Utilização da técnica de GPR (Ground Penetrating Radar) para a caracterização do Maciço Vitória (Espírito Santo, Sudeste do Brasil)

Use of the Ground Penetrating Radar Technique for the characterization of the Vitória Mass (Espírito Santo, Southeast of Brazil)

Abstract

This study aims to characterize, by electromagnetic method, the geological unit Maciço Vitória in the metropolitan region of Vitória-ES, using the technique of GPR- Ground Penetrating Radar. Secondary objectives are to investigate lithotypes and geological structures, to delineate contacts between landfills and Precambrian basement, to investigate and describe geological structure arrangements and to demonstrate the geophysical signature of the studied units. The study area corresponds to the Pedra da Cebola Park area, which belongs to the Maciço Vitória unit, in turn, one unit is located in Vitória, capital of Espírito Santo. Four (4) geophysical profiles were performed in different orientations, so that the different subsurface characteristics were addressed and represented in the radargram. The acquisition of GPR was performed with a 270 MHz (two hundred and seventy megahertz) antenna, the walking was performed using the constant distance method where the antennas rem0ain at a constant distance from each other. The GPR profiles were processed through the RADAN7® program, using advanced data processing until the image obtained showed well-defined reflectors and anomalies. The data of the radargrams showed two important geological aspects: limit of geological units quite delimited and presence of geological structures. Faults and fractures of NE-SW direction and secondarily NNW-SSE and E-W were found, these structures correspond to the regional trend. These structures may be associated with lithostructural controls and neotectonic tensions. The method demonstrated an easy and fast application, highlighting here an optimization of time and cost for analysis of material in subsurface.

Keywords: Ground Penetrating Radar; Fracture; Geophysics.