Генетические особенности золото-сульфидного месторождения Дарасун (Восточное Забайкалье, Россия)статья
Статья опубликована в журнале из списка RSCI Web of Science
Статья опубликована в журнале из перечня ВАК
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 23 августа 2019 г.
Аннотация:The close relationship of an ore forming process responsible for the formation of the Darasun gold-sulfide deposit to the injection of a granodiorite-porphyry stock has been shown on the base of geological, petrochemical, mineralogical, geochemical, and age data. A nearly continuous transition of the physicochemical parameters of fluids from a magmatic megastage (750 to 600 degreesC and 4800 to 2700 bars) to a hydrothermal stage (from 600 to 120 degreesC and from 2040 to 60 bars) has been established. Peculiarities of the composition of ore-forming fluids have been studied. Salt, CO2, and H2S contents range from 52.6 to 0.5 wt % NaCl-equiv., from 2.8 to 0.6 mol/kg of solvent, from 2 x 10(-2) to 10(-4) mol/kg H2O. The P-total/ P-H2O ratio varies within 17.2 to 1.0. The concentrations of several components in ore forming fluids were estimated. The values obtained are as follows (g/kg of solvent): 5 x 10(-3) to 2 x 10(-4) Au, 1.1 to 0.12 Sb, 51.7 to 3.4 Fe, 1.3 to 0.2 Cu, 11 Mn, and 1.4 to 0.8 B. It was shown that gold preferred to occur in high-temperature fluids in hydroxo- and chloride complexes. With decreasing temperature, the predominant gold species in solution changed to a hydrosulfide complex. The sulfur isotope composition of sulfides from auriferous veins is +7.8 to +0.7 parts per thousand. The oxygen isotope ratio in quartz varies from +13.0 to +4.7 parts per thousand. The oxygen and carbon isotope ratios of carbonates correspond to +22.3 to +14.9 parts per thousand and -3.9 to -12.7 parts per thousand, respectively.