Macraes Mine in East Otago is New Zealand's largest gold mine,[1] and consists of a large scale opencast mine[2] opened in 1990, and a newer underground mine, opened in 2008.[3] It is situated close to the settlement of Macraes Flat and is owned by OceanaGold Corporation.
Gold production averaged 193,000 Troy ounces/year for 2008 through 2010. Ore grades have been declining, to 1.26 grams/tonne in 2010, but recoveries have improved slightly to 81% of the gold contained in the ore, in 2010. From 1990 through 2014, gold production totaled about 4 million ounces.[4] The mine's 5 millionth ounce was poured in July 2019.[5] The company claims a gold reserve of 1.53 MM troy oz Au plus a larger subeconomic gold resource; and expects the mine to operate at least through 2021.[3][6] As of July 2019, over 5 million ounces of gold have been extracted.
The gold bearing rocks were formed by the orogenic processes that created the Otago Schist belt.[7]
