DEPOSITIONAL CONTEXT AND STRATIGRAPHIC EVOLUTION OF SHELF SAND BODIES FROM SEISMIC AND ELECTROFACIES CHARACTERIZATION, MAASTRICHTIAN INTERVAL OF ESPÍRITO SANTO BASIN, BRAZIL

Abstract

Shelf sand bodies, as the sand ridges, constitute a significant type of reservoir in continental margin basins, wich draws attention to a better study and characterization of these bodies. This study, located in the central-western region of the Espírito Santo basin, aims to characterize this kind of deposit and interpret in which stratigraphic and depostional context they might have formed, using 3D, 2D seismic and well data, such as lithologic and geophysics logs, and cronostratigraphic data. The sand ridges, shelf sand sheet type, interpreted in the study area are characterized by high positive amplitude in seismic reflections, continuous, and display a sheet geometry. They are inserted between shales layers characterized by high negative amplitude in seismic reflectors. By means of stratigraphical and depositional elements identified, is assumed those sand bodies were deposited due to interactions between a sediment source that use to supply the shelf region, in this case, the Fazenda Cedro “paleocanyon”, and the movement dynamics of the shoreline, besides the coastal currents and wind-driven winter currents, which might have reworked these deposits over the shelf.