Geomorphological evolution in the limit cuestas-depressão periférica at São Paulo State: region of ANALÂNDIA (SP)

Abstract

The relief from the interior of the São Paulo state is characterized by of an extensive cuestas line which goes through in abruptly way to a depression area, distinguishing the local landscape. The genesis of these landforms is widely debated, but there are several questions of origin and processes to be resolved. This research aims to assess the relief evolution processes in the contact Cuesta-Depressão Periférica, considering aspects linked to the Quaternary climate change and tectonic constraints. It is intended to analyze the impact of land use dynamics in the erosion processes from this transitional relief sector, currently submitted to the expansion of sugarcane plantation. The cuestiform region from Analândia municipality, located in central sector of the São Paulo state, has been selected as study area, characterized by a variety of many residual hills, which demonstrate the geomorphology complexity of this area and being submited to a remarkable expansion of sugarcane plantation. The research will be carried out by two differentiated scales, on which morphostructural mapping will be developed on scale of 1:50.000, while land use and geomorphological mapping of several different scenarios (1962, 1974, 1988, 2000, 2005 and current) on scale of 1:10.000. The detailed scale mapping will involve the Cavalheiro Stream Basin, a smaller area which is marked by the presence of linear erosion features in the cuestiform talus and residual hills. The colluvium materials identificated in talus area will be dated by Opticallly Stimulated Luminescence (OSL) dating to assess the Quaternary depositional dynamics. The alluvial materials from Cavalheiro Stream will be dated by lead-210 method to assess the current dynamic. (AU)