Kalinin, A.A.; Kudryashov, N.M.; Savchenko, Y.E. Timing and Evolution of Gold Mineralization in the Maljavr Occurrence (NW Russia), NE Part of the Fennoscandian Shield. Minerals2024, 14, 535.
Kalinin, A.A.; Kudryashov, N.M.; Savchenko, Y.E. Timing and Evolution of Gold Mineralization in the Maljavr Occurrence (NW Russia), NE Part of the Fennoscandian Shield. Minerals 2024, 14, 535.
Kalinin, A.A.; Kudryashov, N.M.; Savchenko, Y.E. Timing and Evolution of Gold Mineralization in the Maljavr Occurrence (NW Russia), NE Part of the Fennoscandian Shield. Minerals2024, 14, 535.
Kalinin, A.A.; Kudryashov, N.M.; Savchenko, Y.E. Timing and Evolution of Gold Mineralization in the Maljavr Occurrence (NW Russia), NE Part of the Fennoscandian Shield. Minerals 2024, 14, 535.
Abstract
Gold occurrence Maljavr, located in amphibolite metamorphosed rocks in the Uragubsky greenstone belt, is the first gold prospect connected with conglomerates of Archean age, found in the Fennoscandian Shield. Gold mineralization is controlled by a series of lenses of altered rocks in biotite gneiss-metaconglomerate. The age of zircon from biotite gneiss in the zone of alteration is 2665±22 Ma, this is considered as the time of alteration processes. Biotite gneiss and altered rocks were later intruded by tourmaline granite pegmatite at 2508±7Ga, the pegmatite caused recrystallization of sulfide minerals in the altered rocks. Visible gold in association with bismuth minerals native bismuth, ehrigite (the second finding in the world), maldonite, bismuthinite, joseite-B, hedleyite was found exceptionally in polymineral inclusions in recrystallized arsenopyrite and löllingite. The age of pegmatite 2508±7Ma we regard as the time of formation of gold-bismuth mineralization. Geological position of the Maljavr occurrence, the linkage of gold mineralization with pegmatite, geochemical association Au-As-Se-Te-Bi in the mineralized rocks – all these characteristics correspond to intrusion-related gold deposits. Biotite gneiss-metaconglomerate, hosting the mineralized altered rocks, was the probable primary source of arsenic and gold for mineralization.
Environmental and Earth Sciences, Geochemistry and Petrology
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