Conclusions

The convergence between Iberia and Europe started in latest Cretaceous and culminated with the formation of the Pyrenean orogen and the Betic Cordillera at the westernmost end of the Alpine-Himalayan belt. The onset of Pyrenean compression took place about 35 My after the end of major rifting events along the Pyrenean branch in Albian times.

The growth of the Pyrenees was greatly influenced by the former extensional geometry at different crustal and lithospheric scales: from controlling the position of the Tertiary Iberian subduction located in the extremely thinned lithosphere along the North Pyrenean Fault Zone plate boundary to the total tectonic inversion of the irregular Mesozoic basins as the case of the South Central Unit in the southern Central Pyrenees.

Most important Pyrenean shortening lasted for about 40 My and was partitioned along several thrusts describing an overall forelandward propagation of deformation. Maximum shortening occurred across the Central Pyrenees and decreased towards the west. The late Oligocene-early Miocene age of the younger compression in the Western Pyrenees was synchronous to the extensional processes, which affected the Eastern Pyrenees related to the formation of the Western Mediterranean.

Western Pyrenees shows the crustal structure acquired at the end of shortening whereas the present-day crustal and lithospheric structure of the Eastern Pyrenees points out the strong overprinting of the Neogene and Quaternary thinning.

The actual Pyrenean landscape, however, was mainly sculpted after the opening of the endorheic fluvial system of the Ebro Basin towards the Mediterranean in the late Miocene times eroding and incising the smooth overfilling of the southern Pyrenean Ebro Basin.