Columnar jointing

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Columnar jointing in Giant's Causeway in Northern Ireland Giant's Causeway 2006 08.jpg
Columnar jointing in Giant's Causeway in Northern Ireland
Columnar jointing in the Alcantara Gorge, Sicily Columnar jointing in the Alcantara Gorge, Sicily.jpg
Columnar jointing in the Alcantara Gorge, Sicily

Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as joints, result in the formation of a regular array of polygonal prisms, or columns. Columnar jointing occurs in many types of igneous rocks and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. [1] Columnar jointing also occurs rarely in sedimentary rocks, due to a combination of dissolution and reprecipitation of interstitial minerals (often quartz or cryptocrystalline silica) by hot, hydrothermal fluids and the expansion and contraction of the rock unit, both resulting from the presence of a nearby magmatic intrusion. [2]

Contents

The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. [1] They are typically parallel and straight, but can also be curved and vary in diameter. [1] 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. [3] The number of sides of the individual columns can vary from 3 to 8, with 6 sides being the most common. [1]

Places

Some famous locations in the United States where columnar jointing can be found are Devils Tower in Wyoming, Devils Postpile in California and the Columbia River flood basalts in Oregon, Washington and Idaho. Other famous places include the Giant's Causeway in Northern Ireland and Fingal's Cave on the island of Staffa, Scotland. [4]

Devils Tower

Devils Tower is an eroded laccolith in the Black Hills National Forest, Wyoming. "This means something. This is important" (19967592275).jpg
Devils Tower is an eroded laccolith in the Black Hills National Forest, Wyoming.

Devils Tower in Wyoming in the United States is about 40 million years old and 382 meters (1,253 feet) high. [1] Geologists agree that the rock forming Devils Tower solidified from an intrusion, but it has not been established whether the magma from this intrusion ever reached the surface. Most columns are 6-sided, but 4, 5, and 7-sided ones can also be found. [5]

Giant's Causeway

The Giant's Causeway (Irish: 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. [1] [6] According to a legend, the giant Finn McCool created the Giant's Causeway, as a causeway to Scotland. [7]

Sōunkyō Gorge

Sōunkyō Gorge, a part of the town of Kamikawa, Hokkaido, Japan, features a 24-kilometre (15 mi) stretch of columnar jointing, which is the result of an eruption of the Daisetsuzan Volcanic Group 30,000 years ago.

Deccan Traps

The late Cretaceous Deccan Traps 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. [8]

High Island Reservoir

Formed in Cretaceous, the columnar rocks are found around the reservoir and the islands nearby in Sai Kung, Hong Kong. It is special that the rocks are not mafic, but felsic tuff instead.

Hexagonal volcanic tuffs at East Dam of High Island Reservoir Hexagonal volcanic tuffs at East Dam of High Island Reservoir 1.jpg
Hexagonal volcanic tuffs at East Dam of High Island Reservoir

Makhtesh Ramon

The columnar jointed sandstone of the HaMinsara (Carpentry Shop) in the makhtesh (erosion cirque) of Makhtesh Ramon, Negev desert, Israel.

Columnar jointing in sandstone, Cerro Koi, Paraguay Cerro Koi 6520 11.jpg
Columnar jointing in sandstone, Cerro Koi, Paraguay

Cerro Kõi

There are several examples of columnar jointed sandstones in the greater Asunción region of Paraguay. The best known is Cerro Kõi in Areguá, but there are also several quarries in Luque.

Mars

Several exposures of columnar jointing have been discovered on the planet Mars by the High Resolution Imaging Science Experiment (HiRISE) camera, which is carried by the Mars Reconnaissance Orbiter (MRO). [9] [10]

Sawn Rocks

Columnar jointing at Sawn Rocks Sawn Rocks.jpg
Columnar jointing at Sawn Rocks

Sawn Rocks, in Mount Kaputar National Park close to Narrabri, New South Wales, Australia, features 40 meters of columnar jointing above the creek and 30 meters below the surface. [11]

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)

At Kampung Balung Cocos, Tawau, Malaysia, the river flows through the area of columnar basalt. One section is seen vertically high on river bank. The rest lies on river bank. The water flows from the lowest area forming waterfall.

Garni gorge Garni Gorge Armenia axxp.JPG
Garni gorge

Gorge of Garni, Armenia

The Garni Gorge is situated 23 km east of Yerevan, Armenia, just below the village of the same name. This portion of the Garni Gorge is typically referred to as the "Symphony of the Stones." On a promontory above the gorge the first-century AD Temple of Garni may be seen.

See also

Related Research Articles

<span class="mw-page-title-main">Staffa</span> Island of the Inner Hebrides in Argyll and Bute, Scotland

Staffa 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 vertically placed tree-logs.

<span class="mw-page-title-main">Giant's Causeway</span> Interlocking basalt columns in Northern Ireland

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 (4.8 km) northeast of the town of Bushmills.

