Giant dyke swarms and the reconstruction of the Canadian Arctic islands, Greenland, Svalbard and Franz Josef Land

The dyke distribution in giant linear and radiating swarms of northern Canada, Greenland, Svalbard and Franz Josef Land are examined to (a) investigate their primary geometry and (b) help characterize relative drift and internal deformation of continental blocks in the region. Many dykes of the Cretaceous High Arctic Large Igneous Province that extends from the Canadian Arctic islands to Franz Josef Land may represent a giant radiating swarm, portions of which were dispersed and distorted as a result of plate tectonic processes in late Cretaceous-Tertiary times. Several dyke sets of the Neoproterozoic Franklin-Thule magmatic event also appear to form a giant radiating swarm in northern Canada and northwestern Greenland after reconstruction of Greenland and North America. In both of the above cases other swarms that may be of roughly similar age crosscut the radiating swarm at high angles. The late Paleoproterozoic Melville Bugt swarm extends 1000 km along Greenland's western coast. However, it has not yet been identified in the Canadian Arctic islands, which, according to most paleocontinental reconstructions, were located nearby at the time of dyke emplacement. Tracing this swarm into Canada would help test such reconstructions and determine the swarm's overall geometry.