Contribuição para o estudo da evolução holocênica da baía de Sepetiba RJ através da aplicação de sísmica rasa

Abstract

The Sepetiba Bay is located in the coastal complex Guaratiba /Sepetiba,there isa semi-confined water, at the western coast of Rio de Janeiro State, Santos basin. The pleisto-Holocene Sepetiba Bay evolution was marked by exposure and drowning periods during the regression and transgression that succeeded. Several authors have proposed evolutionary models for Sepetiba Bay. The goalof the present work was contribute for the understanding about the evolutionary events of pleisto-Holocene at the bay, through the analysis and interpretation of high resolutionreflection seismic records at a particular area inside thebay. The seismic record obtained, although limited, showed depositional facies and seismic units that characterize the region with alternation of estuarine and fluvial environments corresponding to that period. The seismics recordsof internal part of Sepetiba Bay reveals preserved paleo channels, probably relatedwhih channels observed in the continental shelf adjacent to the Marambaiasandrigdge, by other authors. These channels, before the construction of the sandrigdge, were possibly interconnected, constitutingthe anterior drainage system in previous regressive stage the Holocene transgression. Above this record, there was indicative facies of transition from fluvial environment of greater energy, tocalm estuarine environment