Mise En Evidence D’une Alternance D’episodes Climatiques Pendant La Fin Du Pleistocene Superieur : Enregistrements Dans Les Depots Lacustres De Dayet Iffere (Moyen Atlas, Maroc)

Abstract

In northern Middle Atlas, the Dayet Iffère is located in an area affected by karst and tectonic. After its watershed genesis of middle altitude during the upper Pleistocene, two lacustrine formation were deposed. The detailed sedmentological study as well as the correlations between the different lacustrine formations defined in Dayet Afourgagh and Dayet Agoulmam, and the 14C dating allowed to reconstitute the major stages of the filling evolution of the lake basin and its sedimentary dynamic. The variations of sedimentation are interpreted as climatic fluctuations and evolution of vegetation since upper Soltanien. These results show a complex interaction between sedimentary processes and climatic phenomena that tend to a stability marked by heat, permanent humidity and a fairly dense vegetation cover at the end of the Soltanian, after probably a hot arid to semi-arid episode.

Application of Electrical Tomography to Put in Evidence the Thickness and Structure of the Filling of Dayet Iffer (Middle Atlas, Morocco)

“…The studies undertaken on the lake basin of the Dayet Iffer, proceed from a qualitative approach of the contributions; this one concerns the filling whose sedimentation is continuous during the end of the Upper Pleistocene (Soltanian) and the Holocene. On this site, the work allowed to recognize the lithostratigraphy and the morphology of the watershed, to identify the nature and the geometry of the sedimentary filling, to specify the age and to establish correlations with the climatic [4] [5] [6] [7] [8]. The present study aims to specify the thickness, the shape and the structure of the sedimentary filling and the relations between the different bodies of the filling by a recent geophysical method, namely the electric tomography performed for the first time at the Dayet Iffer (high resolution imagery and better detection of lateral and vertical variations in electrical resistivity).…”