Influence of Moho depth in gravity regional-residual separation of the Barreirinhas Basin, Brazil

Influência da profundidade da Moho na separação regional-residual de dados gravimétricos na Bacia de Barreirinhas, Brasil

Abstract

Gravity-forward modeling as a regional-residual separation approach guides geoscientists to improve the analysis and interpretation of potential field data. This procedure is well-known in the geoscience community as it allows us to understand and identify geological structures and sources at different depths. We selected the Barreirinhas Basin for a new interpretation based on gravity data and Moho depth models. Then, we chose Free-Air and Bouguer gravity data sets and evaluated the most suitable for interpretation purposes. After that, we adopted three distinct crustal models to apply the regional-residual separation. Our results of regional data show the same pattern of trend in the SW–NE direction, following the crustal depth decline from the continent to the ocean. In addition, the results of residual data illustrate the principal fault system along the continental-oceanic transition zone and other geological features such as the Pirapemas lineament and Sobradinho platform. Despite acceptable results, the GEMMA and South American models worked differently. The first identified a low-intensity rounded anomaly related to the continental depocenter. The second model showed better results outside the basin and at the continental boundary, identifying a possible horst-graben system and fault’s reactivation.