The passive margin of the Guadalquivir foreland basin records different stages of evolution during the
tortonian transgression, mainly determinate by sedimentary supply/ accommodation space ratio (A/S ratio,
Cattaneo and Steel, 2003). In a first phase, a high supply from the continental and deltaic systems filled
quickly the low accommodation space and produced an agradational/progradational stacking pattern of
sequences. The second episode is characterized by a change in these conditions, so the passive margin
register a high increase of depth and carbonate facies predominates. Finally, the transgressive maximum is
registered by means of the formation of a condensed level constituted by glauconitic sands and silts. This
transgressive pulse supposed the advance of the shoreline several kilometres towards the foreland