A comprehensive morphotectonic image of the Tyrrhenian Back-Arc Basin

Several geological and geophysical studies have been carried out in the Tyrrhenian Sea in order to reconstruct the origin and the evolution of the Tyrrhenian back-arc basin (Mediterranean Sea). This large region can be divided in four main geodynamic settings (Marani et al., 2004): 1) the northern Tyrrhenian province, delimited by the Tuscan Archipelago, the Baronie Seamount and the Pontine Islands; 2) the eastern-passive Sardinia margin, located between the Baronie and the Cornacya Seamounts; 3) the active Appenninic margins of the southern and eastern Tyrrhenian; 4) the ocean floored deep basins, where the Vavilov and Marsili volcanoes and related abyssal plains are located. The aim of this work is to obtain an updated structural interpretation of the Tyrrhenian back-arc basin at a regional scale. A full-scale image of the Tyrrhenian back-arc basin was created to perform the morphotectonic analysis of the sea-bottom features. Several major morphotectonic lineaments, as escarpments and elongated basin axes, allowed us to divide the Tyrrhenian Sea in six main zones, each characterized by different trends and stress fields. Based on this new morphotectonic map, the opening and evolution of the Tyrrhenian back-arc basin may have been more complex than generally assumed. This work has been realized in the frame of cooperation between Geological Survey of Italy-ISPRA and ISMAR- CNR of Bologna, aimed at the production of deliverables for the EMODnet Geology 2 Project. EMODnet (European Marine Observation and Data Network) is a programme supported by the European Commission, Directorate General for Maritime Affairs and Fisheries (DG MARE). Multibeam bathymetry data (200 m scale) have been downloaded from the EMODnet website (http://www.emodnet.eu/) whereas contours (100 m scale) have been obtained from Marani et al. (2004).