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Cerro Porquesa
Cerro Porquesa (Aymara) is an approximately high ( above base) rhyodacite lava dome in the Andes. It has a oval outline, and is high. The lava dome is accompanied by block-and-ash flows and lava flows and the presence of two volcanic cones has been reported. The lava dome is of Pliocene/Pleistocene age with little glacial features on the younger domes indicating young ages. The Quebrada de Piga, which flows to Salar de Huasco, originates at Cerro Porquesa. The dome was formed in at least three different eruption stages, with each stage contributing about two or three different lobes. Further, a rhyolitic ignimbrite with 69.5% SiO2 may be linked to the domes. It fills a valley in the south of the complex about thick. This ignimbrite is dated 0.73±0.16 and 0.63 +0.92/-0.63 mya by potassium-argon dating in biotite, although with low precision. Another 0.28 mya old ignimbrite was originally attributed to Porquesa but instead comes from a wide caldera in Bolivia. Three dates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerro Porquesa Landsat LookViewer Ags Be33d9f4 1c8a 42b7 8aae 395dada8aca4
Cerro is Spanish for "hill" or "mountain". Toponyms ;Bolivia: * Cerro Rico, the "Rich Mountain" containing silver ore near Potosi, Bolivia ;Brazil: *Cerro Branco, a municipality of Rio Grande do Sul *Cerro Grande, Rio Grande do Sul, a municipality of Rio Grande do Sul * Cerro Largo, a municipality of Rio Grande do Sul ;Chile * Cerro de Los Inocentes, in the Juan Fernández Islands ;Cuba: * Cerro, Havana, a district (''municipio'') ;Italy: *Cerro (Bottanuco), a subdivision of Bottanuco in the province of Bergamo *Cerro al Lambro, in the province of Milano *Cerro al Volturno, in the province of Isernia *Cerro Maggiore, in the province of Milano *Cerro Tanaro, in the province of Asti *Cerro Veronese, in the province of Verona ;Mexico: * Cerro Potosí ;United States: * Cerro, New Mexico ;Uruguay: * Cerro Largo Department * Villa del Cerro, in Montevideo * Fortaleza del Cerro, in Montevideo Football clubs * C.A. Cerro, a football club from Montevideo, Uruguay * Club Cerro Cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene Lava Domes
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós ( latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the ... [...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] |
Puerto Varas, Chile
Puerto Varas, also known as "La ciudad de las rosas" or “the city of roses”, is a city and commune located in the southern Chilean province of Llanquihue, in the Los Lagos Region. The city is famous for its German traditions, its natural environment, and its popularity as a tourist destination. It enjoys a scenic location close to mountains, lakes, forests and national parks. It is located from the city of Puerto Montt on the shore of Llanquihue Lake, the second largest lake in Chile. The conical Osorno Volcano and the snowcapped peaks of Mt. Calbuco and Mt. Tronador are clearly visible from the lakefront. Puerto Varas is the southernmost of a string of towns on the western shore of Llanquihue Lake that includes Frutillar, Llanquihue and Puerto Octay. It spans an area of . History The original of the city of Puerto Varas date to 1853 and is named after Antonio Varas, the Minister of the Interior at the time. It was founded by German immigrants who settled the shore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ResearchGate
ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a 2014 study by ''Nature'' and a 2016 article in '' Times Higher Education'', it is the largest academic social network in terms of active users, although other services have more registered users, and a 2015–2016 survey suggests that almost as many academics have Google Scholar profiles. While reading articles does not require registration, people who wish to become site members need to have an email address at a recognized institution or to be manually confirmed as a published researcher in order to sign up for an account. Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, research proposals, methods, presentations, and software source code. Users may also follow the activities of other users and engage in discussions with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SERNAGEOMIN
250px, Sernageomin building in Providencia, Santiago. The National Geology and Mining Service ( es, Servicio Nacional de Geología y Minería; SERNAGEOMIN) is a Chilean government agency. Its function is to provide geological information and advice, technical assistance to government, public and private interests, and to regulate the mining industry in Chile. The service was formed in 1980 by the combination of the previous Institute of Geological Investigations and the State Mines Service. Its director is appointed by the President of Chile The president of Chile ( es, Presidente de Chile), officially known as the President of the Republic of Chile ( es, Presidente de la República de Chile), is the head of state and head of government of the Republic of Chile. The president is re ....United States Geological Survey web site, The volcanos in Chile are monitored by SERNAGEOMIN Since 1974, SERNAGEOMIN has published the scientific journal ''Andean Geology'', formerly the ''R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plagioclase
Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel (1796–1872) in 1826. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in the mineral's crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or 'record-groove' effect. Plagioclase is a major constituent mineral in the Earth's crust, and is consequently an important diagnostic tool in petrology for identifying the composition, origin and evolution of igneous rocks. Plagioclase is also a major constituent of rock in the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hornblende
Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks. The general formula is . Physical properties Hornblende has a hardness of 5–6, a specific gravity of 3.0 to 3.6, and is typically an opaque green, dark green, brown, or black color. It tends to form slender prismatic to bladed crystals, diamond-shaped in cross-section, or is present as irregular grains or fibrous masses. Its planes of cleavage intersect at 56° and 124° angles. Hornblende is most often confused with the pyroxene series and biotite mica, which are also dark minerals found in granite and charnockite. Pyroxenes differ in their cleavage planes, which intersect at 87° and 93°. Hornblende is an inosilicate (chain silicate) mineral, built around double chains of silica tetrahedra. These chains extend the length ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dacite
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained ( aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz. Dacite is relatively common, occurring in many tectonic settings. It is associated with andesite and rhyolite as part of the subalkaline tholeiitic and calc-alkaline magma series. Composition Dacite consists mostly of plagioclase feldspar and quartz with biotite, hornblende, and pyroxene ( augite or enstatite). The quartz appears as rounded, corroded phenocrysts, or as an element of the ground-mass. The plagioclase in dacite ranges from oligoclase to andesine and labradorite. Sanidine occurs, although in small proportions, in some dacites, and when abundant gives rise to rocks that form transitions to the rhyolites. The relative proportions of feldspars a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate hardness, soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable nuclide, stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pica Gap
Pica gap is a segment in the Central Volcanic Zone of Chile where volcanic activity is absent. It is named after the Altos de Pica region. This segment is long and extends between the volcanoes Isluga in the north and Irruputuncu in the south. Volcanoes in the gap are old, Miocene to Pliocene in age and are heavily eroded. Examples include , Cerro Cariquima and Cerro Tatjachura. At the latitude of the Pica gap, an underwater rise known as the Iquique rise is subducted in the Peru-Chile Trench. It is unclear if the subduction of this rise is the cause for the lack of recent volcanism in the Pica gap. The lack of volcanism in the Pica gap appears to be due to unfavourable mantle flow patterns, which prevent the ascent of magma. Geologically, the Pica gap lies between two crustal domains which are defined by their divergent lead isotope ratios, the northerly Arequipa-Antofalla block of Proterozoic age and the southern Chilenia terrane of Paleozoic age. Other phenomena wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
