Granite (light) with sheeted veins of greisen (dark) at Cligga Head, Cornwall
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.
Greisen is a highly altered granitic rock or pegmatite, usually composed predominantly of quartz and micas (mostly muscovite). Greisen is formed by self-generated...
Christopher J. Greisen (born July 2, 1976) is a former American football quarterback who played professionally the National Football League (NFL) for...
Nick A. Greisen (/ˈɡraɪsən/ GRY-sən; born August 10, 1979) is a former American football linebacker. He was drafted by the New York Giants in the fifth...
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contemporary Christian music group composed of sisters Annie Herring and Nelly Greisen and brother Matthew Ward. They began performing in 1972 and enjoyed their...
Brittany Dawn Nelson (formerly Davis and Greisen, and commonly known as Brittany Dawn; born c. 1991 or 1992) is an American former businesswoman and social...
surviving collisions with the cosmic microwave background, through the Greisen–Zatsepin–Kuzmin limit. Theoretical work by Hideki Yukawa in 1935 had predicted...
implications for particle physics and cosmology, due to a theoretical Greisen–Zatsepin–Kuzmin limit to the energies of cosmic rays from long distances...
Bollinger, who was suffering from a rib injury, in favor of backup Chris Greisen. The Tuskers would pull off convincing home wins over Omaha and Hartford...
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...
pegmatite bodies. It has also been found in high-temperature quartz veins, greisens and granite. Lepidolite is a phyllosilicate mineral and a member of the...
Amaterasu particle the third most powerful cosmic ray to have been detected. Greisen–Zatsepin–Kuzmin limit Telescope Array Collaboration; Abbasi, R. U.; Allen...
the original (PDF) on 2013-05-30. Retrieved 2013-03-06. Wells, D. C.; Greisen, E. W.; Harten, R. H. (June 1981). "FITS: A Flexible Image Transport System"...
Granite skin peeling like an onion (desquamation) because of weathering Greisen – Highly altered granitic rock or pegmatite Hypersolvus – Type of granite...
energies of 5×1019 eV, six million times more powerful – the so-called Greisen–Zatsepin–Kuzmin limit – and cosmic rays in vicinity of origin may be more...
metamorphic source. In the igneous environment, metasomatism produces skarns, greisen, and may affect hornfels in the contact metamorphic aureole adjacent to...
and several others after it) have been observed that seem to violate the Greisen–Zatsepin–Kuzmin limit, which is a consequence of special relativity. Paradox...
Alunite, topaz, zunyite, tourmaline, enargite and tennantite may also occur. Greisen alteration is similar. Sericitic alteration Guilbert, John M. and C. F...
contact metamorphic skarns; in high-temperature hydrothermal veins and greisen; less commonly in granite pegmatites. Temperature and pressure of formation...
Geologic occurrence is in granite pegmatites, high-temperature tin veins, and greisens. Amblygonite occurs with spodumene, apatite, lepidolite, tourmaline, and...
more common granitic deposits, wolframite minerals can be found in both greisen and veins as its formation is tied to these two structures. The wolframite...
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