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• W2956104367 endingPage "820" @default.
• W2956104367 startingPage "789" @default.
• W2956104367 abstract "Hydrothermal fluids on the modern seafloor are important carriers of base and precious metals in a wide range of volcanic and tectonic settings. The concentrations and distribution, especially of gold and silver, in associated seafloor massive sulfide (SMS) deposits are strongly influenced by variable source rocks, fluid chemistry, and precipitation mechanisms. Compositional data of 130 SMS deposits around the world show a large range of gold and silver grades, in part reflecting strong buffering of the hydrothermal fluids by their host rocks. Geochemical reaction-path modeling shows that in most cases the investigated hydrothermal fluids are undersaturated with gold and silver, and solubilities can be orders of magnitude higher than the Au and Ag concentrations measured in the corresponding fluids. Precipitation of gold during conductive cooling of mid-ocean ridge black smoker (MOR) fluids occurs at low temperatures but can be very rapid, with > 90% of the gold deposited in the first 25 °C of cooling below ~ 150 °C. The result is a Zn–Au polymetallic assemblage with Au and Ag deposited at the same time together with Pb and sulfosalts. In ultramafic-dominated (UM) systems, the strongly reduced hydrothermal fluids promote the deposition of gold at higher temperatures and explain the correlation between gold and copper in these deposits. In this case, the lower stability of the AuHS° complex at low ƒO2 (buffered by fayalite, magnetite, and quartz) results in gold deposition at > 250 °C with early bornite and chalcopyrite and before sphalerite and silver, producing a high-temperature Cu–Au assemblage. In sediment-hosted (SED) systems, the much higher pH stabilizes Au(HS)2− and keeps gold in solution to very low temperatures, after the precipitation of chalcopyrite, sphalerite, and galena, resulting in Au-poor polymetallic sulfides and very late-stage deposition of gold, commonly with amorphous silica. In arc-related (ARC) systems, gold deposition occurs at somewhat higher temperatures than in the MOR case, in part because the fluids start with higher gold concentrations. This can be explained by probable direct magmatic contributions, and the high ƒO2 of the fluids, which promotes the solubility of gold at the source. During cooling, gold precipitates at about 160 °C with sphalerite, tennantite, silver, and galena, resulting in an Au-rich polymetallic sulfide assemblage. The mixing of hydrothermal fluids with seawater generally causes oxidation and eventually a decrease in the pH at a mixing ratio of 1:1, causing an initial increase in the solubility of gold and silver. This can delay gold deposition from aqueous species to very low temperatures. These complex systematics make prediction of Au and Ag grades difficult. However, important new data are coming to light on the actual concentrations of the precious metals in hydrothermal fluids. In particular, the input of magmatic volatiles and leaching of pre-existing gold can lead to significant increases in the Au and Ag concentrations of the venting fluids and earlier deposition. In several cases, it appears that at least part of the gold load is present as nanoparticles in suspension, allowing bulk gold concentrations that may be far in excess of liquid saturation. Boiling at the seafloor is now widely observed, even at great water depths close to the critical point of seawater. Model calculations of phase separation during boiling show the competing effects on gold solubility of H2, H2S, and CO2 partitioning into the vapor, which can result in highly variable gold-to-base metal ratios in the deposits. Flashing of the vent fluids into steam at high temperatures is also commonly observed and can lead to spectacular Au grades, with a strong Cu–Au association in the deepest and hottest vents." @default.
• W2956104367 created "2019-07-12" @default.
• W2956104367 creator A5023848976 @default.
• W2956104367 creator A5039370924 @default.
• W2956104367 creator A5059933758 @default.
• W2956104367 date "2019-06-29" @default.
• W2956104367 modified "2023-10-02" @default.
• W2956104367 title "Divining gold in seafloor polymetallic massive sulfide systems" @default.
• W2956104367 cites W135505599 @default.
• W2956104367 cites W1434692241 @default.
• W2956104367 cites W1601706052 @default.
• W2956104367 cites W1634224673 @default.
• W2956104367 cites W1668681352 @default.
