The Tyrrhenian back-arc basin is a Neogenic basin that opened in response to the E-SE-ward retreat of the subducting Ionian slab under the Apennine chain. To date a large bibliography is available for this basin (Moeller et al., 2014), but un updated morpho-structural map which takes into account the latest multibeam and multichannel seismic data sets is still lacking. Indeed, the structural maps of the entire Tyrrhenian date back to ‘80/’90. In this work, we present a new morpho-tectonic map of the entire Tyrrhenian basin, from slopes to abyssal plains. This map results from the analysis of 65 multichannel seismic profiles, several sparker profiles and 200-m-grid cell size bathymetry data. All data were georeferenced and interpreted together using the kingdom package (HIS Markit). In detail, the data sets used are composed by the: CROP profiles acquired in the ’90; MS profiles acquired by the OGS during the ’60/’80 (http://snap.ogs.trieste.it/); SITHERE profiles acquired for the site survey of IODP leg 107; MEDOC profiles acquired in 2010; and ISTEGE profiles acquired in the 2010. IODP/DSDP wells (Leg 107 and 42A) and crustal velocity information (Prada et al., 2014, 2015; 2018) were used for the seismo-stratigraphic calibration allowing the mapping of three main units: pre-Messinian; Messinian including evaporites; and Plio-Quaternary. This information allowed to constrain the age of faults activity. Our work results highlight a basin dominated by extension locally overprinted by compression or by transcurrent-motion fault systems. In the western Tyrrhenian, the extension was mostly accommodated by large listric faults forming deep and elongated sedimentary basins. In its eastern (Campania) and southern (Sicily-Calabria) margins the stretching was mainly accomplished through normal faults forming irregular and smaller basins. Furthermore, the central Magnaghi/Vavilov abyssal plain is confined by normal faults that bound the magmatic crust and exhumed mantle rocks (Prada et al., 2016) to continental blocks of the Sardinia-Campania conjugate margins. The Marsili abyssal plain instead is surrounded by fewer, not well expressed, normal faults and, to north and to south, by lithospheric faults (STEP fault)

Congresso congiunto Società Geologica Italiana (SGI) - Società Italiana di Mineralogia e Petrologia (SIMP), Geosciences for the environment, natural hazards and cultural heritage, 12-14 September 2018, Catania.-- 1 page

Peer Reviewed