The Nepean nickel mine may date back to Australia’s first nickel boom in the late 1960s, but owner Auroch Minerals’ view it remains seriously underexplored is being vindicated.

Auroch Minerals (ASX: AOU) has picked out a new conductor 1.8km as the crow flies south of the historic high-grade nickel mine through modern surveying techniques.

A major moving loop electromagnetic survey picked out the underground conductor just 60m from surface, with a strike width of 120km in an area with no previous drilling.

The modelled EM plate ranged between 5000-15,000 siemens in MLEM readings, a number that may not mean much on first reading.

But that is the range of electroconductivity typically found with well-developed massive and semi-massive sulphides, the kind of deposits typically found in and around the bountiful Kambalda region that hosts the Nepean mine.

Three RC holes will be drilled into the target and cased with PVC for down hole EM surveys, targeting depths of 150-250m.

Target adds to Nepean potential

“The purpose of the extensive high-powered ground MLEM survey was to quickly cover a larger portion of the 10km of Nepean strike in order to prioritise smaller areas for follow-up exploration and subsequent drilling,” Auroch MD Aidan Platel said.

“The MLEM survey was successful in doing exactly that, identifying several conductive bodies that warrant follow-up exploration.

“In particular, one of these identified conductors is of immense interest, as its high conductivity and discrete size are typical of an EM response caused by well-developed nickel sulphide mineralisation.”

On top of that the conductor is coincident with a magnetic high believed to be serpentinised komatiitic ultramafic, which is significant because the same type of geological structure hosts Nepean, which produced 32,202t at ~3% between 1970 and 1987.

“The location of this strong conductor coincident with an aeromagnetic anomaly and along strike from the historic high-grade Nepean nickel sulphide mine, in an area that has never been drilled before, significantly add to the high potential of this exciting drill target,” Platel said.

“We knew that much of the Nepean strike was under explored and this result, discovered approximately 1.8km south of the historic mine, is a great indication of the potential of this project.”

Nepean Deeps drilling on the horizon

An RC rig is already onsite with a maiden drilling program into the Nepean Deeps.

The 3000m drill drive will test areas beneath historic workings, believed to show similarities to Western Areas’ 1200m deep Flying Fox nickel mine.

The MLEM survey also uncovered another, less conductive anomaly, around 600m east of the main ultramafic and a strike of around 1000km.
More work is being planned to understand the geology and whether it may be prospective for nickel sulphide deposits.



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.