Those sulfide mines are really bad for the environment, as anybody from the Canadian Shield knows.  The Canadian Shield houses the world's largest supply of fresh water, which makes mining almost certain to contaminate the water underground, as well as surface streams and lakes.  There was a huge discovery of a zinc/copper/lead deposit in Wisconsin in 1976 around the Crandon area, and eventually an Environmental Impact Statement told the truth, that there was no way to mine it without contaminating and ruining vast areas on the surface.  Not only that, but they proposed just flushing all the fresh water downriver to get rid of the water that was in their way!  This, in the Canadian Shield, where all the water is connected in the porous rock layer, would have been a huge disaster.  Of course, many people know by now that the water is, or will become, more precious than gold in the coming years.  And of course, the mine that Kennecott is proposing in the Upper Peninsula of Michigan is lying on, and in, the Canadian Shield, as well.