Study of deepwater portions of the Gulf of Mexico, based on extensive geologic and geophysical data, indicates that the upper continental slope area and the upper portion of submarine fans are most prospective for gas and oil accumulations. However, information developed from the Deep Sea Drilling Project shows that a buried Miocene fan lies in the western abyssal plain of the Gulf, which means even deepest portions of the basin may have excellent potential when technology permits drilling in these extreme water depths.