Bogunay gold deposit in Neoarchean gneisses of the South Yenisei Ridge

DOI: 10.47765/ 0869-5997-2026-10015

Abstract

The paper considers the geochronology of metamorphism, magmatism, and gold ore formation at the Bogunay gold-quartz-sulfide deposit with the gold resource of approximately

32.6 t, localized in the Neoarchean gneisses of the Yenisei Ridge. During its operation (1936–1951), 2.3 t of the metal were extracted. Gold ore bodies of the Bogunay deposit of the pyrite-polymetallic-telluride mineral type occur among Neoarchean gneisses aged 2.4–2.7 Ba. The granulite-gneiss of the Kuzeyeva Sequence were initially enriched in gold, exceeding the geochemical clarke by 2.5–4 times. Repeated diaphthoresis of the host rocks, migmatization, and charnockite formation (in the time interval of 1900–450 Ma) caused redistribution of the metal with its concentration in products of the low-temperature metamorphism and in vein-disseminated hydrothermal mineralization.

The low industrial potential of the Bogunay gold deposit, compared to foreign representatives of this industrial type (500–1000 t), is explained by a number of factors: the host rocks of the Bogunay ore deposit lack komatiite lavas (the main gold producer) typical of lithostratigraphic sections of Neoarchean greenstone belts of North America, Africa, Australia, and India. In addition, the gold ore-forming process in the South Yenisei Ridge among Neoarchean granulite-gneisses took place in the Caledonian time (540–450 Ma ago), during emplacement of a granitoid intrusion in the ore region (521–374 Ma), which distinguishes it from the Neoarchean gold ore genesis in the above mentioned greenstone belts.