![Columnar jointing in the Alcantara Gorge, Sicily](https://upload.wikimedia.org/wikipedia/commons/c/ce/Columnar_jointing_in_the_Alcantara_Gorge%2C_Sicily.jpg)
Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as
joints
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...
, result in the formation of a regular array of polygonal
prisms, or columns. Columnar jointing occurs in many types of
igneous rocks
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...
and forms as the rock cools and contracts. Columnar jointing can occur in cooling
lava flows
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
and ashflow
tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...
s (
ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrou ...
s), as well as in some shallow
intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...
s.
Columnar jointing also occurs rarely in
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s if they have been heated by nearby hot
magma
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 ...
.
The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall.
They are typically parallel and straight, but can also be curved and vary in diameter.
An array of regular, straight, and larger-diameter columns is called a colonnade; an irregular, less-straight, and smaller-diameter array is termed an entablature. The number of sides of the individual columns can vary from 3 to 8, with 6 sides being the most common.
[Oregon State University > Volcano World > ... > Columnar Jointing](_blank)
Accessed 29 December 2013.
Places
Some famous locations in the United States where columnar jointing can be found are the
Devils Tower
Devils Tower (also known as Bear Lodge Butte) is a butte, possibly laccolithic, composed of igneous rock in the Bear Lodge Ranger District of the Black Hills, near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle F ...
in Wyoming, the
Devils Postpile in California and the
Columbia River
The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, C ...
flood basalt
A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot reach ...
s in
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
,
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 ...
and
Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...
. Other famous places include the
Giant's Causeway
The Giant's Causeway is an area of about 40,000 interlocking basalt columns, the result of an ancient volcanic fissure eruption. It is located in County Antrim on the north coast of Northern Ireland, about three miles (5 km) northeast of ...
in
Northern Ireland
Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...
and
Fingal's Cave
Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, known for its natural acoustics. The National Trust for Scotland owns the cave as part of a national nature reserve. It became known as Fingal' ...
on the island of
Staffa
Staffa ( gd, Stafa, , from the Old Norse for stave or pillar island) is an island of the Inner Hebrides in Argyll and Bute, Scotland. The Vikings gave it this name as its columnar basalt reminded them of their houses, which were built from ver ...
,
Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
.
Devils Tower
The Devils Tower in Wyoming in the United States is about 40 million years old and high.
Geologists agree that the rock forming the Devils Tower solidified from an intrusion but it has not been established whether the
magma
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 ...
from this intrusion ever reached the surface. Most columns are 6-sided, but 4, 5, and 7-sided ones can also be found.
Giant's Causeway
The Giant's Causeway (
Irish
Irish may refer to:
Common meanings
* Someone or something of, from, or related to:
** Ireland, an island situated off the north-western coast of continental Europe
***Éire, Irish language name for the isle
** Northern Ireland, a constituent unit ...
: ''Clochán An Aifir'') on the
north Antrim coast of Northern Ireland was created by volcanic activity 60 million years ago, and consists of over 40,000 columns.
According to a legend, the giant
Finn McCool
Fionn mac Cumhaill ( ; Old and mga, Find or ''mac Cumail'' or ''mac Umaill''), often anglicized Finn McCool or MacCool, is a hero in Irish mythology, as well as in later Scottish and Manx folklore. He is leader of the ''Fianna'' bands of y ...
created the Giant's Causeway, as a
causeway
A causeway is a track, road or railway on the upper point of an embankment across "a low, or wet place, or piece of water". It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden causeways is the Sweet Tra ...
to Scotland.
Sōunkyō Gorge
Sōunkyō Gorge, a part of the town of
Kamikawa, Hokkaido
is a town located in Kamikawa Subprefecture, Hokkaido, Japan.
As of December 31, 2017, the town has an estimated population of 3,706, and a density of 3.53 persons per km2. The total area is 1,049.24 km2.
The town is approximately 30 mi ...
, Japan, features a 24-kilometer stretch of columnar jointing, which is the result of an eruption of the
Daisetsuzan Volcanic Group
The is a volcanic group of peaks arranged around the wide caldera in Hokkaidō, Japan. In the Ainu language it is known as ''Nutapukaushipe'' (which means "the mountain above the river"), 30,000 years ago.
Deccan Traps
The late Cretaceous
Deccan Traps
The Deccan Traps is a large igneous province of west-central India (17–24°N, 73–74°E). It is one of the largest volcanic features on Earth, taking the form of a large shield volcano. It consists of numerous layers of solidified flood ...
of India constitute one of the largest volcanic provinces of Earth, and examples of columnar jointing can be found in
St. Mary's Island in the state of Karnataka.
