Dike swarm

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A dike swarm or dyke swarm in geology is a major group of parallel, linear, or radially oriented dikes intruded within continental crust. They consist of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event and are magmatic and stratigraphic. Such dike swarms may form a large igneous province and are the roots of a volcanic province.

The occurrence of mafic dike swarms in Archean and Paleoproterozoic terranes is often cited as evidence for mantle plume activity associated with abnormally high mantle potential temperatures.

Dike swarms may extend over 400 km (249 mi) in width and length. The World's largest dike swarm is the Mackenzie dike swarm in the Northwest Territories of Canada, which is more than 500 km (311 mi) wide and 3,000 km (1,864 mi) long.^[1]

The number of known giant dike swarms on Earth is small, only about 25. However, the primary geometry of most giant dike swarms is poorly known since plate tectonics are thought to destroy them.

[edit] Examples of dike swarms

• Mackenzie dike swarm (northwestern Canada)
• Independence Dike Swarm (eastern California, United States)
• Kangamiut dike swarm (western Greenland)
• Orano Dike Swarm (Elby Island, Italy)
• Warm Springs Mountain Dike Swarm
• Madalena Radial Dike Swarm (southeastern Wyoming)
• Kennedy dike swarm (southeastern Wyoming, United States)
• Egersund dike swarm (southwestern Norway)
• Shirotori-Hiketa Dike Swarm (northeastern Shikoku, Japan)
• Matachewan dike swarm (eastern Ontario, Canada)
• Mistassini dike swarm (western Quebec, Canada)
• Marathon dike swarm (northwestern Ontario, Canada)

[edit] References