A dike swarm or dyke swarm is a large geological

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

 structure consisting of a major group of parallel, linear, or radially oriented dikes

Dike (geology)

A dike or dyke in geology is a type of sheet intrusion referring to any geologic body that cuts discordantly across* planar wall rock structures, such as bedding or foliation...

 intruded

Intrusion

An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...

 within continental crust

Continental crust

The continental crust is the layer of igneous, sedimentary, and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called sial due to more felsic, or granitic, bulk composition, which lies in...

. 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

Large igneous province

A Large Igneous Province is an extremely large accumulation of igneous rocks—intrusive, extrusive, or both—in the earth's crust...

 and are the roots of a volcanic province.

The occurrence of mafic

Mafic

Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron; the term is a portmanteau of the words "magnesium" and "ferric". Most mafic minerals are dark in color and the relative density is greater than 3. Common rock-forming mafic minerals include olivine,...

 dike swarms in Archean

Archean

The Archean , also spelled Archeozoic or Archæozoic) is a geologic eon before the Paleoproterozoic Era of the Proterozoic Eon, before 2.5 Ga ago. Instead of being based on stratigraphy, this date is defined chronometrically...

 and Paleoproterozoic

Paleoproterozoic

The Paleoproterozoic is the first of the three sub-divisions of the Proterozoic occurring between . This is when the continents first stabilized...

 terrains is often cited as evidence for mantle plume

Mantle plume

A mantle plume is a hypothetical thermal diapir of abnormally hot rock that nucleates at the core-mantle boundary and rises through the Earth's mantle. Such plumes were invoked in 1971 to explain volcanic regions that were not thought to be explicable by the then-new theory of plate tectonics. Some...

 activity associated with abnormally high mantle

Mantle (geology)

The mantle is a part of a terrestrial planet or other rocky body large enough to have differentiation by density. The interior of the Earth, similar to the other terrestrial planets, is chemically divided into layers. The mantle is a highly viscous layer between the crust and the outer core....

 potential temperatures.

Dike swarms may extend over 400 km (249 mi) in width and length. The largest dike swarm known on Earth is the Mackenzie dike swarm

Mackenzie dike swarm

The Mackenzie dike swarm, also called the Mackenzie dikes, form a large igneous province in the western Canadian Shield of Canada. It is part of the larger Mackenzie Large Igneous Province and is one of more than three dozen dike swarms in various parts of the Canadian Shield...

 in the western half of the Canadian Shield

Canadian Shield

The Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien , is a vast geological shield covered by a thin layer of soil that forms the nucleus of the North American or Laurentia craton. It is an area mostly composed of igneous rock which relates to its long volcanic history...

 in Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, which is more than 500 km (311 mi) wide and 3000 km (1,864 mi) long.

The number of known giant dike swarms on Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 is small, only about 25. However, the primary geometry of most giant dike swarms is poorly known since plate tectonics

Plate tectonics

Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...

 are thought to destroy them.

Examples of dike swarms

North America

• Mackenzie dike swarm
  Mackenzie dike swarm
  The Mackenzie dike swarm, also called the Mackenzie dikes, form a large igneous province in the western Canadian Shield of Canada. It is part of the larger Mackenzie Large Igneous Province and is one of more than three dozen dike swarms in various parts of the Canadian Shield...
  
   (Northwest Territories, Nunavut, Manitoba and Ontario, Canada)
• Independence dike swarm
  Independence Dike Swarm
  The Independence Dike Swarm is a major Late Jurassic dike swarm extending over from the eastern Transverse Ranges northward to the east-central Sierra Nevada in southeastern California, United States....
  
   (eastern California, United States)
• Kangaamiut dike swarm (western Greenland)
• Warm Springs Mountain Dike Swarm (Nevada, United States)
• Kennedy dike swarm (southeastern Wyoming, United States)
• Madalena Radial Dike Swarm (southeastern Wyoming)
• Matachewan dike swarm
  Matachewan dike swarm
  The Matachewan dike swarm is a large 2,500 to 2,450 million year old Paleoproterozoic dike swarm of Northern Ontario, Canada. It consists of basaltic dikes that were intruded in greenschist, granite-greenstone, and metamorphosed sedimentary terrains of the Superior craton of the Canadian Shield...
  
   (eastern Ontario, Canada)
• Mistassini dike swarm
  Mistassini dike swarm
  The Mistassini dike swarm is a 2.5 billion year old Paleoproterozoic dike swarm of western Quebec, Canada. It consists of mafic dikes that were intruded in the Superior craton of the Canadian Shield...
  
   (western Quebec, Canada)
• Franklin dike swarm
  Franklin dike swarm
  The Franklin dike swarm, also called the Franklin dikes, is a Proterozoic dike swarm of the Franklin Large Igneous Province in Northern Canada. It is one of the several major magmatic events in the Canadian Shield and it was formed 723 million years ago...
  
   (northern Canada)
• Grenville dike swarm
  Grenville dike swarm
  The Grenville dike swarm is a large Proterozoic dike swarm in the Canadian provinces of Ontario and Quebec. It is one of the several major magmatic events in the Canadian Shield and it possibly formed 590 million years ago along a triple junction that might have been related to a mantle plume...
  
   (Ontario and Quebec, Canada)
• Marathon dike swarm (northwestern Ontario, Canada)
• San Rafael Swell
  San Rafael Swell
  The San Rafael Swell is a large geologic feature located in south-central Utah, USA about 30 miles west of Green River, Utah. The San Rafael Swell, approximately by , consists of a giant dome-shaped anticline of sandstone, shale, and limestone that was pushed up during the Paleocene Laramide...
  
   dike swarm (Utah, United States)

Asia

• Shirotori-Hiketa Dike Swarm (northeastern Shikoku, Japan)
• North China dike swarm (North China craton, China)

Australia

• Wood's Point dyke swarm (Victoria, Australia)

Africa

• Cape Peninsula dyke swarm, South Africa

Europe

• Orano Dike Swarm (Elba Island, Italy)
• Egersund dike swarm (southwestern Norway)
• Kildonan
  Kildonan
  Kildonan may refer to:*Kildonan, Skye, a crofting township on the island of Skye*Kildonan, Sutherland, a parish containing the village of Helmsdale.*Kildonan, Arran, a village on the Isle of Arran, Scotland...
  
   Dyke Swarm (Isle of Arran
  Isle of Arran
  Arran or the Isle of Arran is the largest island in the Firth of Clyde, Scotland, and with an area of is the seventh largest Scottish island. It is in the unitary council area of North Ayrshire and the 2001 census had a resident population of 5,058...
  
  , Scotland)