First Evidence of the Archean Age of Orogenic Gold of the Russian Part of the Karelian Craton (Fennoscandian Shield): Sm–Nd Mineral Isochron for Gold-Bearing Metasomatites of the Novye Peski Deposit     

Ivashchenko  V. I.  Bushmin  S. A.  Ruchyev  A. M.  Kornakov  A. S.  Bogomolov  E. S.  Savva  E. V.  Ivanov  M. V.  Tytyk  V. M.  Frolov  P. V. 《Doklady Earth Sciences》2018,480(2):804-809

One unsolved problem of Archean metallogeny of the Russian part of the Fennoscandian Shield is related to the period of formation of orogenic gold deposits, the age of which was previously considered Early Proterozoic. Comprehensive studies identified the complex evolution of ores from the Novye Peski deposit and the first Neoarchean Sm–Nd isochron isotopic age (2583 ± 16 Ma) of the formation of orogenic gold of the Karelian Craton. A significant positive ε_Nd(t) value of +4.7 of gold-bearing metasomatites probably points to the link between the ore-forming fluid and the deep mantle source.

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Gold potential of massive sulfide ores in the Kamennoozero structural unit,Eastern Karelia     

L. V. Kuleshevich  V. M. Tytyk  Z. N. Fedyuk 《Geology of Ore Deposits》2007,49(7):607-613

Two types of massive sulfide ores have been identified in the Kamennoozero segment of the green-stone belt: (1) hydrothermal volcanic-sedimentary strata-bound ores with massive, banded, and disseminated structures and (2) massive, brecciated, and stringer-disseminated Au-bearing base-metal ores, crosscutting the rocks of the Vozhmozero Group. The strata-bound, slightly metamorphosed orebodies are located at several levels along the contact between the Kamennoozero and Kumbuksa groups in the deep fault zones of the same names. These ores are composed of pyrite and pyrrhotite, small amounts of chalcopyrite and sphalerite, and distinguished by low grades of base metals and not higher than 0.06 g/t Au. In the Lebyazhino and Svetloozero areas, close to the sulfide Cu-Ni ore hosted in ultramafic rocks, the strata-bound bodies contain pentlandite and are enriched in Co, Ni, Cu, Zn, and up to 2.0–9.2 g/t Au. Brecciated and recrystallized pyrite ores contain up to 0.08–0.4% Sb and As, and up to 0.6–1 g/t Au in the Kumbuksa Fault Zone near Zolotye Porogi. The North Vozhma and Upper Vozhma base-metal massive sulfide occurrences, composed of pyrite, chalcopyrite, sphalerite, pyrrhotite, galena, bornite, and chalcocite, are considered to be promising Au-bearing prospects. Some samples from the North Vozhma occurrence contain up to 1.2–2.8 g/t Au and up to 167 g/t Ag. A gold grade of up to 20 g/t has been detected in the Upper Vozhma occurrence. The potential gold resources of the North Vozhma occurrence are estimated at about 600 kg.  相似文献