Тип публикации: статья из журнала
Год издания: 2015
Идентификатор DOI: 10.1016/j.rgg.2015.05.007
Ключевые слова: quartz, sulfides, gold, ore-forming fluid, hydrocarbons, delta S-34, Ar-Ar age, S34S, argon-argon dating, crystallization, fluid inclusion, granulite, hydrothermal fluid, P-T conditions, sulfide, Krasnoyarsk [Russian Federation], Russian Federation, Yenisei Ridge
Аннотация: Fluid inclusions in quartz, sulfides from quartz veins, and quartz, garnet, plagioclase, and orthoclase from granulites of the Bogunai gold deposit located in the granulites of the Angara-Kan block of the Yenisei Ridge were studied by thermobarometry, gas chromatography, chromato-mass-spectrometry, Raman spectroscopy, and mass specПоказать полностьюtrometry with inductively coupled plasma. The formation temperatures (850-950 degrees C) and pressures (8.5-9.0 kbar) of minerals of the granulite metamorphic facies are much higher than the crystallization temperatures (220-420 degrees C) and pressures (0.1-1.6 kbar) of gold-quartz veins of the Bogunai deposit. These veins formed with the participation of H2O-CO2-hydrocarbon fluids with a salt (predominantly MgCl2) concentration of 2-19 wt.% NaCl equiv. The gas phase of fluid inclusions from quartz, pyrite, chalcopyrite, galena, and sphalerite contains not only H2O, CO2, CH4, and N-2 but also the first found compounds of sulfur (CS2, O2S, COS, C2H6S2) and nitrogen (C3H7N, C3H7NO, C4H8N2O) and numerous hydrocarbons of different classes (paraffins, arenes, naphthenes, alcohols, aldehydes, ketones, carbonic acids, and furans). The age of the Krasnoyarsk mineralized zone, one of the sites of the Bogunai deposit, is 466 +/- 3.2-461.6 +/- 3.1 Ma, which is almost 1400 Ma younger than the age of granulite metamorphism and 255 Ma younger than the age of diaphthoresis but is close to the age of the Lower Kan granitoid pluton (455.7 +/- 3.4 Ma). The sulfur isotope ratios (delta S-34) of sulfides (pyrite, chalcopyrite, sphalerite, and galena) are close to the mantle values, 0.8 to 3.5%, and are in the range of the granitoid values, which indicates the crustal source of the fluid sulfur. Gold of the Bogunai deposit accumulated with the participation of H2O-CO2-hydrocarbon fluids generated both in deep-fault zones and in granitoid intrusions. (C) 2015, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.
Журнал: RUSSIAN GEOLOGY AND GEOPHYSICS
Выпуск журнала: Vol. 56, Is. 6
Номера страниц: 903-918
ISSN журнала: 10687971
Место издания: AMSTERDAM
Издатель: ELSEVIER SCIENCE BV