Gravimetric and seismic stratigraphy studies applied to Barra Fault System, limit region between Recôncavo and Camamu basins, Bahia, Brazil

Abstract

Gravity data were measured along the extension of the Itaparica Island. In this region, the limit between Recôncavo and Camamu basins, characterized by the Barra Fault System, is located. These data correspond to previously corrected Bouguer anomaly values and they were processed in order to separate the residual component of the anomaly from its regional component. Gravity maps were created and through its analysis the regional gravity variations of subsurface rocks could be identified. A horizontal gradient filter was applied to the data, allowing the identification of the main and secondary components of the Barra Fault System and of transform faults related to the continental separation process that originated the Eocretaceous Brazilian rift basins. Bidimensional gravity models were created using geological and geophysical data obtained from well logs and from previously interpreted seismic sessions. Gravity interpretation provided an improvement to previous assumptions regarding the basement's depth values. This joint interpretation scheme permitted a further investigation of structural features of the aforementioned basins and complemented the seismic interpretations in regions characterized by low seismic resolution.