Análise morfôtectonica da bacia hidrográfica do rio aguapeí, Planalto Ocidental Paulista, mediante fluviomorfometria e fotointerpretação

Abstract

This paper presents morphotectonic evaluation survey of the Aguapeí river valley, by applying stream longitudinal profile and RDE index - Slope vs. River length relationship analysis plus SRTM image interpretation. Cretaceous rocks and Quaternary sediments perform the geologic substrate, encompassing basalts of the Serra Geral Formation and siliciclastic rocks of the Santo Anastácio, Adamantina, and Marília formations. Quaternary is represented by alluvial floodplains and terraces, by colluvium aprons e, locally, by thick regoliths preserved from erosion vanishing. The stream morphometric measurements were performed on topographic sheets at 1:50, 000 scale, edited by IGG (Geographical and Geological Survey) and IBGE (Brazilian Institute of Geography and Statistics). The acquired data were processed to generate Cartesian coordinates graphs, with representation of the longitudinal profile as well as the RDE indexes of each stream. SRTM images were studied with Global Mapper assistance with three main purposes, as follows: to define thicker regolith areas, to delimit the more expressive alluvial deposits and, finally, to obtain the chief lineament traces, whose swarms might represent structural block boundaries. The main results include a delineation of morphostructural zones, whose tectonic behaviors are supposed to be rulled by Neotectonics.