Erosion level of the epithermal Rogovik deposit estimated from geochemical data, northeast Russia

Abstract

The geochemical zoning of the Rogovik epithermal deposit in northeast Russia has been established on the basis of endogenic anomalous geochemical fields (AGCF) of Au–Ag zones, their qualitative and quantitative compositions, and spatial distribution of chemical element indicators of Au–Ag mineralization. The obtained geochemical data (monoelemental AGCF, associations of elements, their composition, contrast, and correlation) allowed us to estimate the erosion level of Au–Ag ore zones. It has been shown that AGCF related to Au–Ag mineralization are distinguished by simple component composition (Au, Ag, Hg, Sb, As, Cu, Pb, Zn) and regular spatial distribution of the elements. It has been established that the least eroded central part of the object is characterized by widespread and the most contrasting Au, Ag, Hg, Sb, and As AGCF closely related to the ore-bearing units of the deposit. The contrast of these fields gradually decreases with depth. Low-contrast Cu, Pb, and Zn AGCF typical of the footwall depth intervals and flanks of Au–Ag zones intervals appear at depth. The northern part of the area is eroded to the deepest level. The contrast of Ag, Hg, Sb, and As geochemical fields abruptly decreases here, and Cu, Pb, and Zn AGCF become widespread with depth. The relatively contrasting fields of anomalous Au concentrations develop here extremely locally and near the surface. It has been concluded that the as yet poorly explored southern part of the Rogovik deposit most likely is promising for further geological exploration and the discovery of new mineralized areas.