Formação do rio transcontinental do Amazonas guiada por processos tectônicos e processos superficiais de erosão e sedimentação

During the Cenozoic, the Andean orogeny induced a great change in drainage pattern in northern South America, culminating in the development of the Amazon River as a transcontinental river. Through simulations using a numerical model, we studied the evolution of the landscape focusing on the onset of the Amazon River. The numerical model accounts for the interaction of orogeny, flexure and isostasy of the lithosphere and surface processes of erosion and sedimentation. In all the different numerical scenarios simulated, it was possible to reproduce the change in the drainage pattern culminating in the formation of the Amazon River followed by the increase in the sedimentation rate in the Amazon Fan. We also analyzed the influence of the effective elastic thickness of the lithosphere and the crustal thickening rate of the andean region in the evolution of the landscape. We concluded that large values of induces a delay in the reversal of the drainage pattern. However, fast uplift rates of the Andes result in a fast reorganization of the drainage in the northern South America, anticipating the formation of the transcontinental Amazon River.