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Mesosiderite
Mesosiderites are a class of stony–iron meteorites consisting of about equal parts of metallic nickel-iron and silicate. They are breccias with an irregular texture; silicates and metal occur often in lumps or pebbles as well as in fine-grained intergrowths. The silicate part contains olivine, pyroxenes, and Ca-rich feldspar and is similar in composition to eucrites and diogenites. They are a rare type of meteorite; as of November 2014 only 208 are known (of which 56 come from Antarctica) and only 7 of these are observed falls. On the other hand, some mesosiderites are among the largest meteorites known. At Vaca Muerta in the Atacama Desert in Chile, many fragments with a total mass of 3.8 tons were found in a large strewnfield. They were first discovered in the 19th century by ore prospectors who mistook the shiny metal inclusions for silver and thought they had found an outcrop of a silver ore deposit. Later when an analysis was made and nickel-iron was found, the true nature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fall (meteorite)
A meteorite fall, also called an observed fall, is a meteorite collected after its fall from outer space was observed by people or automated devices. Any other meteorite is called a "find". There are more than 1,100 documented falls listed in widely used databases, most of which have specimens in modern collections. , the Meteoritical Bulletin Database had 1211 confirmed falls. Importance Observed meteorite falls are important for several reasons. Material from observed falls has not been subjected to terrestrial weathering, making the find a better candidate for scientific study. Historically, observed falls were the most compelling evidence supporting the extraterrestrial origin of meteorites. Furthermore, observed fall discoveries are a better representative sample of the types of meteorites which fall to Earth. For example, iron meteorites take much longer to weather and are easier to identify as unusual objects, as compared to other types. This may explain the increas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stony–iron Meteorite
Stony-iron meteorites or siderolites are meteorites that consist of nearly equal parts of meteoric iron and silicates. This distinguishes them from the stony meteorites, that are mostly silicates, and the iron meteorites, that are mostly meteoric iron. Stony-iron meteorites are all differentiated, meaning that they show signs of alteration. They are therefore achondrites. The stony-irons are divided into mesosiderites and pallasites. Pallasites have a matrix of meteoric iron with embedded silicates (most of it olivine). Mesosiderites are breccias which show signs of metamorphism. The meteoric iron occurs in clasts instead of a matrix.Karl K. Turekian. ''Meteorites, comets, and planets'112/ref> They are in the top rank of all Meteorite classification schemes, usually called "Type". Mineralogy The meteoric iron of stony-irons is similar to that of iron meteorites, consisting mostly of kamacite and taenite in different proportions. The silicates are dominated by olivine. Accessor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16 Psyche
16 Psyche () is a large M-type asteroid discovered by the Italian astronomer Annibale de Gasparis on 17 March 1852 and named after the Greek goddess Psyche. The prefix "16" signifies that it was the sixteenth minor planet in order of discovery. It is the largest and most massive of the M-type asteroids, and one of the dozen most massive asteroids. It has a mean diameter of approximately and contains about one percent of the mass of the asteroid belt. Historically, it was hypothesized to be the exposed core of a protoplanet, but numerous recent studies have all but ruled that out. Psyche will be explored by the spacecraft of the same name, with launch planned in 2023 and arrival in 2029. Symbol Astronomers created icon-like symbols for the first fifteen asteroids to be discovered, as a type of shorthand notation consistent with older notation for the classical planets. Psyche was given an iconic symbol, as were a few other asteroids discovered after 16 Psyche. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamacite
Kamacite is an alloy of iron and nickel, which is found on Earth only in meteorites. According to the International Mineralogical Association (IMA) it is considered a proper nickel-rich variety of the mineral native iron. The proportion iron:nickel is between 90%:10% and 95%:5%; small quantities of other elements, such as cobalt or carbon may also be present. The mineral has a metallic luster, is gray and has no clear cleavage although its crystal structure is isometric-hexoctahedral. Its density is about 8 g/cm3 and its hardness is 4 on the Mohs scale. It is also sometimes called balkeneisen. The name was coined in 1861 and is derived from the Greek root ''καμακ-'' "kamak" or ''κάμαξ'' "kamaks", meaning vine-pole. It is a major constituent of iron meteorites (octahedrite and hexahedrite types). In the octahedrites it is found in bands interleaving with taenite forming Widmanstätten patterns. In hexahedrites, fine parallel lines called Neumann lines are often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinguetti Meteorite
The Chinguetti meteorite is a find reputed to come from a large unconfirmed 'iron mountain' in Africa. The existence of a huge stony-iron mesosiderite approximately 45 kilometers from the Saharan city Chinguetti, Mauritania, has been a mystery since 1916, when Captain Gaston Ripert, a French consular official, claimed to have discovered 'a huge iron hill high and long.' Ripert said that he had been guided blindfolded by a local chieftain to a natural source of iron, after a 12-hour-long camel ride to the south-east of Chinguetti. He bagged a 4 kilogram fragment of the rock, which found its way to Paris some years later, where geologist Alfred Lacroix pronounced that it was an important discovery. However, despite the attempts of several expeditions since, the supposed meteorite could not be found again. Ripert wrote to Professor Théodore Monod in 1934: 'I know that the general opinion is that the stone does not exist; that to some, I am purely and simply an impostor who pick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estherville, Iowa