<span class="mw-page-title-main">Devils Postpile National Monument</span> National monument in California, United States

Devils Postpile National Monument is a U.S. National Monument located near Mammoth Mountain in Eastern California. The monument protects Devils Postpile, an unusual rock formation of columnar basalt, "all closely and perfectly fitted together like a vast mosaic." The monument encompasses 798 acres (323 ha) and includes two main attractions: the Devils Postpile formation and Rainbow Falls, a waterfall on the Middle Fork of the San Joaquin River. In addition, the John Muir Trail and Pacific Crest Trail merge into one trail as they pass through the monument. Excluding a small developed area containing the monument headquarters, visitor center and a campground, the National Monument lies within the borders of the Ansel Adams Wilderness.

<span class="mw-page-title-main">Fingal's Cave</span> Sea cave in Scotland

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's Cave after the eponymous hero of an epic poem by 18th-century Scots poet-historian James Macpherson.

<span class="mw-page-title-main">Dike (geology)</span> A sheet of rock that is formed in a fracture of a pre-existing rock body

In geology, a dike or dyke is a sheet of rock that is formed in a fracture of a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma flows into a crack then solidifies as a sheet intrusion, either cutting across layers of rock or through a contiguous mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack.

<span class="mw-page-title-main">Makhtesh Ramon</span> Erosion cirque in the Negev Desert, Israel

Makhtesh Ramon is a geological feature of Israel's Negev desert. Located some 85 km south of the city of Beersheba, the landform is the world's largest "erosion cirque". The formation is 40 km long, 2–10 km wide and 500 meters deep, and is shaped like an elongated heart. Despite its appearance it is not an impact crater from a meteor nor a volcanic crater formed by a volcanic eruption.

<span class="mw-page-title-main">Trap rock</span> Dark-colored, fine-grained, non-granitic igneous rock

Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro. Trap is also used to refer to flood (plateau) basalts, e.g. the Deccan Traps and Siberian Traps. The erosion of trap rock created by the stacking of successive lava flows often created a distinct stairstep landscape from which the term trap was derived from the Swedish word trappa, which means "stairway".

<span class="mw-page-title-main">Joint (geology)</span> Type of fracture in rock

A joint is a break (fracture) of natural origin in a layer or body of rock that lacks visible or measurable movement parallel to the surface (plane) of the fracture. Although joints can occur singly, they most frequently appear as joint sets and systems. A joint set is a family of parallel, evenly spaced joints that can be identified through mapping and analysis of their orientations, spacing, and physical properties. A joint system consists of two or more intersecting joint sets.

<span class="mw-page-title-main">Tessellated pavement</span> Relatively flat rock surface that is subdivided into more or less regular shapes by fractures

In geology and geomorphology, a tessellated pavement is a relatively flat rock surface that is subdivided into polygons by fractures, frequently systematic joints, within the rock. This type of rock pavement bears this name because it is fractured into polygonal blocks that resemble tiles of a mosaic floor, or tessellations.

<span class="mw-page-title-main">Geology of Hong Kong</span>

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<span class="mw-page-title-main">Basalt fan structure</span> Rock formation

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<span class="mw-page-title-main">Amazonis quadrangle</span> Map of Mars

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<span class="mw-page-title-main">Hong Kong UNESCO Global Geopark</span>

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<span class="mw-page-title-main">Organ Pipes National Park</span> Protected area in Victoria, Australia

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<span class="mw-page-title-main">Cardenas Basalt</span> Rock formation in the Grand Canyon, Arizona

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<span class="mw-page-title-main">Ashangi Basalts</span>

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References

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  2. Velázquez, Victor F.; Giannini, Paolo C. F.; Riccomini, Claudio; Ernandes, Alethéa; Sallun, Martins; Hachiro, Jorge; de Barros Gomes, Celso (1 September 2008). "Columnar joints in the Patiño Formation sandstones, Eastern Paraguay: a dynamic interaction between dyke intrusion, quartz dissolution and cooling-induced fractures". Episodes. 31 (3). International Union of Geological Sciences: 302–308. doi: 10.18814/epiiugs/2008/v31i3/003 . ISSN   2586-1298.
  3. Long, Philip E.; Wood, Bernard J. (1 September 1986). "Structures, textures, and cooling histories of Columbia River basalt flows". Geological Society of America Bulletin. 97 (9): 1144–1155. Bibcode:1986GSAB...97.1144L. doi:10.1130/0016-7606(1986)97<1144:STACHO>2.0.CO;2.
  4. southernhebrides.com > Staffa - A Geological Marvel. Accessed 29 December 2013.
  5. U.S. National Park Service > Devils Tower > Geologic Formations. Accessed 29 December 2013.
  6. National Trust > Giant's Causeway. Accessed 29 December 2013.
  7. Northern Ireland Tourist Board > Causeway Coast & Glens > The Giant's Causeway > Folklore and Legend Archived 2015-05-02 at the Wayback Machine . Accessed 29 December 2013.
  8. Geological Survey of India > Columnar Basalt Retrieved 17 April 2020.
  9. "HiRISE | Columnar Jointing on Mars and Earth (ESP_029286_1885)".
  10. Milazzo, Moses (2009). "Discovery of columnar jointing on Mars". Geology. 183 (3): 171–174. doi:10.1016/S0012-821X(00)00307-1.
  11. Sawn Rocks walking track, Mount Kaputar National Park NSW National Parks and Wildlife Service. Retrieved 3 January 2019.