Reconstructing the Iberian Salt-Bearing Rifted Margin of the Southern Pyrenees: Insights From the Organya Basin

Reinterpretation of the Organya Basin, based on new detailed field observations and subsurface data, emphasizes the key contribution of Upper Triassic evaporites in the tectono-sedimentary evolution of the South-Central Pyrenees. Results are integrated in a 65-km long restored cross-section through the Serres Marginals, Montsec and eastern Organya salt-related depocenters. The reconstructed part of the Jurassic-Cretaceous northern Iberian salt-rich rifted margin shows a template characterized by inherited Permo-Triassic basement normal faults and an initial salt thickness of 0.7 km to the south and 1.5 km to the north. The Organya Basin is part of the South Pyrenean Diapiric Province, a large system of salt related depocenters and minibasins, that is limited to the north by the more than 120-km long Senterada salt wall complex separating the supra-salt and sub-salt domains in the Southern Pyrenees. Three main stages of diapiric activity are recognized along the northern Iberian margin from Asturias to the Eastern Pyrenees: a Jurassic early salt mobilization; a latest Jurassic-middle Albian main diapiric evolution associated with rifting; and a Campanian-Miocene diapiric reactivation during basin inversion that produced salt welds and thrust welds and translated the salt province some 60 km to the south.