The eastern North American passive margin includes the Atlantic continental margin from the Bahamas to Baffin Bay. Formed by the rifting, breakup, and drift of North America away from Africa and Europe, the margin′s thick sedimentary cover of Mesozoic to Cenozoic age lying over the Coastal Plain, continental shelf, slope, and rise straddles three distinct basement types: continental, transitional, and oceanic. The emerged Coastal Plain, which is a seaward-thickening wedge of sediments 1 to 2 km thick, extends from Florida to Long Island (Fig. 1). It exists as a submerged wedge off Canada (Fig. 2). The continental crust under the inner continental shelf, Coastal Plain, and landward is marked by exposed and buried rift basins formed by asymmetric half grabens (Fig. 1). The continental crust consists of three grossly different ages and terranes: the Precambrian shield from Labrador northward (Fig. 2); the Paleozoic orogenic belt from Newfoundland to Georgia (Figs. 1 and 2); and the African Precambrian and Paleozoic Terranes of Florida (Fig. 1). The transitional crust under the outer continental shelves and marginal plateaus is deeply subsided and underlies major sedimentary basins. These deep sedimentary basins are: (1) South Florida Bahamas Basin, (2) Blake Plateau Basin, (3) Carolina Trough, (4) Baltimore Canyon Trough, (5) Georges Bank Basin (Fig. 1), (6) Scotian Shelf Basin, (7) Grand Bank Basins, and (8) Labrador Shelf Basins (Fig. 2). The boundary between the transitional crust and the true oceanic crust is marked by the linear East Coast magnetic anomaly north of Florida, and farther east by the Blake Spur magnetic anomaly in the Blake-Bahamas region (Fig. 1).