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Diatreme
A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe associated with a gaseous explosion. When magma rises up through a crack in Earth's crust and makes contact with a shallow body of groundwater, rapid expansion of heated water vapor and volcanic gases can cause a series of explosions. A relatively shallow crater (known as a '' maar'') is left, and a rock-filled fracture (the actual diatreme) in the crust. Where diatremes breach the surface they produce a steep, inverted cone shape. Etymology and geology The word comes . The term diatreme has been applied more generally to any concave body of broken rock formed by explosive or hydrostatic forces, whether or not it is related to volcanism. Even within volcanology, the term has been used more generally by some than others, and in kimberlite terminology continues to be contentious. A current geological understanding is that diatreme describes the overall structure cut into the substrate (some have used th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross Diatreme
The Cross diatreme is a diatreme in southeastern British Columbia, Canada, located east of the Rocky Mountain Trench and northeast of Elkford. See also *Volcanism in Canada *List of volcanoes in Canada List of volcanoes in Canada is an incomplete list of volcanoes found in Geography of Canada, mainland Canada, in the Islands of Canada, Canadian islands and in Canadian waters. All but two Provinces of Canada, provinces, Prince Edward Island and ... References Diatremes of British Columbia Continental Ranges {{BritishColumbiaInterior-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackfoot Diatreme
The Blackfoot diatreme is a diatreme in southeastern British Columbia, Canada, located northeast of Cranbrook. It is in length with a maximum width of . The diatreme is elongate in shape, and outcrops east of Blackfoot Creek. See also *Volcanism in Canada *List of volcanoes in Canada List of volcanoes in Canada is an incomplete list of volcanoes found in Geography of Canada, mainland Canada, in the Islands of Canada, Canadian islands and in Canadian waters. All but two Provinces of Canada, provinces, Prince Edward Island and ... References Diatremes of British Columbia East Kootenay {{BritishColumbiaInterior-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Pipe
Volcanic pipes or volcanic conduits are subterranean geology, geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of ''diatreme''. Volcanic pipes are composed of a deep, narrow cone of solidified magma (described as "carrot-shaped"), and are usually largely composed of one of two characteristic rock types — kimberlite or lamproite. These rocks reflect the composition of the volcanoes' deep magma sources, where the Earth is rich in magnesium. They are well known as the primary source of diamonds, and are mined for this purpose. Volcanic pipes are relatively rare by this definition based on minerals and depth of the magma source, but on the other hand volcanic diatremes are common, indeed the second commonest form of volcanic extrusion (that is magma that reaches the surface). Formation Volcanic pipes form as the result of violent eruptions of deep-origin volcanoes. These volcanoes originate at least three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moses Rock Dike
In Abrahamic religions, Moses was the Hebrews, Hebrew prophet who led the Israelites out of slavery in the The Exodus, Exodus from ancient Egypt, Egypt. He is considered the most important Prophets in Judaism, prophet in Judaism and Samaritanism, and one of the most important prophets in Christianity, Prophets and messengers in Islam, Islam, the Manifestation of God (Baháʼí Faith)#Known messengers, Baháʼí Faith, and Table of prophets of Abrahamic religions, other Abrahamic religions. According to both the Bible and the Quran, God in Abrahamic religions, God dictated the Mosaic Law to Moses, which he Mosaic authorship, wrote down in the five books of the Torah. According to the Book of Exodus, Moses was born in a period when his people, the Israelites, who were an slavery, enslaved minority, were increasing in population; consequently, the Pharaohs in the Bible#In the Book of Exodus, Egyptian Pharaoh was worried that they might ally themselves with New Kingdom of Egypt, Eg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenolith
A xenolith ("foreign rock") is a rock (geology), rock fragment (Country rock (geology), country rock) that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term ''xenolith'' is almost exclusively used to describe inclusion (mineral), inclusions in igneous rock entrained during magma ascent, emplacement and eruption. Xenoliths may be engulfed along the margins of a magma chamber, torn loose from the walls of an erupting lava conduit or explosive diatreme or picked up along the base of a flowing body of lava on the Earth's surface. A xenocryst is an individual foreign crystal included within an igneous body. Examples of xenocrysts are quartz crystals in a silica-deficient lava and diamonds within kimberlite diatremes. Xenoliths can be non-uniform within individual locations, even in areas which are spatially limited, e.g. rhyolite-dominated lava of Nii-jima, Niijima volcano (Japan) contains two types of gabbroic xenoliths which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) can color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Mantle (Earth)
