Goringe-Alboran-Tell tectonic zone: A transpression system along the Africa-Eurasia plate boundary

Abstract

Neotectonic structures distributed from the Goringe bank to the Tell Atlas mountains show that the Africa-Eurasia plate boundary in the western Mediterranean corresponds to an east-west–trending deforming zone (Goringe-Alboran-Tell). Main Pliocene and Quaternary tectonic structures of the northern Atlas Mountains are northeast-southwest–striking fault-related folds, similar to that of El Asnam, and are related to north-south to northwest-southeast compressional movements. Active tectonics in agreement with the main seismicity distribution and focal mechanisms also support an oblique plate convergence and the existence of a 50–100-km-wide transpression zone from Goringe, across Alboran, to the Tell Atlas mountains. A kinematic model shows the interaction between dextral transcurrent faults and left-lateral faults with block rotations and no lateral extension (pinned model). Shortening and lateral movement rates during the Quaternary are estimated to be 1.0–2.3 mm/yr, and block rotation rate is estimated as 2.5°–3.9° /m.y. The plate boundary may correspond to a transpression zone, active thrust faults being controlled by deep-seated dextral transcurrent faults.