Geophysical investigations for modeling sand ridges at Sepetiba bay, Itaguaí estado do Rio de Janeiro, Brazil

Abstract

This paper presents the modeling of sand ridge deposits located in the coastal region of the Sepetiba bay, at the Itaguaí County, State of Rio de Janeiro, based on a geophysical survey using ground penetration radar (GPR) and electric sounding (VES). Until the present there is no detail regional mapping discussing the origin of these deposits. The purpose of the study is the subsurface geophysical characterization of the sedimentary deposits to be integrated with a geological model for the whole area. The SEV acquired in sand ridges showed high resistivity at the first geo-electrical layer that correlates to sand deposits. However, the VES acquired between sand ridges showed low resistivity on the same deep correlated to clayey deposits. The GPR data on the sand ridges, showed inclined reflectors indicated progradation of the sediments. Gradix IV and IPI2win were used for processing and interpretation of the data. Results showed coherence with the available information about the local geology, beyond a clear correlation with the hand auger soundings in the area.