The gold mineralised Garibaldi vein system; an application of geophysics, geologic mapping and pan concentrate soil sampling to hard rock gold exploration in central Otago
Coote, J.A.; Henderson, S.; Bischoff, A.
Annual General Meeting and Conference - The Australasian Institute of Mining and Metallurgy, New Zealand Branch 45: 83-91
Potentially economic gold and related tungsten and arsenic mineralisation is associated with multiple east-west and northeast-southwest trending epizonal-style quartz + sericite/illite + Fe-sulphide vein sets and intervening host Fe-carbonate + sericite/illite + quartz + Fe-sulphide altered and sheared mafic schist over a 900 metre strike length and 300 metre width in the Omnibus Stream catchment, North Rough Ridge, Central Otago. The epizonal style vein and alteration system is coincident with and deformed in relation to northeast and northwest trending regional scale structures evident in airborne geophysics data sets. Pan concentrate gold from soils has a distribution and individual grain morphology reflecting the style and distribution of gold in relation to the quartz vein system and associated wallrock alteration. A strong gossaneous or supergene Fe-oxide overprint evident in outcrop is mainly the result of strong weathering and leaching of the Fe-carbonate alteration of mafic schist, and late Fe-carbonate veining.