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]

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Africa edit

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  1. ^ Re. Iceland see eg.: A. Gudmundsson: Emplacement and arrest of sheets and dykes in central volcanoes. Journal of Volcanology and Geothermal Research 116 (2002) 279^298 Retrieved 31 August 2020.
  2. ^ "Mackenzie dike swarm". Britannica Online Encyclopedia. geological feature, Canada.
  3. ^ Galgana, Gerald A.; Grosfils, Eric B.; McGovern, Patrick J. (2013). "Radial dike formation on Venus: Insights from models of uplift, flexure and magmatism". Icarus. 225 (1): 538–547. Bibcode:2013Icar..225..538G. doi:10.1016/j.icarus.2013.04.020.
  4. ^ Ernst, R.E.; Grosfils, E.B.; Mège, D. (2001). "Giant Dike Swarms: Earth, Venus, and Mars". Annual Review of Earth and Planetary Sciences. 29: 489–534. Bibcode:2001AREPS..29..489E. CiteSeerX 10.1.1.473.1821. doi:10.1146/annurev.earth.29.1.489.
  5. ^ Winslow, M.A. (1983). "Clastic dike swarms and the structural evolution of the foreland fold and thrust belt of the southern Andes". GSA Bulletin. 94 (9): 1073–1080. Bibcode:1983GSAB...94.1073W. doi:10.1130/0016-7606(1983)94<1073:CDSATS>2.0.CO;2.
  6. ^ Nkouandou, Oumarou Faarouk; Bardintzeff, Jacques-Marie; Mahamat, Oumar; Fagny Mefire, Aminatou; Ganwa, Alembert Alexandre (22 May 2017). "The dolerite dyke swarm of Mongo, Guéra Massif (Chad, Central Africa): Geological setting, petrography and geochemistry". Open Geosciences. 9 (1): 138–150. Bibcode:2017OGeo....9...12N. doi:10.1515/geo-2017-0012. ISSN 2391-5447.
  7. ^ Puchkov, Victor; Ernst, Richard E.; Hamilton, Michael A.; Söderlund, Ulf; Sergeeva, Nina (2016). "A Devonian > 2000 km-long dolerite dyke swarm-belt and associated basalts along the Urals-Novozemelian fold-belt: part of an East-European (Baltica) LIP tracing the Tuzo Superswell". GFF. 138 (1): 6–16. Bibcode:2016GFF...138....6P. doi:10.1080/11035897.2015.1118406. S2CID 130648268.
  8. ^ Larson, E. E.; Strangway, D. W. (1 March 1969). "Magnetization of the Spanish Peaks Dike Swarm, Colorado, and Shiprock Dike, New Mexico". Journal of Geophysical Research. 74 (6): 1505–1514. Bibcode:1969JGR....74.1505L. doi:10.1029/JB074i006p01505.
  9. ^ Druecker, M.D.; Gay, S.P. Jr., Mafic dyke swarms associated with Mesozoic rifting in eastern Paraguay, South America[full citation needed]