Till geochemical signatures of volcanogenic massive sulphide deposits in glaciated terrain: a summary of Canadian examples

Abstract

Volcanogenic massive sulphide deposits are a significant source of Cu, Pb, Zn, and Ag in Canada. In the glaciated landscape of Canada, till geochemistry is an important exploration method for VMS deposits. This open file report provides an overview of the >50 year history of the application of till geochemical methods to VMS exploration in Canada, and also summarizes appropriate size fractions of till to analyze, analytical techniques, and pathfinder elements. Geochemical methods are now well developed and widely used, most commonly employing the <0.063 mm till fraction and an extensive suite of VMS pathfinder elements, including Cu, Pb and Zn, Ag, Au, Tl, Sn, Se, Hg, In, Cd, Bi, As, Sb, and Ge. In order to detect the clastic glacial dispersal signal down-ice of a VMS deposit, collection and analysis of unoxidized to weakly oxidized till is optimal, whereas B-horizon soil is not. Case studies and examples of glacial dispersal patterns associated with VMS deposits from major mining camps and deposits across Canada are highlighted, including Buchans, Bathurst, Timmins, Noranda, Manitouwadge, Flin Flon, Finlayson Lake, Hackett River, and Izok Lake.