Dike swarm

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[1] 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.

Magmatic dikes radiating from West Spanish Peak, Colorado, US

View of the Kattsund-Koster dyke swarm in the Koster Islands, western Sweden

Map of the Mackenzie dike swarm in Canada

Map of the Matachewan and Mistassini dike swarms in Canada

Dike swarms of Caldera de Taburiente, La Palma, Spain

Heavily altered dike swarm of the Torfajökull caldera near Landmannalaugar, Iceland

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 (250 mi) 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 (310 mi) wide and 3,000 km (1,900 mi) long.[2]

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.[3][4]

Sedimentary clastic dike swarms also exist on Earth; for example in Chile.[5]