Salt diapirism constrained by the stratigraphical record of adjacent basins: the Estopanyà Syncline (South-Central Pyrenees, NE Iberian Peninsula)

Abstract

The detailed geological mapping of structural and stratigraphical patterns within the sedimentary succession of the Estopanyà Syncline (South-Central Pyrenees) and surrounding structures provides insights into the evolution of the adjoining diapirs. The present-day stratigraphical and geometric relationships between the diapirs and flanking sedimentary units suggest distinct halokinetic evolution in the ESE and WNW sectors of the studied area. In the ESE sector, flanking successions are characterized by halokinetic breccias and overturned layer attitudes, indicative of an early salt inflation phase during the Late Cretaceous. The advance of the pyrenean compressional front produced the extrusion of these diapirs during the middle Ypresian. In the WNW sector, salt diapirism occurred lately, during the middle Eocene to Oligocene, due to the rotation of the Estopanyà Syncline and the welding of the pre-existing diapirs.