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Hotspots and mantle plumes pdf Continue The mantle feathers area is hot, upwelling the mantle. A hot spot develops above the train. Magma, generated by a hot spot, rises through rigid slabs of the lithosphere and produces active volcanoes on the Earth's surface. As ocean volcanoes move away from the hotspot, they cool and subside, producing old islands, atolls and seamounts. As continental volcanoes move away from the hotspot, they cool, subside and die out. Hot spots are places inside the mantle where stones melt to generate magma. The presence of a hot spot stems from abnormal volcanism (i.e. not on the plate boundary) such as Hawaiian volcanoes within the Pacific Plate. The Hawaiian hotspot has been active for at least 70 million years, producing a volcanic chain that stretches for 3,750 miles (6,000 km) across the Pacific Northwest. Hot spots also develop under continents. Yellowstone hot spot has been active for at least 15 million years, producing a chain of caldera and volcanic features along the plains of the Snake River, which stretches 400 miles (650 km) west from northwest Wyoming to the Idaho-Oregon border. Keep in mind, however, that these are just theories. No one knows the answer. The honest answer is that many people are working on it but have not yet come up with an answer. Graphics After Morgan, J., 1971, Convection feathers in the lower mantle: Nature, art 230, p. 42-43. Volcanic regions, which are thought to feed on the underlying mantle, are abnormally hot compared to the surrounding mantle Diagram, showing a cross-section across the Earth's lithosphere (yellow) with magma rising from the mantle (red). The bottom chart illustrates the track hotspots caused by their relative movement. In geology, places known as hot spots or hot spots are volcanic regions that are thought to feed on the underlying mantle, which is abnormally hot compared to the surrounding mantle. Examples include the hotspots of Hawaii, Iceland and Yellowstone. The position of hot spots on the Earth's surface does not depend on the boundaries of tectonic plates, and therefore hot spots can create a chain of volcanoes as the plates move above them. There are two hypotheses that try to explain their origin. One suggests that hotspots are due to mantle feathers that rise as thermal diapirs from the core-mantle border. Another hypothesis is that the expansion of the lithosphere allows the melt from shallow depths to grow passively. This hypothesis considers the term hot spot incorrect, claiming that the mantle source beneath them is not actually abnormally hot. A scheme of origin showing the physical processes inside the Earth that lead to the generation of magma. Partial melting begins over the synthesis point. Origins hotspots lie in the work of D. Tuzo Wilson, who in 1963 postulated that the formation of Hawaii was the result of slow movement tectonic plate through a hot area below the surface. It was later postulated that the hot spots feed on narrow streams of hot mantle rising from the boundary of the Earth's core in a structure called the mantle plume. Whether such mantle plumes exist is the subject of serious debate in Earth science. Estimates of the number of hot spots postulated for feeding mantle plumes ranged from 20 to several thousand over the years, with most geologists considering the existence of several dozen. Hawaii, Reunion, Yellowstone, the Galapagos Islands and Iceland are among the most active volcanic regions to which the hypothesis applies. Composition Most volcanoes are basalt hotspots (e.g. Hawaii, Tahiti). As a result, they are less explosive than subduction zones where water is trapped under the main slab. Where hot spots occur in continental regions, basalt magma rises through the continental crust, which melts to form riolites. These riolites can form strong eruptions. For example, the Yellowstone caldera was formed by some of the most powerful volcanic explosions in geological history. However, when the riolite is completely erupted, it may be followed by eruptions of basalt magma rising through the same lithospheric cracks (cracks in the lithosphere). An example of this is the Ilgachuz Ridge in British Columbia, which was created as a result of an early complex series of trachite and riolite eruptions, as well as a late extrusion sequence of basalt lava flows. The hot spots hypothesis is now closely related to the mantle plume hypothesis. Comparisons with volcanoes of island arc Hotspot volcanoes are considered of a fundamentally different origin from island arc volcanoes. The latter are formed over subduction zones, on the converging boundaries of plates. When one ocean plate meets another, a denser plate is forced down into a deep ocean trench. This plate, as it is subducted, releases water into the base of the over-riding plate, and this water is mixed with the rock, thereby altering its composition causing some rock to melt and grow. This is what fuels a chain of volcanoes, such as the Aleutian Islands, near Alaska. Hot spots of volcanic chains for millions of years, the Pacific Plate has moved over Hawaiian hotspots, creating a trail of seamounts that stretch across the Pacific Ocean Kilauea is the most active shield of the volcano in the world. The volcano erupted nonstop from 1983 to 2018 and is part of the Hawaii-Emperor Seamount chain. Mauna Loa is a large shield volcano. Its last eruption was in 1984 and is part of the Hawaiian chain of seamounts of the emperor. Bowie Underwater Mountain is a dormant underwater volcano and it is part of the chain Seamount. Axial Seamount is the youngest underwater brother of the chain of underwater mountains Cobb-Eikelberg. The last eruption occurred on April 6, 2011. Mauna Kea Kea volcano in the chain of underwater mountains Hawaii-Emperor. It is at rest and has slag cones growing on the volcano. Ulalay is a massive shield volcano in the Hawaii-Emperor Seamount chain. The last eruption occurred in 1801. The hypothesis of a joint mantle/hot spot provides that the feeding structures will be fixed relative to each other, and continents and sea ice will drift overhead. Thus, the hypothesis predicts that progressive chains of volcanoes are developed on the surface. Examples include Yellowstone, which lies at the end of a chain of extinct caldera that is progressively older to the west. Another example is the Hawaiian archipelago, where the islands are getting older and more deeply blurred in the northwest. Geologists have tried to use hot spots of volcanic chains to track the movement of Earth's tectonic plates. These efforts have been vexed by the lack of very long chains, the fact that many of them are not progressive in time (e.g. the Galapagos Islands) and the fact that hot spots do not appear to be fixed in relation to each other (e.g. Hawaii and Iceland). 12) Postulated chain volcanoes hotspots An example of the location of a plume of mantle, proposed by one recent group. Illustration from Folger (2010). Hawaiian-Emperor Chain Underwater Mountains (Hawaii Hotspot) Louisville Ridge (Louisville Hotspot) Walvis Ridge (Gough and Tristan Hotspot) Kodiak-Bowie Seamount Chain (Bowie Hotspot) Cobb-Eikelberg Seamount Chain (Hotspot Cobb) New England Seamounts (New England Hotspot) Anahim Volcanic Belt (Anahim hotspot) Tasmantid Seamount Chain (Tasmantid Hotspot) Ninety East Ridge (Kergelen Hotspot) Fernandez Ridge (Juan Fernandez Hotspots) Tasmantid Seamount Chain (Tasmantid Hotspots) List of volcanic regions postulated as hotspots It was suggested that this section be divided into another article titled List of Hotspots and Hotspots. (Discuss) (June 2015) Distribution of hotspots in the list on the left, with numbers corresponding to those on the list. Hot spot Afar (29) is inappropriate. Map of all coordinates using: OpenStreetMap Download coordinates as: KML Access Points GPX Eifel (8) 50'12'N 6'42'E / 50.2'N 6.7'E / 50.2; 6.7 (Eiffel Hotspot), w'1 a 082 ±8 speed 12 ±2 mm/year 15 Iceland hotspot (14) 6424'N 17'18'W / 64.4'N 17.3'W/ 64.4; -17.3 (Icelandic hot spot) (15) Eurasian Plate, w'0.8 az'075 ±10 speed 5 ±3 mm/year North American Plate, w'8 az' 287 ±10 speed 15 ±5 mm/year Possibly related to the North Atlantic Continental Fault (62 M), Greenland. Hot spot of the Azores (1) 26'00'W / 37.9'N 26.0'W / 37.9; -26.0 (Азорские точки доступа) в.5 азз 110 ±12 Североамериканская плита, in .3 az '280 ±15 Ян Майен hotspot (15) 71 00N 9 00W / 71,0 N 9,0W / 71,0; -9.0 (точка доступа Январь-Майен) (15) горячая точка Хайнань (46) 20'00'n 110'00'E / 20.0'N 110.0'E / 20.0; 110.0 (хайнаньская горячая точка), азэ 000 ±15 гора Этна (47) 3745'N 15'00'E / 37.750'N 15.000'E / 37.750; 15.000 (Гора Этна) ( 15) Хоггар горячая точка (13) 23'18'N 5'36'E / 23.3'N 5.6'E / 23.3; 5.6 (Горячая точка Хоггара), in '3 az' 046 ±12 (15) Тибести го Точка (40) 20'48'N 17'30'E / 20.8'N 17.5'E / 20.8; 17.5 (горячая точка Тибести), w.2 аз 030 ±15 Джебель Марра/Дарфур горячая точка (6) 13 00N 24'12'E / 13.0'N 24.2'E / 13.0; 24.2 (горячая точка Дарфура), in '5 az'045 ±8 Афар hotspot (29, неуместно на карте) 7 '00'N 39'30'E / 7.0'N 39.5 'E / 7.0; 39.5 (Афарская горячая точка), in '2 az'030 ±15 скорость 16 ±8 мм/год, возможно, связанные с Афар Тройной Джанкшн, 30 Ма.
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    Index [Italic page numbers indicate major references] Abaco Knoll, 359 116, 304, 310, 323 Bahama Platform, 11, 329, 331, 332, Abathomphalus mayaroensis, 101 Aquia Formation, 97, 98, 124 341, 358, 360 Abbott pluton, 220 aquifers, 463, 464, 466, 468, 471, Bahama volcanic crust, 356 Abenaki Formation, 72, 74, 257, 476, 584 Bahamas basin, 3, 5, 35, 37, 39, 40, 259, 261, 369, 372, 458 Aquitaine, France, 213, 374 50 ablation, 149 Arcadia Formation, 505 Bahamas Fracture Zone, 24, 39, 40, Abyssal Plain, 445 Archaean age, 57 50, 110, 202, 349, 358, 368 Adirondack Mountains, 568 Arctic-North Atlantic rift system, 49, Bahamas Slope, 12 Afar region, Djibouti, 220, 357 50 Bahamas-Cuban Fault system, 50 Africa, 146, 229, 269, 295, 299 Ardsley, New York, 568, 577 Baja California, Mexico, 146 African continental crust, 45, 331, Argana basin, Morocco, 206 Bajocian assemblages, 20, 32 347 Argo Fan, Scotian margin, 279 Balair fault zone, 560 African Craton, 368 Argo Salt Formation, 72, 197, 200, Baltimore Canyon trough, 3, 37, 38, African margin, 45, 374 278, 366, 369, 373 40, 50, 67, 72 , 81, 101, 102, African plate, 19, 39, 44, 49 arkoses, 3 138, 139, 222, 254, 269, 360, Afro-European plate, 197 artesian aquifers, 463 366, 369, 396, 419,437 Agamenticus pluton, 220 Ashley Formation, 126 basement rocks, 74 age, 19, 208, 223 Astrerosoma, 96 carbonate deposits, 79 Agulhas Bank, 146 Atkinson Formation, 116, 117 crustal structure, 4, 5, 46 Aiken Formation, 125 Atlantic basin, 6, 9, 264 faults in, 32 Aikin, South Carolina, 515 marine physiography, 9 geologic