A dike swarm (American spelling) or dyke swarm (British spelling) is a large geological structure consisting of a major group of parallel, linear, or radially oriented magmatic dikes intruded within continental crust or central volcanoes in rift zones. Examples exist in Iceland and near other large volcanoes, (stratovolcanoes, calderas, shield volcanoes and other fissure systems) around the world. They consist of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event, are magmatic and stratigraphic, and may form a large igneous province. The occurrence of mafic dike swarms in Archean and Paleoproterozoic terrains is often cited as evidence for mantle plume activity associated with abnormally high mantle potential temperatures. Dike swarms may extend over 400 km in width and length. The largest dike swarm known on Earth is the Mackenzie dike swarm in the western half of the Canadian Shield in Canada, which is more than 500 km wide and 3000 km long. About 25 giant dike swarms are known on Earth. The primary geometry of most giant dike swarms is poorly known due to their old age and subsequent tectonic activity. Dike swarms have also been found on Venus and Mars. Sedimentary clastic dike swarms also exist on Earth; for example in Chile.

Examples

Africa

Antarctica

Asia

Australia

Europe

North America

Canada

Greenland

United States

South America