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Lodranite
Lodranites are a small group of primitive achondrite meteorites that consists of meteoric iron and silicate minerals. Olivine and pyroxene make up most of the silicate minerals. Like all primitive achondrites lodranites share similarities with chondrites and achondrites. Naming and history The lodranite group is named after Lodhran, Pakistan, where the type specimen fell on 1 October 1868 at 14:00. Eyewitnesses of the fall reported a loud bang accompanied by a rising dust cloud to the east of the city, which led to the discovery and retrieval of the meteorite. The "meteorite from Lodran" was first described by Gustav Tschermak in 1870. He described the meteorite being "''apart from the nickel-iron it is an olivine-bronzite aggregates of such outstanding sort, that has never been found in a meteorite before only similar to the terrestrial olivine rock''". George Thurland Prior was the first to classify the lodran meteorite as the only member of the lodranite group. He als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Achondrite
Primitive achondrites are a subdivision of meteorites. They are classified on the same rank (historically called "Class") and lying between chondrites and achondrites. They are called primitive because they are achondrites that have retained much of their original chondritic properties. Very characteristic are relic chondrules and chemical compositions close to the composition of chondrites. These observations are explained as melt residues, partial melting, or extensive recrystallization. History The concept of primitive achondrites was first summarized in 1983. In 2006 a classification was published that assigned 7 groups to the primitive achondrites, but the classification remains controversial. The authors define primitive achondrites as meteorites "''that exceeded their solidus temperature on the parent body''" and thus would partially melt. Meteorites that have been fully melted are included if they did not reach isotopic equilibrium on their parent body. Description There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Achondrite
Primitive achondrites are a subdivision of meteorites. They are classified on the same rank (historically called "Class") and lying between chondrites and achondrites. They are called primitive because they are achondrites that have retained much of their original chondritic properties. Very characteristic are relic chondrules and chemical compositions close to the composition of chondrites. These observations are explained as melt residues, partial melting, or extensive recrystallization. History The concept of primitive achondrites was first summarized in 1983. In 2006 a classification was published that assigned 7 groups to the primitive achondrites, but the classification remains controversial. The authors define primitive achondrites as meteorites "''that exceeded their solidus temperature on the parent body''" and thus would partially melt. Meteorites that have been fully melted are included if they did not reach isotopic equilibrium on their parent body. Description There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes. Achondrites account for about 8% of meteorites overall, and the majority (about two-thirds) of them are HED meteorites, possibly originating from the crust of asteroid 4 Vesta. Other types include Martian, Lunar, and several types thought to originate from as-yet unidentified asteroids. These groups have been determined on the basis of e.g. the Fe/ Mn chemical ratio and the 17O/18O oxygen isotope ratios, thought to be characteristic "fingerprints" for each parent body. Classification Achondrites are classified into the following groups:O. Richard Norton. The Cambridge encyclopedia of meteorites. U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondrites
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes. Achondrites account for about 8% of meteorites overall, and the majority (about two-thirds) of them are HED meteorites, possibly originating from the crust of asteroid 4 Vesta. Other types include Martian, Lunar, and several types thought to originate from as-yet unidentified asteroids. These groups have been determined on the basis of e.g. the Fe/ Mn chemical ratio and the 17O/18O oxygen isotope ratios, thought to be characteristic "fingerprints" for each parent body. Classification Achondrites are classified into the following groups:O. Richard Norton. The Cambridge encyclopedia of meteorites. ... [...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 highlan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acapulcoite
Acapulcoites are a group of the primitive achondrite class of stony meteorites. Naming and history The acapulcoites are named after the only specimen of the group, with a witnessed fall. The Acapulca meteorite fell on 11 August 1976 at 11:00 near El Quemado Colony (), outside Acapulco, Guerrero, Mexico. It had a mass of . The stone was retrieved 15 minutes afterwards from a deep crater and was cool to the touch. Following that discovery, 52 meteorite specimens have been classified as acapulcoites. Chemical composition Acapulcoites are primarily composed of olivine, orthopyroxene, plagioclase, meteoric iron, and troilite. Like all primitive achondrites, acapulcoites have chemical composition and mineralogical similarities with chondrites, some specimen even show relic chondrules. Their mineral composition lies between H and E chondrites. See also * Glossary of meteoritics This is a glossary of terms used in meteoritics, the science of meteorites. # * 2 Pallas – an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ureilite
