Geological interpretation of geophysical data (magnetic, gravimetric and seismic) on the western European and eastern Canadian shelves indicates a transatlantic correlation between the major late Paleozoic fractures of those areas.East–west megafractures, which are primarily grouped in two latitudinal belts at 44° N and 48° N, are the most obvious and correlative. The first zone of fractures was an extension of the South Armorican shear zone, which continued to the north of Flemish Cap. The second was an eastwards extension of the Cobequid–Chedabucto–Scatarie Fault, which crossed Galicia Bank, northern Spain and southern France. A third zone possibly existed between the Clinton–Newbury Fault of New England and mid-Spain, Corsica and Sardinia (when they are moved back to their late Paleozoic positions). The location of the shortening trajectories shows that the first two zones (and perhaps the third one) belonged to the same stress system during late Carboniferous. As a hypothesis, different rates of displacement between 'peri-Atlantic' plates during their northward movement in Late Carboniferous time could be the source of the stress.