Fig. 6

Mechanisms proposed for the development of the Variscan oroclines. The Iberian Peninsula is outlined as a reference for position and scale. a Aerden (2004) envisages sinistral transpression for the coeval formation of the two arcs. b Carreras and Druguet (2014) consider dextral transpression, and emphasize gradual crustal-scale strain partitioning with dominantly dextral wrench domains. The arcs would form as back rotation folds develop between ductile shear zones. c Martínez Catalán (2011) proposes a compressive bridge inside a dextral shear zone, kinematically equivalent to an intracontinental transform fault. MT Moldanubian thrust. d Model of concentric buckling of Johnston et al. (2013) for coupled oroclines modified as to yield a geometry like that of the Iberian oroclines. e Model of indentation and left-lateral shearing of Simancas et al. (2013) simplified. CIZ Central Iberian Zone, OMZ Ossa-Morena Zone. f Late Visean stage of the reconstruction of the Variscan domain by Stampfli et al. (2013). The Iberian arcs would have formed after the collision between the Galatian and Hanseatic terranes, and before complete closure of the Palaeotethys and Rhenohercynian oceans