Arizona Sonoran expands Cactus copper resource, new PEA pending

Arizona Sonoran (TSX: ASCU) has increased its measured and indicated resource tonnage for the Cactus copper project in Arizona by more than a quarter after a seven-month drilling program.

Total measured and indicated resources came to 632.6 million tonnes at 0.58% copper for 7.3 billion lb. of copper, a 26% increase over the previous estimate after infill drilling at the Parks/Salyer area, Arizona Sonoran said on Wednesday. Inferred resources jumped 60% to 474 million tonnes at 0.41% copper for 3.8 billion lb. of copper, it said.

The brownfield project converted 1.2 billion lb. of copper into the measured category and confirmed the Parks/Salyer resource area and the new MainSpring property as one single deposit. It contains about two-thirds of the total mineral resource (4.8 billion lb. measured and indicated, and 2.6 billion lb. inferred) at Cactus.

“The new Parks/Salyer deposit, inclusive of MainSpring, could be transformational for the company,” CEO George Ogilvie said in a release. “We foresee the opportunity to right-size a larger operation and rescope Parks/Salyer to an open pit mine.

“The pending result would lead to reduced mining execution risks and lowered operating costs which could manifest themselves in improved project economics.”

Compared to the project’s first resource established in 2021, the new estimate shows 353% more measured and indicated contained copper. The jump was 94% in inferred contained copper.

Open-pit concept

The expanded Parks/Salyer deposit is amenable as an open pit to be incorporated into a new preliminary economic assessment (PEA) the company aims to complete this summer. A positive PEA and a new prefeasibility study could see a completed definitive feasibility study by the end of next year.

Also comprising the project are the Cactus West and Cactus East deposits as well as the Stockpile area, all located along a 5.5-km trend. No material changes were reported for these resource areas since the last update.

According to Doug Bowden, Arizona Sonoran’s vice-president of exploration, these mineral resource areas have responded “favorably and impressively” to infill drilling with a consistently high conversion rate into higher classifications.

The company completed a prefeasibility study for the Cactus project this year outlining a 21-year copper operation producing 110 million lb. of payable metal annually. Its after-tax net present value at an 8% discount is estimated at $515 million, with an internal rate of return of 15.3%.