Earth:Dike swarm

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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

A dike swarm or dyke swarm is a large geological structure consisting of 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 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.[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 due to their age and subsequent tectonic activity.

Dike swarms have also been found on Venus and Mars.[2][3]

Examples

Africa

  • Cape Peninsula dyke swarm (South Africa)
  • Okavango Dyke Swarm (Botswana)
  • Dolerite dikes in Guéra Massif (Chad, Central Africa)[4]

Antarctica

  • Vestfold Hills dike swarms (East Antarctica)

Asia

  • North China dike swarm (North China craton, China)
  • Sayan dike swarm (Russia)
  • Shirotori-Hiketa dike swarm (northeastern Shikoku, Japan)

Australia

  • Gairdner dyke swarm (South Australia)
  • Mundine Well dyke swarm (Western Australia)
  • Wood's Point dyke swarm (Victoria, Australia)

Europe

  • Egersund dike swarm (southwest Norway)
  • Kattsund-Koster dyke swarm (southeast Norway, Swedish west coast)
  • Kildonan dyke swarm (Isle of Arran, Scotland)
  • Kirov dike swarm (Russia)
  • Scourie dyke swarm (northwest Scotland)
  • Orano dike swarm (Elba, Italy)
  • Satakunta dike swarms, Finland
  • Sayda-Bergiesshuebel dike swarm (Saxony, Germany)
  • Uralian dike swarm, Russia[5]
  • Barents Sea dike swarm

North America

Canada

Greenland

United States

South America

  • Dyke swarms associated with the Paraná and Etendeka traps
    • Cuaró dyke swarm, Uruguay
    • Eastern Paraguay dyke swarm[7]
  • Ocros dyke swarm, Peru
  • Uruguayan dyke swarms
    • Florida dyke swarm
    • Nico Perez dyke swarm
    • Treinta y Tres dyke swarm
  • Dyke swarms of Tandil and Azul (Buenos Aires Province, Argentina)
  • Rio Ceará-Mirim dyke swarm

See also

References

  1. "Mackenzie dike swarm". Britannica Online Encyclopedia. geological feature, Canada. http://www.britannica.com/eb/topic-354866/Mackenzie-dike-swarm. 
  2. 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. doi:10.1016/j.icarus.2013.04.020. Bibcode2013Icar..225..538G. 
  3. 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. doi:10.1146/annurev.earth.29.1.489. Bibcode2001AREPS..29..489E. 
  4. Nkouandou, Oumarou Faarouk; Bardintzeff, Jacques-Marie; Mahamat, Oumar; Fagny Mefire, Aminatou; Ganwa, Alembert Alexandre (2017-05-22). "The dolerite dyke swarm of Mongo, Guéra Massif (Chad, Central Africa): Geological setting, petrography and geochemistry". Open Geosciences 9 (1): 138–150. doi:10.1515/geo-2017-0012. ISSN 2391-5447. Bibcode2017OGeo....9...12N. 
  5. 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: 6–16. doi:10.1080/11035897.2015.1118406. 
  6. Larson, E. E.; Strangway, D. W. (1969-03-01). "Magnetization of the Spanish Peaks Dike Swarm, Colorado, and Shiprock Dike, New Mexico". Journal of Geophysical Research 74 (6): 1505–1514. doi:10.1029/JB074i006p01505. Bibcode1969JGR....74.1505L. 
  7. Druecker, M.D.; Gay, S.P., Jr., Mafic dyke swarms associated with Mesozoic rifting in eastern Paraguay, South America [full citation needed]