Neotectonic and Mass Movements on the New Fez-Taza Highway (Northern Morocco)

Abstract

The reflection initiated here, is in connection with an area poorly known from the geological point of view as it is composed of clayey, silty turbiditic sediments and structurally characterized by different geological domains (Saiss basin, Middle Atlas Mountain and Prerif ridges). Furthermore it is also characterized by the frequent mass movements of different nature and volume and a variety of erosion processes (such as rockfalls and rockslides, subsidence and collapse of roads, landslides, gully erosion and rain). We face here a unique chance to have a better geological and geomorphological control due to the construction of the new Fez-Taza highway in northern Morocco. Consequently, this study shows that mass movements are quite important especially in the Prerif ridge, where clayey rocks (clay-stones, marls, shales, muds, flyschs) newly outcrop on both side of this new highway. The factors that affect their occurrence are especially geology and soils, neotectonic movements and climate. The combination of satellite data interpretation, detailed mapping surveys, geophysical investigation, Digital Topographic Model, morphological and finally precise fieldwork campaigns, integrated within a Geographic Information System (GIS) helped to create geo-mapping documents for multi-source developer’s in order them to pay attention to the potentially dangerous areas and to optimize safety works along such roads in some sections of the highway. At least such works lead us to differentiate Neotectonics and landslides (s.l.) and therefore simplify the passed and recent neotectonic history of the studied area.