanzaro Basin. Combining on land geo-structural with marine geophysical data, we performed a detailed analysis of processes that during last 5 My have controlled the evolution of western portion of the Catanzaro Trough. The fieldwork study, focused on the onshore area, has allowed to acquired more than the 500 fault planes, classified on the base of kinematics and fault directions, whereas the geophysical data (sub-bottom, multi- and mono-channel seismic profiles), coming from some scientific cruises within the Sant'Eufemia Gulf (SE Tyrrhenian Sea), gave us the opportunity to reconstruct the tectono-stratigraphic evolution of the offshore area. Sedimentary basin hosted by the Catanzaro Trough looks to be mainly controlled by NW-SE and NE-SW oriented fault systems. The data analysis allowed us to state the activity of NW-SE oriented faults with strike slip and oblique kinematics. This faults system can be considered responsible for the opening of a WNW-ESE paleo-strait connecting the Tyrrhenian Sea with the Ionian Sea during multi-phases tectonics that have acted since Miocene. The integrated geo-structural and geophysical data show a change from left-lateral to right-lateral kinematics during lower Pleistocene, as the result of the a change of field strength. During Pleistocene, the study area experienced an extensional phase, WNW-ESE oriented, controlled mainly by NE-SW and subordinately N-S oriented normal faults, which split obliquely the western Catanzaro Trough. We have identified two separate NE- SW normal faults dipping toward each other which create a downthrown block, arranged as a graben-type system: the SE-dipping Sant' Eufemia Fault, already defined in previous works, extending from onshore likely to offshore area represents the western edge, whereas in the eastern margin we have recognized NW-dipping lineament, which could correspond to the northern left-stepping en-echelon segment of the Vibo Valentia faults. The current proposal aims to perform scientific knowledge about Neogene-Quaternary evolution of western Catanzaro Trough, and its role as element of tectonic accomodation between northern and southern Calabrian arc, to contributed at this purpose, a multidisciplinary and multi-scale approach has been applied to provide a more reliable and detailed structural frame and, where it is possible to improve the correlation between recent faults activity and seismicity in the central Calabria segment.