The accumulation of gold in Otago involved a wide range of processes beginning with the formation of the Otago Schist basement. Progressive uplift and erosion of the schist released the gold into the sedimentary environment where it was further concentrated by physical and chemical processes.
- Origins of the gold
- Alluvial mining
- Hard-rock mining
- Economies of Scale
- Environmental aspects of mining
- Gold at St Bathans
- Gold at Gabriels Gully
- Gold at Alexandra and Ophir
- Crustal structure and topography of the Otago northeast margin
- Initiation of the fault zones on the northeast Otago margin
- Faulting and erosion of the Macraes gold deposit
- Gold-bearing veins at Oturehua
- Blue Lake Fault Zone
- Graphite and gold on the northeast schist margin
- Gold and arsenic in pyrite
- Waipounamu Erosion Surface
- Alluvial gold along the northeast Otago margin
- Rise of modern mountains on Otago’s northeast margin
- Patearoa gold: Alluvial concentrations in a dynamic environment
Gold occurs in thin veins of white quartz near the crest of the Southern Alps. It is transported in rivers and deposited near the sea. The action of the sea concentrates the gold in beach sands.
The Macraes gold deposit is the largest active gold mine in New Zealand. The mine has produced more than 1.8 million ounces of gold at an average grade of 1.6 grams/tonne since opening in 1990.