Orogenic Gold Mineralization of the Adycha Ore Region (East Yakutia, Russia): Geological Setting and Geochemical Features of Gold-Quartz Ores

The analysis of features of the geological structure of the Adycha gold placer region shows that flat structures of the early collision stage control the setting of the ore fields. The ores are similar to host rocks in the main components, lithofile trace elements, and REEs. The features of the trace-element pattern and indicative ratios agree with the suggested metamorphic origin of the main volume of fluids, their weakly reduced and almost neutral conditions, and sorption rock-fluid interaction. A group of elements, the distribution of which is significantly distinct from those of the host rocks, is determined. The geochemical type of the ore region is caused by Mo, Au, Bi, and Sb, the contents of which are higher in all studied ore objects. Chromium, As, Pb, and Te are present in all ore fields, but not in all objects. The Co-Ni-W-Zn-Cd-Ag, Co-Ni-W-In-Mn-Cu-Sr, and Sn-In-Mn-Cu-Zn-Cd-Sr-Ag associations supplement the geochemical type of the Delyuvial'ny, Lazo, and Sentachan ore fields, respectively. Our studies along with thermobarogeochemical data refine the metamorphic-magmatic model of the formation of the gold-quartz deposits of the Kular-Nera belt and outline approaches for the practical application of these features.