naa a22 4500 510736580 CHVBK 20180411083012.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1134/S1075701513020025 doi (NATIONALLICENCE)springer-10.1134/S1075701513020025 Genesis of massive sulfide deposits in the Verkhneural'sk ore district, the South Urals, Russia: Evidence for magmatic contribution of metals and fluids [Elektronische Daten] [V. Karpukhina, V. Naumov, I. Vikent'ev] Melt inclusions and aqueous fluid inclusions in quartz phenocrysts from host felsic volcanics, as well as fluid inclusions in minerals of ores and wall rocks were studied at the Cu-Zn massive sulfide deposits in the Verkhneural'sk ore district, the South Urals. The high-temperature (850-1210°C) magmatic melts of volcanic rocks are normal in alkalinity and correspond to rhyolites of the tholeiitic series. The groups of predominant K-Na-type (K2O/Na2O = 0.3-1.0), less abundant Na-type (K2O/Na2O = 0.15-0.3), and K-type (K2O/Na2O = 1.9-9.3) rhyolites are distinguished. The average concentrations (wt %) of volatile components in the melts are as follows: 2.9 H2O (up to 6.5), 0.13 Cl (up to 0.28), and 0.09 F (up to 0.42). When quartz was crystallizing, the melt was heterogeneous, contained magnetite crystals and sulfide globules (pyrrhotite, pentlandite, chalcopyrite, bornite). High-density aqueous fluid inclusions, which were identified for the first time in quartz phenocrysts from felsic volcanics of the South Urals, provide evidence for real participation of magmatic water in hydrothermal ore formation. The fluids were homogenized at 124-245°C in the liquid phase; the salinity of the aqueous solution is 1.2-6.2 wt % NaCl equiv. The calculated fluid pressure is very high: 7.0-8.7 kbar at 850°C and 5.1-6.8 kbar at 700°C. The LA-ICP-MS analysis of melt and aqueous fluid inclusions in quartz phenocrysts shows a high saturation of primary magmatic fluid and melt with metals. This indicates ore potential of island-arc volcanic complexes spatially associated with massive sulfide deposits. The systematic study of fluid inclusions in minerals of ores and wall rocks at five massive sulfide deposits of the Verkhneural'sk district furnished evidence that ore-forming fluids had temperature of 375-115°C, pressure up to 1.0-0.5 kbar, chloride composition, and salinity of 0.8-11.2 (occasionally up to 22.8) wt % NaCl equiv. The H and O isotopic compositions of sericite from host metasomatic rocks suggest a substantial contribution of seawater to the composition of mineral-forming fluids. The role of magmatic water increases in the central zones of the feeding conduit and with depth. The dual nature of fluids with the prevalence of their magmatic source is supported by S, C, O, and Sr isotopic compositions. The TC parameters of the formation of massive sulfide deposits are consistent with the data on fluid inclusions from contemporary sulfide mounds on the oceanic bottom. Pleiades Publishing, Ltd., 2013 Karpukhina V. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, 119991, Moscow, Russia aut Naumov V. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, 119991, Moscow, Russia aut Vikent'ev I. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut Geology of Ore Deposits SP MAIK Nauka/Interperiodica 55/2(2013-03-01), 125-143 1075-7015 55:2<125 2013 55 11477 https://doi.org/10.1134/S1075701513020025 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1075701513020025 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Karpukhina V. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Naumov V. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Vikent'ev I. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut NATIONALLICENCE 773 0- Geology of Ore Deposits SP MAIK Nauka/Interperiodica 55/2(2013-03-01), 125-143 1075-7015 55:2<125 2013 55 11477 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer