Abstract The Kidd Creek massive sulfide deposit is one of the world’s largest and highest grade Cu-Zn deposits, with total past production, reserves, and resources to the 9,800-ft level (2,990 m) of 170.9 million tonnes (Mt). The discovery hole, K55-1, was drilled in 1963 and encountered ore at a depth of only 7 m. It intersected 190 m grading 1.21% Cu, 8.5% Zn, 0.8% Pb, and 138 g/t Ag. The deepest ore intersection at 10,200 ft (more than 3,100 m) cut 442 m of mineralization with an average grade of 1.16% Cu, 7.8% Zn, 0.73% Pb, and 84 g/t Ag, remarkably similar to the very first ore intersected 44 years earlier and nearly 3 km above the bottom of the mine. After 50 years of continuous mining (1966–2016), the deposit has produced a total of 140.4 Mt of ore at grades of 2.29% Cu, 6.15% Zn, 0.22% Pb, and 86.2 g/t Ag, worth an estimated US$50 billion. The contained metal (3.8 Mt of Cu, 10.5 Mt of Zn, 0.38 Mt of Pb, and 12.7 million kg of Ag) accounts for nearly one-third of all metal in Archean Cu-Zn massive sulfide deposits worldwide. At the time of writing, production had reached a depth of 9,500 ft (2,896 m), and because of the remarkable continuity of both the tonnage and grade, mining below 9,800 ft (2,990 m) is now being planned to increase the mine life to 2021. It is currently the deepest base metal mine in the world, and after more than 1.8 million meters of drilling (1,800 km), the deposit remains open at depth.

Abstract ARCHEAN Cu-Zn deposits are among the most important mineral deposit types in Canada. The Superior province of Canada contains nearly 80 percent of the known Archean Cu-Zn deposits in the world (about 100 of 125 deposits). These deposits are concentrated in 10 separate mining camps, including Sturgeon Lake, Manitouwadge, Mattagami Lake, Chibougamau, Joutel, Val d’Or, Bous-quet, Noranda, Kidd Creek, and Kamiskotia (Fig. 1 and Table 1). A few deposits in rocks of similar age and composition are also known in the Slave province, the Churchill province, and in the Archean of Western Australia, southern Africa, China, and Brazil. Known deposits of this age worldwide account for more than 650 million metric tons (Mt) of massive sulfides, containing 10 Mt of Cu metal, 29 Mt of Zn, 1 Mt of Pb, 33 Mkg Ag, and 750,000 kg Au. The giant Kidd Creek volcanogenic massive sulfide deposit in the western Abitibi subprovince of Canada is the largest known deposit of this age currently in production. The Superior province is the world’s largest exposed Archean craton, occupying an area of more than 1.5 million km 2 , bounded by the Trans-Hudson orogen to the west and the Grenville province to the east. A number of distinct subprovinces are recognized, assembled into east-west-trending granite-greenstone terranes and metasedi-mentary belts (Fig. 1). The granite-greenstone terranes are composed of gneissic rocks of plutonic origin, supracrustal rocks of dominantly volcanic origin, and a variety of syn- to late kinematic granitoids. Volcanic rocks comprise about 12 percent of the total area. The greenstone belts have been described variously as successive lateral accretions of volcano-plutonic arcs, oceanic islands, oceanic plateaus, and rift-related assemblages (e.g., Langford and Morin, 1976; Percival and Card, 1985; Ludden and Hubert, 1986; Ludden et al., 1986; