Greens Creek

Hecla’s 100%-owned and operated Greens Creek mine in southeast Alaska is one of the largest and lowest-cost primary silver mines in the world, last year producing 7.8 million ounces of silver at a cash cost, after by-product credits, per silver ounce of $2.89 (a non GAAP measure)(1). Production in 2015 is expected to be 7.3 million ounces.

The Greens Creek deposit is a polymetallic, stratiform, massive sulfide deposit. The host rock consists of predominantly marine sedimentary, and mafic to ultramafic volcanic and plutonic rocks, which have been subjected to multiple periods of deformation. These deformational episodes have imposed multiple folding of the orebodies to create a complex geometry. Mineralization occurs discontinuously along the contact between a structural hanging wall of quartz mica carbonate phyllites, and a structural footwall of graphitic and calcareous argillite.