Hecla drills extension

Hecla Mining (HL-N) says it expects to make a decision in the last half of the year on whether to go underground on the Hugh Zone, a deep extension of the main vein now mined out at its San Sebastian silver mine in Durango state, Mexico.

Exploration since June has extended the length of the Hugh Zone by 500 metres, to a total of 1,200 metres. The zone strikes southeast with a shallow southeast plunge. Most of the mineralization drilled so far is between 200 and 500 metres vertical depth.

Grades in the zone range from 76 to 789 grams silver per tonne across horizontal widths mainly 2 to 2.8 metres, though some parts of the zone swell to 4.5 metres. The zone also has high base metal grades, typically 1% to 4% copper, 3% to 9% zinc, and 1% to 6% lead, with a fraction of a gram of gold per tonne.

Among the better intersections were a 2.7-metre width grading 539 grams silver and 0.02 gram gold per tonne, plus 5.21% copper, 12.25% lead and 8.52% zinc, and a 3.2-metre width averaging 352 grams silver and 0.04 gram gold per tonne, with 2.97% copper, 7.72% lead and 11.56% zinc.

Fluid-inclusion work on samples from the zone indicate that the Hugh Zone and the Francine Vein structurally above it are part of an intermediate-sulphidation epithermal system. Hecla geologists believe the two may have been feeders to smaller veins at the surface.