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Calderas Of Chad
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 gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning "coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Mazama Eruption Timeline
Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, Cornwall, England * Mounts, Indiana, a community in Gibson County, Indiana, United States People * Mount (surname) * William L. Mounts (1862–1929), American lawyer and politician Computing and software * Mount (computing), the process of making a file system accessible * Mount (Unix), the utility in Unix-like operating systems which mounts file systems Displays and equipment * Mount, a fixed point for attaching equipment, such as a hardpoint on an airframe * Mounting board, in picture framing * Mount, a hanging scroll for mounting paintings * Mount, to display an item on a heavy backing such as foamcore, e.g.: ** To pin a biological specimen, on a heavy backing in a stretched stable position for ease of dissection or display ** To ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Origin Of Volcanic Caldera Via Analogue Model
Origin(s) or The Origin may refer to: Arts, entertainment, and media Comics and manga * ''Origin'' (comics), a Wolverine comic book mini-series published by Marvel Comics in 2002 * ''The Origin'' (Buffy comic), a 1999 ''Buffy the Vampire Slayer'' comic book series * Origins (''Judge Dredd'' story), a major ''Judge Dredd'' storyline running from 2006 through 2007 * ''Origin'' (manga), a 2016 manga by Boichi * '' Mobile Suit Gundam: The Origin'', a 2002 manga by Yoshikazu Yasuhiko * '' Wolverine: Origins'', a Marvel Comics series Films and television * ''Origin'' (TV series), 2018 science-fiction TV series * "Origin" (''Angel''), a fifth-season episode of ''Angel'' * '' Origin: Spirits of the Past'', a 2006 anime movie also known as ''Gin-iro no Kami no Agito'' * Origin (''Stargate''), the religion of the Ori * "Origin" (''Stargate SG-1''), a ninth-season episode of ''Stargate SG-1'' * '' X-Men Origins: Wolverine'', a 2009 superhero film, prequel to the ''X-Men'' film tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturgeon Lake Caldera
Sturgeon Lake Caldera is a large extinct caldera complex in Kenora District of Northwestern Ontario, Canada. It is one of the world's best preserved mineralized Neoarchean caldera complexes, containing well-preserved mafic-intermediate pillow lavas, pillow breccias, hyaloclastite and peperites, submarine lava domes and dome-associated breccia deposits. The complex is some 2.7 billion years old Retrieved on 2007-07-20 with a minimum length of . Geology The Sturgeon Lake Caldera contains a well preserved north facing homoclinal chain of |
Mineralization (geology)
In geology, mineralization is the deposition of economically important metals in the formation of ore bodies or "lodes" by various process. The first scientific studies of this process took place in the English county of Cornwall by J.W.Henwood FRS and later by R.W. Fox, FRS.Embrey, P. G. and Symes, R. F. ''Minerals of Cornwall and Devon'', London, British Museum of Natural History, 1987. hardback, 0-565-00989-3 paperback. page 14, and bibliography Fox: 135, Henwood: 137/8 The term can also refer to the process by which waterborne minerals, such as calcium carbonate (calcite), iron oxide (hematite or limonite) or silica (quartz), replace organic material within the body of an organism that has died and was buried by sediments. Mineralization may also refer to the product resulting from the process of mineralization. For example, mineralization (the process) may introduce metals (such as iron) into a rock. That rock may then be referred to as possessing iron mineralization. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ore Deposit
Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 April 2021Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of Geology: American Geological Institute, 799 p. Ore is extracted from the earth through mining and treated or refined, often via smelting, to extract the valuable metals or minerals. The ''grade'' of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore. Minerals of interest are generally oxides, sulfides, silicates, or native metals such as copper or gold. Ores must be processed to extract the elements of interest from the waste rock. O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera Formation
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 gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning "co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Dike
A ring dike or ring dyke is an intrusive igneous body that is circular, oval or arcuate in plan and has steep contacts. While the widths of ring dikes differ, they can be up to several thousand meters. The most commonly accepted method of ring dike formation is directly related to collapse calderas.Gudmundsson, Agust. "Formation of collapse calderas." ''Geology'' 16.9 (1988): 808–10. Caldera collapse and ring dike formation Collapse calderas form due to the emptying of a magma chamber. Effusive eruptions that take place on the flanks of the associated volcano and a fissure system that direct magma away from the chamber are both mechanisms that can empty a magma chamber. As pressure in the magma chamber changes, an increase in tensile stresses create tension fractures at the surface of the volcano. The geometry of the top of the magma chamber dictates the location and magnitude of the tension fractures. In addition, it was found that the higher the radius to depth ratio of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained (phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture (geology)
A fracture is any separation in a geologic formation, such as a Joint (geology), joint or a Fault (geology), fault that divides the Rock (geology), rock into two or more pieces. A fracture will sometimes form a deep fissure or crevice in the rock. Fractures are commonly caused by Stress (physics), stress exceeding the rock strength, causing the rock to lose cohesion along its weakest plane. Fractures can provide Permeability (fluid), permeability for fluid movement, such as water or hydrocarbons. Highly fractured rocks can make good aquifers or Oil reservoir, hydrocarbon reservoirs, since they may possess both significant Permeability (fluid), permeability and fracture porosity. Brittle deformation Fractures are forms of brittle deformation. There are two types of primary brittle deformation processes. Tensile fracturing results in ''joints''. ''Shear fractures'' are the first initial breaks resulting from shear forces exceeding the cohesive strength in that plane. After those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bárðarbunga
Bárðarbunga (), is a stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland's most extensive glacier. The second highest mountain in Iceland, above sea level, Bárðarbunga is also part of a volcanic system that is approximately long and wide. Description Bárðarbunga is a subglacial stratovolcano under the ice cap of Vatnajökull glacier in the Vatnajökull National Park in Iceland. It rises to above sea level, making it the second highest mountain in Iceland, about lower than Hvannadalshnjúkur. The caldera is about 80 square kilometres, up to 10 km wide and about deep. The surrounding edges rise to 1,850 metres, but the base is on average close to 1,100 metres. The volcano is covered in ice to a depth of 850m, hiding the glacier-filled crater. The associated volcanic system and fissure swarm is about 190 km long and 25 km wide. Bárðarbunga was a little-known volcano in Iceland due to its remote location and infrequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piton De La Fournaise
Piton de la Fournaise (; en, "Peak of the Furnace") is a shield volcano on the eastern side of Réunion island (a French overseas department and region) in the Indian Ocean. It is currently one of the most active volcanoes in the world, along with Kīlauea in the Hawaiian Islands, Stromboli and Etna in Italy and Mount Erebus in Antarctica. A previous eruption began in August 2006 and ended in January 2007. The volcano erupted again in February 2007, on 21 September 2008, on 9 December 2010, which lasted for two days, and on 1 August 2015. The most recent eruption began on 7 December 2020. The volcano is located within Réunion National Park, a World Heritage Site. Residents of Réunion sometimes refer to Piton de la Fournaise simply as ''le Volcan'' ("the Volcano"). It is a major tourist attraction on Réunion island. Geology The uppermost section of the volcano is occupied by the Enclos Fouqué, a caldera wide. High cliffs, known as ''remparts'' in French, form the calder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
