Cananéia-Iguape coastal system is located in the Southern part of São Paulo State. A 72 km long barrier beach named Ilha Comprida separates it from the Atlantic Oceano Based on studies of the evolution of channel margins, bottom sediment distribution and hydrodynamic pattern of the Cananéia-Iguape system, a relationship between the general pattern of water circulation (tidal currents and time variable river discharge) and the spatial distribution of bottom sediments within the system were stablished. Sedimentary structures, like large sand waves (1-2 m heigth and 20 to 30 m length), were identified in the central part ofthe studied area (ponta do Frade - Mar de Cananéia) as also near the Subauma river (Mar Pequeno). These bottom structures are the result of strong tidal currents acting over sandy sediments, originated from quaternary deposits. The dividing point between the ebb tidal currents of opposite direction were inferred through the asymmetry of sand waves indicating in the middle of Mar Pequeno channel, about 10 km apart from the former inferred point.
Sediment transport; Tidal currents; Bottom morphology; Cananéia-Iguape; Sidescan sonar; Seismic profiling; São Paulo