The role of tectonic accommodation on the evolution of the western Catanzaro Trough (Calabria, South Italy): a multiscale and multidisciplinary approach

The Catanzaro Trough is a Neogene-Quaternary basin developed between the Serre and the Sila Massif, filled by up to 2000 m of Upper Miocene to Holocene sedimentary succession, belonging to the central Calabrian Arc and extended from offshore, Sant'Eufemia Basin (SE Tyrrhenian Sea), to the onshore, Catanzaro Basin. By joining 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 the western portion of the Catanzaro Trough. The fieldwork study, focused on the onshore area, has allowed to acquire more than 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. The combination among abrupt sea level changes, transpressional and trans/extensional tectonics and back-arc Tyrrhenian subsidence during SE-drifting of Calabrian Arc controlled sedimentary basin hosted by the Catanzaro Trough. As s result we have recognized three unconformity surfaces formed in the late Miocene (Messinian), mid- Pliocene (late Zanclean- early Piacezian) and early Pleistocene (Gelasian). The data analysis provide information about stratigraphy and tectonics in the strata and also give some indication of the tectono-stratigraphic architecture. Sedimentary basin, in fact, looks to be mainly controlled by the activity of NW- SE and NE-SW oriented fault systems. The NW-SE oriented faults showing strike slip and oblique kinematics 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 in the study area 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 a change of the stress field. 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, producing up-faulted and down-faulted blocks, arranged as graben-type systems, extending from onshore to offshore area. The current proposal, by using a multidisciplinary and multi-scale approach, aims to perform scientific knowledge about Neogene-Quaternary evolution of western Catanzaro Trough, and its role as element of tectonic accommodation between northern and southern Calabrian Arc.