The Pyrenean orogen: pre-, syn-, and post-collisional evolution

Jaume Vergés, Manel Fernàndez, and Albert Martìnez

The Pyrenean Mountains represent the westernmost end of the long Alpine-Himalayan collisional system. The excellent preservation of foreland basin deposits in conjunction with folds and thrusts has been the basis for the numerous papers on the syn-tectonic evolution of the Pyrenees. Many of these papers quantified the geological processes: inversion tectonics, fold-and-thrust development, foreland and hinterland sequences of thrusting, growth strata, and control of stratigraphy on tectonics as well as tectonics on sedimentation. Geophysical data also constrain the crustal and lithospheric structure. The pre-orogenic Mesozoic rift basins exerted a significant influence on the Pyrenean thrust system. Later, the opening of the València trough was also important for the late development of the Eastern Pyrenees. Both, the pre- and post-orogenic evolution deserve more attention.

In this paper we present an integrated synthesis of the Pyrenees from the middle Cretaceous to the present showing the pre-, syn- and post-collisional evolution ranging from plate tectonics to single anticlines and thrusts. Special emphasis is given to the timing of deformation related to both compression during collision and the later extension related to the opening of the València trough.

A lithospheric section across the Central Pyrenees and another along the strike of the Eastern Pyrenees show the present-day structure at depth. The present-day crustal structure of the Western Pyrenees almost reflects the final stage of the Pyrenean orogenic growth, since there have not been major post-collisional events in the region. The eastern Pyrenees, however, show a relatively rapid thinning of the crust and lithosphere towards the E due to the strong overprinting of Neogene and Quaternary extensional events. Most of the easternmost Pyrenean landscape is related to block uplift related to normal faulting.