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Laramide Orogeny
The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 80 to 70 million years ago, and ended 55 to 35 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute. The Laramide orogeny occurred in a series of pulses, with quiescent phases intervening. The major feature that was created by this orogeny was deep-seated, thick-skinned deformation, with evidence of this orogeny found from Canada to northern Mexico, with the easternmost extent of the mountain-building represented by the Black Hills of South Dakota. The phenomenon is named for the Laramie Mountains of eastern Wyoming. The Laramide orogeny is sometimes confused with the Sevier orogeny, which partially overlapped in time and space. The orogeny is commonly attributed to events off the west coast of North America, where the Kula and Farallon Plates were sliding under the North American Plate. Most hypotheses propo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Building
Mountain formation occurs due to a variety of geological processes associated with large-scale movements of the Earth's crust (List of tectonic plates, tectonic plates). Fold (geology), Folding, Fault (geology), faulting, Volcano, volcanic activity, igneous intrusion and metamorphism can all be parts of the Orogeny, orogenic process of mountain building. The formation of mountains is not necessarily related to the structural geology, geological structures found on it. From the late 18th century until its replacement by plate tectonics in the 1960s, geosyncline, geosyncline theory was used to explain much mountain-building. The understanding of specific landscape features in terms of the underlying tectonics, tectonic processes is called ''geomorphology, tectonic geomorphology'', and the study of geologically young or ongoing processes is called ''neotectonics''. Types of mountains There are five main types of mountains: volcanic, fold, plateau, fault-block, and dome. A more de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year. Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Plate
Continental may refer to: Places * Continental, Arizona, a small community in Pima County, Arizona, US * Continental, Ohio, a small town in Putnam County, US Arts and entertainment * ''Continental'' (album), an album by Saint Etienne * Continental (card game), a rummy-style card game * ''Continental'' (film), a 2013 film * Continental Singers, a Christian music organization Companies * ContiGroup Companies or Continental Grain * Continental AG, a German automotive parts and technologies manufacturer * Continental Airlines, a former American airline * Continental Electronics, an American radio transmitter manufacturer * Continental Films, a German-controlled French film company during the Nazi occupation of France * Continental Illinois, a defunct large bank * Continental Mortgage and Loan Company (later known as Continental, Inc.), the former name of HomeStreet Bank * Continental Motors, Inc., a Chinese manufacturer of aircraft engines * Continental Oil Company, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horst (geology)
In physical geography and geology, a horst is a raised fault block bounded by Fault (geology), normal faults. Horsts are typically found together with grabens. While a horst is lifted or remains stationary, the grabens on either side Subsidence, subside. This is often caused by Extensional tectonics, extensional forces pulling apart the crust. Horsts may represent features such as plateaus, mountains, or ridges on either side of a valley. Horsts can range in size from small fault blocks up to large regions of stable continent that have not been folded or warped by tectonic forces. The word ''Horst'' in German language, German means "mass" or "heap" and was first used in the geological sense in 1883 by Eduard Suess in ''The Face of the Earth.''Originally published in 1883 in German as "Das Antlitz der Erde", translated and published in English in 1904 Geomorphology Horsts may have either symmetrical or asymmetrical cross-sections. If the normal faults to either side have similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Basin
A structural basin is a large-scale structural geology, structural formation of rock stratum, strata formed by tectonics, tectonic warping (Fold (geology), folding) of previously flat-lying strata into a syncline fold. They are geological depression (geology), depressions, the inverse of dome (geology), domes. Elongated structural basins are a type of geological Trough (geology), trough. Some structural basins are sedimentary basins, aggregations of sediment that filled up a depression or accumulated in an area; others were formed by tectonic events long after the sedimentary layers were deposited. Basins may appear on a geologic map as roughly circular or elliptical, with concentric layers. Because the strata dip toward the center, the exposed strata in a basin are progressively younger from the outside in, with the youngest rocks in the center. Basins are often large in areal extent, often hundreds of kilometers across. Structural basins are often important sources of coal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basin And Range Province
