NW-oriented features on both sides of the Atlantic Ocean: evidence for a Paleozoic collision that formed the Labrador-Biscay wrench fault zone?

Northwest-oriented features have been recognized for many years as fundamen tal components of the geology of the northwestern European continental shel ves. Similarly oriented lineations and faults have been mapped throughout s outhwestern Britain, western France and across the English Channel. On land in Europe, similar trends are identified as far east as the Urals. Feature s of similar orientation, extending over a broad area on the North American continental shelf, have recently been identified from geophysical trends. On land in eastern Canada NW-SE faults have been mapped geologically and de tected using geophysical and remote sensing data. A Mercator projection map on which the Atlantic Ocean has been restored to its pre-Mesozoic configur ation, i.e, before the initiation of the most recent opening of the North A tlantic Ocean, shows that the features are similarly oriented. Although some of the trends showing this direction may be younger, the geol ogical data from both sides of the Atlantic Ocean suggest that the event th at led to the formation of these NW-SE features post-dated the Variscan oro geny and may have been associated with the collision between Gondwana and L aurasia The geometric patterns of the features interpreted as associated wi th the collision are consistent with patterns produced by a simple physical sandbox model of indentation with a rigid confinement to the west and a sm all lateral confinement to the east. This configuration is similar to that expected of Gondwana and Laurasia during the late Paleozoic. Faults conside red younger than this collision may represent tectonic rejuvenations associ ated with the initiation of the opening of the North Atlantic Ocean.