Ureilite is a rare type of stony meteorite that has a unique mineralogical composition very different from that of other stony meteorites. This dark grey or brownish meteorite type is named after the village Novy Urey ( Cyrillic: ''Новый Урей''), Mordovia Republic of Russia, where a meteorite of this type fell on 4 September 1886. Notable ureilites are the Novo Urei and the Goalpara, also named for the town in which it landed (Goalpara, Assam India). On 7 October 2008, tiny asteroid 2008 TC3 entered Earth's atmosphere and exploded an estimated above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite. Scientists have discovered amino acids in meteorite 2008 TC3 where none were expected, taking into account high temperatures reached in the explosion of about 1000 °C. Composition A technical name for ureilite would be olivine-pigeonite achondrite. Compared to most other meteorites, ureili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Thurland Prior
George Thurland Prior FRS (16 December 1862 – 8 March 1936) was a British mineralogist. He made great contributions to mineralogical chemistry, petrology and meteoritics. He was born in Oxford, England, and attended Magdalen College there in 1881. He received a first class in the Honour School in Chemistry in 1885 and Physics in 1886. Later he went to study in Germany. He obtained his Doctor of Science degree from Oxford University in 1905. He entered the British Museum in 1887, where he was Keeper of Minerals from 1909 to 1927. He was elected a Fellow of the Royal Society in 1912. Selected publications * * * * * * See also * 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 b ... * Prior Island * Meteorite classification#History References {{DEF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peridotite
Peridotite ( ) is a dense, coarse-grained igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium (Mg2+), reflecting the high proportions of magnesium-rich olivine, with appreciable iron. Peridotite is derived from Earth's mantle, either as solid blocks and fragments, or as crystals accumulated from magmas that formed in the mantle. The compositions of peridotites from these layered igneous complexes vary widely, reflecting the relative proportions of pyroxenes, chromite, plagioclase, and amphibole. Peridotite is the dominant rock of the upper part of Earth's mantle. The compositions of peridotite nodules found in certain basalts are of special interest along with diamond pipes (kimberlite), because they provide samples of Earth's mantle brought up from depths ranging from about 30 km to 200 km or more. Some of the nodules preserve isotope ratios of osm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate (geology)
In the Earth sciences, aggregate has three possible meanings. In mineralogy and petrology, an aggregate is a mass of mineral crystals, mineraloid particles or rock particles. Examples are dolomite, which is an aggregate of crystals of the mineral dolomite, and ''rock gypsum'', an aggregate of crystals of the mineral gypsum. Lapis lazuli is a type of rock composed of an aggregate of crystals of many minerals including lazurite, pyrite, phlogopite, calcite, potassium feldspar, wollastonite and some sodalite group minerals. In the construction industry, an aggregate (often referred to as a construction aggregate) is sand, gravel or crushed rock that has been mined or quarried for use as a building material. In pedology, an aggregate is a mass of soil particles. If the aggregate has formed naturally, it can be called a ped; if formed artificially, it can be called a clod. Construction aggregate examples * basalt * dolomite * granite * gravel * limestoneSame Day Agg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronzite
Bronzite is a member of the pyroxene group of minerals, belonging with enstatite and hypersthene to the orthorhombic series of the group. Rather than a distinct species, it is really a ferriferous variety of enstatite, which owing to partial alteration has acquired a bronze-like sub-metallic luster on the cleavage surfaces. Enstatite is magnesium silicate, MgSiO3, with the magnesium partly replaced by small amounts (up to about 12%) of Fe+2. In the bronzite variety, (Mg,Fe)SiO3, the iron(II) oxide ranges from about 12 to 30%, and with still more iron there is a passage to hypersthene.Klein, Cornelis and Cornelius Hurlbut, Jr. (1985) ''Manual of Mineralogy,'' Wiley, 20th ed., The ferriferous varieties are liable to a particular kind of alteration, known as schillerization, which results in the separation of the iron as very fine films of oxide and hydroxides along the cleavage cracks of the mineral. The cleavage surfaces therefore exhibit a metallic sheen or schiller, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickly on the surface. For this reason, olivine has been proposed as a good candidate for accelerated weathering to sequester carbon dioxide from the Earth's oceans and atmosphere, as part of climate change mitigation. Olivine also has many other historical uses, such as the gemstone peridot (or chrysolite), as well as industrial applications like metalworking processes. The ratio of magnesium to iron varies between the two endmembers of the solid solution series: forsterite (Mg-endmember: ) and fayalite (Fe-endmember: ). Compositions of olivine are commonly expressed as molar percentages of forsterite (Fo) and fayalite (Fa) (''e.g.'', Fo70Fa30). Forsterite's melting temperature is unusually high at atmospheric pressure, almost , while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
