Inversión cenozoica de la Cuenca mesozoica del Maestrat: evolución cinemática del cinturón de pliegues y cabalgamientos desarrollado en su margen norte (Cadena Ibérica oriental)

Abstract

The Maestrat basin was one of the most subsident basins of the Iberian Rift system during the Late Jurassic- Early Cretaceous, generated by a normal fault system which divided it into sub-basins. The E-W-trending, N-verging Maestrat Basement Thrust developed during its Cenozoic inversion, traversing the entire basin, as a result of the inversion of the Mesozoic fault system within the basement. As this thrust reached the Mesozoic cover, it propagated across the Middle Muschelkalk detachment level, transporting the supra-salt cover, and the normal fault segments within it, about 11-13 km towards the North. The basement thrust is deduced to have a ramp-flat geometry, with a low dip ramp which reaches 8 km depth, rooted in the upper crust. The displacement of the basement in the hanging wall of this ramp generated a 40 km-wide uplifted area, in the N-S direction, bounded to the N by the Calders monocline, interpreted as a fault-bend-fold adapted to the ramp to flat transition in the basement thrust. It also indicates the transition from a thick-skinned style of deformation in the S, to a thin-skinned style to the N. The superficial shortening accumulated in the northern margin of the basin, containing the thinnest Mesozoic cover, developing the Portalrubio- Vandellòs fold-and-thrust belt.