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Quartzolite
Quartzolite or silexite is an intrusive igneous rock, in which the mineral quartz is more than 90% of the rock's felsic mineral content, with feldspar at up to 10%. Typically, quartz forms more than 60% of the rock, the rest being mostly feldspar although minor amounts of mica or amphibole may also be present. Quartzolite occurs as dykes, sills, veins, bosses and segregation masses; it is also found in association with greisen and pegmatite. Quartzolite is an extremely rare type of rock. No extrusive rock equivalent of quartzolite is known. Synonyms The use of the synonym "''silexite"'' is discouraged because it is the French word for chert, which is a sedimentary rock. Other less common synonyms are "''igneous quartz''" and "''peracidite''". Examples * Chrastava, Czech Republic * Crag Mountain, Northfield, Massachusetts, United States * Jabal Hamra, Saudi Arabia * Keivy, Kola Peninsula, Russia * Lyon Mountain quadrangle, New York state, United States * Moulting Pond, Ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of Silicon dioxide, SiO2. Quartz is, therefore, classified structurally as a Silicate mineral#Tectosilicates, framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Torrington, New South Wales
Torrington (formerly Torington) is a small village in northern New South Wales in Tenterfield Shire. It is 29 kilometres north west of Deepwater and south west of Tenterfield and 61 kilometres from Glen Innes (South-East). It is situated on a plateau known as the Mole Tableland in close proximity to the Queensland border on the Northern Tablelands. A feature of Torrington is its abundance of boulders and rocky outcrops. The most notable boulder outcrop located in the village being "Goat Rock" and just out of town is "Old Mystery Face" History Torrington was named after its English counterpart in Devon. The discovery of the extremely rich Torrington tin lode in 1881 created much excitement but in a very short time the small prospectors had lost control to overseas mining companies, the precursors of today's multi-nationals. In the 1920s, 500 men were employed at the mines. There were sixteen batteries working, and the community enjoyed the convenience of five gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Greisen
Greisen is a highly altered granitic rock or pegmatite, usually composed predominantly of quartz and micas (mostly muscovite). Greisen is formed by self-generated alteration of a granite and is a class of moderate- to high-temperature magmatic-hydrothermal alteration related to the late-stage release of volatiles dissolved in a magma during the solidification of that magma. Greisens are usually variably altered rocks, grading from coarse, crystalline granite, commonly vuggy with miarolitic cavities, through to quartz and muscovite rich rocks, which may be locally rich in topaz, tourmaline, cassiterite, fluorite, beryl, wolframite, siderite, molybdenite and other sulfide minerals, and other accessory minerals. They may occur as small to large veins, or large zones in the roof of some granites. The rocks can sometimes be mined as ores of tin and other minerals. Petrogenesis Greisens are formed by endogenous alteration of granite during the cooling stages of emplacement. Greisen f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sedimentary Rock
Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedimentation is any process that causes these particles to settle in place. Geological detritus originates from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or Mass wasting, mass movement, which are called agents of denudation. Biological detritus is formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (marine snow). Sedimentation may also occur when dissolved minerals precipitate from aqueous solution, water solution. The sedimentary rock cover of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained ( phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dike (geology), dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF diagram, QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Topaz
Topaz is a silicate mineral made of aluminium, aluminum and fluorine with the chemical formula aluminium, Alsilicon, Sioxygen, O(fluorine, F, hydroxide, OH). It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden-brown to yellow-orange. Topaz is often treated with heat or radiation to make it a deep blue, reddish-orange, pale green, pink, or purple. Topaz is a nesosilicate mineral, and more specifically, an aluminosilicate mineral. It is one of the hardest naturally occurring minerals and has a relatively low index of refraction. It has the orthorhombic crystal system and a dipyramidial crystal class. It occurs in many places in the world. Some of the most popular places where topaz is sourced are Brazil and Russia. Topaz is often mined in open pit or alluvial settings. Etymology The word "topaz" is usually believed to be derived (via Old French: Topace and Latin: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
South Mountains (Arizona)
The South Mountains (O'odham language, O'odham: ''Muhaḍagĭ Doʼag'', Yavapai language, Yavapai: ''Wi:ki'tiyeda'', ), known locally as simply South Mountain, is a mountain range in central Arizona in south Phoenix, Arizona. The majority of the range is public land managed by the City of Phoenix as South Mountain Park, but a small portion extends into the Gila River Indian Community. Geologically, the South Mountains are thought to be a metamorphic core complex: evidence of movement of the North American tectonic plates from southwest to northeast and northeast to southwest, pushing up a series of mountain ranges including South Mountain. Other ridges with parallel orientation lie within the basin covered by basin fill sediments. The structural basin forms the Phoenix metro area, which appears flat like a lake around mountains that rise over it like islands. The buried ridges are in the same orientation as the South Mountains, about one km high, and about one km apart from peak to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
South Georgia
South Georgia is an island in the Atlantic Ocean, South Atlantic Ocean that is part of the British Overseas Territories, British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. Stretching in the east–west direction, South Georgia is around long and has a maximum width of . The terrain is mountainous, with the central ridge rising to at Mount Paget. The northern coast is indented with numerous bays and fjords, serving as harbor, harbours. Discovered by Europeans in 1675, South Georgia had no indigenous population due to its harsh climate and remoteness. Captain James Cook in made the first landing, survey and mapping of the island. On 17 January 1775, Cook claimed it a British possession, naming it "Isle of Georgia" after George III, King George III. Through its history of South Georgia and the South Sandwich Islands, history, it served as a whaling and seal hunting base, with intermittent population scattere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Saveh County
Saveh County () is in Markazi province, Markazi province, Iran. Its capital is the city of Saveh. History After the 2011 National Census, the village of Aveh, Markazi, Aveh was elevated to the status of a city. Demographics Population At the 2006 census, the county's population was 235,843 in 63,672 households. The following census in 2011 counted 259,030 people in 75,650 households. The 2016 census measured the population of the county as 283,538 in 87,444 households. Administrative divisions Saveh County's population history and administrative structure over three consecutive censuses are shown in the following table. Gallery Masjed-jame-saveh.JPG, Jameh Mosque of Saveh Imamzadeh Seyed Haroun 1.jpg, Imamzadeh Seyed Haroun See also Notes References {{Saveh County, state=collapsed Saveh County Counties of Markazi province ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
