Réflexions sur la « révolution danienne » dans les Pyrénées

This work disproves the magmatic (ophitic rises) and sedimentological (submarine trans-Pyrenean trough filled with breccias and hemipelagites) arguments presented in favour of a Danian distension step following a major Upper to Late Cretaceous Pyrenean compression phase. In the western Pyrenees (Bearn area) the tholeiitic magmatism is really Triassic or Lowermost Liassic in age. The ophites cross mechanically the Jurassic and Cretaceous enclosing sedimentary beds without any contact metamorphism, which could give proof of a Palaeocene age for the magmatic emplacement. As for the supposed submarine breccias rich in planktonic foraminifera, they really correspond to diapiric Early Cretaceous breccias, to Cretaceous or Tertiary tectono-karstic breccias or to Quaternary colluvial deposits. The Danian/Selandian trough does not exist. The proposed interpretation assigns that the Palaeocene interval must be included within the long compression (transpression) period, which begins in the Upper Cretaceous times and increases during the Early Cenozoic, leading to the main structural step of the Pyrenean cycle, towards the Middle–Upper Eocene. To cite this article: J. Canérot, C. R. Geoscience 338 (2006).