
A dike swarm (
American spelling
Despite the various English dialects spoken from country to country and within different regions of the same country, there are only slight regional variations in English orthography, the two most notable variations being British and America ...
) or dyke swarm (
British spelling) is a large
geological
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...
structure consisting of a major group of parallel, linear, or radially oriented
magmatic
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
dikes intruded
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March ...
within
continental crust
Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial' ...
or
central volcanoes in
rift zones. Examples exist in
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...
and near other large volcanoes, (
stratovolcanoes,
calderas
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
,
shield volcanoes
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more vi ...
and other
fissure system
A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes.
Ground fissure
A ...
s) 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
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation ...
.
The occurrence of
mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks includ ...
dike swarms in
Archean
The Archean Eon ( , also spelled Archaean or Archæan) is the second of four eon (geology), geologic eons of History of Earth, Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozo ...
and
Paleoproterozoic
The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions ( eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's ...
terrains is often cited as evidence for
mantle plume
A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hot ...
activity associated with abnormally high
mantle potential temperatures.
Dike swarms may extend over in width and length. The largest dike swarm known on Earth is the
Mackenzie dike swarm in the western half of the
Canadian Shield
The Canadian Shield (french: Bouclier canadien ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the anc ...
in
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...
, which is more than wide and long.
About 25 giant dike swarms are known on
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...
. The primary geometry of most giant dike swarms is poorly known due to their old age and subsequent
tectonic
Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...
activity.
Dike swarms have also been found on
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...
and
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmos ...
.
Examples
Africa
*
Cape Peninsula dyke swarm (South Africa)
*
Okavango Dyke Swarm
The Okavango Dyke Swarm is a giant dyke swarm of the Karoo Large Igneous Province in northeast Botswana, southern Africa. It consists of a group of Proterozoic and Jurassic dykes, trending east-southeast across Botswana, spanning a region nearl ...
(Botswana)
* Dolerite dikes in
Guéra Massif (
Chad
Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Repub ...
, Central Africa)
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
The Isle of Arran (; sco, Isle o Arran; gd, Eilean Arainn) or simply Arran is an island off the west coast of Scotland. It is the largest island in the Firth of Clyde and the seventh-largest Scottish island, at . Historically part of Butesh ...
, Scotland)
*
Kirov dike swarm (Russia)
*
Scourie dyke swarm (northwest Scotland)
*
Orano dike swarm
Orano SA is a multinational nuclear fuel cycle company headquartered in Châtillon, Hauts-de-Seine, France. The company is engaged in uranium mining, conversion-enrichment, spent fuel recycling, nuclear logistics, dismantling, and nuclear cy ...
(
Elba
Elba ( it, isola d'Elba, ; la, Ilva) is a Mediterranean island in Tuscany, Italy, from the coastal town of Piombino on the Italian mainland, and the largest island of the Tuscan Archipelago. It is also part of the Arcipelago Toscano Nation ...
, Italy)
*
Satakunta dike swarms, Finland
*
Sayda-Bergiesshuebel dike swarm (
Saxony
Saxony (german: Sachsen ; Upper Saxon: ''Saggsn''; hsb, Sakska), officially the Free State of Saxony (german: Freistaat Sachsen, links=no ; Upper Saxon: ''Freischdaad Saggsn''; hsb, Swobodny stat Sakska, links=no), is a landlocked state of ...
, Germany)
*
Uralian dike swarm, Russia
*
Barents Sea dike swarm
North America
Canada
*
Bella Bella and Gale Passage dike swarms
The Bella Bella and Gale Passage dike swarms are two parallel dike swarms on the Central Coast of British Columbia, Canada. They range in age from 14.5 to 12.5 million years old. They are both chemically bimodal, consisting of rocks such ...
(central
British Columbia Coast
, settlement_type = Region of British Columbia
, image_skyline =
, nickname = "The Coast"
, subdivision_type = Country
, subdivision_name = Canada
, subdivision_type1 = Province
, subdivision_name1 = British ...
)
*
Franklin dike swarm (
Northern Canada
Northern Canada, colloquially the North or the Territories, is the vast northernmost region of Canada variously defined by geography and politics. Politically, the term refers to the three territories of Canada: Yukon, Northwest Territories and ...
