Schematic representation of onshore stratigraphy illustrating the geometric relationship between pre- and post- MSC units below and above the MES. 4A shows the Ibiza sketch: Late Miocene units laying in unconformity on Mesozoic carbonate basement and the MES drawing a valley filled with U4, as in Portinatx. 4B displays the East-Sardinian sketch: various types of eroded basement, reduced pre-MSC Miocene (?) detritals witnesses of continentalization and well developed marine Pliocene filling the MES. See Figure 3 for locations.