VANCOUVER (miningweekly.com) – The TSX-listed stock of precious metals producer Primero Mining on Monday rose as much as 4% after it reported positive exploration results at its Black Fox mine, in Ontario, as well as at its San Dimas mine and the Lechugilla concession, in Mexico.

Vancouver-based Primero reported that initial mining at the Deep Central zone at Black Fox generated 3 885 t of production ore grading 8.3 g/t gold, which is above the underground mine’s current reserve grade of 6.2 g/t gold.

Primero stated that developmental ore of 4 350 t had seen grades of 10.9 g/t gold. Delineation drilling continues to confirm the high-grade tenure of the Deep Central zone with drill hole 520-EX346-06 intercepting 27.9 g/t gold over 5.8 m at a depth of 800 m. The company expects to publish results by year-end.

Meanwhile, exploration drilling immediately to the west of the Deep Central zone encountered 28.1 g/t gold over 2.7 m, 4.6 g/t gold over 5.4 m and 9.1 g/t gold over 1.2 m. Primero expects long-hole production to continue to ramp up from this area, with underground production expected to average 800 t/d by the fourth quarter.

At San Dimas, Primero has successfully extended the high-grade Victoria vein north-east, returning grades as high as 208.7 g/t gold and 3 037 g/t silver over 1.3 m (true widths), 11.5 g/t gold and 590 g/t silver over 3.5 m, and 12.6 g/t gold and 817 g/t silver over 2.3 m. The company plans to undertake delineation drilling of this new area before the end of September. The vein remains open to the north-east.

Further, Primero reported a high-grade discovery near the surface at its Lechugilla concession. Located about 18 km south of the San Dimas mill and outside of the silver purchase agreement area with Silver Wheaton, Primero estimates that the Causitas vein covers 200 m of strike length along surface with true widths of up to 6 m. It is located close to the main road, which connects with the provincial capital, Durango.

Highlights from the vein sampling at Causitas include 7.1 g/t gold equivalent over 4.5 m (true widths), 10.9 g/t gold equivalent over 2 m and 5 g/t gold equivalent over 3 m.

“At San Dimas, it is reassuring to see that our high-grade veins can continue to be extended with similar or greater widths than currently being mined. And as we look regionally at San Dimas, onto our concession not covered by the Silver Purchase Agreement, I am optimistic about the initial results from the Causitas vein, which has the potential to augment current mill feed, given its proximity to an existing main road,” president and CEO Ernest Mast advised.

The company’s TSX-quoted stock rose 4% on Monday, before settling up 2.5% at C$2.05 apiece by market close.