Navegando por Assunto "Presidente Figueiredo - AM"

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Fáceis litorâneas glaciais da formação Nhamundá (Siluriano inferior), na região de Presidente Figueiredo, AM, Bacia do Amazonas
(Universidade Federal do Pará, 1998-11-29) SOARES, Emílio Alberto Amaral; TRUCKENBRODT, Werner Hermann Walter; http://lattes.cnpq.br/5463384509941553
Acesso aberto (Open Access)
Sedimentação coluvial pleistocênica na região de Presidente Figueiredo, nordeste do estado do Amazonas
(2009-06) SARGES, Roseane Ribeiro; NOGUEIRA, Afonso César Rodrigues; RICCOMINI, Claudio
This paper describe Upper Pleistocene colluvial deposits in the Presidente Figueiredo region, northestern State of Amazonas, Brazil. Outcrop-based sedimentologic and stratigraphic study, integrated with geomorphologic analysis and optically stimulated luminescence dating, allowed to characterize the architecture and lithofacies of these sedimentary successions and provided information about the denudation history and landscape changes in the central Amazonian region during the Pleistocene. The colluvial deposits consist of sands and mainly matrix-suppported gravels with massive beddding, locally with inverse grading, suggestive of deposition by gravitaty and torrential flows. Two types of colluvial deposits were identified: Colluvial deposits 1, dated at 57.000±5.000 years BP, constituted of gravels and sands with fragments of pelite, lateritic crusts and ferruginous sandstone, overlying Early Paleozoic rocks; and Colluvial deposits 2, yielding 22.100±2.600 years BP, consisting of gravels with fragments of semi-flint kaolin and lateritic crust, overlying Cretaceous kaolinic silciclastic deposits of the Alter do Chão Formation. The types of fragments indicate as sources Phanerozoic weathered rocks and lateritic bauxitic and ferruginous laterites which were removed during denudation of plateau. The two colluvial events described here seem to confirm that the main phases of geomorphogenesis are correlated with periods of forest retreat related to the two dry climatic events recorded during the Upper Pleistocene in Amazonia.
Acesso aberto (Open Access)
A usina hidrelétrica de Balbina e as populações locais: um retrato da comunidade Carlos Augusto Nobre Ribeiro
(Universidade Federal do Pará, 2010-10-04) BRANDÃO, Isabel Leidiany de Sousa; ROCHA, Gilberto de Miranda; http://lattes.cnpq.br/2436176783315749
This dissertation work has as objective to study the interactions stablished between the local population and the Balbina hydroelectric power station. We have as focus the Carlos Augusto Nobre Ribeiro Comunity. In this dissertation we select the pattern of generation of hidraulic energy to get a little knowledge about how this system works and it importance to a region development. This way we opted to study the Balbina hydroelectric power, detaching principally, it director paper in respect of the generation of energy to development of the Amazonas State. Since that we emphased the social situation of the communities located in ebb tide of the hydroelectric power, with emphasis to Carlos Augusto Nobre Ribeiro comunity. That comunity was choosed because it did not present cataloging in the Director Plan of the municipality of Presidente Figueiredo and because it has relative importance about the social environment aspects. In this study we got evidences that the hydroelectric power was built in an illconsidered region, because the Uatumã riverbed did not present in the period of the building, suficient conditions to generate the energy that would feed Manaus Free Zone, because this region has pratically a plane raise. The building of the hydroelectric, contributed to since alterations in the scene, populational displacements as also implatation of substructures that nowadays are responsable for the raising of the Presidente Figueiredo municipality. This study showed us that hydroelectric power, in spite of big impacts they generate, they are yet considerated the renewable fountains of energy and cheap also if we compare to the density of energy in other fountains. From the critical view of several authors on the impacts resulting from the construction of the hydroelectric plant of Balbina, we noted that the size of the pervasive impacts on the same line of intensity, since studies have shown the multiplicity of effects on local communities.