The relationship between the sedimentary basins and the tectonic fabrics that underlie the continental shelves of the British Isles and Newfoundland are examined using a new predrift reconstruction of the North Atlantic. Digital geophysical data sets are used to create bathymetric, magnetic anomaly, and Bouguer anomaly reconstructions for closure and two postrift periods. These reconstructions provide the framework in which the signatures of the potential field data over these sedimentary basins can be compared. Horizontal derivatives of the magnetic and Bouguer anomalies are used to delineate the outlines of the basins. These outlines show remarkable correlation with those mapped from the seismic data. The derivative maps show the presence of several trends which cut across the basins on the southern Grand Banks and the Porcupine Bank and are parallel to each other. In contrast, the group of trends observed in Orphan basin bear little relationship to those seen on the Eurasian side. The orientation of the trends on the southern Grand Banks seems to match the initial direction of plate motion between North America and Iberia, whereas the trends in the Orphan basin match the initial direction of motion between North America and Eurasia. These correlations suggest a linkage between the tectonic episodes that led to the formation of these basins and the intervening oceanic crust.