Widespread Cretaceous inversion event in northern Spain: evidence from subsurface and palaeomagnetic data

Abstract

Abstract: In this paper we present geological evidence of a mid-Cretaceous inversion event in the Polientes basin (northern Iberian plate) based on geological data. Analysis of seismic profiles across the basin indicates that this tectonic event resulted in the uplift of the basin depocentre and the formation of an upright gentle anticline before Cenomanian times. The presence of a pre-Alpine, syntectonic remagnetization in the Jurassic and Lower Cretaceous rocks of the Polientes basin allows us to define the geometry of the basin at the time between this early inversion event and the main Alpine compressional period. The early inversion in the Polientes basin is consistent with a transpressional tectonic setting, contemporaneous with the left-lateral strike-slip movement of Iberia with respect to Europe. This study shows the successful use of two approaches to unravel the geodynamic scenario of the northern Iberian plate during the Cretaceous, which was later obliterated during the Tertiary Pyrenean orogeny.