Conclusions: Key Controls on Making of a World Class Deposit

Abstract

Widely dispersed disseminated gold has ensured that large volumes of low grade ore are amenable to mining at Macraes. This arose because mineralisation was driven by a late metamorphic fluid that percolated pervasively along a focused shear zone, with a footprint that extended >500 m. Replacement reactions in host rocks dominated mineralisation, in contrast to many orogenic deposits that are dominated by quartz veins. Macraes mineralisation style was affected by subtle lithological variation, with micaceous schists predominating.