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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. 相似文献
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Konstantinov E. A. Panin A. V. Karpukhina N. V. Bricheva S. S. Borisova O. K. Naryshkina N. N. Gurinov A. L. Zakharov A. L. 《Water Resources》2021,48(5):635-645
Water Resources - Lake Seliger has been always classified as a former glacial water body, a remnant of a vast proglacial lake, which has existed since the disappearance of the last glacial Ice... 相似文献
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Vikent’ev I. V. Borisova A. Yu. Karpukhina V. S. Naumov V. B. Ryabchikov I. D. 《Doklady Earth Sciences》2012,443(1):401-405
Doklady Earth Sciences - 相似文献
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Karpukhina N. V. Makkaveyev A. N. Zakharov A. L. Konstantinov E. A. Kurbanov R. N. Bricheva S. S. Sychev N. V. Baranov D. V. 《Doklady Earth Sciences》2022,506(1):S73-S83
Doklady Earth Sciences - Studying the Izborsk-Malskaya Valley, the authors focus on the origin of glaciolacustrine terraces in overdeepened valleys widespread in the Late Valdai (Ostashkov,... 相似文献
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Konstantinov E. A. Karpukhina N. V. Zakharov A. L. Bricheva S. S. Ukraintsev V. Yu. Lazukova L. I. Rudinskaya A. I. 《Doklady Earth Sciences》2022,506(1):S48-S54
Doklady Earth Sciences - The paleohydrological settings in the Rostov lowland (Yaroslavl oblast) have been the subject of long-standing of disputes. The concepts for the Holocene fluctuations in... 相似文献
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Doklady Earth Sciences - After the end of the Mikulino interglacial, in connection with the increasing cooling trend, the Scandinavian ice sheet began to form on the territory of Fennoscandia. Its... 相似文献
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