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Impact Glass
Impactite is rock created or modified by one or more impacts of a meteorite. Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. On Earth, impactites consist primarily of modified terrestrial material, sometimes with pieces of the original meteorite. Creation When a large meteorite hits a planet, it can radically deform the rocks and regolith that it hits. The heat, pressure, and shock of the impact changes these materials into impactite. Only very massive impacts generate the heat and pressure needed to transform a rock, so impactites are created rarely. Characteristics Impactite includes shock-metamorphosed target rocks, melts ( suevites) and mixtures of the two, as well as sedimentary rocks with significant impact-derived components (shocked mineral grains, tektites, anomalous geochemical signatures, etc.). In June 2015, NASA reported that impact glass has been detected on the planet Mars. Such mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it is the oldest continuously published magazine in the United States. ''Scientific American'' is owned by Springer Nature, which in turn is a subsidiary of Holtzbrinck Publishing Group. History ''Scientific American'' was founded by inventor and publisher Rufus Porter in 1845 as a four-page weekly newspaper. The first issue of the large format newspaper was released August 28, 1845. Throughout its early years, much emphasis was placed on reports of what was going on at the U.S. Patent Office. It also reported on a broad range of inventions including perpetual motion machines, an 1860 device for buoying vessels by Abraham Lincoln, and the universal joint which now can be found in nearly every automobile manufactured. Current issues includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neugrund Crater
Neugrund is a meteorite crater in Estonia. It is in diameter and was previously estimated to have been formed in the Ordovician around 470 Ma, with later research revealing a possible Cambrian origin (around 535 Ma). The crater is at the bottom of the sea and is not exposed at the surface. Boulders of gneissic breccia found on the coast of Osmussaar, a nearby island, are believed to have been thrown there by the explosion. It has been proposed that the Neugrund crater was created during the Ordovician meteor event when a hypothetical large asteroid transferred directly into a resonant orbit with Jupiter, which shifted its orbit to intercept Earth. This attractive theory may need to be changed as more recent study puts the age of the impact in the Cambrian.S. SUUROJA1, K. SUUROJA & T. FLODÉN (2013). A comparative analysis of two Early Palaeozoic marine impact structures in Estonia, Baltic Sea: Neugrund and Kärdla Bulletin of the Geological Society of Finland, Vol. 85, 2013, pp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manicouagan Reservoir
Manicouagan Reservoir (also Lake Manicouagan) is an annular lake in central Quebec, Canada, covering an area of . The lake island in its centre is known as René-Levasseur Island, and its highest point is Mount Babel. The structure was created 214 (±1) million years ago, in the Late Triassic, by the impact of a meteorite in diameter. The lake and island are clearly seen from space and are sometimes called the "eye of Quebec". The lake has a volume of . Geography The reservoir is located in Manicouagan Regional County Municipality in the Côte-Nord region of Quebec, Canada, about north of the city of Baie-Comeau, although its northernmost part is located in Caniapiscau Regional County Municipality. Quebec Route 389 passes the eastern shore of the lake. The crater is a multiple-ring structure about across, with the reservoir at its diameter inner ring being its most prominent feature. It surrounds an inner island plateau called René-Levasseur Island and Mount Babel is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Lappajärvi
Lappajärvi is a lake in Finland, in the municipalities of Lappajärvi, Alajärvi and Vimpeli. It is formed in a wide, partly eroded meteorite impact crater. The lake is part of Ähtävänjoki ( sv, Esse å) basin together with Lake Evijärvi that is located downstream (north) of it. The Lappajärvi impact structure is estimated to be 77.85 ± 0.78 million years old (Campanian age of the Late Cretaceous time period). Experts working on Finland's Onkalo spent nuclear fuel repository project have studied Lake Lappajärvi to help them project how Finnish landscapes might look one million years in the future and beyond. An island in the middle of the lake, Kärnänsaari (Kärnä Island), gives the name to the black impact melt rock (impactite) found there, locally called kärnäite. The towns on the shore are Lappajärvi and Vimpeli. Although not very near any, the nearest major city is Seinäjoki. Earlier the lake was thought to have been an ancient volcano crater. In 1967 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin Glass
Darwin glass is a natural glass found south of Queenstown in West Coast, Tasmania. It takes its name from Mount Darwin in the West Coast Range, where it was first reported, and later gave its name to Darwin Crater, a probable impact crater, and the inferred source of the glass. Occurrence Fragments of Darwin glass are found scattered over a 410 km2 (160 miles squared) area. Such an area is called a strewn field. On slopes and flat ground between 250 and 500 m elevation, the glass occurs with quartzite fragments buried under peat and soil. The peat is normally around 20 cm thick, and the quartzite fragment horizon is typically 30 cm thick. On mountain peaks higher than 500 m, the bedrock is directly exposed to the air, and Darwin glass occurs occasionally on the surface. In valleys below 220 m the Darwin glass is buried below peat and sediments. The glass occurs north, west and south from the crater. Its distribution extends to Kelly Basin and the lower nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin Crater
