An investment presentation earlier this month said Waihi had delivered about 300,000oz of gold during calendar 2015-16, had a total estimated gold resource of 570,000oz as at last December, and had an estimated mine life beyond 2019.
Of 147,956oz of gold produced by Oceana in the first quarter of the year, in New Zealand Martha delivered 25,860oz while the Macraes mine, in East Otago, delivered 38,550oz.
In a recent Waihi community update, Oceana said it had identified potential underground mine opportunities next to the remnant Martha, Royal, Edward, Empire and Welcome ore bodies, beneath the Martha open pit.
Oceana bought Waihi from Newmont in May 2015 for $132million, and in 2016 planned to spend $10million to $12million on exploration, while continuing underground mining.
Other than processing ore taken when the new horizontal tunnel drives are made, Oceana cannot go on to mine more ore, as a new and separate consent is required.
Oceana said yesterday it had prepared a resource consent application to construct and open the two drill drives to get a better understanding of the quantity and grade of the potential gold and silver resource, and assess geotechnical conditions.
''These drives would run from the existing Correnso and SUPA underground mines and travel under the south wall of the Martha open pit,'' Oceana said.
Both tunnel drives would extend from the Daybreak gold vein, with one running 40m above the bottom of the Martha pit for 680m, and the other about 100m below the pit for 570m. They would be connected by a vertical fresh air shaft, which would also provide an escape way between the two tunnels.
For the first time in 27 years, Oceana is estimating its gold production for calendar 2017 will push beyond 500,000oz, with 50% from New Zealand, 30% from its South Carolina Haile mine and 20% from Didipio, on the northern Philippine island of Luzon.
