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Akimotoite
Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula . It is polymorphous with pyroxene and with bridgmanite, a natural silicate perovskite that is the most abundant mineral in Earth's silicate mantle. Akimotoite has a vitreous luster, is colorless, and has a white or colorless streak. It crystallizes in the trigonal crystal system in space group R. It is the silicon analogue of geikielite (MgTiO3). Crystal structure The crystal structure is similar to that of ilmenite (FeTiO3) with Si and Mg in regular octahedral coordination with oxygen. The Si and Mg octahedra align in discrete layers alternating up the c-axis. The space group is R (trigonal) with a = 4.7284 Å; c = 13.5591 Å; V = 262.94 Å3; Z = 6.Horiuchi, H., Hirano, M., Ito, E., and Matsui, Y. (1982) MgSiO3 (ilmenite-type): single crystal X-ray diffraction study. American Mineralogist, 67, 788-793 Occurrence Akimotoite was found in the Tenham meteorites in Queen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide Minerals
The oxide mineral class includes those minerals in which the oxide anion (O2−) is bonded to one or more metal alloys. The hydroxide-bearing minerals are typically included in the oxide class. The minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately. Simple oxides: *XO **Periclase group ***Periclase ***Manganosite **Zincite group ***Zincite *** Bromellite ***Tenorite ***Litharge * **Cuprite **Ice * **Hematite group ***Corundum ***Hematite ***Ilmenite * **Rutile group ***Rutile ***Pyrolusite *** Cassiterite ** Baddeleyite **Uraninite **Thorianite * **Spinel group ***Spinel ***Gahnite ***Magnetite ***Franklinite *** Chromite **Chrysoberyl **Columbite *Hydroxide subgroup: **Brucite **Manganite ** Romanèchite **Goethite group: ***Diaspore ***Goethite Nickel–Strunz Classification -04- Oxides IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 2009). This list uses it to mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite Minerals
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples " bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and impact the Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditionally been divided into three broad categories: stony meteorites that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Meteoritics
This is a glossary of terms used in meteoritics, the science of meteorites. # * 2 Pallas – an asteroid from the asteroid belt and one of the likely parent bodies of the CR meteorites. * 4 Vesta – second-largest asteroid in the asteroid belt and likely source of the HED meteorites. * 221 Eos – an asteroid from the asteroid belt and one of the likely parent bodies of the CO meteorites. * 289 Nenetta – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites. * 3103 Eger – an asteroid from the asteroid belt and one of the likely parent bodies of the aubrites. * 3819 Robinson – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites. * IA meteorite – an iron meteorite group now part of the IAB group/complex. * IAB meteorite – an iron meteorite and primitive achondrite of the IAB group/complex. * IB meteorite – an iron meteorite group now part of the IAB group/complex. * IC meteorite – an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate 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 the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Mantle
Earth's mantle is a layer of silicate rock between the crust and the outer core. It has a mass of 4.01 × 1024 kg and thus makes up 67% of the mass of Earth. It has a thickness of making up about 84% of Earth's volume. It is predominantly solid but, on geologic time scales, it behaves as a viscous fluid, sometimes described as having the consistency of caramel. Partial melting of the mantle at mid-ocean ridges produces oceanic crust, and partial melting of the mantle at subduction zones produces continental crust. Structure Rheology Earth's mantle is divided into two major rheological layers: the rigid lithosphere comprising the uppermost mantle, and the more ductile asthenosphere, separated by the lithosphere-asthenosphere boundary. Lithosphere underlying ocean crust has a thickness of around 100 km, whereas lithosphere underlying continental crust generally has a thickness of 150–200 km. The lithosphere and overlying crust make up tectonic plates, which mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randall County, Texas
Randall County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 140,753. Its county seat is Canyon. The county was created in 1876 and later organized in 1889. It is named for Horace Randal, a Confederate brigadier general killed at the Battle of Jenkins Ferry. The reason the county name differs from his is because the bill creating the county misspelled Randal's name. Randall County, alongside adjacent Potter County is part of the Amarillo Metropolitan Statistical Area. At one time, the large JA Ranch, founded by Charles Goodnight and John George Adair, which reached into six counties, held acreage in Randall County. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.2%) is covered by water. Palo Duro Canyon, the second-largest canyon in the United States, is located in Randall County. Major highways * Interstate 27 * U.S. Highway 60 * U.S. Highway 87 * State Highwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbarger Meteorite
Umbarger ( ) is an unincorporated community and census-designated place in Randall County, Texas, United States. According to the Handbook of Texas, the community had an estimated population of 327 in 2000. The community is part of the Amarillo, Texas Metropolitan Statistical Area. Geography Umbarger is located at (34.9545022, -96.2510895). The community is situated along U.S. Highway 60 in west central Randall County, approximately 10 miles southwest of Canyon and 26 miles southwest of Amarillo. Climate According to the Köppen Climate Classification system, Umbarger has a semi-arid climate, abbreviated "BSk" on climate maps. History The origins of the community date back to the mid-1890s. In 1895, rancher S.G. Umbarger leased the site from the Houston and Great Northern Railroad survey lands. He purchased it two years later and established several businesses that catered to area settlers and travelers. The Panhandle and Santa Fe Railway established a switch near Umbarger's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea to the south in the Atlantic Ocean. It covers an area of , and with a population of over 225 million, it is the most populous country in Africa, and the world's sixth-most populous country. Nigeria borders Niger in the north, Chad in the northeast, Cameroon in the east, and Benin in the west. Nigeria is a federal republic comprising of 36 states and the Federal Capital Territory, where the capital, Abuja, is located. The largest city in Nigeria is Lagos, one of the largest metropolitan areas in the world and the second-largest in Africa. Nigeria has been home to several indigenous pre-colonial states and kingdoms since the second millennium BC, with the Nok civilization in the 15th century BC, marking the first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katsina State
Katsina State ''(Hausa: Jihar Katsina) (Fula: Leydi Katsina 𞤤𞤫𞤴𞤣𞤭 𞤳𞤢𞥁𞤭𞤲𞤢)'' is a state in the northwestern geopolitical zone of Nigeria. Katsina State was created in 1987, when it split from Kaduna State. Today, Katsina State borders Kaduna, Zamfara, Kano, and Jigawa States. Nicknamed the "Home of Hospitality", both the state capital and the town of Daura have been described "ancient seats of Islamic culture and learning" in Nigeria. With over 5,800,000 residents as at 2006, Katsina State is the fifth largest state in the country by population, despite the fact that it only ranks 17th out of 36 states in terms of area. Demographically, the Hausa people are the largest ethnic group in the state, and Islam is the most practiced religion. In 2005, Katsina became the fifth state in Nigeria to adopt Sharia law. The current Governor of Katsina State is Aminu Bello Masari, a member of the All Progressives Congress and ally of President Muhammadu Bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