Darwin Crater is a suspected meteorite impact crater in Western Tasmania about south of Queenstown, just within the Franklin-Gordon Wild Rivers National Park. The crater is expressed as a rimless circular flat-floored depression, in diameter, within mountainous and heavily forested terrain. It is east of the West Coast Range and the former North Mount Lyell Railway formation. Discovery and description The crater was discovered by the geologist R. J. Ford in 1972, after a search for the source of Darwin glass, an impact glass found over more than of southwestern Tasmania. Geophysical investigations and drilling have shown that the crater is filled with up to of breccia capped by Pleistocene lake sediments. Although definitive proof of an impact origin of the crater is lacking, the impact hypothesis is strongly supported by the relationship of the glass to the crater, as well as the stratigraphy and deformation of the crater-filling material. If the crater is indeed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charlevoix Impact Structure
The Charlevoix impact structure is a large eroded meteorite impact structure in the Charlevoix region of Quebec, Canada. Only part of the impact structure is exposed at the surface, the rest lying beneath the Saint Lawrence River. Description The original impact structure is estimated to have been in diameter and the age of the impact is estimated to be 450 ± 20 million years (Ordovician to Silurian age).Schmieder, M., Shaulis, B.J., Lapen, T.J., Buchner, E. and Kring, D.A., 2019. ''In situ U–Pb analysis of shocked zircon from the Charlevoix impact structure, Québec, Canada.'' ''Meteoritics & Planetary Science.'' 54(8) pp. 1808-1827. The projectile was probably a stony asteroid, at least in diameter, and weighing an estimated . The Mont des Éboulements, situated in the exact centre of the impact structure, is interpreted as the central uplift, a consequence of elastic rebound.Interpretation Centre, Parc national des Grands-Jardins, Charlevoix The impact structure is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barringer Crater
Meteor Crater, or Barringer Crater, is a meteorite impact crater about east of Flagstaff and west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Cañon Diablo. Because the United States Board on Geographic Names recognizes names of natural features derived from the nearest post office, the feature acquired the name of "Meteor Crater" from the nearby post office named Meteor. Meteor Crater lies at an elevation of above sea level. It is about in diameter, some deep, and is surrounded by a rim that rises above the surrounding plains. The center of the crater is filled with of rubble lying above crater bedrock. One of the interesting features of the crater is its squared-off outline, believed to be caused by existing regional jointing (cracks) in the strata at the impact site. Despite historic attempts to make the cra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A-G
A&G, AG, Ag or ag may refer to Businesses and organizations * A&G Railroad (former reporting mark AG) * Action Group (Nigeria), a political party during the Nigerian First Republic * Aktiengesellschaft, a German type of corporation * Assemblies of God, the world's largest Pentecostal organization * Associated Group, a Pakistani company * Astronomische Gesellschaft, a German astronomical society * IATA code for Aruba Airlines Entertainment * '' American Gladiators'' (1989–1996 TV series) * ''American Gladiators'' (2008 TV series) Government and military * Adjutant general, the Army branch responsible for personnel * Administrator-General of South West Africa, the head of government in Namibia prior to independence in 1990 * Aerographer's mate, a rating or specialty in the US Navy that deals with weather and oceanography * American Holland-class submarine (''Amerikansky Golland''), a class of Imperial Russian submarines * Army green, the color of the US Army service un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alamo Bolide Impact
The Alamo bolide impact occurred 377–378 million years ago, when one or more hypervelocity objects from space slammed into shallow marine waters at a site that is now the Devonian Guilmette Formation of the Worthington Mountains and Schell Creek Range of southeastern Nevada; the event is named for breccias of metamorphosed crushed rock deposits, found near the town of Alamo, Nevada (the "Alamo Breccia"). This catastrophic impact event resulted in what is one of the best-exposed and has become the most accurately dated impact events; it occurred within the Frasnian age of the Devonian at about 377-378 Ma, a moment in time that was about 5.9 Ma prior to the Frasnian/Famennian extinction events, which it is unlikely to have affected. The actual impact site has not yet been significantly documented—even its precise diameter and its internal structural features are not yet clear enough to make speculations on the mass and trajectory genuinely useful. The "tectonic overprint" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