• W2956104367 cites W1863407988 @default.
• W2956104367 cites W1902887711 @default.
• W2956104367 cites W1963882982 @default.
• W2956104367 cites W1963935934 @default.
• W2956104367 cites W1966750556 @default.
• W2956104367 cites W1968784557 @default.
• W2956104367 cites W1969051824 @default.
• W2956104367 cites W1969099558 @default.
• W2956104367 cites W1970433717 @default.
• W2956104367 cites W1973976633 @default.
• W2956104367 cites W1976550881 @default.
• W2956104367 cites W1976984795 @default.
• W2956104367 cites W1977664265 @default.
• W2956104367 cites W1977878142 @default.
• W2956104367 cites W1977911061 @default.
• W2956104367 cites W1980608636 @default.
• W2956104367 cites W1981491722 @default.
• W2956104367 cites W1984714014 @default.
• W2956104367 cites W1985307582 @default.
• W2956104367 cites W1986119055 @default.
• W2956104367 cites W1990029207 @default.
• W2956104367 cites W1991565667 @default.
• W2956104367 cites W1996135927 @default.
• W2956104367 cites W1997524176 @default.
• W2956104367 cites W1999573076 @default.
• W2956104367 cites W2002996244 @default.
• W2956104367 cites W2003331679 @default.
• W2956104367 cites W2003334234 @default.
• W2956104367 cites W2003825787 @default.
• W2956104367 cites W2006687407 @default.
• W2956104367 cites W2007766604 @default.
• W2956104367 cites W2008589747 @default.
• W2956104367 cites W2013515927 @default.
• W2956104367 cites W2013943493 @default.
• W2956104367 cites W2014159640 @default.
• W2956104367 cites W2017152376 @default.
• W2956104367 cites W2017209895 @default.
• W2956104367 cites W2017811628 @default.
• W2956104367 cites W2018478404 @default.
• W2956104367 cites W2019844886 @default.
• W2956104367 cites W2020976208 @default.
• W2956104367 cites W2024231885 @default.
• W2956104367 cites W2024914768 @default.
• W2956104367 cites W2027177435 @default.
• W2956104367 cites W2027411519 @default.
• W2956104367 cites W2029933843 @default.
• W2956104367 cites W2030134340 @default.
• W2956104367 cites W2030812919 @default.
• W2956104367 cites W2034058675 @default.
• W2956104367 cites W2039066042 @default.
• W2956104367 cites W2042940134 @default.
• W2956104367 cites W2043747344 @default.
• W2956104367 cites W2046754847 @default.
• W2956104367 cites W2047214446 @default.
• W2956104367 cites W2049474990 @default.
• W2956104367 cites W2049544811 @default.
• W2956104367 cites W2052123038 @default.
• W2956104367 cites W2053308667 @default.
• W2956104367 cites W2053702065 @default.
• W2956104367 cites W2062672327 @default.
• W2956104367 cites W2071444558 @default.
• W2956104367 cites W2074699188 @default.
• W2956104367 cites W2078105038 @default.
• W2956104367 cites W2078288112 @default.
• W2956104367 cites W2079629767 @default.
• W2956104367 cites W2083691222 @default.
• W2956104367 cites W2088522209 @default.
• W2956104367 cites W2091027805 @default.
• W2956104367 cites W2092237459 @default.
• W2956104367 cites W2093729673 @default.
• W2956104367 cites W2095209242 @default.
• W2956104367 cites W2095817848 @default.
• W2956104367 cites W2095912588 @default.
• W2956104367 cites W2098839042 @default.
• W2956104367 cites W2100582229 @default.
• W2956104367 cites W2104076266 @default.
• W2956104367 cites W2111473359 @default.
• W2956104367 cites W2111763116 @default.
• W2956104367 cites W2114044449 @default.
• W2956104367 cites W2114082272 @default.
• W2956104367 cites W2116745296 @default.
• W2956104367 cites W2124375364 @default.
• W2956104367 cites W2126545892 @default.
• W2956104367 cites W2134054556 @default.
• W2956104367 cites W2135965020 @default.

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