Recent deposits of dejection cones and of the flood plain of the valley of Middle Beht River (South Rif corridor,Morocco): Sedimentology and environmental study

The watershed of the beht river is located northwest of morocco and occupies the southwestern part of the sebou basin. this study focuses on the sedimentological and physico-chemical analysis of recent deposits of dejection cone and flood plain of the middle beht river. the results revealed that the sediments exhibit an alkaline ph,low levels of carbonates,low values of the electrical conductivity and relatively high contents of organic matter mostly in the finest sediments. deposits are organized in grano-decreasing and repetitive elementary sequences much more expressed and fines in the floodplain deposits,which is wider and extensive,than those of alluvial fan. they are the sedimentological expression of the variation of hydrodynamisme related to the succession of flood-receding floods cycles in relation to climate changes. they are set up on the often rocky texture deposits of fund of abandoned channels. the sequence of these elementary sequences,sandy and silty clay at the base and silty-sandy clay on the top,gives larger sequences grano-decreasing. © 2017,university of mohammed premier oujda morocco.