Early mover advantage puts Antipa in the middle of Paterson frenzy

Special report: Like the Fraser Range and Bryah Basin before it, the Paterson Province has become a Western Australian mineral exploration hotspot following strong evidence that Rio Tinto has made a world-class copper discovery in the region.

For Antipa Minerals (ASX:AZY), the hype that has emerged over the past few months is further vindication of its decision seven years ago to make the Paterson the sole focus of its exploration activities.

Antipa listed on the ASX in 2011 with its main asset being a 1,700km²package of tenements in the Paterson acquired from Centaurus Metals (ASX:CTM) known as the Citadel Project.

Additional ground was picked up shortly thereafter in a deal with Paladin Energy, while some tenements were also acquired from legendary WA prospector and dealmaker Mark Creasy.

Today Antipa has an interest in more than 5,500km²of prime exploration ground in the region, including Citadel which is now a joint venture with Rio.

“What drove us to the Paterson Province initially was it had the capacity to generate tier one assets as proven by the world class Telfer gold and copper mine owned by Newcrest Mining,” executive chairman Stephen Power said.

“Telfer has been mined for 40 years and pre-mining it had 32 million ounces of gold and one million tonnes of copper, making it one of Australia’s largest gold deposits.”

Paterson Province accommodation camp. Each tent comes with built-in air-conditioning unit to keep the drillers in comfort.

When Antipa was establishing itself in the Paterson in 2011, the address was far from fashionable, with the province having received only very limited exploration after the mid-1980s.

In fact, most of the main players including Newcrest were reducing their landholdings, which to a degree allowed Antipa to cherry pick what it regarded as the best ground.

Key considerations included proximity to the existing Telfer infrastructure, prospective geology and the amount of prevailing “cover”.

While Telfer was discovered because the mineralised rocks outcropped at surface, in most parts of the Paterson the rocks of interest lie under a layer of sandy material, otherwise known as cover.

The less cover there is, the easier and more effective the exploration is likely to be.

It also follows that a discovery has more chance of being economic if there is less cover, as there will be less waste material to move to get to the ore.

“The ground that we picked up has shallow cover, at most 80 metres and more than 50% is under less than 50 metres,” Power said.

“Once you go east, west and south of our landholding, it drops off a cliff and you’re talking 400 metres to even kilometres of cover.”

In recent times, companies operating in the Paterson have typically employed modern exploration techniques such as airborne electromagnetic (AEM) surveying that allows them to see through the cover and identify drilling targets.

Airborne electromagnetic surveys have played a part in several discoveries in the Paterson, including Rio Tinto's recent find. — Airborne electromagnetic surveys have played a part in several discoveries in the Paterson, including Rio Tinto’s recent find.

Indeed, the story around the Rio discovery has the company flying an AEM survey over its ground neighbouring Antipa in late 2017 through which it identified a large anomaly.

Three holes were drilled testing the anomaly and that’s all it took to confirm a potential new tier one copper deposit.

Earlier this year Antipa flew an AEM survey over a structure that runs through its ground that it refers to as the El Paso Corridor.

The company has exposure to 140 strike kilometres of this corridor which is “book-ended” to the north by Rio Tinto’s purported world-class copper discovery and to the south by Greatland Gold Plc’s stunning Havieron gold-copper drill hits.

The El Paso AEM survey identified 11 priority gold-copper targets that will be drill tested in the first half of 2019 providing the opportunity for a game-changing discovery.

The company also advised the market last week that Rio had opted to fly an additional AEM survey over the Citadel Project this year in another sign that the major is excited about what it is onto in the Paterson.

Although Antipa can’t claim a tier one discovery just yet, its efforts in the Paterson to date have not been without success, with the company making several discoveries and delivering resources totalling 2.4 million ounces of gold and 154,000 tonnes of copper.

With the assistance of AEM, the company discovered the Calibre gold-copper deposit and the Corker polymetallic deposit at Citadel.The company has defined a resource at Citadel of 1.64 million ounces of gold and 127,000 tonnes of copper from the Calibre and Magnum deposits.

It has also defined a resource of 723,000 ounces of gold and 26,000 tonnes of copper at the Minyari and WACA deposits, part of its 100% owned North Telfer Project.

Substantially increasing the company’s resource base has been one of two key focuses of this year’s exploration programme, with an update slated for early 2019.

The other key focus, of course, is making greenfields discoveries.