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Showing 1 to 20 of 26 for “"magmatic-hydrothermal"”.
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Fluid Inclusion Characteristics in Magmatic-Hydrothermal Ore Deposits
Magmatic-hydrothermal ore deposits are formed in association with aqueous fluids that exsolve from hydrous silicate melts during ascent and crystallization. These fluids are invariably trapped as inclusions in vein-filling minerals associated with hydrothermal fluid flow, and their composition may …
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Modelling and analytical studies of magmatic-hydrothermal processes
Hydrothermal processes play a major role in transporting mass and energy in Earth’s crust. These processes rely on hydrothermal fluid, which is dissolving, transporting and precipitating minerals and distribute heat. The composition of the hydrothermal fluid is specific for various geological …
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Magmatic-hydrothermal evolution of the Tuvatu alkalic epithermal Au-Telluride deposit, Viti Levu, Fiji
… marcasite to reconstruct the evolution of the magmatic-hydrothermal system and to identify the relative timing of Au mineralization. Eight vein types have been identified, including four porphyry-style veins which formed at higher temperatures and larger pressures, and four epithermal-style …
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CO₂ and Heat Release from Magmatic Hydrothermal Systems: Insights from CO₂ Flux and Other Modern Methods
Magmatic hydrothermal systems are of interest as a renewable energy source. In areas of high permeability, these systems are commonly manifested at the Earth’s surface as areas of steam heated ground. Ground based heat flux and CO2 flux surveys typically result in 100’s or 1000’s of individual flux …
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Spatial and temporal evolution of fluids in hydrothermal ore deposits
Magmatic-hydrothermal systems typically have vertical extents of several hundred<br />meters and their geochemical characteristics (e.g. mineral assemblages) vary considerably<br />over that vertical extent. As a consequence the expression in outcrop varies depending on<br />the level of erosion. …
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The magmatic-hydrothermal fluid history of the Harrison Pass Pluton, Ruby Mountains, NV: implications for the Ruby Mountains-East Humboldt Range metamorphic core complex and Carlin-type Au deposits
… Harrison Pass Pluton (HPP) occurred as magmatic fronts migrated southwest across the Great Basin during the Eocene. The HPP was locally intruded into the Ruby Mountains-East Humboldt Range (RMEHR), a classic Cordilleran metamorphic core complex that would undergo rapid tectonic …
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White mica: spectrometer design, district-scale mapping, and integration of imaging spectrometer and lidar data
… lidar data. White micas are common products of hydrothermal alteration associated with mineral deposits. A review of spectral studies conducted at a variety of mineral deposits determined that shifts in the position of the diagnostic 2.2 µm combination feature in white micas of as little as 1 nm …
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The igneous petrology, thermal history, and genesis of sedimentary rock-hosted Au deposits in the northern Battle Mountain mining district, Nevada
… in north-central Nevada hosts deposits of magmatic-hydrothermal origin, including porphyry, skarn, and distal disseminated deposits, as well as sedimentary-rock hosted Au deposits of uncertain origin. This dissertation examines the ages of magmatism and mineralization in the Battle Mountain …
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Physical and chemical aspects of fluid evolution in hydrothermal ore systems
… an economic porphyry copper deposit. Neither non-magmatic sources nor an additional hidden magma source are necessary to provide copper to the system and an elevated initial copper concentration in the melt is not necessary. Melts in shallow systems with initial water concentrations of at least …
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Thallium Isotope Implications for the Metalliferous Source of Carlin-type Deposits in northern Nevada
… Cambrian clastic sedimentary rocks, and (3) magmatic-hydrothermal fluids evolved from magmas. Traditional geochemical and isotopic tracers, including Pb, H, O, S, and C, have yielded ambiguous results, and sources of hydrothermal fluids and their components, especially gold remain …
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In situ mineral geochemistry as a guide to ore-forming processes
… trace element analyses in quartz and pyrite from magmatic-hydrothermal Cu-Au deposits. These studies revealed complex chemical zonation, providing a detailed record of cryptic fluid chemistry and depositional processes. A distinct isotopic signature and residual metastable silica hydrates in …
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In situ mineral geochemistry as a guide to ore-forming processes
… trace element analyses in quartz and pyrite from magmatic-hydrothermal Cu-Au deposits. These studies revealed complex chemical zonation, providing a detailed record of cryptic fluid chemistry and depositional processes. A distinct isotopic signature and residual metastable silica hydrates in …
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The Uranium Mineralization of the Macusani District, Southeast Peru: Mineralogy, Geochemistry, Geochronology and Ore-Genetic Model.
… The absence of U4+ minerals, as well as any hydrothermal alteration associated with the U ore, strongly suggests that meta-autunite is the primary U mineral. LA-ICP-MS U-Th-Pa geochronology of the meta-autunite revealed that the main ore-forming events occurred at 69 ka, 130 ka and 314-317 …
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Ghost granophyre: A new texture with implications for plagiogranite differentiation and Ti-in-Quartz thermometry
… low temperature silicate liquids which span the magmatic-hydrothermal transition, as well as a way to make granophyre without the involvement of a silicate melt. These findings expand the definition of the term granophyre, which still sees heavy usage in the petrology literature as being …
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Applications of Melt Inclusions to Problems in Igneous Petrogenesis
… associated with volcanoes in populated regions, magmatic hydrothermal ore deposition, and tectonic processes. One method of obtaining geochemical data that can help constrain petrogenetic processes is through the study of melt and fluid inclusions. The research presented here examines melt …
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Geochemical and isotopic characteristics of palaeo-hydrothermal fluids related to granite magmatism, S W England
… characterised the earliest episodes of palӕohydrothermal activity associated with the granites of S W England indicates that the abundance of trace carbon species (CO<sub>2</sub> , CH<sub>4</sub> ) and nitrogen in the fluids was correlated with the metasedimentary contribution to the …
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Metal- and alteration-zoning, and hydrothermal flow paths at the moderately-tilted, silica-saturated Mt. Milligan copper-gold alkalic porphyry deposit
… porphyries. Sulfur isotope contours reflect the magmatic-hydrothermal fluid evolution, and indicate late-stage ingress of peripheral fluids into the Cu-Au zone. Carbonate C- and O-isotope compositions corroborate the magmatic fluid path from the Cu-Au rich zone to Au-rich zone with decreasing …
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PVTX and Raman Spectral Properties of Fluids at Elevated Pressures and Temperatures
… at temperatures and pressures relevant to magmatic-hydrothermal systems using synthetic fluid inclusions. The partitioning behavior is then combined with literature data to calculate the Na/K ratio of the original silicate melt phase in a magma body before the exsolution of a fluid phase. …
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Application of fluid inclusions in geological thermometry
Many geologic processes occur in association with hydrothermal fluids and some of these fluids are eventually trapped as fluid inclusions in minerals formed during the process. Fluid inclusions provide valuable information on the pressure, temperature and fluid composition (PTX) of the environment …
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