Distribución de facies recientes en los fondos de la Bahía de Cádiz

Abstract

Thè distribution of fàcies in thè bottoms ofthe Bay of Cadiz is studied in a preliminary phase of a wider study about the sedimentary èxchange between the continent and continental margin. Two sectors are distinguished, the inner one is clayely-muddy and the external one is sandy showing the grain size distribution the main transport path ofthe ebb tidal current and of those generated by the stórm wa ve. The quartz is majority in sandy areas and phyllosilicates in muddy sectors. The day fraction is Hite> kaolin ite > smectite = iiite-smectité (l-S) = chlorite. The sedimentation rate is contro led by the supp/yes of Guadatele riverir) the northern margin. To the south, the lack of rivers is supplemented for the action of tidal currents that drain the inner areas of the bay, and by the contributions of the emerged tidal flat through tidal inlets and sudicia/ drainage waters. The sediments deposited in the bottom of the lagoon, after their remotion by the east'and south wave, are transported toward the external bay zone by the ebb current, leaving a muddy trace which follows the morphology ofthe coast and bottom until to reach the continental shelf