Although one of the most extensively surveyed areas on earth, there remains extensive debate on the origin, nature and evolution of the crust in the deep Gulf of Mexico (GoM). Key reasons include a lack of basement penetration by drilling (reflecting the thick sediment cover that makes the basin prospective), and inadequate deep imaging data from seismic refraction, magneto-tellurics, and other geophysical techniques. The interpretation of potential fields data is complicated but can provide important constraints on deep crustal structure when combined with analysis of the shape and stratigraphic fill of the basin. The geometry and the nature of...