TY - JOUR

T1 - Au‐Ag‐S‐Se‐Cl‐Br mineralization at the corrida deposit (Russia) and physicochemical conditions of ore formation

AU - Kolova, Elena E.

AU - Savva, Nataly E.

AU - Zhuravkova, Tatiana V.

AU - Glukhov, Anton N.

AU - Palyanova, Galina A.

N1 - Funding Information: Funding: The studies were carried out by the grant № 13.1902.21.0018 "Fundamental Problems of the Development of the Mineral Resource Base of the High‐Tech Industry and Energy in Russia" from the Ministry of Science and Higher Education of the Russian Federation. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/2

Y1 - 2021/2

N2 - The mineral and chemical compositions of ores from the Corrida epithermal Au‐Ag deposit (Chukchi Peninsula, Russia) were studied using the optical and scanning electron microscopy with X‐ray energy‐dispersion microanalysis. The deposit was formed at the time close to the period when the basic volume of acid magmas had been emplaced within the Okhotsk–Chukotka belt (84 to 80 Ma). The Au–Ag mineralization is distinguished with Au‐Ag sulphides and selenides (uytenbogaardtite‐fischesserite solid solution, Se‐acanthite, S‐naumannite) and Ag halides of the chlorargyrite‐embolite‐bromargyrite series. The ores were formed in two stages. Using microthermometric methods, it has been established that the ore‐bearing quartz was formed in the mediumtemperature environment (340–160 °С) with the participation of low‐salt (3.55 to 0.18 wt. % NaCl eq.) hydrotherms, mostly of the NaCl composition with magnesium, iron and low‐density СО2. According to our results of thermodynamic modeling at temperatures from 300 to 25°C and data on mineral metasomatic alterations of the host rocks, the Au‐Ag‐S‐Se‐Cl‐Br mineralization was formed at decreasing temperature and fugacity of sulphur (logƒS2 from −6 to −27), selenium (logƒSe2 from −14 to −35), and oxygen (logƒО2 from −36 to −62), with near‐neutral solutions replaced by acid solutions. Analysis of the obtained data shows that the Corrida refers to the group of the LS‐type epithermal deposits. This deposit is a new example of epithermal deposits with significant quantities of Au–Ag chalcogenides (acanthite, uytenbogaardtite, fischesserite, naumannite and others).

AB - The mineral and chemical compositions of ores from the Corrida epithermal Au‐Ag deposit (Chukchi Peninsula, Russia) were studied using the optical and scanning electron microscopy with X‐ray energy‐dispersion microanalysis. The deposit was formed at the time close to the period when the basic volume of acid magmas had been emplaced within the Okhotsk–Chukotka belt (84 to 80 Ma). The Au–Ag mineralization is distinguished with Au‐Ag sulphides and selenides (uytenbogaardtite‐fischesserite solid solution, Se‐acanthite, S‐naumannite) and Ag halides of the chlorargyrite‐embolite‐bromargyrite series. The ores were formed in two stages. Using microthermometric methods, it has been established that the ore‐bearing quartz was formed in the mediumtemperature environment (340–160 °С) with the participation of low‐salt (3.55 to 0.18 wt. % NaCl eq.) hydrotherms, mostly of the NaCl composition with magnesium, iron and low‐density СО2. According to our results of thermodynamic modeling at temperatures from 300 to 25°C and data on mineral metasomatic alterations of the host rocks, the Au‐Ag‐S‐Se‐Cl‐Br mineralization was formed at decreasing temperature and fugacity of sulphur (logƒS2 from −6 to −27), selenium (logƒSe2 from −14 to −35), and oxygen (logƒО2 from −36 to −62), with near‐neutral solutions replaced by acid solutions. Analysis of the obtained data shows that the Corrida refers to the group of the LS‐type epithermal deposits. This deposit is a new example of epithermal deposits with significant quantities of Au–Ag chalcogenides (acanthite, uytenbogaardtite, fischesserite, naumannite and others).

KW - Arctic

KW - Au‐Ag‐S‐Se‐Cl‐Br mineralization

KW - Corrida deposit (Chukchi Peninsula, Russia)

KW - Epithermal mineralization

KW - LS‐type of deposits

KW - Physicochemical parameters of ore formation (Т, Р, FO2, FS2, FSe2, PH)

UR - http://www.scopus.com/inward/record.url?scp=85100043847&partnerID=8YFLogxK

U2 - 10.3390/min11020144

DO - 10.3390/min11020144

M3 - Article

AN - SCOPUS:85100043847

VL - 11

SP - 1

EP - 20

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 2

M1 - 144

ER -