‘Winu-style’ undercover copper drives ASX debutante West Cobar's exploration

Some explorers live their lives in search of the next mineral elephant. Those at the helm of the ASX’s newest copper play, West Cobar Metals, believe they’re onto a big one.

West Cobar (ASX:WC1) joined the boards today with a big vision for its namesake region – one which remains surprisingly underexplored.

While Cobar and the area to its east have become synonymous with copper mineralisation on the back of a storied history of red-metal output, the area to its west has largely been ignored by those in the exploration game.

That’s a trend which West Cobar, with a management team led by experienced geologist and CEO David Pascoe, will waste no time in changing – having already discovered mineralisation under cover in the area.

The rigs are planned to hit the ground at the company’s flagship Bulla Park project this month, following up stratabound copper-silver mineralisation intersected in limited exploration work carried out over the area to date.

The word “stratabound” could make all the difference at Bulla Park.

While copper mineralisation in the Cobar region typically comes in the form of higher grade but smaller pipelight sulphides, stratabound deposits are generally lower grade but much larger in size. Think Rio Tinto’s Winu deposit, or Mount Isa in Queensland.

West Cobar’s management believes it could be listing with a copper elephant by the ear – albeit under some surface cover.

“We’re not looking for a Cobar-style 10 million tonne deposit,” Pascoe told Stockhead.

“We’re looking for a much larger Winu-style deposit, which are invariably lower grades but big tonnes, and a longer mine life.”

West Cobar’s management has good reason to put faith in Bulla Park. Pascoe and non-executive director Ron Roberts, who co-founded the company, have spent plenty of time mulling over historical and more recent exploration data from the region and compiled a compelling model which will be put to the test when the rigs hit the ground later this month.

Pascoe picked up the ground after reviewing data collated from shallow rotary air blast holes drilled by BHP in the 1970s which detected anomalous lead in an area around 4km by 1km, and later drilling by Thomson Resources which hit around 100m of geochemical copper response.

Sandfire Resources then came in on an option agreement, spending around two years and more than $2 million on exploration before withdrawing, leaving the technical data in the hands of West Cobar.

Best drilling intersected a copper zone of 135m at 0.24% copper, including 33m at 0.45% copper, interpreted as part of a copper mineralised stratabound horizon.

From the combined data, an new interpretation has since been formed which theorises stratabound copper mineralisation beneath geological cover which increases in grade and width, with West Cobar predicting potential for +1% copper in a 1.5km by 1.5km gravity high which is virtually untested to date.

West Cobar — A cross section of existing drilling against the theorised Bulla Park copper zone. Pic: supplied.

Five diamond drill holes are planned for late October, which will test the full potential of the copper horizon for the first time.

Tier one discoveries don’t come easily in Australia anymore, and Roberts said the company’s namesake region was ripe for exactly that.

“Our focus has been to move away from the trodden path – everyone is in Cobar and Kalgoorlie and the Pilbara because there’s big rocks sticking out of the ground,” he said.

“Those with a bit of imagination and vision, I suppose, then start to look elsewhere.

“Look at what’s happened in the Paterson Province. Antipa got in there as a first mover in that area and now they have JVs with Rio, Newcrest and IGO.

“We’re the first and only movers out where we are. We’re explorers, and we’re very excited to get out there and start drilling.”

Prospect potential aplenty

In its early months on the market, West Cobar expects its diamond rig to alternate between drilling at Bulla Park and its Mt Jack prospect.

Mt Jack is prospective for more traditional Cobar-style sulphide mineralisation, and had a single hole drilled in the mid-2000s which was abandoned in rock cover before reaching its modelled target and was never followed up.

The depths of the abandoned hole generated strong geochemical traces of copper and gold, which West Cobar thinks may be leakage from a mineralised system below it.

The prospect is drill ready, and the rig is expected to move to it once initial drilling at Bulla Park is completed.

“We’ve got a near-perfect magnetic anomaly and very encouraging Geochem there, so the plan there is to deep drill an initial hole vertically, straight into that magnetic anomaly,” Pascoe said.

Only three holes have directly tested the structures at the Cawkers Well gold project, where drilling hit 18m at 0.22g/t gold from 135m and 8m at 0.84g/t gold from 170m.

Geology mapping and aeromagnetic surveying are expected to take place over Cawkers Well in January ahead of proposed RC drilling later in the year.

The company’s fourth prospect is Nantilla, an early-stage play where no previous drilling has been carried out.

Geophysical work carried out has identified an aeromagnetic high adjacent to a gravity high, an interesting geological formation which West Cobar plans to assess with aeromagnetics and ground gravity surveys in the new year.

No shortage of newsflow to come.

But the immediate priority will be the potential elephant in the room – Bulla Park.

“There are no previous stratabound copper discoveries in all of New South Wales, despite it being a state with huge copper endowment,” Roberts said.

“You’ve got all these porphyries on the east side of the Lachlan Fold Belt, and you’ve got the Cobar-style mineralisation down the middle, but no stratabound deposits.

“We’re in a position where we have found stratabound mineralisation in a new province, and we need to drill it out and see the extent of what we have.

“We are very, very excited about getting to work on it.”