In the wake of the discovery of the giant Olympic Dam Cu-U-Au-Ag-REE deposit in South Australia in 1975, a conception developed of an important class of ore deposits not previously recognised as such. Subsequent realisation of its significance by the discovery of new deposits of this type attracted keen interest both from academic institutions and exploration companies worldwide.
Due to its economic importance, over the last two decades, the socalled iron oxide copper-gold (IOCG or FeOx-Cu-Au) class of deposits has become a prime target for exploration. Since the first definition and description of the IOCG deposit, new discoveries, re-classification and increasing worldwide research have shown that IOCG deposits encompass a wide spectrum of hydrothermal ore deposits.