Occurrence of the gold-arsenic type Niyakhoy-2 in the Polar Urals (Manitanyrd ridge)

The Niyahoy-2 occurrence of the gold-arsenic type belongs to the Niyayusk gold ore node, within the boundaries of which the Niyahoyskoye and Verkhneniyayus gold ore fields are distinguished. The gold occurrence is localized in the volcanogenic-terrigenous flyschoid of the Enganepey Formation of the Upper Vendian - Lower Cambrian. Within the occurrence, gold-bearing quartz-sulfide veins and streaks are developed. Inter-vein intervals in mineralized zones are also gold-bearing. The surface parts of the ore occurrence to a depth of 15-60 m are significantly affected by weathering processes, representing an oxidation zone. The main ore mineral is arsenopyrite, pyrite is present in a subordinate amount. Minor minerals are represented by chalcopyrite, silver-containing tetrahedrite, lead and copper sulfosalts (aikinite), native bismuth, and gold. As microinclusions in arsenopyrite and pyrite, tetrahedrite, sphalerite, galena, lead sulfosalts and copper of variable composition with bismuth are present. Hypergenic minerals - scorodite, covellite, barite, lead hydroxy sulfosalts with bismuth. The mineral composition of ores, including rare minerals, and the features of native gold, the occurrence of Niyahoy-2 and Verkhneniyayus-2 deposit are close, which may indicate their formation in a single hydrothermal system.