Pyrenees: From Mesozoic salt tectonics and hyperextension to Eocene compression
The Pyrenees are an Alpine fold-thrust belt formed during the Late Cretaceous–early Miocene as the result of south-to-north continental collision of the Iberian and European plates. The Pyrenean orogeny inverted a precursor rift, that was an east-west-trending aborted branch of the Mid Atlantic spreading ridge that opened from the Jurassic to Late Cretaceous, connecting the Atlantic and the Tethys oceans. A cross section through the central Pyrenees has a fan like geometry with an axial antiformal stack of Variscan basement rocks flanked by both northward- and southward-directed cover thrust sheets detached above Triassic salt. New research shows that the Pyrenees are also an excellent lab for studying salt tectonics; see an advance in the paper: Rising and falling diapirs, shifting depocenters, and flap overturning in the Cretaceous Sopeira and Sant Gervàs subbasins (southern Pyrenees) by Saura et al., 2016, Tectonics. As a novelty, this field trip incorporates an exhaustive examination of all available seismic data, constrained to surface geology.
October 4-8, 2021