Repartition Granulometrique et mineralogique des sediments de surface dans la frange littorale de Gabes entre Oued Melah et Oued Gabes

Abstract

To understand Sedimentary dynamics in the littoral fringe betweenOued Melah  and Oued Gabes , sub-surface marine sediments were collected between the isobaths 0.3 and 23 m in order to study the grain size characteristics and the mineralogy of the sediments . Analyses of the granulometric parameters of surface sediments show that the sands of the submarine beach of the Gabes region are covered by fine sands, medium sands and coarse sands. The coarse and poorly graded sands are located at great depths, while the fine and well-graded sands cover the bottom less than 15 m depth. The sands of the shallows have a uniform grain size. They moved by saltation and suspension graded in the shallow depths between the breaking zone (5-7m). On the other hand, they moved by thrusting and rolling in more than 7 m depth. Mineralogical analysis shows that the most abundant non-clay minerals are gypsum, quartz, aragonite, calcite, magnesian calcite and less important dolomite.