TY - JOUR

T1 - Physicochemical conditions of formation of gold and silver parageneses at the valunistoe deposit (Chukchi peninsula)

AU - Zhuravkova, T. V.

AU - Palyanova, G. A.

AU - Kalinin, Yu

AU - Goryachev, N.

AU - Zinina, V. Yu

AU - Zhitova, L.

PY - 2019/11/1

Y1 - 2019/11/1

N2 - The mineral composition of ores from the Gornyi occurrence of the Valunistoe epithermal Au–Ag deposit (Chukchi Pen-insula) has been studied. It has been found that, in addition to native gold, the Au–Ag mineralization comprises chalcogenides (uytenbo-gaardtite, petrovskaite, acanthite, naumannite, and cervelleite) and minerals of the pearceite–polybasite series, which occur as microinclu-sions in fine-grained pyrite. The physicochemical conditions of formation of productive mineral assemblages have been estimated based on the chemical composition of Au and Ag minerals and their relationships with other minerals. It is shown that ores were deposited from weakly acid solutions at the late stages, on the background of a temperature decrease from 350 to 100 ºС, a decrease in the fugacities of sulfur (logƒS2, from –2 to –23), tellurium (logƒTe2 , from –5 to –27), and selenium (logƒSe2 , from –16.5 to –28), and changes in the redox conditions (logƒO2, from –23 to –48).

AB - The mineral composition of ores from the Gornyi occurrence of the Valunistoe epithermal Au–Ag deposit (Chukchi Pen-insula) has been studied. It has been found that, in addition to native gold, the Au–Ag mineralization comprises chalcogenides (uytenbo-gaardtite, petrovskaite, acanthite, naumannite, and cervelleite) and minerals of the pearceite–polybasite series, which occur as microinclu-sions in fine-grained pyrite. The physicochemical conditions of formation of productive mineral assemblages have been estimated based on the chemical composition of Au and Ag minerals and their relationships with other minerals. It is shown that ores were deposited from weakly acid solutions at the late stages, on the background of a temperature decrease from 350 to 100 ºС, a decrease in the fugacities of sulfur (logƒS2, from –2 to –23), tellurium (logƒTe2 , from –5 to –27), and selenium (logƒSe2 , from –16.5 to –28), and changes in the redox conditions (logƒO2, from –23 to –48).

KW - Ag chalcogenides

KW - Ag solid solutions

KW - Au

KW - Chukchi volcanic belt

KW - Gornyi occurrence

KW - Okhotsk

KW - Physicochemical parameters of ore formation

KW - Valunistoe deposit

KW - Okhotsk-Chukchi volcanic belt

KW - THERMODYNAMIC PROPERTIES

KW - SULFIDES

KW - SOLID-SOLUTIONS

KW - SPHALERITE

KW - SELENIDES

KW - GENESIS

KW - REGION

KW - AU-AG DEPOSIT

KW - ORES

KW - physicochemical parameters of ore formation

KW - TELLURIDES

KW - Au-Ag solid solutions

KW - Au-Ag chalcogenides

UR - http://www.scopus.com/inward/record.url?scp=85074539307&partnerID=8YFLogxK

U2 - 10.15372/RGG2019118

DO - 10.15372/RGG2019118

M3 - Article

AN - SCOPUS:85074539307

VL - 60

SP - 1247

EP - 1256

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 11

ER -