Tectono-Sedimentary Cenozoic Evolution of the El Habt and Ouezzane Tectonic Units (External Rif, Morocco)

Abstract

An interdisciplinary study based on lithostratigraphic, biostratigraphic, petrographic and mineralogical analyses has been performed in order to establish the Cenozoic tectono-sedimentary evolution of the El Habt and Ouezzane Tectonic Units (External Intrarif Subzone, External Rif, Morocco). The reconstructed record allowed identification of the depositional architecture and related sedimentary processes of the considered units. The Cenozoic successions were biochronologically defined allowing, at the same time, identification of unconformities and associated stratigraphic gaps. The presence of five unconformities allowed for the definition of the main stratigraphic units arranged in a regressive trend: (1) lower Paleocene interval (Danian p.p.) assigned to a deep basin; (2) Eocene interval (lower Ypresian-lower Bartonian p.p.) from a deep basin to an external carbonate-siliceous platform; (3) lower Rupelian-upper Chattian p.p. interval deposited on unstable slope with turbidite channels passing upward to an external siliciclastic platform; (4) Burdigalian p.p. interval from a slope; (5) Langhian-Serravallian p.p. interval from slope to external platform realms. The petrography of the arenites and calcarenites allowed for the identification of the supplies derived from erosion of a recycled orogen (transitional and quartzose subtypes). The clay-mineralogy analysis indicates an unroofing (first erosion of Cretaceous terrains followed by upper Jurassic rocks) always accomplished by erosion of Cenozoic terrains. Several tectofacies checked in some stratigraphic intervals seem to indicate the beginning of deformation of the basement generating gentle folds and first activation of blind thrusts, mainly during the Paleogene. A preorogenic tectonic framework is considered as responseto the generalized tectonic inversion (from extension to compression) as frequently registered in the central-western peri-Mediterranean areas. The large volumes of reworked terrigeneous supply during the latest Oligocene-Miocene p.p. indicates the beginningsof the synorogenic sedimentation (foredeep stage of the basins) controlled by active tectonics.

Design of Cost-Effective and Sustainable Treatments of Old Landslides Adapted to the Moroccan Road Network: A Case Study of Regional Road R410 Crossing the Rifan Structural Domain

“…phase: folds, thrust layers, overlaps, and fracturing [33,34]. In this area, a relatively calm structure is found, consisting of gray marls of the Upper Cretaceous (Senonian mainly), white marls and marl limestones from Eocene, and gray marls with sandstone banks of the Oligo-Miocene (sandstone "Larachian").…”

“…From a geological point of view, the region of Ksar Kbir belongs to the basin of the lower Lokkous (Figure 2), which is located at the limit of the meso-Rifan zone and constitutes the entirety of its eastern and northeastern edge. The structuring of the region is part of the Alpine tectonic evolution that marks the Rif range, the dominant Meso-Cenozoic and Mio-Plio-Quaternary lands record the different structures that mark the major Alpine phase: folds, thrust layers, overlaps, and fracturing [33,34]. In this area, a relatively calm structure is found, consisting of gray marls of the Upper Cretaceous (Senonian mainly), white marls and marl limestones from Eocene, and gray marls with sandstone banks of the Oligo-Miocene (sandstone "Larachian").…”

Tectono-Sedimentary Evolution of Cenozoic Basins

“…The tectono-sedimentary Cenozoic evolution of the El Habt and Ouezzane Tectonic Units (External Rif, Morocco) belonging to the western North African margin was studied by Martín-Martín et al (2020) [2]. This was an interdisciplinary study that reconstructed the depositional architecture and related sedimentary processes of the considered units.…”