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Tenham (meteorite)
Tenham meteorites are the fragments of a larger meteorite that fell in 1879 in a remote area of Australia near the Tenham station, South Gregory, in western Queensland. Although the fall was seen by a number of people, its exact date has not been established. Bright meteors were seen to be moving roughly from west to east. Stones were subsequently recovered from over a large area, about long by wide. Because the Tenham meteorites were recovered quite soon after they fell, from a remote and dry region in which weathering and other alterations had not set in, they have been invaluable for scientific study of meteorites and their mineral contents. They are examples of chondritic meteorites, containing a high level of organic compounds, and rich in silicates, oxides, and sulfides. Many scientific studies have explored the mineralogy of these meteorites and their non-terrestrial features. Because the Tenham meteorites show evidence of high pressure deformations, they have been used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrite
A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by (whether quickly, or after many orbits) arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%. Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of organic compounds, the origin of life and the presence of water on Earth. One of their characteristics is the presence of chondrules (from the Ancient Greek χόνδρος ''chondros'', grain), which are round grains formed as molten, or partially molten droplets, in the space by distinct minerals, that normally consti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ted Ringwood
Alfred Edward "Ted" Ringwood FRS FAA (19 April 1930 – 12 November 1993) was an Australian experimental geophysicist and geochemist, and the 1988 recipient of the Wollaston Medal. The mineral ringwoodite is named after him. Early life and study Ringwood was born in Kew, only child of Alfred Edward Ringwood. He attended Hawthorn West State School where he played cricket and Australian Rules football. In 1943 he was successful in gaining a scholarship to Geelong Grammar School where he boarded. On matriculation, he enrolled in Geology a science degree at the University of Melbourne where he held a Commonwealth Government Scholarship, and was awarded a resident scholarship at Trinity College. He represented the college and the university in football. He obtained First Class Honours degree in Geology and began a MSc degree in field-mapping and petrology of the Devonian Snowy River volcanics of northeastern Victoria, graduating with Honours in 1953. Ringwood then undertook a PhD, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Queensland
The geology of Queensland can be subdivided into several regions with different histories. Along the east coast is a complex of Palaezoic to Cainozoic rocks while much of the rest of the state is covered by Cretaceous and Cainozoic rocks. A Precambrian basement is found in the north west and Cape York regions. The Thomson Orogen occurs in the central and southern parts of Queensland, but is mostly covered by younger basins. The North Queensland Orogen is along the coast from Charters Towers to Princess Charlotte Bay. The Bowen Gunndedah Sydney basin can be considered as one system that extends into Queensland. The New England Orogen is on the coastal parts from the border with New South Wales north to Ayr. Devonian The Drummond Basin is a geological basin in central and northern Queensland which consists of Late Devonian to early Carboniferous shallow-marine and continental sediments. Precambrian The Precambrian basement in Queensland is west of the Tasman Line. It includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrite Meteorites
A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by (whether quickly, or after many orbits) arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%. Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of organic compounds, the origin of life and the presence of water on Earth. One of their characteristics is the presence of chondrules (from the Ancient Greek χόνδρος ''chondros'', grain), which are round grains formed as molten, or partially molten droplets, in the space by distinct minerals, that normally const ... [...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] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferric
In chemistry, iron(III) refers to the element iron in its +3 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe3+. The adjective ferric or the prefix ferri- is often used to specify such compounds — as in "ferric chloride" for iron(III) chloride, . The adjective "ferrous" is used instead for iron(II) salts, containing the cation Fe2+. The word ferric is derived from the Latin word ''ferrum'' for iron. Iron(III) metal centres also occur in coordination complexes, such as in the anion ferrioxalate, , where three bidentate oxalate ions surrounding the metal centre; or, in organometallic compounds, such as the ferrocenium cation , where two cyclopentadienyl anions are bound to the FeIII centre. Iron is almost always encountered in the oxidation states 0 (as in the metal), +2, or +3. Iron(III) is usually the most stable form in air, as illustrated by the pervasiveness of rust, an insoluble iron(III)-containing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals including h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicate Perovskite
Silicate perovskite is either (the magnesium end-member is called bridgmanite) or (calcium silicate known as davemaoite) when arranged in a perovskite structure. Silicate perovskites are not stable at Earth's surface, and mainly exist in the lower part of Earth's mantle, between about depth. They are thought to form the main mineral phases, together with ferropericlase. Discovery The existence of silicate perovskite in the mantle was first suggested in 1962, and both and had been synthesized experimentally before 1975. By the late 1970s, it had been proposed that the seismic discontinuity at about 660 km in the mantle represented a change from spinel structure minerals with an olivine composition to silicate perovskite with ferropericlase. Natural silicate perovskite was discovered in the heavily shocked Tenham meteorite. In 2014, the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA) approved the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forsterite
Forsterite (Mg2SiO4; commonly abbreviated as Fo; also known as white olivine) is the magnesium-rich end-member of the olivine solid solution series. It is isomorphous with the iron-rich end-member, fayalite. Forsterite crystallizes in the orthorhombic system (space group ''Pbnm'') with cell parameters ''a'' 4.75 Å (0.475 nm), ''b'' 10.20 Å (1.020 nm) and ''c'' 5.98 Å (0.598 nm). Forsterite is associated with igneous and metamorphic rocks and has also been found in meteorites. In 2005 it was also found in cometary dust returned by the Stardust probe. In 2011 it was observed as tiny crystals in the dusty clouds of gas around a forming star. Two polymorphs of forsterite are known: wadsleyite (also orthorhombic) and ringwoodite ( isometric, Cubic crystal system). Both are mainly known from meteorites. Peridot is the gemstone variety of forsterite olivine. Composition Pure forsterite is composed of magnesium, oxygen and silicon. The chemical formula is Mg2SiO4. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordinary Chondrite
The ordinary chondrites (sometimes called the O chondrites) are a class of stony chondritic meteorites. They are by far the most numerous group, comprising 87% of all finds. Hence, they have been dubbed "ordinary". The ordinary chondrites are thought to have originated from three parent asteroids, with the fragments making up the H chondrite, L chondrite and LL chondrite groups respectively. Origin It is suspected that they are not representative of typical asteroid parent bodies, but rather of a select few which are advantageously placed to send impact fragments to Earth-crossing orbits. Such positions are e.g. near Kirkwood gaps and/or secular resonances in the main asteroid belt. In fact, only the one rather insignificant asteroid 3628 Božněmcová has been identified to have a spectrum close to the ordinary chondrites. A probable parent body of the H chondrites (comprising about 46% of the ordinary chondrites) is 6 Hebe, but its spectrum is dissimilar due to what is likel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringwoodite
Ringwoodite is a high-pressure phase of Mg2SiO4 (magnesium silicate) formed at high temperatures and pressures of the Earth's mantle between depth. It may also contain iron and hydrogen. It is polymorphous with the olivine phase forsterite (a magnesium iron silicate). Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure. In this case two hydroxide ions usually take the place of a magnesium ion and two oxide ions. Combined with evidence of its occurrence deep in the Earth's mantle, this suggests that there is from one to three times the world ocean's equivalent of water in the mantle transition zone from 410 to 660 km deep. This mineral was first identified in the Tenham meteorite in 1969, and is inferred to be present in large quantities in the Earth's mantle. Ringwoodite was named after the Australian earth scientist Ted Ringwood (1930–1993), who studied polymorphic phase transitions in the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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