Using the concept of deposition in both shallow and deep basins during the Messinian (i.e. assuming that both Basin types existed during this period), two major groupings are evident: one that favours a synchronous deposition (image c) of the first evaporites in all the basins before the major phase of erosion (Krijgsman et al., 1999); and the other that favours a diachronous deposition (image a) of the evaporites through more than one phases of desiccation which would first have affected the marginal basins and later the central basins.