A NEW PERSPECTIVE OF THE SANTOS OUTER BASIN HIGH

The Santos Basin offshore Brasil is at the northern end of a large volcanic rifted margin that extends down the entire southeastern margin of S. America. There are diverging interpretations on the nature of the crustal architecture and the role of volcanism and extension in the Santos Basin. A detailed mapping effort from multiple 3D seismic surveys and more sparse regional 2D seismic data in the Santos Basin has helped refine the view of the various forms of the magmatism and apparent interplay with tectonics in the basin. The seismic data suggests that the Santos Outer Basin High may be a large igneous province [LIP] potentially associated with the Tristan da Cunha hostpot and characterized by what appear to be flood basalts, shield volcanoes and a collapse caldera (similar to other oceanic LIP like the Shatsky Rise and Ontong Java Plateau) that have been interpreted to formed on extended thin crust. This proposed LIP appears to be tectonically extended which suggests a pulsing of volcanic activity and extension. The data that support this interpretation will be presented here.