Silver miner Endeavour Silver (TSX: EDR; NYSE: EXK) has expanded the size of its Terronera development project in Jalisco State, Mexico. The property now covers 201.3 sq. km, with the addition of the adjacent La Sanguijuela and Cerro Gordo groups of concessions.
“These two acquisitions not only expand our property footprint at Terronera, they add multiple new mineralized vein structures with strong resource potential where we can add value through the drill bit,” Bradford Cooke, Endeavour’s chief executive, said in a statement. We look forward to increasing our drill budget next year to advance our sizable resource base in this district-scale, high-grade, low sulfidation epithermal vein system.”
The company has the option to purchase the 27.6-sq.-km La Sanguijuela concession for US$500,000, which would be payable over a four-year period. These grounds adjoin the northern Terronera boundary and are approximately 10 km northwest of the historic adit on the Terronera vein. The concession covers the potential northwest extension of the Terronera vein, as well as the possible western extension of the Los Reyes vein.
At La Sanguijuela, mapping and sampling have defined five mineralized veins. The main vein, Los Cuates, has been traced over 1.5 km of strike and over a thickness of 2 to 6 metres. All five of the veins appear to be within the same rock sequence as the Terronera and La Luz veins on the main Terronera site.
According to the company, upcoming exploration at these new veins will focus on the ‘bonanza zone’, which is a band of higher-grade mineralization.
The 22-sq.-km Cerro Gordo concession was added through staking. The grounds, 10 km south of the historic Terronera vein adit, cover possible southeast extensions of four Terronera footwall veins, and three additional veins. These are also in the same unit as the existing Terronera veins, although at a higher elevation.
The main mineralized structures at La Sanguijuela and Cerro Gordo have never been drilled. Endeavour plans to drill portions of these veins in the fourth quarter of this year.
In July, the company released the results of an updated prefeasibility study on Terronera, which outlines a 1,600-tonne-per-day, 10-year underground operation, producing an average of 5.9 million oz. silver-equivalent annually at all-in sustaining costs of US$8.96 per oz. silver. With an initial capital cost of US$99.1 million, the after-tax net present value estimate for Terronera is US$137 million, at a 5% discount rate, with a 30% internal rate of return, based on US$15.97 per oz. silver and US$1,419 per oz. gold. Over the next nine to 12 months, Endeavour plans to complete a feasibility study for the asset.
— This article first appeared in the Canadian Mining Journal, part of Glacier Resource Innovation Group