Ore Petrology and Wallrock Alteration Studies at the Lake Shore Gold Mine, Kirkland Lake, Ontario

Abstract

<p> The Lake Shore Mine has accounted for over a quarter of the gold produced in the Kirkland Lake camp. Petrography suggests that gold is a later phase in the paragenesis of ore minerals. Sulphides precipitated first followed by tellurides and gold. Wallrock alteration adjacent to the quartz veins was studied by thin section and geochemical analysis. Petrography enabled an alteration facies scheme based on predominant alteration minerals to be established. The alteration assemblages suggest the fluid had a high K and CO2 content, low Na, and reduced S content. Geochemical analysis of these samples confirm petrographic observations and suggests major additions of K2O, SiO2, Rb, Sb and Au to the wallrock, and losses of Na2O, Ba and Zr from the wallrock.</p>