Matches in SemOpenAlex for { <https://semopenalex.org/work/W2124642451> ?p ?o ?g. }
- W2124642451 endingPage "356" @default.
- W2124642451 startingPage "333" @default.
- W2124642451 abstract "The giant Bingham Canyon porphyry Cu-Mo-Au deposit (Utah) is associated with Eocene subvolcanic intrusions. It shows a distinct metal zonation above a barren core, with dominantly shallow Cu-Au mineralization (Cu stage) following the early quartz monzonite porphyry (QMP) intrusion, and spatially deeper Mo mineralization (Mo stage) occurring in a separate vein set exclusively after a late quartz latite porphyry (QLP) intrusion that truncates earlier Cu-Au veins. To understand this metal separation and the geochemical process of molybdenite mineralization, we investigated fluid inclusions by microthermometry, Raman spectroscopy, and laser ablation inductively couple plasma mass spectrometry (LA-ICP-MS) microanalysis in low- and high-grade quartz veins of both mineralization stages.In deep, low-grade quartz veins interpreted to represent the root zone of the Cu stage we found high concentrations of Cu, S, and Mo in the fluid inclusions, whereas in low-grade Mo-stage veins, we found lower Cu, but similar concentrations of S and Mo, compared to the inferred input fluids to the Cu stage. Sulfur and copper concentrations were similar in intermediate-density-type fluid inclusions in deep low-grade Cu-stage samples, whereas intermediate-density-type inclusions in low-grade Mo-stage veins have S contents that exceed their Cu contents. In high-grade Mo-stage vein, we found large variations of Mo concentrations in coexisting brine and vapor inclusions. Compared to the P-T conditions of the Cu precipitation stage (90–260 bars and 320°–430°C), the Mo-precipitating fluids were trapped at higher pressures and temperatures of 140 to 710 bars and 360° to 580°C. Mass-balance calculation based on the compositions of intermediate-density inclusions and brine + vapor assemblages, interpreted to be derived by phase separation during decompression of the ascending single-phase intermediate-density fluid, indicate that the mass of vapor phase exceeded that of brine by about 9:1 in both mineralization stages. Combining this mass balance with the analyzed vapor/brine partitioning data indicates that more than 70% of Mo and S (by mass) in the deposit were deposited from the vapor phase. Earlier Cu-Au deposition was similarly dominated by vapor, but recently published data about postentrapment Cu diffusion in and out of fluid inclusions cast doubt on previous quantifications, suggesting that almost none of the copper was deposited by brine.Mo is less likely to be modified by selective diffusion, and high Mo contents (max 0.0054 Mo/Na in intermediate density; 380 μ g/g Mo in brine) in the hydrothermal fluids were maintained from the early Cu stage to the late Mo stage. This indicates that Mo concentration was not the decisive factor for separate precipitation of late Mo ore at Bingham Canyon. Instead, the metal separation may be explained by a reduction in redox potential and an increase in acidity in the evolving source region of the fluids, i.e., a large subvolcanic magma reservoir. This is indicated by the stoichiometry of chalcopyrite and molybdenite precipitation reactions, a tentative difference in the Fe/Mn ratio in fluids of both veining stages, incipient muscovite alteration along high-temperature molybdenite veins, and an increasing tendency for Mo to fractionate from brine to vapor. We suggest that the early Cu-stage fluids were slightly more oxidized and neutral, allowing Cu-Fe sulfides to saturate first, while molybdenite saturation was suppressed and Mo was lost from the early ore stage. By contrast during the later Mo stage, the fluids were more reduced and acidic, thereby allowing selective saturation of molybdenite as the first precipitating sulfide in the cooling and expanding two-phase fluid, consistent with textural observations. This interpretation may imply more generally that small differences in redox potential and acid/base balance of the magmatic source of porphyry-mineralizing systems may be decisive in the temporal and spatial separation of the two metals." @default.
- W2124642451 created "2016-06-24" @default.
- W2124642451 creator A5000185699 @default.
- W2124642451 creator A5024299583 @default.
- W2124642451 creator A5052663025 @default.
- W2124642451 date "2012-02-15" @default.
- W2124642451 modified "2023-10-02" @default.
- W2124642451 title "Separation of Molybdenum and Copper in Porphyry Deposits: The Roles of Sulfur, Redox, and pH in Ore Mineral Deposition at Bingham Canyon" @default.
- W2124642451 cites W123098611 @default.
- W2124642451 cites W1492000624 @default.
