THE MESSINIAN SALINITY CRISIS IN THE WEST-MEDITERRANEAN BASINS: COMPARISON BETWEEN TWO RIFTED MARGINS

In this work we present a comparison between two seismic datasets acquired by the oceanographyc research vessel OGS-Explora through the passive margins of the West Mediterranean sea: the West Sardinia continental margin of the Sardo-Provencal basin (WS10 dataset acquired in 2010) and the South Balearic continental margin of the Algerian basin (SF2012 dataset, acquired in 2012 within SALTFLU project). The West Sardinia margin was originated by the Oligocene-Early Miocene breakup of European plate followed by the drift of the Sardinian block and the southern French margin; the Algero-Balearic basin opened later respect the Balearic basin, dating its oldest oceanic crust 16My following the rift of the Kabylide thrust belt (Muffret et al., 2004 and cited literaure). Although the margins are different in age and geodynamic histories, here we intend to focus on differences and analogies concerning the geological features that characterize the Messinian and Post Messinian period, starting from the availability of already processed and interpreted seismic dataset of Western Sardinia (Geletti et al., 2014) and of processed by OGS and partly interpreted profiles of South Balearic margin. In particular this approach should allow us to correlate the Messinian and Plio-Quaternary units that deposited in the West Mediterranean. The comparison let to make considerations about the seismic facies of the Messinian sedimentary sequence that characterize the basinal domain and the slope of the North Algerian margin; analogies with the seismic facies of the Upper evaporite Unit recognized in the Sardo Provencal basin have been observed, represented by a thick well stratified package of high amplitude reflectors and intercalation of transparent layers. Observation about deformation structures mainly due to salt tectonic activity will be presented, basing on the already identification by Camerlenghi et al., (2009), of different kind of salt-induced abyssal plain sediment deformation. Basing on the fact that there are lack of information in this sector of Western Mediterranean due to the absence of calibrating boreholes, this work could be a starting point to a major comprehension of the distribution of the Messinian Salinity Crisis processes within the basins of the Mediterranean sea.