Katakekaumene or Catacecaumene ( Greek : Κατακεκαυμένη ) was a name for a district in Lydia (modern western Turkey ), and a union of ten cities in the area, during the Hellenistic and Roman periods.
24-401: The name means "burnt land" or "burnt country", referring to the pitch-black color of the lava and the dormant volcanic belt of Kula , which was first described by Strabo . Strabo ( Geographica , 12.8.19 ) reported that some place Katakekaumene as the site of the mythological battle between Zeus and the giant Typhon . Cities of the ancient decapolis included: This article about
48-424: A chain of volcanoes as the plates move above them. There are two hypotheses that attempt to explain their origins. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary. The alternative plate theory is that the mantle source beneath a hotspot is not anomalously hot, rather the crust above is unusually weak or thin, so that lithospheric extension permits
72-404: A distinction between primary hotspots coming from deep within the mantle and secondary hotspots derived from mantle plumes. The primary hotspots originate from the core/mantle boundary and create large volcanic provinces with linear tracks (Easter Island, Iceland, Hawaii, Afar, Louisville, Reunion, and Tristan confirmed; Galapagos, Kerguelen and Marquersas likely). The secondary hotspots originate at
96-511: A few tens to exist. Hawaii , Réunion , Yellowstone , Galápagos , and Iceland are some of the most active volcanic regions to which the hypothesis is applied. The plumes imaged to date vary widely in width and other characteristics, and are tilted, being not the simple, relatively narrow and purely thermal plumes many expected. Only one, (Yellowstone) has as yet been consistently modelled and imaged from deep mantle to surface. Most hotspot volcanoes are basaltic (e.g., Hawaii , Tahiti ). As
120-447: A location in ancient Lydia is a stub . You can help Misplaced Pages by expanding it . Volcanic belt A volcanic belt is a large volcanically active region. Other terms are used for smaller areas of activity, such as volcanic fields or volcanic systems. Volcanic belts are found above zones of unusually high temperature (700 to 1,400 °C (1,292 to 2,552 °F)) where magma is created by partial melting of solid material in
144-421: A narrow stream of hot mantle convecting up from the mantle-core boundary called a mantle plume . But more recently some geologists, such as Gillian Foulger view upper-mantle convection as a cause. This in turn has re-raised the antipodal pair impact hypothesis, the idea that pairs of opposite hot spots may result from the impact of a large meteor. Geologists have identified some 40-50 such hotspots around
168-500: A result, they are less explosive than subduction zone volcanoes, in which water is trapped under the overriding plate. Where hotspots occur in continental regions , basaltic magma rises through the continental crust, which melts to form rhyolites . These rhyolites can form violent eruptions. For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history. However, when
192-406: A result, they are less explosive than subduction zone volcanoes, which have high water contents. Where hotspots occur under continental crust, basaltic magma is trapped in the less dense continental crust, which is heated and melts to form rhyolites. These rhyolites can be quite hot and form violent eruptions, despite their low water content. For example, the Yellowstone Caldera was formed by some of
216-480: A structure called a mantle plume . Whether or not such mantle plumes exist has been the subject of a major controversy in Earth science, but seismic images consistent with evolving theory now exist. At any place where volcanism is not linked to a constructive or destructive plate margin, the concept of a hotspot has been used to explain its origin. A review article by Courtillot et al. listing possible hotspots makes
240-479: A subduction-zone related volcanic belt is the Okhotsk-Chukotka Volcanic Belt in northeastern Eurasia , which is one of the largest subduction-zone related volcanic provinces in the world, stretching some 3,200 kilometres (2,000 mi) and comprising about 2 × 10 cubic kilometres (4.8 × 10 cu mi) of volcanic and plutonic material. Volcanic belts may also be formed by hotspots , which
264-469: Is a location on the Earth's surface that has experienced active volcanism for a long period of time. These volcanic belts are called volcanic chains. Canadian geologist John Tuzo Wilson came up with the idea in 1963 that volcanic chains like the Hawaiian Islands result from the slow movement of a tectonic plate across a "fixed" hot spot deep beneath the surface of the planet, thought to be caused by
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#1732855044124288-477: Is now closely linked to the mantle plume hypothesis. The detailed compositional studies now possible on hotspot basalts have allowed linkage of samples over the wider areas often implicate in the later hypothesis, and it's seismic imaging developments. Hotspot volcanoes are considered to have a fundamentally different origin from island arc volcanoes. The latter form over subduction zones, at converging plate boundaries. When one oceanic plate meets another,