Estherville is a city in Emmet County, Iowa, United States. The population was 5,904 in the 2020 census, a decline from 6,656 at the 2000 census. It is the county seat of Emmet County. History Emmet County was initially created by an act of the Iowa Legislature in 1851. The area that is now Estherville witnessed the arrival of its first settlers around 1856 and into 1857. In 1859 the city was selected as the county seat and was eventually incorporated in 1881. Estherville was named after Esther A. Ridley, one of the first white female settlers in the area. Many of Estherville's current residents are the descendants of the original Scandinavian, German and Irish immigrants that arrived in the community in the 1870's. Features and attractions The Regional Wellness Center was a joint project of Estherville Lincoln Central Community School District and the National Guard. Beyond standard gym equipment, the facility boasts an indoor track, pools with slides, and multiple group fit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaca Muerta Meteorite
Vaca, is an abbreviation of "vacation". Vaca also may refer to: Geography *Vaca Mountains, a mountain range in Napa County, California *Vaca Díez Province, Bolivia *Vaca Mare River, a tributary of the Siriu River in Romania *Vaca Mică River, a tributary of the Siriu River in Romania *Mount Vaca, located in northern California *Key Vaca, an island in the middle Florida Keys *Vaca, the former name for Crișan village, Ribița Commune, Hunedoara County, Romania People *Danny Vaca (born 1990), Ecuadorian football (soccer) player *Doyle Vaca (born 1979), Bolivian football (soccer) player *Edder Vaca (born 1985), Ecuadorian football (soccer) player *Eduardo Vaca, Argentine politician *Jorge Vaca (born 1959), Mexican boxer *Joselito Vaca José "Joselito" Vaca Velasco (born August 12, 1982 in Santa Cruz de la Sierra) is a Bolivian footballer. He currently plays as an attacking midfielder for Blooming in the Liga de Fútbol Profesional Boliviano (Bolivian Professional League). C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prospecting
Prospecting is the first stage of the geological analysis (followed by exploration) of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking. Traditionally prospecting relied on direct observation of mineralization in rock outcrops or in sediments. Modern prospecting also includes the use of geologic, geophysical, and geochemical tools to search for anomalies which can narrow the search area. Once an anomaly has been identified and interpreted to be a potential prospect direct observation can then be focused on this area. In some areas a prospector must also make claims, meaning they must erect posts with the appropriate placards on all four corners of a desired land they wish to prospect and register this claim before they may take samples. In other areas publicly held lands are open to prospecting without staking a mining claim. Historical methods The traditional methods of prospecting involved combi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strewnfield
The term strewn field indicates the area where meteorites from a single fall are dispersed. It is also often used for the area containing tektites produced by large meteorite impact.''Tektites in the geological record: showers of glass from the sky''. Gerald Joseph Home McCall. Geological Society of London, 2001page 10/ref> Formation There are two strewnfield formation mechanisms: # Mid-air fragmentation: when a large meteoroid enters the atmosphere it often fragments into many pieces before touching the ground due to thermal shock. This mid-air explosion disperses material over a large oval-shaped area. The long axis of this oval is along the flight path of the meteoroid. When multiple-explosions occur, the material can be found in several overlapping ovals. # Impact fragmentation: when there is almost no mid-air fragmentation the fragmentation can occur upon impact. In this case the strewnfield shape can be different, usually circular. (e.g. Canyon Diablo at Meteor Crater; Austra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east and the Pacific Ocean to the west. Chile covers an area of , with a population of 17.5 million as of 2017. It shares land borders with Peru to the north, Bolivia to the north-east, Argentina to the east, and the Drake Passage in the far south. Chile also controls the Pacific islands of Juan Fernández, Isla Salas y Gómez, Desventuradas, and Easter Island in Oceania. It also claims about of Antarctica under the Chilean Antarctic Territory. The country's capital and largest city is Santiago, and its national language is Spanish. Spain conquered and colonized the region in the mid-16th century, replacing Inca rule, but failing to conquer the independent Mapuche who inhabited what is now south-central Chile. In 1818, after declaring in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Desert
The Atacama Desert ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, just behind some very specific spots within the McMurdo Dry Valleys as well as the only hot true desert to receive less precipitation than the polar deserts, and the largest fog desert in the world. Both regions have been used as experimentation sites on Earth for Mars expedition simulations. The Atacama Desert occupies , or if the barren lower slopes of the Andes are included. Most of the desert is composed of stony terrain, salt lakes (''salares''), sand, and felsic lava that flows towards the Andes. The desert owes its extreme aridity to a constant temperature inversion due to the cool north-flowing Humboldt ocean current and to the presence of the strong Pacific anticyclone. The most arid re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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