Planning is underway for a 3,000m drill program to test the high priority ‘Nepean Deeps’ nickel target for the very first time.

Due to kick off late July, the program of up to five drillholes will target economic nickel sulphide mineralisation below the historic high-grade Nepean operation in WA, the second producing nickel mine in Australia.

Nepean produced over 32,202 tonnes of nickel metal at an average recovered grade of 2.99% until very low nickel prices below $US4,000/t in 1987 forced production to halt.

Prices, now $US17,700/t, are expected to go even higher over the next decade as demand from the lithium-ion battery sector builds a head of steam.

The depth extent of the nickel mineralisation below the mine workings remains underexplored Auroch Minerals (ASX:AOU) says, “with effectively no previous drilling at depth”.

A Flying Fox lookalike

That’s despite similarities to Western Area’s (ASX:WSA) Flying Fox mine which, like Nepean, was supposedly constrained at depth.

Western Areas acquired Flying Fox in 2003 after it had produced ~8,000t of nickel before encountering a granitic dyke at depth.

Western Areas subsequently drilled below the granite and discovered significantly more high-grade nickel sulphide mineralisation. It has since produced over 100,000t of contained nickel metal.

A large flat-lying pegmatite vein similarly crosscuts the nickel sulphide mineralisation at the base of the Nepean mine workings.

Western Area’s later discovery of the ‘Spotted Quoll’ nickel sulphide deposit along strike from the Flying Fox adds further weight to the analogy, with the Nepean nickel project containing over 10km of strike of mine sequence stratigraphy that has seen very little historic drilling below the weathered profile.

Auroch knew when it acquired this project that it still had a lot more to give, managing director Aidan Platel says.

“The presence of the flat-lying pegmatite vein at the base of the old mine workings is an important factor in our drilling strategy as we know geologically that the pegmatite veins are later features that developed a long time after the massive nickel sulphides were emplaced in the basal channel, and hence, logically, the channel and the nickel mineralisation should continue beneath the pegmatite, exactly as was the case at Flying Fox.”

Down-hole electromagnetic (DHEM) surveys will be undertaken on all drillholes to assist in modelling and definition of any potential further mineralisation.

DHEM surveying involves sending a probe attached to a wire cable down a completed drill-hole.

The probe is able to detect conductive sulphide mineralisation off-hole, with the potential to “see” mineralisation up to 75m away.

The results from the drilling and DHEM surveys will be released to the market as they are received.




This article was developed in collaboration with Auroch Minerals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.