312-479: Is one of the world's largest greenstone belts. Volcanic belts are similar to a mountain range , but the mountains within the mountain range are volcanoes, not mountains that are formed by faulting and folding by the collision of tectonic plates . Volcanic belts may be formed by multiple tectonic settings. They may be formed by subduction zones , which is an area on Earth where two tectonic plates meet and move towards one another, with one sliding underneath
336-648: The Earth's crust and upper mantle . These areas usually form along tectonic plate boundaries at depths of 10 to 50 kilometres (6.2 to 31.1 mi). For example, volcanoes in Mexico and western North America are mostly in volcanic belts, such as the Trans-Mexican Volcanic Belt that extends 900 kilometres (560 mi) from west to east across central-southern Mexico and the Northern Cordilleran Volcanic Province in western Canada . In
360-921: The case of Iceland, the geologist G.G. Bárdarson in 1929 identified clusters of volcanic belts while studying the Reykjanes Peninsula . The deeply deformed and eroded remnants of ancient volcanic belts are found in volcanically inactive regions such as the Canadian Shield . It contains over 150 volcanic belts (now deformed and eroded down to nearly flat plains ) that range from 600 to 1,200 million years old. These are zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated sedimentary rocks that form what are known as greenstone belts . They are thought to have formed at ancient oceanic spreading centers and island arc terranes . The Abitibi greenstone belt in Ontario and Quebec , Canada
384-466: The denser plate is forced downward into a deep ocean trench. This plate, as it is subducted, releases water into the base of the over-riding plate, and this water mixes with the rock, thus changing its composition causing some rock to melt and rise. It is this that fuels a chain of volcanoes, such as the Aleutian Islands , near Alaska . The joint mantle plume /hotspot hypothesis originally envisaged
408-504: The feeder structures to be fixed relative to one another, with the continents and seafloor drifting overhead. The hypothesis thus predicts that time-progressive chains of volcanoes are developed on the surface. Examples are Yellowstone , which lies at the end of a chain of extinct calderas, which become progressively older to the west. Another example is the Hawaiian archipelago, where islands become progressively older and more deeply eroded to
432-666: The globe, with Hawaii , Réunion , Yellowstone , Galápagos , and Iceland overlying the most currently active. An example of a hotspot volcanic belt is the Anahim Volcanic Belt in British Columbia , Canada , which was formed as a result of the North American Plate sliding westward over the Anahim hotspot . Most hotspot volcanoes are basaltic because they erupt through oceanic lithosphere (e.g., Hawaii, Tahiti). As
456-492: The most powerful volcanic explosions in geologic history. Hotspot (geology) In geology , hotspots (or hot spots ) are volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. Examples include the Hawaii , Iceland , and Yellowstone hotspots . A hotspot's position on the Earth's surface is independent of tectonic plate boundaries , and so hotspots may create
480-534: The northwest. Geologists have tried to use hotspot volcanic chains to track the movement of the Earth's tectonic plates. This effort has been vexed by the lack of very long chains, by the fact that many are not time-progressive (e.g. the Galápagos ) and by the fact that hotspots do not appear to be fixed relative to one another (e.g. Hawaii and Iceland ). That mantle plumes are much more complex than originally hypothesised and move independently of each other and plates
504-405: The other and moving down into the mantle , at rates typically measured in centimeters per year. An oceanic plate ordinarily slides underneath a continental plate; this often creates an orogenic zone with many volcanoes and earthquakes . In a sense, subduction zones are the opposite of divergent boundaries , areas where material rises up from the mantle and plates are moving apart. An example of
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#1732855044124528-414: The passive rising of melt from shallow depths. The origins of the concept of hotspots lie in the work of J. Tuzo Wilson , who postulated in 1963 that the formation of the Hawaiian Islands resulted from the slow movement of a tectonic plate across a hot region beneath the surface. It was later postulated that hotspots are fed by streams of hot mantle rising from the Earth's core–mantle boundary in
552-516: The rhyolite is completely erupted, it may be followed by eruptions of basaltic magma rising through the same lithospheric fissures (cracks in the lithosphere). An example of this activity is the Ilgachuz Range in British Columbia, which was created by an early complex series of trachyte and rhyolite eruptions, and late extrusion of a sequence of basaltic lava flows. The hotspot hypothesis
576-526: The upper/lower mantle boundary, and do not form large volcanic provinces, but island chains (Samoa, Tahiti, Cook, Pitcairn, Caroline, MacDonald confirmed, with up to 20 or so more possible). Other potential hotspots are the result of shallow mantle material surfacing in areas of lithospheric break-up caused by tension and are thus a very different type of volcanism. Estimates for the number of hotspots postulated to be fed by mantle plumes have ranged from about 20 to several thousand, with most geologists considering
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