Two size fractions of till, <250 μm and <2 μm, humus, moss and black spruce bark, as well as sulphides, host rocks and Palaeozoic cover dolostone from drill cores were sampled at the Talbot Lake volcanogenic massive sulphide (VMS) prospect in the Flin Flon-Snow Lake terrane, Manitoba, Canada. Lead isotope-ratios in organic surface media indicate significant input of anthropogenic Pb from the Flin Flon smelter at 160 km distance to the northwest, with 206Pb/204Pb between 16.5 and 18.2, whereas background till and upper dolostone range between 21.6 and 23.1. At deeper levels, the influx of Pb from Proterozoic mineralization from greater than 100 m depth is recognized. Strontium isotope ratios in these media indicate enhanced vertical fluid flow in the till cover at a fault zone, coincident with the Pb isotope anomaly, as well as relative contributions of Sr from carbonates, silicates and vegetation to the till profile. In humus, sphagnum moss and black spruce bark, the Pb isotope ratios are progressively more similar to that of the feed of the Flin Flon smelter. Measurements of Pb and Sr isotope ratios reveal that Pb from Proterozoic mineralization situated beneath 100 m of Palaeozoic dolostone can be distinguished from Pb contributed by anthropogenic and other geogenic sources.

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