- W2124642451 cites W1674455985 @default.
- W2124642451 cites W1964939334 @default.
- W2124642451 cites W1965524050 @default.
- W2124642451 cites W1968879168 @default.
- W2124642451 cites W1977211014 @default.
- W2124642451 cites W1977339814 @default.
- W2124642451 cites W1979418505 @default.
- W2124642451 cites W1984112525 @default.
- W2124642451 cites W1984666367 @default.
- W2124642451 cites W1985696630 @default.
- W2124642451 cites W1990822942 @default.
- W2124642451 cites W1991108678 @default.
- W2124642451 cites W1992363956 @default.
- W2124642451 cites W1994184986 @default.
- W2124642451 cites W2000886616 @default.
- W2124642451 cites W2001947407 @default.
- W2124642451 cites W2008533057 @default.
- W2124642451 cites W2009958649 @default.
- W2124642451 cites W2013645350 @default.
- W2124642451 cites W2015662347 @default.
- W2124642451 cites W2018820772 @default.
- W2124642451 cites W2020454914 @default.
- W2124642451 cites W2030139888 @default.
- W2124642451 cites W2030484090 @default.
- W2124642451 cites W2040220664 @default.
- W2124642451 cites W2044777650 @default.
- W2124642451 cites W2046166301 @default.
- W2124642451 cites W2049111683 @default.
- W2124642451 cites W2049153634 @default.
- W2124642451 cites W2050203573 @default.
- W2124642451 cites W2054002371 @default.
- W2124642451 cites W2056833090 @default.
- W2124642451 cites W2058642293 @default.
- W2124642451 cites W2062957061 @default.
- W2124642451 cites W2063547595 @default.
- W2124642451 cites W2070096426 @default.
- W2124642451 cites W2070255162 @default.
- W2124642451 cites W2079257222 @default.
- W2124642451 cites W2082583308 @default.
- W2124642451 cites W2083691222 @default.
- W2124642451 cites W2088581377 @default.
- W2124642451 cites W2089615853 @default.
- W2124642451 cites W2093814974 @default.
- W2124642451 cites W2098449299 @default.
- W2124642451 cites W2100998381 @default.
- W2124642451 cites W2102879515 @default.
- W2124642451 cites W2108353466 @default.
- W2124642451 cites W2111713335 @default.
- W2124642451 cites W2112478515 @default.
- W2124642451 cites W2114504059 @default.
- W2124642451 cites W2123126910 @default.
- W2124642451 cites W2144436564 @default.
- W2124642451 cites W2145245409 @default.
- W2124642451 cites W2145631550 @default.
- W2124642451 cites W2146959098 @default.
- W2124642451 cites W2152980848 @default.
- W2124642451 cites W2155137417 @default.
- W2124642451 cites W2159868744 @default.
- W2124642451 cites W2163044580 @default.
- W2124642451 cites W2165394332 @default.
- W2124642451 cites W2165498879 @default.
- W2124642451 cites W2320645792 @default.
- W2124642451 cites W2325088857 @default.
- W2124642451 cites W2950850760 @default.
- W2124642451 cites W3109746116 @default.
- W2124642451 cites W3122225555 @default.
- W2124642451 cites W3122755600 @default.
- W2124642451 doi "https://doi.org/10.2113/econgeo.107.2.333" @default.
- W2124642451 hasPublicationYear "2012" @default.
- W2124642451 type Work @default.
- W2124642451 sameAs 2124642451 @default.
- W2124642451 citedByCount "124" @default.
- W2124642451 countsByYear W21246424512012 @default.
- W2124642451 countsByYear W21246424512013 @default.
- W2124642451 countsByYear W21246424512014 @default.
- W2124642451 countsByYear W21246424512015 @default.
- W2124642451 countsByYear W21246424512016 @default.
- W2124642451 countsByYear W21246424512017 @default.
- W2124642451 countsByYear W21246424512018 @default.
- W2124642451 countsByYear W21246424512019 @default.
- W2124642451 countsByYear W21246424512020 @default.
- W2124642451 countsByYear W21246424512021 @default.
- W2124642451 countsByYear W21246424512022 @default.
- W2124642451 countsByYear W21246424512023 @default.
- W2124642451 crossrefType "journal-article" @default.
- W2124642451 hasAuthorship W2124642451A5000185699 @default.
- W2124642451 hasAuthorship W2124642451A5024299583 @default.
- W2124642451 hasAuthorship W2124642451A5052663025 @default.