LITHO-STRUCTURAL CONTROL ON VALLEY DEVELOPMENT IN THE PARANA BASIN EDGE, SANTA CATARINA STATE, SOUTHERN BRAZIL

This paper investigates valley evolution in a subtropical humid morphoclimatic zone, in the edge of Parana Basin, Santa Catarina state through: i) descriptions and field observations of valley morphologies; ii) measurements of fractures direction in outcrops and iii) information survey about valleys in remote sensing products (Landsat imagery and SRTM data). The obtained results indicate that in the edge of Parana Basin in Santa Catarina relief striping is captained by drainage network from tributaries of: Canoas and Peixe (Uruguay river tributaries) in southwest and Itajai-Acu, eastwards. Drainage network is characterized by showing two shapes of valleys more frequently: i)'V' shaped profound valleys, without floodplains, where generally river runs over bedrocks and ii) wide-open valleys, with flat bottoms, and great floodplains. In the studied area valley morphology results from structural characteristics of rocks, mainly attitude/fracturing and faults. Therefore, the present study shows the importance of considering lithostructure as a controlling factor of valley morphology for better understanding morphogenesis and morphodynamics of sedimentary basins edge areas, especially under humid subtropical climate.