CHARACTERIZATION OF ENERGY GRADIENT IN ENCLOSED BAYS OF UBATUBA REGION, SOUTH-EASTERN BRAZIL

This paper deals with the characterization of the energy gradient of t he sedimentary dynamics of enclosed bays of south-eastern Brazil throu gh the utilization of coarse fraction analysis. In the Ubatuba coastal region, south-eastern Brazil, the use of traditional sedimentological techniques, such as grain size and compositional analysis of surface sediments revealed little information on the spatial variability of th e bottom dynamics. Many advances in the comprehension of the sedimenta ry processes were obtained with the utilization of coarse fraction ana lysis, which allowed the identification of the sectors of marine and c ontinental influence. The utilization of a multivariate technique, the correspondence analysis, on coarse fraction analysis data reveals, th rough a plot of the two first factors produced by the multivariate tec hnique, the existence of an energy gradient acting over the area, insi de and between the bays, leading to the deposition of different consti tuents. (C) 1998 Academic Press.