| At McCreedy West Mine, Sudbury, Ontario, petrographic and quantitative (SEM-EDS, electron microprobe, Laser Ablation ICP-MS) analysis has been completed on sulphides from contact magmatic ore and footwall vein ore. This study has characterized the footwall ore as consisting dominantly of chalcopyrite-pentlandite-millerite with minor Pt-Pd bismuth tellurides and native gold. Analysis of vein pentlandite has revealed higher Ni and Pd contents but lower Co compositions than contact ore pentlandite. The identification of numerous hydrous Cl-bearing Fe-Mg silicates (chlorite, greenalite and pyrosmalite) associated with these vein sulphides, and the occurrence of fluid inclusions within vein hosted quartz and chalcopyrite suggest that the footwall ore was formed by hydrothermal means.;Assay analysis of ∼30,000 ore samples has revealed the Cu-PGE rich character of the footwall veins with respect to the Ni-Co rich contact ore. Significant trends have been identified within the contact ore through the use of Pearce Element Ratio diagrams, DataMine sections, and histograms. These methods have suggested that Pt and Pd content increases from the Sublayer ore, through the Footwall Breccia ore and into the footwall vein ore, and that Ni decreases from the Lower Main Ore Zone to the Middle Main Ore Zone. Comparison of this data with data from other North Range contact deposits may prove beneficial towards the discovery of other footwall vein ore bodies. |
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