Synsedimentary tectonics of the Triassic Carbonate Formation of the Oujda Mountains (Eastern Meseta, Morocco): geodynamic Implications

The Ladinian-Carnian tectonic instability is well recorded within the Carbonate Formation of the Oujda Mountains (Eastern Meseta, Morocco). It was induced by a bidirectional extensional palaeo-state of stress (ENE-WSW and NNW-SSE) resulting in the development of the Oujda Mountains Triassic basins that open towards the Western Tethyan domain. This extensional event correlates with an early episode of Tethyan rifting, which is coeval with the Ladinian-Carnian extensional episode of the Alpine domain. The structural development of these basins was controlled by an extensional reactivation of Hercynian faults, with N70°E and N160°E fault trends predominating over the N35°E and N120°E ones. Therefore, the Ladinian-Carnian palaeo-state of stress of the Oujda Mountains is fundamentally different from that of the Triassic-Liassic basins to the west, in Central Morocco and the Atlas belts, where the N45°E-trending sinistral fault trend predominates over the N70°E and N90°E fault trends.