Tinka Resources (TSXV: TK) has doubled the resource at its 100%-owned Ayawilca polymetallic sulphide project, located 200 km northeast of Lima in Peru’s Department of Pasco.
The four zinc zones and one tin zone are located on the larger Ayawilca property at altitudes between 3,800 and 4,300 metres, with the zinc resource open in several directions. In the report, Tinka uses a US$55-per-tonne net smelter return cut-off rate for both the zinc zones and the tin zone.
The new estimate includes another 15,000 metres drilled in 2017. Tinka now estimates the zinc resource at Ayawilca as 42.7 million inferred tonnes grading 6% zinc, 0.2% lead, 17 grams silver per tonne and 79 grams indium per tonne. Its previous estimate pegged the resource at 18.8 million inferred tonnes grading 5.9% zinc, 0.2% lead, 15 grams silver and 74 grams indium.
It also updates the tin resource, bringing the estimate to 10.5 million inferred tonnes grading 0.63% tin, 0.23% copper and 12 grams silver from 5.4 million inferred tonnes grading 0.76% tin, 0.31% copper and 18 grams silver.
It does not overlap with the zinc resource, meaning the metals could be mined separately.
The tin zone is comprised of disseminated cassiterite and chalcopyrite in massive to semi-massive pyrrhotite lenses at the contact between the Pucara group and the underlying phyllite of the Devonian Excelsior group. Part of the mineralization occurs as quartz sulphide stockwork veinlets hosted by the phyllite.
The zinc zone is hosted by 200-metre-thick Triassic Pucara group limestone. It’s located beneath the Goyllarisguizga group sandstone unit, which outcrops and hosts the Colquipucro silver oxide project, located 1.5 km north. This is where Tinka originally began exploring the property.
Tinka picked up the Ayawilca property in 2005, when Minas Buenaventura (NYSE: BVN), who owned it for 60 years and drilled four holes in Colquipucro, dropped it.
During its first six years as the owner, Tinka looked for silver in Colquipucro, and drilled 40 holes. It eventually expanded its exploration south and ended up finding zinc in 2012.
Colquipucro has 7.4 million indicated tonnes at 60 grams silver per tonne for 14.3 million contained oz. silver and 8.5 million inferred tonnes at 48 grams silver for 13.2 million contained oz. silver.
However, Tinka president and CEO Graham Carman says it’s not a focus for Tinka right now. He says the project needs a higher silver price to be feasible — noting that it could one day stand alone.
“It’s never going to be a world class asset,” Carman says. “But we think the zinc will be.”
The Ayawilca project database contains 44,800 metres of drilling across 122 holes.
The 2017 drill permit covers three times the area of the previous 2013–15 drill permit, and focused on the previously unexplored south zone, which Carman calls the “crown jewel” of the project.
It contains 13 million tonnes grading 7.6% zinc, 0.2% lead, 25 grams silver and 118 grams indium — and is also the shallowest part of the system.
As per the previous resource estimate, the central zone was the richest zone, measuring 13 million inferred tonnes grading 4.7% zinc, 0.3% lead, 13 grams silver and 54 grams indium.
Carman says Tinka is still drilling on the property and awaiting drill results on nine of the holes. He expected the company to release those results before the end of 2017, leading to a preliminary economic assessment in the first half of 2018. He says in 2018 Tinka will de-risk the existing resource, but also continue expansion drilling.
Tinka is looking to expand Zone Three to the northeast but also fill in gaps between the west and the south.
Carmen notes that the strong geophysical anomaly trending northeast — the same one that contains the south zone — is only half-drilled. Tinka intends to explore the anomaly further.
Tinka also says there’s potential mineralization underneath the current resource.
Part of the plan for 2018 is to put in some deeper holes and see if the resource can be extended at depth.
“We’re looking to expand and turn this thing into a real monster,” Carman says.
The company recently listed on the Lima Stock Exchange using the symbol TK — a move Carman says gives the company better exposure to South American investors.
At press time, Tinka’s shares were priced at 64¢ with a 52-week range of 20¢ to 87¢. Tinka’s market cap is $136 million.