The nature and origin of the ore-forming fluid in the Kidston gold deposit, north Queensland

Mineralization and alteration are associated spatially and temporally with brecciation and rhyolite intrusion. Three stages of alteration have been recognized: pre-brecciation, and early and late stage post-brecciation. Gold is known to be particularly associated with late stage post-brecciation cavity infill and sheeted veins. Fluid inclusion data and alteration assemblages define the prevailing chemical conditions. Gold transport under these conditions would have been primarily as a bisulfide complex. -Authors