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Los Colorados (caldera)
Los Colorados is the name of a caldera in Chile. It is part of the Central Volcanic Zone of the Andes. The caldera has a diameter of and was formed 9.8 million years ago within a basement consisting of Paleozoic rocks, Miocene ignimbrites and older volcanoes. The caldera is the source of the Los Colorados ignimbrite, which was erupted 7.9-7.76 million years ago. This ignimbrite is formed by highly welded dacite, is rich in pumice and has a dark pink colour. Quartz, sherds are also widespread. This ignimbrite covers a surface area of , spilling into Argentina. Part of the Los Colorados ignimbrite has been identified at the Laguna Amarga caldera. After the formation of the caldera, between 6.9 and 6.8 million years ago the Abra Grande, Aguas Calientes and Río Grande stratovolcanoes grew in the caldera. Lava flows from Cerro Bayo and Cordón del Azufre have invaded the northwestern sector of the caldera. The Los Colorados caldera coalesces with the Lazufre structure along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Colorados, La Rioja, Argentina
LOS, or Los, or LoS may refer to: Science and technology * Length of stay, the duration of a single episode of hospitalisation * Level of service, a measure used by traffic engineers * Level of significance, a measure of statistical significance * Line-of-sight (other) * LineageOS, a free and open-source operating system for smartphones and tablet computers * Loss of signal ** Fading **End of pass (spaceflight) * Loss of significance, undesirable effect in calculations using floating-point arithmetic Medicine and biology * Lipooligosaccharide, a bacterial lipopolysaccharide with a low-molecular-weight * Lower oesophageal sphincter Arts and entertainment * ''The Land of Stories'', a series of children's novels by Chris Colfer * Los, or the Crimson King, a character in Stephen King's novels * Los (band), a British indie rock band from 2008 to 2011 * Los (Blake), a character in William Blake's poetry * Los (rapper) (born 1982), stage name of American rapper Carlos Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the List of countries and dependencies by area, eighth-largest country in the world. Argentina shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a Federation, federal state subdivided into twenty-three Provinces of Argentina, provinces, and one autonomous city, which is the federal capital and List of cities in Argentina by population, largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a Federalism, federal system. Argentina claims sovereignty ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Calderas
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and hominoids into Eurasia. During the late Miocene, the connections between the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma Chamber
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upwards. If the magma finds a path to the surface, then the result will be a volcanic eruption; consequently, many volcanoes are situated over magma chambers. These chambers are hard to detect deep within the Earth, and therefore most of those known are close to the surface, commonly between 1 km and 10 km down. Dynamics of magma chambers Magma rises through cracks from beneath and across the crust because it is less dense than the surrounding rock. When the magma cannot find a path upwards it pools into a magma chamber. These chambers are commonly built up over time, by successive horizontal or vertical magma injections. The influx of new magma causes reaction of pre-existing crystals and the pressure in the chamber to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overthrust
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular '' klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is called a ''blind thrust'' fault. Because of the lack of surface evidence, blind thrust fau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerro Archibarca
Cerro Archibarca is a volcano in the Andes, in Salta Province, Argentina. It covers a surface area of . Lava flows descend from a conical edifice. It was active 11 million years ago. The youngest deposits are eroded andesites on the northern side. A major volcaniclastic unit is associated with Archibarca, named the La Torre formation after the valley where its lower bright red unit reaches a thickness of . The red unit is formed from unconsolidated pyroclastics with spherical clasts ( up to ). Granite and pumice are materials also present in this unit. The upper white unit is a thick pyroclastic flow from Archibarca. A thick rhyolitic flow with banding structures is also present as well as an associated lava dome that intruded the La Torre formation on the volcano's southern side. Andesites from this volcano are partly derived from crustal assimilation, with the crustal component constituting 40% of total rock. The Caballo Muerto and Archibarca ignimbrite Ignimbrite is a typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lazufre
