Results 171 to 180 of about 1,193 (219)
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Petrogenesis of leucogranites in collisional orogens
Geological Society, London, Special Publications, 2019Abstract Leucogranites are a characteristic feature of collisional orogens. Their generation is intimately related to crustal thickening and the active deformation and metamorphism of metapelites. Data from Proterozoic to present day orogenic belts show that collisional leucogranites (CLGs) are peraluminous, with muscovite ...
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Himalayan Leucogranites: Petrogenesis and Significance
ElementsHimalayan leucogranites crop out intermittently over 2000 km along the crest of the world’s youngest and largest mountain range. They are derived from partial melting of continental crust during a classic continental collisional orogeny. Studies of these leucogranites have significantly advanced knowledge of crustal anatexis, felsic magmatic ...
Fang-Zhen Teng, Fu-Yuan Wu
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Lithogeochemical exploration for uranium in leucogranites
Journal of Geochemical Exploration, 1989Abstract In certain leucogranitic massifs in France and Spain, anomalies of uranium that extend for kilometers have been observed in rocks close to uranium deposits. Some of these anomalies were used to direct a reconnaissance survey which led to the discovery of a small blind deposit.
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JURASSIC LEUCOGRANITE-GRANITE FORMATION IN ALTAI
Russian Geology and Geophysics, 1991A Middle-Mesozoic (Jurassic) leucogranite-granite formation, 180–200 Ma of age, has been recognized in Rudny and Gorny Altai on the basis of U–Pb geochronological dating, analysis of petrochemical data and metallogenic characteristics. In adjacent geostructural environments, granitoid massifs differ in completeness of manifestation of granite and ...
M. S. Kozlov +3 more
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Himalayan Leucogranites: Field Relationships and Tectonics
ElementsHimalayan peraluminous leucogranites were derived from in-situ melting of sillimanite + K-feldspar-bearing pelite-migmatite, and were transported via layer-parallel sill complexes and cross-cutting dykes to feed giant sills up to 5 km thick. Partially melted Himalayan middle crust was extruded southwards between two large-scale, north-dipping ...
Mike Searle, John Cottle
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Journal of Volcanology and Geothermal Research, 1990
Abstract Two types of leucogranite have been identified in a collisional setting in the Himalaya. Type-a (e.g., Manaslu, High Himalaya) are syn-tectonic crustal melts related to “hot over cold” thrusting and subsequent fluid fluxing. Type-b (e.g., Baltoro, Karakoram) is related to lower crustal melting during/following crustal thickening and thermal ...
Mark B. Crawford, Brian F. Windley
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Abstract Two types of leucogranite have been identified in a collisional setting in the Himalaya. Type-a (e.g., Manaslu, High Himalaya) are syn-tectonic crustal melts related to “hot over cold” thrusting and subsequent fluid fluxing. Type-b (e.g., Baltoro, Karakoram) is related to lower crustal melting during/following crustal thickening and thermal ...
Mark B. Crawford, Brian F. Windley
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Himalayan Leucogranites: A Minimal Role in Deformation
ElementsA popular model of Himalayan metamorphic and structural evolution argues that partial melting of deeply buried rocks triggered crustal weakening, ductile flow, orogenic collapse, and genesis of leucogranites. Here, we review the origins and evolution of partial melts and leucogranites to demonstrate that they are largely incidental to deformation ...
Matthew J. Kohn +2 more
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Leucogranites and the Time of Extension in the East Greenland Caledonides
The Journal of Geology, 2005Abstract Leucogranites provide timing estimates for deformation, particularly extension, in many orogens. On this basis, the time of extension in the East Greenland Caledonides has been estimated at 420–430 Ma. U‐Pb SHRIMP (sensitive, high‐resolution ion‐microprobe) analysis of zircon and monazite from selected leucogranites was undertaken to establish
Jane A. Gilotti, William C. McClelland
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Granites, Leucogranites, Himalayan Leucogranites…
ElementsPREFACE I am not an expert on Himalayan leucogranites, although I have followed their coverage in the literature for more than 40 years and have studied granites and rhyolites more generally for over 50 years (cf. Fig. 1). Coming from this perspective, I aim—in this Elements Perspective—to provide a felsic magma context for pondering ...
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Himalayan Leucogranites: Rare-metal Resources
ElementsHimalayan leucogranites were once overlooked for rare-metal resources because they initially were thought to have formed by in-situ partial melting of underlying high-grade metamorphic rocks. However, recent findings have revealed widespread rare-metal mineralizations of Be, Nb/Ta, Li/Rb/Cs, and W/Sn associated with leucogranites in the area ...
Fu-Yuan Wu +4 more
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