High Island Reservoir
Formed in Cretaceous, the columnar rocks are found around the reservoir and the islands nearby in
Sai Kung
Sai Kung may refer to:
* Sai Kung Town, or just Sai Kung, a town and administrative area in the Sai Kung District, Hong Kong
* Sai Kung Peninsula, a peninsula in Hong Kong
* Sai Kung District, an administrative district in Hong Kong, which does no ...
,
Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...
. It is special that the rocks are not mafic, but felsic
tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...
instead.
Makhtesh Ramon
The columnar jointed sandstone of the ''HaMinsara'' (Carpentry Shop) in the
makhtesh
A makhtesh ( he, מַכְתֵּשׁ (), Hebrew plural: ( – ''Makhteshim'') is a geological landform considered typical for the Negev desert of Israel and the Sinai peninsula of Egypt. A makhtesh has steep walls of resistant rock surrounding a ...
(erosion
cirque
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...
) of
Makhtesh Ramon,
Negev desert,
Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
.
![Cerro Koi 6520 11](https://upload.wikimedia.org/wikipedia/commons/c/c3/Cerro_Koi_6520_11.jpg)
Cerro Kõi
There are several examples of columnar jointed sandstones in the greater
Asunción
Asunción (, , , Guarani: Paraguay) is the capital and the largest city of Paraguay.
The city stands on the eastern bank of the Paraguay River, almost at the confluence of this river with the Pilcomayo River. The Paraguay River and the Bay of ...
region of
Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
. The best known is Cerro Kõi in
Areguá
Areguá () is the capital of Central Department in Paraguay, located from the capital, Asunción. The city lies between Ypacaraí Lake to the east and hills to the west. Areguá is known for its colonial architecture and historic cobblestone s ...
, but there are also several quarries in
Luque
Luque () is a city in Central Department of Paraguay, part of the Gran Asunción metropolitan area. Both 1635 and 1750 have been recorded as dates of its founding.
It was temporarily the capital of Paraguay in 1868 during the Paraguayan War be ...
.
Mars
Several exposures of columnar jointing have been discovered on the planet Mars by the High Resolution Imaging Science Experiment (
HiRISE
High Resolution Imaging Science Experiment is a camera on board the ''Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction o ...
) camera, which is carried by the
Mars Reconnaissance Orbiter
''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, an ...
(MRO).
Sawn Rocks
![Sawn Rocks](https://upload.wikimedia.org/wikipedia/commons/5/52/Sawn_Rocks.jpg)
Sawn Rocks, in
Mount Kaputar National Park
The Mount Kaputar National Park is a national park located in New South Wales, Australia, surrounding the proximities of Mount Kaputar, a volcano active between 17 and 21 million years ago. It is located east of Narrabri and northwest of ...
close to
Narrabri
Narrabri ( ) is a locality and seat of Narrabri Shire local government area in the North West Slopes, New South Wales, Australia on the Namoi River, northwest of Sydney. It sits on the junction of the Kamilaroi Highway and the Newell Highway. At ...
,
New South Wales, Australia
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, features 40 meters of columnar jointing above the creek and 30 meters below the surface.
Sawn Rocks walking track, Mount Kaputar National Park
NSW National Parks and Wildlife Service. Retrieved 3 January 2019.
Basaltic Prisms of Santa María Regla
Alexander von Humboldt documented the prisms located in Huasca de Ocampo, in the Mexican state of Hidalgo.
Columnar Basalt of Tawau (Batu Bersusun)
River flows through the area of columnar basalt. One section is seen vertically high on river bank. The rest lays on river bank. Water flows from the lowest area forming waterfall and scenic view.
Location is at Kampung Balung Cocos, Tawau
See also
*Basalt fan structure
A basalt fan structure is a basalt formation composed of columnar jointed basalt columns that have slumped into a fan shape.
They are most likely created when basalt lava is intruded into a soft material, such as loose volcanic
A volcano ...
* Prism (geology)
*Honeycomb conjecture
The honeycomb conjecture states that a regular hexagonal grid or honeycomb has the least total perimeter of any subdivision of the plane into regions of equal area. The conjecture was proven in 1999 by mathematician Thomas C. Hales.
Theorem
Let ...
References
External links
*Aydin, A., and J. Zhong (nda
Columnar Joints
Stanford University, Stanford, California.
{{Structural geology
Igneous rocks
Geomorphology
Structural geology
Metamorphic rocks