We report here the discovery of Miocene, Pliocene, and early Pleistocene shallow-marine carbonates on Mayaguana Island (southeastern Bahamas) that have so far not been observed on any other Bahamian island. Spanning more than 17 m.y., but <12 m thick, this stratigraphic succession only occurs along the northern coast of the island, indicating that the Mayaguana Bank underwent minor subsidence throughout the late Cenozoic and was tilted toward the south during the Quaternary. In addition to considerably extending the stratigraphic record of the Bahamas Islands, our findings demonstrate that these carbonate banks were at different elevations and subsided at different rates during the Neogene. The young age of the tilting event detected on Mayaguana further shows that parts of the southeastern margin of North America have recently undergone tectonic activity a long way from its actual boundary with the Caribbean plate.