Characterization of three mineralization styles of the Revenue Au occurrence, Dawson Range, Yukon Territory, Canada : implications for a large-scale, intrusion related system

Abstract

The Revenue Au occurrence, located in Dawson Range, Yukon, Canada is a complex magmatic-hydrothermal system comprised of at least three styles of mineralization with distinct mineral assemblages and textures, though the paragenic relationship between styles is poorly understood. This integrated field and microanalytical study aims to characterize the styles of mineralization using petrography, mineral chemical analysis, and thermometric methods. Methods applied include SEM-BSE imaging, EMPA analysis of the major and minor chemical compositions of sulfides and sulfarsenides, and LA-ICP-MS analysis of trace elements in major sulfides. The data show that in the Blue Sky Zone of the Revenue granite host rock, style 1 mineralization is divided into an earlier, porphyry-like mineralization stage (Cu-Au) which is later overprinted by a later, epithermal-like (Cu-Ag-Au-Mo) mineralization stage. The breccia-hosted and W-Sn enriched style 2 mineralization (Cu-Au-Mo-W) cross-cuts the early style 1 mineralization, and both early style 1 and style 2 mineralization are cross-cut by diatreme-hosted style 3 mineralization. Additionally, regional quartz-feldspar porphyry dykes are commonly associated with Au mineralization in the Dawson Range. This study shows that at the Revenue location there is evidence that these dykes formed pre- to syn- mineralization with respect to late style 1 and style 2 mineralization, suggesting their involvement in the formation of Au mineralization on site.