Till geochemical signatures of magmatic Ni-Cu deposits, Thompson Nickel Belt, Manitoba, Canada

Sampling around the Ni-Cu deposits in the northern Thompson Nickel Belt (TNB), central Canada, was conducted to document Ni-Cu mineralization signatures in till. Samples used in this study include archived material collected in 1996 and new samples collected in 2005 and 2006. During the Late Wisconsinan, the Laurentide Ice Sheet flowed southwestward and subsequently westward across the TNB striating outcrops and transporting metal-rich till. Exploration along the belt and in the surrounding terranes should consider both the older SW and younger westward ice flow events when interpreting and following up till geochemical results. Till geochemistry of the <0.063 mm fraction is a useful tool for Ni-Cu exploration in the region and the following pathfinder elements are most useful: Ni, Cu, Pd, Pt, Co, As, Cd, Ag, Sb, Bi, Se, S, and Te. This multi-element signature is similar to those identified in till for other Ni-Cu-Platinum Group Element (PGE) deposits. Pd: Pt ratios of >3 offer further discrimination of significant till geochemical anomalies. Using the deposit signatures in till as a guide, five anomalous till samples outside the belt represent new exploration targets because they contain significant elevated concentrations of, in various combinations, Pt, Pd, Cu, Cr, Mo, Sb, Bi and Fe.