In comparing and contrasting the two most successful mining and mineral regions in the world, the key difference that maintains the segregated status, particularly in terms of economics, is the nature of ore occurrence (Zientek, 2012). This is especially the case concerning Cu-Ni-PGE sulfide deposits which are the desired commodities. The Bushveld Complex is host to one of the world's largest Cu reserves, sourced primarily from the Merensky Reef and to a lesser extent, the UG2 chromitite layer. Economic Ni sulfide mineralization occurs as has been previously described, in the upper gabbro portion of the complex. Trace Cu and Ni sulfide occurrences are found throughout the entire stratigraphy of BC, but these are usually very low in concentration and not economically viable. In contrast to this, all sulfide mineralization in the Duluth Complex has been cited as 'economic due to the elevated Cu/Ni ratios of the abundant disseminated and lower Cu/Ni sulfides and the need for metals with strategic uses' (Bonnichsen, 1974). It is this difference in grade that directly influences the nature of processing. In the BC, ore is fed directly from mining into flotation and smelting phases to produce a sulfide concentrate. This is due to the high concentration and relatively simple mineral type of sulfides in the Reefs. In contrast, the Duluth Complex has a lower concentration of Cu-Ni sulfides and more complex mineral types due to magmatic processes (Kanitpanyacharoen and Boudreau, 2013). Further, the style of mineralization in the BC dictates a closed magmatic system of emplacement. This has resulted in the formation and concentration of sulfide melts at highly specific stratigraphic horizons close to the floor of the complex. Ore is, therefore, very well constrained and this is an advantage for resource exploration and modeling. In the Duluth Complex, however, mineralization is more scattered, and it is not uncommon during exploration drilling to find a complete lack of ore in several sulfide-bearing layers. This led to the closure of certain mines and the opening of new ones in an attempt to locate better Cu-Ni mineralized deposits. Any change in mine location is said to have a large economic impact.