Fahlores in paleozoic vent chimneys from the Urals and Rudny Altai volcanogenic massive sulfide deposits
V.V. Maslennikov, S.P. Maslennikova, G.A. Tretyakov, A.S. Tseluyko, V.A. Kotlyarov, Yu. D. Kraynev, E.I. Churin, R.J. Herrington
Tennantite, tetrahedrite-tennantite, tetrahedrite and their Ag-, Bi-, Hg-, and Te-containing fahlore varieties including pure end-member of goldfeldite occur in mid-temperature galena-sphalerite, quartz-marcasite and quartz-chalcopyrite zones of vent chimneys from the Urals (Yubileynoye, Yaman-kasy, Valentorskoye, Molodezhnoye, Oktyabrskoye, Uzelga-1, Uzelga-4, and Alexandrin-skoye) and Rudny Altai (Artemyevskoye, Nikolaevskoye, Zarechenskoye) Paleozoic volcanogenic massive sulphide deposits. The composition of fahlores decrease in Fe/(Fe+Zn) and, commonly, in As/(As+Sb)) while portion of acid volcanic rocks is expanded in relation to basalts or black shales in the range from Cu-Zn to Pb-Zn-Ba-Cu volcanogenic massive sulfde deposits. In this range, the consistent pertain is interpreted in terms of increasing in pH and state of solution oxidation due to most efcient seawater interaction with hydrothermal fuid and acid volcanic host rocks. The dependence of fahlores composition from host rock composition (basalts or sediments) and maturity of the hydrothermal systems are verifed by physical-chemical simulation.
Figures 13. Tables 3. References 62.
Key words: fahlores, Paleozoic black smokers, Ural, Rudny Altai, volcanogenic massive sulphide deposits.
МINERALOGY № 4 2015