Hydrocarbons in Fluid Inclusions from Native Gold, Pyrite, and Quartz of the Sovetskoe Deposit (Yenisei Ridge, Russia) According to Pyrolysis-Free Gas Chromatography-Mass Spectrometry Data

Abstract

Abstract ––The first results on the composition of fluids from native gold and associated pyrite and quartz have been obtained. Despite the small amount of analytical data, these results are of scientific and practical interest. The identified geochemical criteria can be used for the assessment of gold ore shoots and the substantiation of prospecting in the region. The one-act shock-destructive extraction of volatiles from fluid inclusions and their pyrolysis-free gas chromatography–mass spectrometry analysis made it possible to determine the composition of fluids in native gold and in associated pyrite and quartz. Based on these data, we have first shown that fluids in native gold, pyrite, and quartz are a mineral-forming multicomponent system. In addition to water and carbon dioxide, the studied fluid inclusions contain representatives of at least 11 homologous series of organic compounds, including oxygen-free aliphatic and cyclic hydrocarbons (paraffins, olefins, cyclic alkanes and alkenes, arenes, and polycyclic aromatic hydrocarbons), oxygenated hydrocarbons (alcohols, esters, furans, aldehydes, ketones, and carboxylic acids), and nitrogened, sulfonated, halogenated, and siliconorganic compounds. The portion of hydrocarbons together with S–N–Cl–F–Si compounds reaches 52.0 rel.% in fluid inclusions from native gold, 10.1 rel.% in fluid inclusions from pyrite, and 18.0 rel.% in fluid inclusions from quartz. Gold-transporting gas fluids have reducing properties. Pyrite and quartz contain oxidized water–carbon dioxide fluids with low contents of hydrocarbons and nitrogen–halogenated compounds.