Lazufre is a Quaternary volcanic dome in the central Andes, on the border between Chile and Argentina. It is part of the Central Volcanic Zone (CVZ), one of the four distinct volcanic belts of South America. The CVZ includes a number of calderas and supervolcanoes that have emplaced ignimbrites in the region. Lazufre and the majority of the Andean volcanoes formed from the subduction of the oceanic Nazca Plate under the continental South American continental lithosphere. The dome has been uplifting for the past 400,000 years and features three recent volcanoes, Lastarria, Cordón del Azufre and Cerro Bayo Complex. It may be a volcano that will in the future develop a caldera. The dome began uplifting in the late 19th century at an increasing rate, before slowing down since 2010. The uplift is among the largest in the world and has drawn attention from the scientific communities. Various explanations have been proposed, the most common being that a magma chamber is filling up. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordón Del Azufre
Cordón del Azufre is an inactive complex volcano located in the Central Andes, at the border of Argentina and Chile. It consists of three stages of volcanic cones and associated lava flows, and its activity is a consequence of the subduction of the Nazca Plate underneath the South American Plate. North of it are the dormant volcano Lastarria and the actively uplifting Lazufre region. Geography and geology The volcano, which is sometimes conflated with Lastarria, lies at the border between Argentina and Chile and contains a series of lava flows and volcanic craters and lava flows, covering a surface area of . Four craters are aligned in a north–south direction on a ridge, which could reflect a north-south trending lineament. Numerous monogenetic volcanoes and stratovolcanoes developed on it and buried most of its central crater under lava flows. A pile of lava flows covers an area of on the eastern side. The eastern component is formed by lava flows and craters in Argent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerro Bayo Complex
Cerro Bayo is a complex volcano on the northern part border between Argentina and Chile. It consists of four overlapping stratovolcanoes along a north–south line. The main volcano face is located on the Argentine side, thought the summit of the complex is just west of the border, in Chile. The volcano is about 800,000 years old, but it is associated with ongoing ground uplift encompassing also the more northerly Lastarria and Cordón del Azufre volcanoes. The high summit is the source of two viscous dacitic lava flows with prominent levees that traveled to the north. Elemental sulfur can be found at Bayo, both in the form of high-grade massive deposits and as extinct fumarole chimneys. The volcano formed in three separate phases that produced lava flows. One is dated to 1.6±0.4 million years ago. The volcano can bear snow in winter. The youngest dated rocks are about 23,000 years old; in 2007 a steam eruption were observed by researchers investigating nearby salt pans such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is often also called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. Etymology The word ''lava'' comes from Italian and is probably derived from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratovolcano
A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and explosive eruptions. Some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and solidifies before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high to intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less viscous mafic magma. Extensive felsic lava flows are uncommon, but can travel as far as 8 km (5 mi). The term ''composite volcano'' is used because strata are usually mixed and uneven instead of neat layers. They are among the most common types of volcanoes; more than 700 stratovolcanoes have erupted lava during the Holocene Epoch (the last 11,700 years), and many ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laguna Amarga
Laguna Amarga is a caldera and associated ignimbrite in the Andes of northwestern Argentina. Laguna Amarga is part of the southern Central Volcanic Zone and one among several Miocene-Pliocene-Pleistocene volcanic centres of this volcanic region. The formation of magma chambers and thus of large volcanic systems has apparently been influenced by tectonic changes. The Laguna Amarga caldera is associated with the Cordillera Claudio Gay faults together with the Laguna Escondida and Wheelwright calderas, all of which are between 6.5 and 4 mya old. Laguna Amarga and Laguna Verde are sometimes associated with the Vallecito ignimbrite instead. The formation of the Laguna Amarga volcanic centre was probably influenced by orogenic changes in the Andes which triggered the formation of fractures in the crust. The Laguna Amarga caldera has a diameter of and is linked to the Laguna Escondida caldera. It is the largest caldera in the area and may be part of an eastward migrating volcanic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
