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NEOTECTONICS, RIVER CAPTURE AND LANDSCAPE EVOLUTION IN THE HIGHLANDS OF SE BRAZIL

neotectônica, capturas fluviais e evolução do relevo nas terras altas do SE do Brasil

Abstract

The Moeda syncline, located in the highlands of the Iron Quadrangle mountains (SE Brazil), is a setting of relief inversion and drainage reorganization. In this work, we investigate the Rio do Peixe and Ribeirão Mata Porcos watersheds from this syncline. Morphological and morphometric analyses were carried out on GIS environment. The results indicate that the Ribeirão Mata Porcos watershed was captured first, allowing a wave of incision propagation that denuded the watershed and lowered the base level. During the last phase of river capture, drainage reversal and elbows of capture developed in certain channels. During these events, there was a preferential migration of river channels to the east, groundwater piracy and beheading of the Rio do Peixe's area. Based on such results, we believe that the events responsible for the landscape evolution of the Moeda syncline during the Quaternary were particularly those associated with river capture (sensu strictu, diversion and beheading) driven by both neotectonics and litho-structural influences.

Key words:
Iron Quadrangle; Moeda Syncline; Mata Porcos river; Peixe river; Velhas river

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