Yeah, a single lift surprised me. The original mine had numerous sub levels and, by chasing the high grade veins, looked like a rabbits warren. The old and new mines have a lot of big differences. The source of the copper was in the porphyry deposit but the high grade was in hydrothermal veins. Bornite was a common ore and, at 65% was directly smelted after bringing the grade down actually.
—fascinating—having spent the most productive part of my life as a miner and boss at the Climax mine in Colorado—