Análise morfotectônica da região entre Tefé e Coari, Amazonas

Abstract

Through a morphostructural analysis integrated to information about remote sensors products (SRTM images), by geology and geomorphology of the region between the cities of Tefé and Coari, the Solimões River borders in the state of Amazonas, it was defined the effect of neotectonic structuring and its influence in the elaboration of the relief shapes and of the drainage net in the researc red area. The characterization of geological unities, comparing them to the drainage and the relief systems, based on analysis of satellites images (Landsat7 ETM+ and SRTM) in which they were described and evidenced the region outcropping units, contributed for the understanding of the processes that control the neotectonic evolution of the area. The drainage net evidences a compartmentalization of the relief in plains systems, related to the present fluvial dynamics and in the tabulars areas between rivers normally leveled by a planning surface. The relief system is differentiated by the drainage net development degree, where there is a clear gradation from the most evolutioned (Içá Formation) to the less evolutioned (Holocenics Alluviums) at the left border. With the integration of datas of drainage and relief, obtained from the images interpretation, it was evidenced that the area has two different morphotectonics compartments, mainly in terms of topographical surface, development of the drainage net, being a compartment in the right border of the Solimões River and another in the left border, separated by a regular failure zone in the NW-SE direction. Na confluência do rio Solimões com o lago Coari há a ocorrência de falhas de direção N-S, posteriores as às falhas de direção NW-SE e E-W, o que provavelmente promoveu a captura do rio Solimões para sul, em um trecho em que o canal principal abandona sua planície antiga, a qual descreve uma curvatura para norte. In the confluence of the Solimões River with the Coari Lake there is an occurrence of failures of NS direction, posteriors to failures of NW-SE and E-W, which probably promoted the capture of the Solimões River to south, in a space where the main canal abandons its older plain, which describes a curvature to the north.