The Basin and Range Province is a vast United States physiographic region, physiographic region covering much of the inland Western United States and Northern Mexico, northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins. The physical geography, physiography of the province is the result of Extensional tectonics, tectonic extension that began around 17 million years ago in the early Miocene epoch. The numerous ranges within the province in the United States are collectively referred to as the "Great Basin Ranges", although many are not actually in the Great Basin. Major ranges include the Snake Range, the Panamint Range, the White Mountains (California), White Mountains, and the Sandia Mountains. The highest point fully within the province is White Mountain Peak in California, while the lowest point is the Badwater Basin in Death Valle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Canada, to New Mexico in the Southwestern United States. Depending on differing definitions between Canada and the U.S., its northern terminus is located either in northern British Columbia's Terminal Range south of the Liard River and east of Rocky Mountain Trench, the Trench, or in the northeastern foothills of the Brooks Range/British Mountains that face the Beaufort Sea coasts between the Canning River (Alaska), Canning River and the Firth River across the Alaska-Yukon border. Its southernmost point is near the Albuquerque metropolitan area, Albuquerque area adjacent to the Rio Grande rift and north of the Sandia–Manzano Mountains, Sandia–Manzano Mountain Range. Being the easternmost portion of the North American Cordillera, the Rockie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthenosphere
The asthenosphere () is the mechanically weak and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between c. below the surface, and extends as deep as . However, the lower boundary of the asthenosphere is not well defined. The asthenosphere is almost solid, but a slight amount of melting (less than 0.1% of the rock) contributes to its mechanical weakness. More extensive decompression melting of the asthenosphere takes place where it wells upwards, and this is the most important source of magma on Earth. It is the source of mid-ocean ridge basalt (MORB) and of some magmas that erupt above subduction zones or in regions of continental rifting. Characteristics The asthenosphere is a part of the upper mantle just below the lithosphere that is involved in plate tectonic movement and isostatic adjustments. It is composed of peridotite, a rock containing mostly the minerals olivine and pyroxene. The lithosphere-asthenosphere boundary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magmatic Gap
A magmatic lull is a period of declined magmatic activity in volcanically active regions. They may occur as a result of underthrusting of hinterland lithosphere beneath a volcanic arc, changes in subduction parameters such as relative velocity, direction and slab dip (e.g. flat slab subduction), arc-arc collisions and subduction hinge advance. Individual magmatic lulls may last tens of millions of years between periods of volcanicity. Magmatic lulls can be related to volcanic gaps, which are regions lacking volcanic activity that separate two distinct volcanic zones. For example, the Andean Volcanic Belt of South America has three major volcanic gaps: the Peruvian flat-slab segment (3 °S–15 °S), the Pampean flat-slab The Pampean flat-slab is the flat slab subduction, low angle subduction of lithosphere, oceanic lithosphere beneath Northern Argentina. The Pampean flat-slab is one of three flat slabs in South America, the other being the Peruvian flat-slab and t ... segment (27 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction Zone
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year. Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorado Mineral Belt
The Colorado Mineral Belt (CMB) is an area of ore deposits from the La Plata Mountains in Southwestern Colorado to near the middle of the state at Boulder, Colorado, and from which over 25 million troy ounces (778 t) of gold were extracted beginning in 1858. The belt is a "northeast-striking zone defined by: a Proterozoic shear zone system (McCoy, 2001); a suite of Laramide-aged plutons and related ore deposits ( Tweto and Sims, 1963); a major gravity low (Isaacson and Smithson, 1976); low- crustal velocities; and high heat flow (Decker et al., 1988)." Mining districts includ * Central City-Idaho Springs district * Leadville mining district, named for Leadville, Colorado * Sneffels-Red Mountain-Telluride district The belt lies within a zone that has been geologically active at intervals beginning from near the time of crustal accretion in central Colorado at least 1.6 billion years ago until the present. Parts of the CMB follow shear zones of Precambrian age and the Paleozoic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andes
The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18th parallel south, 18°S and 20th parallel south, 20°S latitude) and has an average height of about . The Andes extend from south to north through seven South American countries: Argentina, Chile, Bolivia, Peru, Ecuador, Colombia, and Venezuela. Along their length, the Andes are split into several ranges, separated by intermediate depression (geology), depressions. The Andes are the location of several high plateaus—some of which host major cities such as Quito, Bogotá, Cali, Arequipa, Medellín, Bucaramanga, Sucre, Mérida, Mérida, Mérida, El Alto, and La Paz. The Altiplano, Altiplano Plateau is the world's second highest after the Tibetan Plateau. These ranges are in turn grouped into three majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
