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 fundamental components of the geology of the northwestern European continental shelves. Similarly oriented lineations and faults have been mapped throughout southwestern Britain, western France and across the English Channel. On land...

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Bibliographic Details
Published in:Atlantic Geology
Main Authors: Lefort, J. P., Miller, H. G.
Format: Article in Journal/Newspaper
Language:English
Published: Atlantic Geoscience Society 1999
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Online Access:https://journals.lib.unb.ca/index.php/ag/article/view/2034
Description
Summary:Northwest-oriented features have been recognized for many years as fundamental components of the geology of the northwestern European continental shelves. Similarly oriented lineations and faults have been mapped throughout southwestern Britain, western France and across the English Channel. On land in Europe, similar trends are identified as far east as the Urals. Features 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 detected using geophysical and remote sensing data. A Mercator projection map on which the Atlantic Ocean has been restored to its pre-Mesozoic configuration, i.e. before the initiation of the most recent opening of the North Atlantic Ocean, shows that the features are similarly oriented. Although some of the trends showing this direction may be younger, the geological data from both sides of the Atlantic Ocean suggest that the event that led to the formation of these NW-SE features post-dated the Variscan orogeny and may have been associated with the collision between Gondwana and Laurasia. The geometric patterns of the features interpreted as associated with the collision are consistent with patterns produced by a simple physical sandbox model of indentation with a rigid confinement to the west and a small lateral confinement to the east. This configuration is similar to that expected of Gondwana and Laurasia during the late Paleozoic. Faults considered younger than this collision may represent tectonic rejuvenations associated with the initiation of the opening of the North Atlantic Ocean. RÉSUMÉ L'orientation obscrvée du nord-est vers le sud-est des formations rocheuses est reconnue depuis de nombreuses années comme une caractéristique géologique fondamentale des plateaux continentaux du nord-ouest de l'Europe. Des structures linéaires et des failles ...