Impact Minerals looks to be sneaking up on a large copper system at Apsley in New South Wales. The company says its analysis of surface and drilling data indicates it may be touching on the margins of a significant porphyry copper-gold system not dissimilar to Newcrest’s revered nearby Cadia-Ridgeway mine.
Drilling shows the system extending to more than 350 metres below surface, with drill holes returning wide intervals anomalous in both copper and molybdenum mineralisation. The results and associated alteration are indicative of the outer zone of a copper-gold porphyry deposit and hint that Impact may be dancing around the high-grade core of the deposit according to the company.
Impact’s identification of a mineralised porphyry system at Apsley potentially has wide ranging ramifications for the company with recent discoveries of intrusive systems throughout Australia creating significant market interest.
Lefroy Exploration’s discovery of the Burns copper-gold porphyry east of Kambalda earlier this year saw the company’s share price run up from just 20c in February to more than $1.50 by the end of March. A little closer to Apsley, Alkane’s Boda discovery in late 2019 resulted in the miner’s stock climbing from $0.38 in September 2019 to $1.48 a year later, as the market realised the potential value of the deposit.
Whilst it is very early days yet, geochemical and alteration studies at Impact’s Apsley have now identified three key target zones, with the company now designing a comprehensive drilling program to test the system once it gets back on the ground in the months ahead.
In the interim, Impact will now turn its attention to its new project areas in Western Australia, including its Doonia and Arkun tenure. The Doonia project lies just 25km to the east of Lefroy’s Burns discovery and is a similar porphyry-style target. The company also recently completed roadside sampling across much of its extensive Arkun tenure, which lies to the south-east of Perth and is prospective for a range of mineralisation styles including Julimar-style nickel-PGE mafic intrusive complexes according to Impact.
Assays from the Arkun geochemical program are starting to roll in now and the company is likely to start reporting results soon as modelling takes shape and begins delineating targets for drilling in the weeks ahead.
Further east, Impact’s previous work at Doonia identified a deep-seated intrusive complex which is likely to be porphyritic in origin and similar in nature to the company’s Apsley discovery according to Impact. The main porphyry body at Doonia sits in the west of company’s tenement and spans more than 6km across. However, it is an interpreted swarm of magnetic porphyry units on the eastern margin of this parent body which has drawn Impact’s attention.
The porphyry dyke swarm has a peculiar high-magnetic geophysical signature and stretches over more than 3km of strike. The target is further validated by historical geochemical sampling, which shows a 2,500m long and 1,000m wide gold-copper-bismuth-antimony anomaly which is coincident with the magnetic target. Impact says the geochemical signature of this swarm is regarded as a “text-book” signature for porphyry mineralisation, making it a priority target for drill testing.
Impact is now in the final stages of the approvals process for drilling at Doonia and is set to secure a drill rig for its upcoming exploration program imminently. However, with a flow of sample results coming from the lab for Arkun and ongoing modelling of its copper, nickel and PGE targets in NSW, the company looks spoilt for choice as its 2021 work program takes hold.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
