Site visit: Prismo Metals’ Hot Breccia project blooms in Arizona copper belt

The helicopter arcs around the scrubland hills like the start of a M*A*S*H episode. Except these hills are in Arizona, not Korea, and they’re studded with giant saguaro cactuses on Prismo Metals’ (CSE: PRIZ, US-OTC: PMOMF) Hot Breccia copper property.  

Vancouver-based Prismo has raised $5 million, including $2 million from Vizsla Silver (TSXV: VZLA; NYSE: VZLA), to start drilling on the 14-sq.-km property 140 km southeast of Phoenix as it works to earn three-quarters of the project from Infinitum Copper (TSXV: INFI, US-OTC: INUMF). Hot Breccia joins Prismo’s two other earn-in projects in Mexico: Palos Verdes in Sinaloa and Los Pavitos in Sonora.  

The chopper lands on a narrow hillside drill road dating from the 1970s, like the TV army medics, flattening yellow poppies and purple lupine flowers. It is a Papal-coloured path just before Easter, made possible by more winter rainfall than usual in the Sonoran Desert, the world’s wettest. Craig Gibson, co-founder and CEO of Prismo, eyes a rock formation guarded by three saguaros taller than most houses.  

“Parallel and in contact with this dyke we have a polylithic breccia with copper mineralization and fragments of underlying sedimentary rocks that have been brought up,” Gibson said. “This is a very active area hydrothermally and we think it’s going to be a pretty good project for drilling later this year.”  

Prismo is aiming to develop Hot Breccia, which is 2 km from Grupo Mexico’s mothballed Hayden smelter and twice that from Freeport-McMoRan’s (NYSE: FCX) past-producing Christmas mine. They’re all in the same Arizona copper porphyry belt that supplies more than two-thirds of the U.S. output of the metal used in wiring and plumbing. Analysts expect demand for copper, considered a battery metal for electric vehicles, to rise for decades as countries transition to greener energy to fight climate change.  

Still, the project is very early stage, lacking even data from airborne geophysical surveys. The first are planned in a few months to probe the breccia system, Gibson said while negotiating a slope to avoid ocotillo thorn bushes and barrel cactuses. Also, even the few historic drill holes for which Prismo has data show mineralization is at considerable depth for a potential open-pit operation. While the copper price – US$4.07 per lb. on April 4 – has been buoyed by resurgent Chinese demand, it was still 12% lower than it was a year earlier, according to mining.com.  

Geologists posse

Further along the flowered path lies the spot where Kennecott Utah Copper, now a unit of Rio Tinto (NYSE: RIO; LSE: RIO; ASX: RIO), drilled hole OCC-8 in the late 1970s. It cut 7.6 metres grading 1.7% copper and 0.1% zinc including 4.6 metres grading 1.4% copper and 0.9% zinc at a depth of 716.3 metres.  

Near the old drill hole, Peter Megaw, a co-founder of Prismo and chief exploration officer for MAG Silver (TSX: MAG; NYSE-AM: MAG), was part of a posse of visiting investors and geologists navigating gingerly across a skin of loose rock, that slid at times like ball bearings, to study the 60-65-milion-year-old formations that give the property its name.  

“This looks like a fragment that came up from the deep part of the Paleozoic sedimentary section below the volcanic, so it’s probably been transported a minimum of a kilometre,” Megaw said. “The rock is mineralized, so that’s what you want to see in these breccias.”  

The nearby former Christmas mine produced 363 million lb. of copper from 20.2 million tonnes grading 1.2% copper from 1905 to 1982. It was shut when copper prices fell to about US55¢ per lb., Megaw said. He’s lived and worked in the region for more than 40 years.  

The Hayden smelter shut in 2019 after a strike but its concentrator is still producing at about a fifth of its capacity, Steve Robertson, chairman of Infinitum, said during a presentation at the town of Kearny, population 1,950, from where the helicopter shuttled visitors to Hot Breccia.  

The project’s earn-in agreement with Infinitum required Prismo to pay $350,000 and half a million shares followed by spending $5.25 million on exploration through 2026. Prismo shares traded at 36¢ each on Wednesday afternoon in Toronto, within a range of 12¢ to 73¢, valuing the company at $14 million.  

Mexico projects

South of the border on the 53-sq.-km Los Pavitos project, Prismo said this week channel sampling returned 20.3 grams gold per tonne over 0.6 metre. Mexican company Minera Cascabel is offering the concession to Prismo for $1.5 million in exploration expenses over five years ending in October 2024 plus $500,000 and 2 million Prismo shares. 

Over at the 23-hectare Palos Verdes concession 65 km northeast of Mazatlan, the company is working with neighbour Vizsla — which bought a 10% stake in Prismo in January — to start a 2,500-metre drilling program. Drilling by past owners in 2018 cut 2.3 metres grading 3.8 grams gold per tonne, 1,098 grams silver, 0.7% copper, 2% lead and 3% zinc from 45.3 metres down hole PV-02. 

Prismo bought a quarter of Palos Verdes from a Mexican owner in 2021 and is working to earn the remaining three quarters from ProDeMin, a mining services company owned by Gibson. 

“Vizsla has a first right of refusal on the project so I don’t really see them taking us out, but maybe the project itself,” Gibson said. “Here at Hot Breccia, it’s too early to say.”  

Back on the ground in Kearny after the rotors stopped, the posse paused for a bite and considered the mission ahead for Prismo.  

“They have an incredible land package and team of geology advisers,” said Frank Port, president and chief investment officer of Kelowna, B.C.-based Bridgeport Capital, a potential investor in the project. “They have enough capital to advance the project for two years while copper prices rise even more.”