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Libyan Desert Glass
Libyan desert glass or Great Sand Sea glass is an impactite, made mostly of lechatelierite, found in areas in the eastern Sahara, in the deserts of eastern Libya and western Egypt. Fragments of desert glass can be found over areas of tens of square kilometers. Like obsidian, it was knapped and used to make tools during the Pleistocene. Geologic origin The origin of desert glass is uncertain. Meteoritic origins have long been considered possible, and recent research links the glass to impact features, such as zircon breakdown, vaporized quartz and meteoritic metals, and to an impact crater. Some geologists associate the glass with radiative melting from meteoric large aerial bursts, making it analogous to trinitite created from sand exposed to the thermal radiation of a nuclear explosion. Libyan Desert glass has been dated as having formed about 29 million years ago. Analysis of samples with the electron backscatter diffraction (EBSD) technique revealed zircon Zi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libyan Desert Glass
Libyan Desert glass or Great Sand Sea glass is an impactite, made mostly of lechatelierite, found in areas in the eastern Sahara, in the deserts of eastern Libya and western Egypt. Fragments of desert glass can be found over areas of tens of square kilometers. Geologic origin The origin of desert glass is uncertain. Meteoritic origins have long been considered possible, and recent research links the glass to impact features, such as zircon breakdown, vaporized quartz and meteoritic metals, and to an impact crater. Some geologists associate the glass with radiative melting from meteoric large aerial bursts, making it analogous to trinitite created from sand exposed to the thermal radiation of a nuclear explosion. Libyan Desert glass has been dated as having formed about 29 million years ago. Like obsidian, it was knapped and used to make tools during the Pleistocene. The glass is nearly pure silica which requires temperatures above 1,600 °C to form – hotter than a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. 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 classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral definin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Event Minerals
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *''Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a student magazine for the University of Nottingham, England * '' Bath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Libya
The geology of Libya formed on top of deep and poorly understood Precambrian igneous and metamorphic crystalline basement rock. Most of the country is intra-craton basins, filled with thick layers of sediment. The region experienced long-running subsidence and terrestrial sedimentation during the Paleozoic, followed by phases of volcanism and intense folding in some areas, and widespread flooding in the Mesozoic and Cenozoic due to a long marine transgression. Libya has the largest hydrocarbon reserves in Africa, as well as deposits of evaporites. Stratigraphy, tectonics & geologic history Libya is underlain by Precambrian igneous and metamorphic basement rock, which only outcrops at a few locations. These ancient rocks include schist, gneiss, quartzite and granite, known from boreholes. Paleozoic (539-251 million years ago) An angular unconformity separates the overlying Hassaouna sandstones from lower Precambrian rocks. These sandstones are inferred to be Cambrian rocks, formed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass In Nature
Glass is a non-Crystallinity, crystalline, often transparency and translucency, transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the Melting, molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silicon dioxide, silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and glasses, eyeglasses, are so commonly made of silicate- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tutankhamun Pendant With Wadjet
Tutankhamun (, egy, twt-ꜥnḫ-jmn), Egyptological pronunciation Tutankhamen () (), sometimes referred to as King Tut, was an Egyptian pharaoh who was the last of his royal family to rule during the end of the Eighteenth Dynasty (ruled in the conventional chronology) during the New Kingdom of Egyptian history. His father is believed to be the pharaoh Akhenaten, identified as the mummy found in the tomb KV55. His mother is his father's sister, identified through DNA testing as an unknown mummy referred to as "The Younger Lady" who was found in KV35. Tutankhamun took the throne at eight or nine years of age under the unprecedented viziership of his eventual successor, Ay, to whom he may have been related. He married his paternal half-sister Ankhesenamun. During their marriage they lost two daughters, one at 5–6 months of pregnancy and the other shortly after birth at full-term. His names—''Tutankhaten'' and ''Tutankhamun''—are thought to mean "Living image of Aten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reidite
