Copper and gold explorer Middle Island Resources has completed its maiden drilling program for iron oxide-copper-gold, or “IOCG”-style mineralisation at the company’s copper gold project in the NT’s Barkly region, east of Tennant Creek.
After intersecting IOCG style alteration at the project’s Crosswinds prospect in its first 808m diamond drill hole at the start of the month, the explorer has chewed through another 2217m in search of a large-scale and lucrative IOCG deposit.
The core derived from the total 3025m of drilling is being logged and processed at the company’s nearby Tennant Creek operational base with laboratory assay results expected in a few months.
Preliminary XRF measurements will be obtained whilst the explorer waits for definitive assays.
The initial results will be interesting because the last time Middle Island ran the portable XRF over the surface of Crosswinds, it yielded readings of between 24.8 per cent and an astounding 76.2 per cent copper.
The company also expects an airborne geophysical analysis to be returned soon, providing a further geological substance to its model and support in prioritising its drill targets.
Middle Island says whilst it intersected IOCG-style alteration in its first hole, ultimately there was an absence of the targeted sulphides. The company believes it may have intersected the edge of the mineral deposition and has now drilled in the opposite direction, aiming to intersect the centre of the potential sulphide zone.
The IOCG classification was defined after the discovery of the Olympic Dam deposit in South Australia, now operated by ASX’s largest market-capped company, BHP.
According to BHP’s 2012 annual report, the sulphide resource at Olympic Dam exceeded 9 billion tonnes at a grade of 0.86 per cent copper and 0.32 grams per tonne gold.
Interestingly, IOCG deposits are known to be enriched in a suite of elements including uranium for which Olympic Dam currently hosts the largest individual resource in the world.
Australia has two major IOCG provinces of global significance — the Olympic IOCG province and the Cloncurry district in north-west Queensland.
Interestingly, geological body Geoscience Australia says several other provinces may contain small or medium-sized IOCG deposits and the Tennant Creek district, where Middle Island is operating, is one of them.
Other ASX-listed companies exploring the area include Newcrest Mining, Rio Tinto, Emmerson Resources and a joint venture between Greenvale Mining and Astro Resources.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
