Tier One Silver on cusp of drilling Curibaya in Peru

In October, Auryn Resources was reorganized and split into three separate companies — Canada focused Fury Gold Mines (TSX: FURY NYSE-AM: FURY) and Peru-focused Sombrero Resources and Tier One Silver.

Ivan Bebek, who co-founded Auryn with Shawn Wallace in 2015, has roles at each of the new companies. He is chairman of Fury Gold Mines, president and CEO of Sombrero Resources and co-chairman of Tier One Silver.

In an interview about the soon-to-be listed Tier One Silver, Bebek says the junior explorer hopes to drill 12,000 metres this year at its 100%-owned Curibaya project in southern Peru, about 48 km from the city of Tacna, near the country’s border with Chile.

The 11,000 hectare project, which has never been drilled, sits near some of Peru’s largest porphyry deposits. Curibaya is about 42 km and 68 km, respectively, from Southern Copper’s (NYSE: SCCO) Toquepala and Quajone deposits; about 57 km from Anglo American’s (LSE: AAL; US-OTC: AAUK) Quellaveco deposit; and roughly 175 km from Freeport-McMoRan‘s (NYSE: FCX) Cerro Verde.

“Curibaya was acquired because it sat on a trend of world-class deposits and it was ground Anglo was shedding,” Bebek says, recalling Auryn’s rationale for picking up the project six years ago. It is also adjacent to the Incapuquio fault zone, which according to the company, is a control on the copper porphyry and epithermal deposits in the region.

After the initial acquisition in 2015, Auryn went on to acquire in 2019 some of the ground surrounding Curibaya (the Sambalay and Salvador concessions), at the urging of its then vice president of exploration, David Smithson, now Tier One Silver’s senior vice president of exploration.

Hard at work at the Curibaya project in Peru. Credit: Tier One Silver.

“David was the one who championed the project about two years ago when we owned one-third of it and he was adamant we should go and consolidate it,” says Bebek, noting that prior to joining Auryn, Smithson had worked as a global gold specialist at Newmont (TSX: NGT; NYSE: NEM) where he worked on reserve expansions at the Ahafo mine in Ghana, about 307 km northwest of Accra, and at Yanacocha, Newmont’s largest mine in South America, about 800 km northeast of Lima.

Smithson, along with Tier One Silver’s chief geologist, Michael Henrichsen, who had also previously worked at Newmont as a global structural geologist (and also at Ahafo), started a surface sampling program at Curibaya.

The first results from the Sambalay and Salvador concessions were reported in October 2019, and included more than 20 rock samples assaying at above 200 grams silver per tonne. The samples were taken from a 1.5 km by 3 km quartz-sericite-pyrite alteration system. At the time, Henrichsen noted that the high-grade precious metal mineralization seen in the samples “makes for a compelling intermediate-sulphidation epithermal target in addition to the strong potential for porphyry and skarn mineralization at shallow depths.”

Additional rock sample results were released in November 2019, with highlights including up to 7,990 grams silver per tonne, 17.65 grams gold per tonne and 6.97% copper. The results extended the surface area where mineralization has been found by 1.5 km to the west.

At the beginning of last year, mapping and sampling at Curibaya, about 1 km to the northeast of the previous sampling area in 2019, returned surface sample grades of up to 946 grams silver per tonne and 1.96 grams gold per tonne. In addition, a float sample taken about 800 metres to the northeast of the sampled veins ran 42.6 grams gold and 9,180 grams silver. By the end of February, the company had sampled high-grade veins across a 4 km by 4 km alteration system.

By the end of 2020, Tier One completed a 450-line-km airborne magnetic survey and a 30-line-km ground-based induced polarization survey over a 20-sq-km alteration zone. The surveys pinpointed a 2 km by 750 metre chargeability anomaly near surface, which it believes is a precious metals target, and a magnetic anomaly below the chargeability anomaly, which it believes is the intrusion responsible for the gold and silver mineralization it has sampled at surface. It could also represent a potential porphyry target.

“We don’t know if that intrusion is going to be copper-gold or whether it will be an epithermal intrusion, but we do know there’s a lot of gold and silver at surface,” Bebek says, “that could have been delivered by both.”

“There are very big mines around us and we’re the first epithermal occurrence of significance in this world-class porphyry belt that anyone has seen,” Bebek says. “It’s sitting on the border between the coastal porphyry metallogenic belt and Peru’s southern epithermal belt. … It is unique by its precious metal endowment.”

Earlier this year, Tier One obtained permits to drill up to 40 holes from 20 platforms over an area of 473 hectares, which lies within the 20-sq-km mineralized alteration zone, and in March closed a $13.45 million financing. Now, Bebek says, Tier One Silver is on the cusp of drilling the project. The company is now fully financed to drill 5,000 metres in the first program and 7,000 metres in a second program.

A bird’s eye view of the camp at Curibaya. Credit: Tier One Silver.

“Based on the speed of drilling, we’ll probably get in the range of 6,000 and 10,000 metres this year [and] we’ll look to add a second or third rig if we make a discovery.”

Curibaya is “telescoping from precious metals to a porphyry and we believe it to be a porphyry because of the style of the deposits along the belt,” Bebek says. “It looks like Toquepala and Quellaveco, some of the mines 40 to 50 km away. Their precious metals systems have been eroded away but at Curibaya they haven’t been.”

Bebek adds that the age-dating work Tier One has competed estimates the alteration found at Curibaya to be between 55 million and 61 million years old, which is the same as Quellaveco, Toquepala and Cuajone, according to the company.

“Curibaya is one of the rare opportunities you come by maybe once in a career as an exploration geologist; it sits on a world class belt with exuberantly high grades and has never been drilled prior,” Smithson writes in an email. “The most appealing features to me are the abundance and wide-spread nature of high-grade silver and gold, the vertical extent of sulphide targets identified through chargeability and most importantly the age dating of the mineralization being the same as world class mines on the belt just to our northwest.”