Dynamic remelting and zone refining of Ni-Cu-PGE mineralization in the Sudbury igneous complex, Ontario, Canada

摘要

Ni-Cu-(PGE) ores in the Sudbury Structure occur in two fundamentally different environments: Ⅰ) in contact ± footwall systems near the base of the Sudbury Igneous Complex and Ⅱ) in radial and concentric quartz diorite dikes that extend further into the footwall rocks.Type la ore systems occur in footwall embayments and are hosted by Sublayer and footwall breccias. Ores are typically less fractionated over mafic lithologies and more fractionated (from Cu-PPGE-poor to Cu-PPGE-rich) over felsic lithologies. Systematic variations in fragment compositions, orientations, and textures, mineralogy, and geochemistry from Sublayer-hosted mineralization and inclusion-bearing massive mineralization through 'granite' breccia-hosted mineralization to footwall vein mineralization (see Table 1) suggest that sulfide melts infiltrated and mechanically-eroded footwall rocks (see Fig. 1).