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Abstract

A detailed methodology has been devised and tested for establishing metal zoning patterns in and about oreshoots within the plane of Ag-Pb-Zn veins of the Keno Hill - Galena Hill mining camp, Yukon Territory, using whole rock vein geochemistry of run-of-mine samples. These ideal metal distribution patterns are easily interpretable in more classical zoning terms as mineral distribution patterns. To establish a zoning model samples that span a wide range of grades are rearranged in order of decreasing silver contents. The resulting "rearranged" profiles for other elements are then evaluated relative to silver. Computer-based curve fitting methods are useful means of generalizing these "rearranged" metal profiles. The foregoing procedure has been used to develop a general model for the Keno Hill - Galena Hill camp based on analytical results from 3 main deposits (Keno, Husky, No Cash) including 6 veins. Essential character of the model is embodied in analyses of Ag, Pb, Zn, and Ca and the Zn/Ag ratio. Additional but in cases ambiguous detail is added to the model by Hg, and Co and/or Ni analyses. These elements allow vein mineralogy to be monitored in a quantitative manner and provide a practical zoning model that can be used as an exploration, tool in evaluating underground workings for proximity to oreshoots in the more than 60 deposits known in the camp. A companion study involving whole rock K-Ar age determinations of small stockwork zones adjacent to Ag-Pb-Zn veins indicated an age of mineralization of about 87±2 Ma. for the Ag-Pb-Zn veins.