La fracturation et les bandes de déformation dans la région d’El Kohol (Atlas saharien central, Algérie): analyse fractale, lois d’échelles et modèle de réseaux de fractures discrètes

The aim of this paper is focused on the study of natural fractures and deformation bands in El Kohol structure, located in the Djebel Amour in the Central Saharan Atlas, Algeria. The field observations and measurements were performed through two localities on the forelimb and two others on the backlimb of the structure. The outcrop study has shown the existence of five fracture sets and three deformation bands sets. The spacing and length distribution models of the different fractures sets obey to a power law. The mechanical layer thickness analysis for the whole formations shows the existence of twelve mechanical units with a stratabound control. The deformation bands show an increasing in their numbers, and a decreasing in their spacing when they approach the major faults. The fractal analysis of faults and fractures, as well as the deformation bands show a fractal character of 2D dimension. A good correlation coefficients is obtained from the comparison between the density and the intensity parameters (Pxy) calculated from the discrete fracture network (DFN) modelling, and those from the outcrops. The model developed is discussed related to deformation events recognized in the area.