Mineralogical, fluid inclusion, and stable isotope constraints on the origin of footwall-style "high sulfide" and "low sulfide" Cu-Ni-PGE mineralization at the Coleman Mine, Sudbury Igneous Complex (SIC), Sudbury, Ontario, Canada

Abstract

The Sudbury Igneous Complex, Ontario, Canada, is associated with polymetallic ore bodies that have achieved world-class status due to their high concentrations of nickel, copper, and platinum group elements. Relatively small-volume footwall deposits along the North and East ranges represent <10% of the historical metal resource at Sudbury but have garnered progressive exploration interest in recent years due to their marked enrichments in copper and precious metals. Within the last decade footwall systems have been subdivided into “high sulfide” and “low sulfide” members (sulfide content, alteration mineralogy, bulk rock characteristics) and the relationship between them can be oversimplified in the literature. The Coleman Mine (Onaping-Levack embayment, North Range) contains both high sulfide and low sulfide mineralization and mineralogical, bulk rock, fluid inclusion, and stable isotope results on rocks sampled here suggest that these two mineralization styles constitute independent geochemical systems that deposited Cu-Ni-PGE mineralization after evolving in opposite redox directions.