A large seismic dataset has allowed us to regionally study the West Mediterranean Sea with particular
focus on the West Sardinia and South Balearic continental margins and adjacent oceanic basins. The main
seismic and geological evidences are related to the presence of the Messinian Trilogy in the deep basins
and lower slopes, and coeval erosional truncation on the intermediate and upper margins. During the
deposition of the upper Messinian sequence (UU), a thin salt layer has been highlighted, thanks to the high
resolution of recent profiles. This salt layer, precipitated during the initial re-filling of the Mediterranean
Sea, has been correlated to an erosional surface on the lower slope inner the UU and interpreted as the
effect of a temporary sea level drop. The underlying salt layer (MU) shows halokinetic deformations in the
deep basins which started since the Upper Messinian and developed principally during the Pliocene,
sometimes until the Present, as testified by sea bottom piercings. The halokinetics has affected by different
intensity, on the base of its original thickness, of the sediments and water load, and of the proximity of the
lower slopes, where the sliding of salt toward the deep basin determined compressive stress and enhancing
diapirism.
