Lithostratigraphic and geodynamic architecture of Cretaceous deposits in the Southern Front of the High Atlas (Preafrican Trough, Morocco)

The lithostratigraphic and structural analysis of the Errachidia-Boudenib Basin reveals several key geological features. From a lithostratigraphic perspective, there is a lateral variation in facies from west to east within the Cretaceous series, indicating diverse depositional conditions influenced by tectonic and environmental factors. Additionally, the gradual eastward expansion of the sedimentary prism between the Albian and Senonian periods suggests a process of tectonic reorganization, creating environments favorable for sediment accumulation. Finally, a paleorelief at Goulmima indicates inherited topographic irregularities that were major in controlling sedimentary deposition and structural development."Structurally, the tectonic evolution of the basin is marked by two major phases. The first is an extensional phase during the Triassic-Jurassic period, associated with the emplacement of basalt within reddish detrital facies and the development of synsedimentary normal faults. This period is reflected by significant crustal extension, which leads to the formation of trough-like structures that are conducive to sediment accumulation. The second phase corresponds to a compressional event linked to the Alpine orogeny in the Cenozoic. It is characterized by narrow anticlines with faulted cores, extensive synclines, and E-W-trending thrusts with a southward vergence, localized along the South Atlasic Fault. These structures reflect compressive tectonics driven by the closure of sedimentary basins and crustal thickening under the influence of regional orogenic forces."