Reidite is a rare polymorph of ZrSiO4 created when zircon experiences high pressure and temperature. Reidite is denser than zircon and has the same crystal structure as scheelite. All natural occurrences of reidite are associated with meteorite impact events. On Earth, reidite has been reported from ten impact structures: the Chesapeake Bay Crater in Virginia; Ries Crater in Germany; Xiuyan Crater in China; Woodleigh Crater in Western Australia; Rock Elm Crater in Wisconsin; Dhala Crater in India; Stac Fada in Scotland; Haughton in Canada; Steen River in Canada, and Rochechouart in France. Reidite has also been found in one lunar meteorite. Name origin and discovery Reidite is named after Alan F. Reid, the scientist who first synthesized it during high-pressure experiments in the laboratory in 1969. Reidite was first discovered in natural samples by B.P. Glass and Shaobin Liu in 2001. Occurrence Reidite is formed from zircon above ~30GPa in shock recovery experiments. How ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Backscatter Diffraction
Electron backscatter diffraction (EBSD) is a scanning electron microscope–based microstructural-crystallographic characterization technique commonly used in the study of crystalline or polycrystalline materials. The technique can provide information about the structure, crystal orientation, phase, or strain in the material. These types of studies have been carried out using X-ray diffraction (XRD), neutron diffraction and/or electron diffraction in a Transmission electron microscope and spatially resolved acoustic spectroscopy ( SRAS) which analyses elastic waves instead of analysing a diffraction event. The choice of which technique is adopted depends upon various factors, including spatial resolution, area/volume analysed, and whether the measurements are static or dynamical. Geometry For an EBSD measurement a flat/polished crystalline specimen is placed in the SEM chamber at a highly tilted angle (~70° from horizontal) towards the diffraction camera, to increase the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effects Of Nuclear Explosions
The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lower atmosphere can be approximately divided into four basic categories: *the blast itself: 50% of total energy *thermal radiation: 30–50% of total energy * ionizing radiation: 5% of total energy (more in a neutron bomb) * residual radiation: 5–10% of total energy with the mass of the explosion. Depending on the design of the weapon and the location in which it is detonated, the energy distributed to any one of these categories may be significantly higher or lower. The physical blast effect is created by the coupling of immense amounts of energy, spanning the electromagnetic spectrum, with the surroundings. The environment of the explosion (e.g. submarine, ground burst, air burst, or exo-atmospheric) determines how much energy is distribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a soil texture, textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Somewhat more rarely, sand may be compose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trinitite
Trinitite, also known as atomsite or Alamogordo glass, is the glassy residue left on the desert floor after the plutonium-based Trinity nuclear bomb test on July 16, 1945, near Alamogordo, New Mexico. The glass is primarily composed of arkosic sand composed of quartz grains and feldspar (both microcline and smaller amount of plagioclase with small amount of calcite, hornblende and augite in a matrix of sandy clay) that was melted by the atomic blast. It was first academically described in ''American Mineralogist'' in 1948. It is usually a light green, although red trinitite was also found in one section of the blast site,G. Nelson Eby1, Norman Charnley, Duncan Pirrie, Robert Hermes, John Smoliga, and Gavyn RollinsTrinitite redux: Mineralogy and petrology''American Mineralogist'', Volume 100, pages 427–441, 2015 and rare pieces of black trinitite also formed. It is mildly radioactive but safe to handle. Pieces of the material may still be found at the Trinity site as of 2018, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Burst
An air burst or airburst is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target. The principal military advantage of an air burst over a ground burst is that the energy from the explosion (as well as any shell fragments) is distributed more evenly over a wider area; however, the peak energy is lower at ground zero. History Air burst artillery has a long history. The shrapnel shell was invented by Henry Shrapnel of the British Army in about 1780 to increase the effectiveness of canister shot. It was widely used by the time of the War of 1812 and stayed in use until it was superseded during the First World War. Modern shells, though sometimes called "shrapnel shells", actually produce fragments and splinters, not shrapnel. Air bursts were used in the First World War to shower enemy positions and men with shrapnel balls to kill the largest possible number with a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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