GOLD MINERALIZATION OF THE KHAAK-SAIR GOLD-QUARTZ ORE OCCURRENCE IN LISTWАNITES (western Tuva)
R.V. Kuzhuget1, V.V. Zaikov2, V.I. Lebedev1, A.A. Mongush1
a:2:{s:4:"TEXT";s:320:"1Tuvinian Institute for Exploration of Natural Resources, Siberian Branch of the Russian Academy of Sciences, ul. Internatsional’naya 117a, Kyzyl, Tyva Republic, 667007, Russia
2Institute of Mineralogy, Uralian Branch of the Russian Academy of Sciences, Miass, Chelyabinsk Region, 456317, Russia";s:4:"TYPE";s:4:"html";}
Keywords: Native gold, Au-Ag-Hg system minerals, tellurides, hessite, coloradoite, selenides, tiemannite, naumannite, fischesserite, fahlores, Tuva
Subsection: PETROLOGY, GEOCHEMISTRY, AND MINERALOGY
Abstract
We consider mineral assemblages and mineralogical and geochemical peculiarities of hypogene gold from the Khaak-Sair multistage low-sulfide gold-quartz ore occurrence in listwänites. Three productive substages of Au- and Ag-mineral formation have been recognized on the basis of mineralogical studies: gold-sulfosalt-sulfide-quartz, gold-mercury-quartz, and gold-selenide-telluride-sulfide-quartz. These substages were characterized by the following sequences of mineral formation: (1) ultrahigh-fineness gold → high-fineness gold → argental gold (medium- and low-fineness gold) → electrum + Ag-bearing and argental fahlores (up to 50 wt.% Ag) ± acanthite ± hessite; (2) high-fineness gold → Hg-bearing and mercurian gold → mercurian electrum → mercurian kustelite → Au-bearing mercurian silver; and (3) high-fineness gold → mercurian gold → mercurian electrum + naumannite + Te-bearing naumannite + fischesserite + tiemannite + hessite + coloradoite + Ag-bearing minerals of the galena-clausthalite series (up to 6 wt.% Ag) ± Se-cinnabar ± Se-imiterite. Productive mineral assemblages of the ore occurrence formed in the hypabyssal facies (depth ~1.5 km, P ~0.5 kbar) on the background of a temperature decrease from 290 to 160 °C and variations in f (O
2), f (S
2), f (Se
2), and f (Te
2).
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