Contribuição aos estudos da evolução da escarpa entre as bacias hidrográficas dos rios Doce e Paraíba do Sul, na Serra da Mantiqueira-MG-Brasil

Abstract

The Serra da Mantiqueira, in the state of Minas Gerais, constitute an escarpment separating river basins located into distinct topographic steps, with the Doce river basin on the upper altimetric level and the Paraíba do Sul river basin on the lower level. In the escarpment area, hanging valleys provide the most striking record of the evolution of these basins, which occur through river capture. The present study investigated the recent evolution of this escarpment based on geomorphological elements and secondary geo-chronological data. The results demonstrate that the escarpment investigated evolved through river capture from downwearing and backwearing. These spread the upstream in the knickpoint zone along the principal channel and the tributaries. The importance of the action of the slope should also be considered. These processes lead to the lateral enlargement of the valley and the consequent build-up of debris in the principal channel, a response of geomorphological dynamics in the quest to adjust to the new post-capture base level.