Seismic lines displaying the Margin Erosion Surface offshore. A. Seismic profiles showing onlap of the MSC unit on the MES, for the Valencia Basin (UU; industrial line, A-1) and the Balearic Promontory (BU; academic Simbad-cruise high-resolution line, A-2). Note that UU is onlapping mostly horizontally and BU is tilting and gliding on a basal decollement surface. B. Seismic profiles showing the MES on the East-Sardinia margin, onlap of MSC unit (UU) on the MES (B-1); rugged morphology of the MES in Orosei valley (B-2). Both areas show truncation of pre-MSC units. Vertical exaggeration of the lines is approximately x2.5 for the pre-MSC unit and x5 for the Messinian to Quaternary units. Each line is located on its respective area map.