Carbonaceous matter in sulfide-quartz veins at the Kurultyken base-metal deposit,eastern Transbaikal region,Russia

The carbonaceous matter filling cavities in sulfide-quartz veins at the Kurultyken hydrothermal base-metal deposit in the Khapcheranga ore district, Transbaikal region, was studied using chromatography/mass spectrometry, X-ray diffraction, thermal and isotopic analyses, and IR spectroscopy. It was established that carbonaceous matter was a maltha composed of polycyclic aromatic hydrocarbons (PAHs). Chrysene, pyrene, and benzpyrelene identified among PAHs are evidence for the hydrothermal origin of the initial carbonaceous matter of maltha. The main mass of carbonaceous matter was synthesized under reductive conditions and at a low temperature, i.e., at the final stage of base-metal ore formation. Nevertheless, the thermometric data indicate that part of the carbonic compounds could have formed at 480°C, i.e., at the high-temperature stage of the postmagmatic process. The contribution of host rocks as a source of carbonaceous matter was minimal.