Geographical and geological map of the studied region (Dubourdieu, 1956). The morsott profiles studied are located in a sedimentary basin, consisting mainly of the Cretaceous formations covered by fluvio-lacustrine deposits of quaternary age. These quaternary deposits come from several phases of alterations and erosions, these different phases produced a coarse and fine material, and which was deposited on the slopes and plains forming a cover for the old lands.