World class base and precious metal deposits; a quantitative analysis

Platinum-group elements

“…Mineral deposits occur rarely in Earth's crust, and large ones are especially uncommon (Singer, 1995). Most of the known metal for many mineral commodities is contained in a few, very large deposits (Singer and DeYoung, 1980).…”

Volcanogenic Massive Sulfide Deposit Density

“…Classification of the subtypes is not generally agreed upon in the scientific literature, but this study recognizes two broad subtypes of volcanogenic massive sulfide deposits, designated as kuroko-and Cyprus-type as defined by Cox and Singer (1986). In known world resources, these deposits contain 5 percent of the world's copper, 22 percent of the world's zinc, 10 percent of the world's lead, 2 percent of the world's gold, and 9 percent of the world's silver (Singer, 1995).…”

Geology and mineral resources of the North-Central Montana Sagebrush Focal Area: Chapter D in <em>Mineral resources of the Sagebrush Focal Areas of Idaho, Montana, Nevada, Oregon, Utah, and Wyoming</em>

“…Mining resumed in the area in the 1970s with the introduction of gold and silver recovery from heap leaching using cyanide recovery techniques. This led to recovery of an additional 2.5 million oz (Moz) of gold and 20.7 Moz of silver from the Zortman and Landusky deposits (Maehl, 2002), so together the Zortman and Landusky deposits form an orebody that is nearly world-class (>3.2 Moz of gold, Singer, 1995) in size.…”