Structure of the Alpujarride Complex and hydrogeological observations to the NW of Sierra Tejeda (Granada and Malaga provinces, Betic Internal Zone, Spain)

Abstract

In the NW of Sierra Tejeda (Spain) it is possible differentiate only two Alpujarride tectonic units, i.e. the Almijara and, in an upper position, the Robledal unit, simplifying previous divisions. Hydrogeological data support this interpretation since a hydraulic connection exists between the two areas occupied by marbles (Sierra Tejeda and Rodaderos sectors). Both areas has been previously considered as belonging to two different tectonic units not directly connected. In the Robledal unit, gneisses in the lower part of the lithologic sequence correlate with other units of the Guájares-Jubrique/Los Reales group (upper group of Alpujarride units). Extensional deformations are superposed over these tectonic units, but, according to field observations, they have not the enormous importance attributed to them in previous models, as they do not differentiate new tectonic units, at least in this area. New E-W faults are drawn along the northern edge of Sierra Tejeda, contributing to the westward drift of the Betic Internal Zone.