The structural configuration of the eastern Sierra de los Filabres, SE Spain

Abstract

The eastern Sierra de los Filabres is constituted of several generations of thrust sheets which were formed during entirely different tectonic events. The oldest thrust sheets are present in the Mulhacen Complex. They were formed during the first phase of penetrative Alpine deformation, Dx-1, which is related to Cretaceous continent-continent collision. The second phase of penetrative deformation Dx is also related to this collisional event. During the second phase of thrust sheet formation, Dx+1 rocks from the Alpujarride Complex were placed directly on top of the Mulhacen Complex. These thrust sheets are related to a regional phase of heterogeneous extension and crustal thinning, active during the Late Oligocene to Early Miocene. At least two subsequent phases of folding and overthrusting, Dx+2 and Dx+3 strongly modified the original superposition of tectonic units. Dx+2 deformation , characterized by strain partitioning, resulted in a detachment zone. In the northeastern part of the Sierra de los Filabres an imbricate stack was formed. During Dx+3 the detachment zone was reactivated. These movements were followed by development of low-angle extensional faults, dextral tear faults and finally a foreland dipping duplex. For the Dx+3 structures a Miocene age is suggested. Dx+1, Dx+2, and Dx+3. deformations have largely determined the present structure of the eastern Sierra de los Filabres.