Bold porphyry copper exploration program aims to unearth sleeping giant in South Australia

By / 17th of March, 2017

A JUNIOR Adelaide-based resources company has high hopes that a bold new drilling program will trigger a copper exploration boom in South Australia.

ASX-listed Investigator Resources, which last year shifted its head office from Brisbane to the South Australian capital Adelaide, announced this week a four-hole drill program at its Nankivel prospect on Eyre Peninsula. The first drill hole is scheduled to start before the end of this month.

The drill program is a much-anticipated follow up to the discovery of a major system of copper-mineralised porphyry rocks at Nankivel last September. Porphyry copper is a deposit style that produces most of the world’s copper, but is entirely new to South Australia and found in only a handful of locations around Australia.

Investigator’s first and only drill hole encountered mineralised porphyry rocks along its entire 600-metre length. Assays later showed uneconomic but highly encouraging intervals with up to 0.16% copper and 0.47 grams/tonne gold.

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Situated on the northern part of Eyre Peninsula, about 350km northwest of Adelaide, Nankivel is only 4km southeast of the company’s 33-million-ounce Paris silver deposit, another entirely new deposit style in South Australia. Investigator defied accepted knowledge in the minerals industry when it made the discovery in 2011, and hopes to do it again at Nankivel, but on a much bigger scale.

Managing director, John Anderson, said the Northern Eyre Peninsula was an “incredibly exciting” place to search for ore bodies.

“We know the area is rich with mineralisation generated by the same event that created the super-giant Olympic Dam deposit, but we are still at a very early stage of understanding the mineral systems in this region.

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“Our approach has always been to look at what the rocks beneath our feet tell us, rather than listen to conventional wisdom. You would be surprised how many geologists believe you can’t find a particular deposit style because it hasn’t been found previously. We are happy to be trailblazers, which is how we made the discovery at Paris.”

Eyre Peninsula has already been identified as having rich JORC graphite deposits in its east but its northern reaches are only lightly explored.

Anderson said he was confident this area had the potential for world-class discoveries.

“I have had the view for some time that Paris would be a pathfinder to even bigger deposits nearby such as porphyry copper, and we have high hopes that Nankivel will bear this out.”

He said a porphyry copper discovery would be “a huge shot in the arm” for the flagging mineral exploration industry in South Australia.

“We have fantastic geology for which the understanding is evolving, and a very supportive state government. More money is flowing into exploration after a very lean few years, but not much of that is finding its way to South Australia. That could change overnight with success at Nankivel because porphyry copper is such a high-priority target for mineral explorers worldwide,” Anderson said.

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A discovery would also be a major boost to the South Australian Government’s copper strategy, which aims to triple the state’s annual copper production to one million tonnes within the next two decades. The ambitious plan would make South Australia the world’s third largest copper producer.

The government is encouraging success with its Plan for Accelerating Exploration (PACE) program, which includes co-funding a number of high-impact exploration holes, including Investigator’s new drill program at Nankivel.

Anderson said SA’s copper strategy was achievable but “you have to have bold explorers who are prepared to have a go, and the more of those we can attract to South Australia, the better it will be for everyone”.