Latest drilling has upgraded the significance of deeper ore found below and adjacent to the Martha open cut mine at Waihi.
OceanaGold Corporation (TSX & ASX: OGC) said last night it has updated the mineral resource at Martha, where open cut operations were curtailed after a major wall slip.
Chief executive Mick Wilkes said the company increased the indicated resource by 700% to 760,000 tonnes grading 5.8 grams/tonne for 140,000 ounces. The inferred resource was increased by 250% to 2.49 million tonnes @ 4.3 g/t gold for 339,000 oz.
The silver content was not detailed despite the fact some of the Waihi mines have had silver grades much higher than the gold.
Wilkes said latest results significantly expand the Martha project exploration target.
“With only 30% of the planned drill metres completed, we are excited about the future and remain optimistic with respect to the ultimate size of the Martha resource.
“The results to date have been much better than we expected and therefore the exploration target that is being tested through drilling has been revised and expanded.”
Wilkes said the Waihi mining operations are an important part of the town of Waihi, directly employing 350 people and contributing about 40% of the local economy.
“Increasing the mine life of the operation allows us to continue delivering these socio-economic benefits and provides greater certainty to the town’s residents and local and regional businesses we are proud to be in partnership with.”
Since August 2017 about 16,200m of drilling has been completed at the Martha underground project from two underground drill drives and represents about 30% of the planned exploration drill metres to the end of December 2019.
Drilling has focussed on identifying and defining mineralisation along sections of the Martha, Royal and Empire veins which, in combination with the Edward vein, have in total a combined strike length of about 3.2 kilometres and a maximum dip extent of about 500m.
As exploration has progressed the company has identified mineralised veins that sit outside the initial exploration target.
As a result, and following the incorporation of further data, including that from recent drilling, the exploration target has been revised and is now outlined as a potential volume of between 5 Mt and 8 Mt at a grade of between 4-6 g/t gold for between 1 M to 1.5 M oz of gold, inclusive of the indicated and inferred resources already detailed.
OceanaGold will increase the number of diamond drills from the current four up to six to accelerate testing of the Martha, Empire, Royal and Edward veins and the numerous linking splays that make up the Martha vein system.