A new tectonic discontinuity in the Betic Cordillera deduced from active tectonics and seismicity in the Tabernas Basin

Abstract

In the Tabernas Desert, a Neogene basin situated in SE Spain, major E-W folds coexist with large E-W dextral faults and abundant NNW-SSE faults. These faults affect the Plio-Quaternary sediments. The palaeostress ellipsoids indicate a roughly constant tension (σ3 axe) in the ENE-WSW direction, coexisting with a changeable direction of the main compression (σ1 axe) from the vertical to the NW-SE direction. The numerous NNW-SSE faults in southern areas, directly to the east of the city of Almería, tend to propagate northwards, forming a tectonic discontinuity of the Betic Internal Zone. The 2002 seismic swarm of the Gergal earthquake occurred in this NNW-SSE fault zone. In this setting, the E-W fractures act as transfer faults.