Instability of the slopes linked to a neo-tectonic activity, Mahouna, North-East, Algeria

Abstract

The Mahouna region located in northeastern Algeria, in a margin considered active; it constitutes a fragmented landscape, extremely varied, with a very complex substratum characterised by a tectonic heritage of several geological units. The sedimentary soil dates from the Permo-Triassic to the Plio-Quaternary. It is distinguished by a structural relief, young, active, due to its geodynamic evolution during the Upper Tertiary (convergence of the Africa- Eurasia plates). The instability of the slopes by the size and extent of the affected masses constitutes a serious threat and pose problems of development of this region. It is recommended on the one hand to discern the different revealers of recent tectonics; and on the other hand, the highlighting of the relationship between neo-tectonic activity and disorder whose main purpose is to improve the geological balance of a region that remains very little explored from the morpho-structural point of view. The multi-source mapping and analysis through the GIS, the deciphering of a mosaic of aerial photos, coupled with the field study, give us new results and show that the construction and the genesis of this relief is closely linked to the neo- tectonic activity, whose activation is confirmed by the disorder, dismemberment and quite significant deformation that affect both ancient and recent geological formations and the morphology of the region.