The upper mantle of Earth is a very thick layer of rock inside the planet, which begins just beneath the crust (at about under the oceans and about under the continents) and ends at the top of the lower mantle the . Temperatures range from approximately at the upper boundary with the crust to approximately at the boundary with the lower mantle. Upper mantle material that has come up onto the surface comprises about 55% olivine, 35% pyroxene, and 5 to 10% of calcium oxide and aluminum oxide minerals such as plagioclase, spinel, or garnet, depending upon depth. Seismic structure The density profile through Earth is determined by the velocity of seismic waves. Density increases progressively in each layer, largely due to compression of the rock at increased depths. Abrupt changes in density occur where the material composition changes. The upper mantle begins just beneath the crust and ends at the top of the lower mantle. The upper mantle causes the tectonic plates to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dike (geology)
In geology, a dike or dyke is a sheet of rock that is formed in a fracture of a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma flows into a crack then solidifies as a sheet intrusion, either cutting across layers of rock or through a contiguous mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack.Essentials of Geology, 3rd Ed, Stephen Marshak Magmatic dikes A magmatic dike is a sheet of igneous rock that cuts across older rock beds. It is formed when magma fills a fracture in the older beds and then cools and solidifies. The dike rock is usually more resistant to weathering than the surrounding rock, so that erosion exposes the dike as a natural wall or ridge. It is from these natural walls that dikes get their name. Dikes preserve a record of the fissures through which most mafic magma (fluid magma low in silica) reaches the surface. They are studied by geologists for the clues they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimberlite
Kimberlite is an igneous rock and a rare variant of peridotite. It is most commonly known as the main host matrix for diamonds. It is named after the town of Kimberley, Northern Cape, Kimberley in South Africa, where the discovery of an 83.5-Carat (mass), carat (16.70 g) diamond called the Star of South Africa (diamond), Star of South Africa in 1869 spawned a diamond rush and led to the excavation of the open-pit mine called the Big Hole. Previously, the term kimberlite has been applied to olivine lamproites as Kimberlite II, however this has been in error. Kimberlite occurs in the Earth's Crust (geology), crust in vertical structures known as Volcanic pipe, kimberlite pipes, as well as igneous Dike (geology), dykes and can also occur as horizontal Sill (geology), sills. Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within Earth's mantle. Formation occurs at depths between 150 and 450 kilometres ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism
Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a heat source, usually internally generated, inside the body; the heat is generated by various processes, such as radioactive decay or tidal heating. This heat partially melts solid material in the body or turns material into gas. The mobilized material rises through the body's interior and may break through the solid surface. Causes For volcanism to occur, the temperature of the mantle must have risen to about half its melting point. At this point, the mantle's viscosity will have dropped to about 1021 Pascal-seconds. When large scale melting occurs, the viscosity rapidly falls to 103 Pascal-seconds or even less, increasing the heat transport rate a million-fold. The occurrence of volcanism is partially due to the fact that melted materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatics
Hydrostatics is the branch of fluid mechanics that studies fluids at hydrostatic equilibrium and "the pressure in a fluid or exerted by a fluid on an immersed body". The word "hydrostatics" is sometimes used to refer specifically to water and other liquids, but more often it includes both gases and liquids, whether compressible or incompressible. It encompasses the study of the conditions under which fluids are at rest in stable equilibrium. It is opposed to ''fluid dynamics'', the study of fluids in motion. Hydrostatics is fundamental to ''hydraulics'', the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical explanations for many phenomena of everyday life, such as why atmospheric pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
