PADRÕES DE LINEAMENTOS E SUA RELAÇÃO COM A MORFOLOGIA FLUVIAL DO RIO DOCE (MG) E SEUS AFLUENTES

The rupture of the Fundao Dam (Mariana/MG) resulted in a significant inflow of sediments in the Gualaxo do Norte, Carmo and Doce rivers, altering their hydrogeomorphological processes. Thus, the geomorphological and geological-structural characterization of this fluvial system is relevant for the prognosis of their new geomorphological equilibrium. The objective of the present work was to analyze the orientation and distribution of lineaments associated with the morphologies of the Gualaxo do Norte, Carmo and Doce rivers and their correlation with the structural attitudes of the outcropping lithotypes. For that, satellite images prior to the rupture were used to characterize the river patterns and identify different lineaments. It was noted that the river system had meandering characteristics, with a tendency to evolve towards an interlaced pattern. Regarding sinuosity, the fluvial system is sinuous (54 to 73% of the extension), containing meandering segments. As for the orientation of the different lineaments and fluvial segments, a correspondence was observed between the strike N50°-59°W and N60°-69°W and the fracture planes, and between the strike N20°-29°W and the planes of foliation. This correspondence suggests a tectonic control of the fluvial morphology, responsible for the main strike of the channels and the sediment deposition areas, which must be considered when implementing actions aiming the restoration of the fluvial system.