Seismo?Tectonic Model for the Southern Pre?Rif Border (Northern Morocco): Insights From Morphochronology

Located at the southern boundary of Alpine chain in Morocco, deformation front Southern Rif Mountains is a region moderate tectonic activity, which makes it good natural laboratory to understand whether, and how, low compressional strains are located on specific structures. Along ?80 km-long left-lateral, transpressive reverse fault zone that runs toe Pre-Rif Ridges, an analysis high-resolution digital topography provides new geomorphic lines evidence supporting Quaternary activity along, 20 segments. The can be divided into Meknès Fès segments, constrained depth by reactivated, NE-trending basement faults, delimitating paleo-grabens associated with Late Triassic-Jurassic opening Atlantic Ocean. For selected sites, we used situ-produced 36Cl, 10Be, 26Al infer timing abandonment fluvial markers, suggest incision rates order 0.6–2 mm/yr. Given their lengths, scaling laws identified segments should root about 7–12 km-depth, possibly reactivating former normal faults making them potential seismogenic sources capable generating Mw6+ earthquakes, return times several hundreds years. Our morphochronological data set confirms key structure may have accommodated most lateral extrusion between Nubia Iberia plates.