)
*
Grenville dike swarm (
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
and
Quebec
Quebec ( ; )According to the Government of Canada, Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is ...
)
*
Mackenzie dike swarm (
Northwest Territories
The Northwest Territories (abbreviated ''NT'' or ''NWT''; french: Territoires du Nord-Ouest, formerly ''North-Western Territory'' and ''North-West Territories'' and namely shortened as ''Northwest Territory'') is a federal territory of Canada. ...
,
Nunavut
Nunavut ( , ; iu, ᓄᓇᕗᑦ , ; ) is the largest and northernmost territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the '' Nunavut Act'' and the '' Nunavut Land Claims Agreement Act'' ...
,
Saskatchewan
Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North ...
,
Manitoba
, image_map = Manitoba in Canada 2.svg
, map_alt = Map showing Manitoba's location in the centre of Southern Canada
, Label_map = yes
, coordinates =
, capital = Win ...
and Ontario)
*
Marathon dike swarm
The marathon is a long-distance foot race with a distance of , usually run as a road race, but the distance can be covered on trail routes. The marathon can be completed by running or with a run/walk strategy. There are also wheelchair div ...
(northwestern Ontario)
*
Matachewan dike swarm (eastern Ontario)
*
Mistassini dike swarm (western Quebec)
*
Sudbury dike swarm The Sudbury dike swarm, also called the Sudbury dikes, is a Mesoproterozoic dike swarm in northeastern Ontario, Canada. With an age of 1,238 million years, it is younger than the Sudbury Basin
The Sudbury Basin (), also known as Sudbury Struc ...
(northeastern Ontario)
Greenland
*
Kangaamiut dike swarm The Kangaamiut dike swarm (old spelling: ''Kangâmiut'') is a 2.04 billion year old dike swarm located in the Qeqqata region of western Greenland. The dikes cut Archean orthogneisses and are exposed along approximately of the coast and a similar ...
(western
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is ...
)
United States
*
Chief Joseph dike swarm (southeastern
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
, northeastern
Oregon
Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...
)
*
Kennedy dike swarm (southeastern
Wyoming
Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the sou ...
)
*
Magdalena radial dike swarm
Magdalena may refer to:
* Magdalena (given name), a given name derived from Mary Magdalene (including a list of people with the name)
Entertainment
* Magdalena (comics), an American comic book superheroine
* ''Magdalena'' (film), a 1920 Czecho ...
(central
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
)
*
San Rafael Swell dike swarm (
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...
)
*
Spanish Peaks Dike Swarm, southern
Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
*
Warm Springs Mountain dike swarm (
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
)
South America
*Dyke swarms associated with the
Paraná and Etendeka traps
The Paraná-Etendeka traps (or Paraná and Etendeka Plateau; or Paraná and Etendeka Province) comprise a large igneous province that includes both the main Paraná traps (in Paraná Basin, a South American geological basin) as well as the sma ...
**Cuaró dyke swarm, Uruguay
**
Eastern Paraguay dyke swarm
*
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
Rio or Río is the Portuguese, Spanish, Italian, and Maltese word for "river". When spoken on its own, the word often means Rio de Janeiro, a major city in Brazil.
Rio or Río may also refer to:
Geography Brazil
* Rio de Janeiro
* Rio do Sul, a ...
See also
*
Sheet intrusion
A sheet intrusion, or tabular intrusion, is a planar sheet of roughly the same thickness, that forms inside a pre-existing rock.Essentials of Geology, 3rd Ed, Stephen Marshak When it cuts into another unlayered mass, or across layers, it is called ...
*
Sheeted dyke complex
A sheeted dyke complex, or sheeted dike complex, is a series of sub-parallel intrusions of igneous rock, forming a layer within the oceanic crust. At mid-ocean ridges, dykes are formed when magma beneath areas of tectonic plate divergence travels ...
*
Sill swarm A sill swarm or sill complex in geology is a major group of sills intruded within continental crust. They are located under volcanic edifices, including flood basalt provinces and large lava plateaus. The volume of sill swarms can be similar to dik ...
References
{{reflist
Volcanism
Magmatic systems