Is the northwestern Betic Cordillera mountain front active in the context of the convergent Eurasia–Africa plate boundary?

Abstract

AbstractThe present relief of the Betic‐Rif Cordillera has been mainly developed since the Late Miocene in the context of the Eurasia–Africa NW–SE oblique convergence and other interacting processes like slab roll‐back or delamination. However, seismicity distribution and field observations reveal that most of the external mountain front of the Betics is not clearly active at Present and tectonic activity is generally concentrated towards the innermost zones (Alborán Domain). New seismological data and recent faulting evidence from the northwesternmost front – the one best oriented with respect to the plate convergence – allow to discuss the present behaviour. Surface observations mainly indicate a N–S extensional tectonic regime, contrasting with the shallow reverse NW–SE compressive and the strike‐slip earthquake focal mechanisms. Altogether, these data suggest the activity of a tectonic wedge with top‐to‐the‐NW tectonic transport, bounded by a NW–SE transfer fault that separates the active western from the inactive eastern segments of the mountain front.