Gravity-induced recumbent folds and low-angle normal faults in the Alpujarras region (Betic Cordilleras, Spain): indications of Miocene extensional tectonics in the western Mediterranean

Abstract

Large north-facing recumbent folds found in the Alpujarride Domain of the Betic orogen, heretofore related with a contractional nappe-stacking episode predating the early- to middle-Miocene extension, can be reinterpreted as gravitational folds, their development being connected with the extensional event that produced the low-angle normal faults and extensional detachments in Miocene times. This conclusion is based on detailed research carried out in the eastern part of the Alpujarras region (southern Betics) and includes the establishment of the fold geometry and metamorphic frame by means of field and mineralogical techniques, and the analysis of the relationships between recumbent folds and extension-related structures such as low-angle normal faults, stretching lineations, boudinage structures, etc.