Granulometric aspects of the siliciclastic sediments of the beach - foredune system of Sombrio sheet, southern Santa Catarina State, Brazil

Abstract

This paper shows some granulometric characteristics of the siliciclastics sediments referent to beach - foredune system of Sombrio sheet, southern Santa Catarina State, Brazil, and the morphologic and hydrodynamic characteristics associated. Along of 24 km of beach it shows homogeneity in the main characteristics. Among these detach fine sands, quartzose, well sorted and positive asymmetry, even in the beach or as in the foredune. Some heterogeneous characteristics were observed in the granulometry, morphology and hydrodynamic of this beach, as: one modal frequency in fraction 2,5 phi in the beach and in fractions 2,5 phi and 3 phi in the foredune; variations in the beach width and distribution of the washouts. By across to the observation of aerial photography’s and measures obtained in loco, the beach may be classify like a dissipative beach, with fine sands, low beach face slope and multiple bars, dominated by high wave energy. The characteristics of the beach - foredune system of Sombrio sheet, with successive bars and thoughts and wave breakers, washouts in direction to the beach and fine sands, well sorted, show strongly influenced by Holocene progradant barriers adjacent.