MINERALOGICAL FEATURES OF GOLD ORE MANIFESTATIONS OF THE SOLOLI UPLIFT OF THE OLENEK ARCH

Abstract

The paper deals with studied mineralogical and geochemical features of gold-sulphide manifestations of the Sololi uplift of the Olenek arch (northeast of the Siberian Platform) in order to identify their mineralogical features and prospects for their further research. The identical mineral composition of gold-sulphide formations developed by Early Proterozoic rocks of the Eekitian series and rhyolites of the same age gave reason to assume the simultaneity of their formation and to refer them to the general stage of ore formation. According to the established mineral paragenesis, described gold sulphide manifestations are attributed to the gold-quartzsulphide formation type. The discovery of gold sulphide mineralization in the zone of tectonic fracturing of Early-Middle Permian sandstones indicates the formation of ore occurrences in the area associated with the processes of tectonomagmatic activation of the Mesozoic. The identification of indicators of low-temperature hydrothermal processes as mineral paragenesis – mercury-containing gold, cinnabar and barite, testifies to shallow and low-temperature conditions for the formation of this ore manifestation. It was found that according to the Co/Ni ratio, 28% of pyrites (including gold-bearing ones) are associated with hydrothermal processes. In general, the detection of native gold in quartz veins in free form and as microinclusions and impurities in pyrite, as well as the discovery of relatively large poorly rounded attachments of gold to quartz in stream flows dewatering the studied ore formations, allows researchers to positively assess the prospects for further study of ore manifestations of the Sololi uplift of the Olenek arch.