Oceana Gold has posted upbeat ``high mineralisation'' gold test results from its Waihi mine in the central North Island, from beneath the historical Martha pit.
Oceana chief executive Mick Wilkes said the test drilling was designed to unlock a million ounces of gold resource-target at Waihi, which could push out mining at current levels as far as 2030.
``The latest drill results further demonstrates the significant mineralisation that resides beneath the Martha pit,'' Mr Wilkes said.
In May, Oceana lodged resource consent applications to develop another underground mine adjacent to the Martha pit, and also to resume open pit operations; with the permitting process expected to be complete by the end of 2019.
Mr Wilkes said the test drilling ``exceeds expectations'' and he highlighted four examples.
One test drill 5m in length indicated 65.3 grams of gold per tonne (g/t), another 9m at 29.4 g/t, 3.6m at 31.9 g/t, and 7.9m at 14.1 g/t.
During the next year, Mr Wilkes said more than 47,000m of test drilling would be undertaken by drill rigs both from underground platforms and the surface.
The Martha underground exploration target is estimated to shift 3.5million-5million tonnes of ore and deliver between 500,000-700,000 oz of gold.
Mr Wilkes said Oceana's strategy is to continue to own and operate high-margin, long life assets, which includes the overall ``Martha project'', he said in a market update.