The
Reefton Goldfield has had the largest hard-rock gold production (64 t Au) on the
West Coast of the South Island of New Zealand, and is currently under renewed
development by Oceana Gold. The gold predominantly occurs in variably sheared
quartz veins that are associated with zones of tighter, shorter wavelength folds
in the host Greenland Group metasediments. The quartz veins typically occur as a
series of plunging shoots that align with specific fold limbs or fold hinge
zones. Shear zones containing disseminated mineralisation and quartz veins have
thickness variations that relate to the angular relationship between the shear
and host-rock bedding. Exploration strategies and targeting can be developed
around both types of structural control.