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Juan Fernández Ridge
The Juan Fernández Ridge is a volcanic island and seamount chain on the Nazca Plate. It runs in a west–east direction from the Juan Fernández hotspot to the Peru–Chile Trench at a latitude of 33° S near Valparaíso. The Juan Fernández Islands are the only seamounts that reach the surface. Subduction of the ridge beneath South America is thought to have caused the Pampean flat-slab The Pampean flat-slab is the low angle subduction of 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 the Bucaramanga flat-slab. It is ... and its associated inland tectonic deformation and reduced magmatic activity. References * Juan Fernández Islands Underwater ridges of the Pacific Ocean Oceanography Hotspot tracks Volcanoes of Valparaíso Region {{tectonics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seamount
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to in height. They are defined by oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form.IHO, 2008. Standardization of Undersea Feature Names: Guidelines Proposal form Terminology, 4th ed. International Hydrographic Organization and Intergovernmental Oceanographic Commission, Monaco. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nazca Plate
The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively. The movement of the Nazca Plate over several hotspots has created some volcanic islands as well as east-west running seamount chains that subduct under South America. Nazca is a relatively young plate both in terms of the age of its rocks and its existence as an independent plate having been formed from the break-up of the Farallon Plate about 23 million years ago. The oldest rocks of the plate are about 50 million years old. Boundaries East Pacific and Chile Rise A triple junctio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juan Fernández Hotspot
The Juan Fernández hotspot is a volcanic hotspot located in the southeastern Pacific Ocean. The hotspot created the Juan Fernández Ridge which includes the Juan Fernández Archipelago and a long seamount chain that is being subducted in the Peru–Chile Trench at the site of Papudo giving origin to the Norte Chico Volcanic Gap. See also * Easter hotspot *Liquiñe-Ofqui Fault The Liquiñe-Ofqui Fault is major geological fault that runs a length of roughly in a NNE-SSW orientation and exhibits current seismicity. It is located in the Chilean Northern Patagonian Andes. It is a dextral intra-arc strike-slip fault. Most ... * Patagonian Volcanic Gap Volcanism of Chile Hotspots of the Pacific Ocean Juan Fernández Islands {{Volcanology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru–Chile Trench
The Peru–Chile Trench, also known as the Atacama Trench, is an oceanic trench in the eastern Pacific Ocean, about off the coast of Peru and Chile. It reaches a maximum depth of below sea level in Richards Deep () and is approximately long; its mean width is and it covers an expanse of some . The trench delineates the boundary between the subducting Nazca Plate and the overriding South American Plate. Geology The trench is a result of a convergent plate boundary, where the eastern edge of the oceanic Nazca Plate is being subducted beneath the continental South American Plate. The trench is also a part of the Chile Triple Junction, an unusual junction that consists of a mid-oceanic ridge and the Chile Rise being subducted under the South American plate at the Peru-Chile Trench. Two seamount ridges within the Nazca Plate enter the subduction zone along this trench: the Nazca Ridge and the Juan Fernández Ridge. From the Chile Triple Junction to Juan Fernández Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valparaíso
Valparaíso (; ) is a major city, seaport, naval base, and educational centre in the commune of Valparaíso, Chile. "Greater Valparaíso" is the second largest metropolitan area in the country. Valparaíso is located about northwest of Santiago by road and is one of the Pacific Ocean's most important seaports. Valparaíso is the Capital city, capital of Chile's second most populated administrative region and has been the headquarters for the Chilean Navy since 1817 and the seat of the National Congress of Chile, Chilean National Congress since 1990. Valparaíso played an important geopolitical role in the second half of the 19th century when it served as a major stopover for ships traveling between the Atlantic and Pacific oceans by crossing the Straits of Magellan. Valparaíso experienced rapid growth during its golden age, as a magnet for European immigrants, when the city was known by international sailors as "Little San Francisco" and "The Jewel of the Pacific". Notable inhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juan Fernández Islands
The Juan Fernández Islands ( es, Archipiélago Juan Fernández) are a sparsely inhabited series of islands in the South Pacific Ocean reliant on tourism and fishing. Situated off the coast of Chile, they are composed of three main volcanic islands: Robinson Crusoe, Alejandro Selkirk and Santa Clara. The group is part of Insular Chile. The islands are primarily known for having been the home to the marooned sailor Alexander Selkirk for more than four years from 1704, which may have inspired Daniel Defoe's ''Robinson Crusoe''. Most of the archipelago's present-day inhabitants reside on Robinson Crusoe Island, and mainly in the capital, San Juan Bautista, located at Cumberland Bay on the island's north coast.The islands' area and population data retrieved from the 2012 census. The group of islands is part of Chile's Valparaíso Region (which also includes Easter Island) and, along with the Desventuradas Islands, forms one of the nine communes of Valparaíso Province. The is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pampean Flat-slab
The Pampean flat-slab is the low angle subduction of 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 the Bucaramanga flat-slab. It is thought that the subduction of the Juan Fernández Ridge, a chain of extinct volcanoes on the Nazca Plate, is the underlying cause of the Pampean flat-slab. Effects The shallowing of subducted slab beneath north-central Chile and Argentina is linked to a series of changes in volcanism and tectonics. Deformation of crust The flat-slab has caused an uplift of Sierras Pampeanas which begun first in the north and then moved southwards over millions of years. The oldest noted uplift episode associated with Pampean flat-slab is that of Sierra de Aconquija (27 °S) from 7.6 to 6 million years ago (Ma) in the Late Miocene epoch. This was followed by the uplift of massifs further south such as Sierra de Famatina (29 °S) that rose 4.5 to 4.19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of South American Earth Sciences
The ''Journal of South American Earth Sciences'' is a peer-reviewed scientific journal published by Elsevier. It covers the earth sciences, primarily on issues that are relevant to South America, Central America, the Caribbean, Mexico, and Antarctica. The journal was established in 1988 and the editor-in-chief is James Kellogg ( University of South Carolina). According to the ''Journal Citation Reports'', the journal has a 2012 impact factor of 1.533. See also *''Ameghiniana'' *''Andean Geology'' *''Brazilian Journal of Geology'' *''Latin American Journal of Sedimentology and Basin Analysis'' *''Revista de la Asociación Geológica Argentina The ''Revista de la Asociación Geológica Argentina'' is an open access peer-reviewed scientific journal published by the Asociación Geológica Argentina. The journal is released under a CC-BY-NC 2.5 license. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andean Geology
''Andean Geology'' (formerly ''Revista Geológica de Chile'') is a peer-reviewed scientific journal published three times per year by the National Geology and Mining Service, Chile's geology and mining agency. The journal covers the field of geology and related earth sciences, primarily on issues that are relevant to South America, Central America, and Antarctica with a particular focus on the Andes. The journal was established in 1974 and articles are published in English and Spanish. The editor-in-chief An editor-in-chief (EIC), also known as lead editor or chief editor, is a publication's editorial leader who has final responsibility for its operations and policies. The highest-ranking editor of a publication may also be titled editor, managing ... is Waldo Vivallo (National Geology and Mining Service). References External links * Geology journals Geology of South America Geology of Antarctica Publications established in 1974 Andes Multilingual journals Open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
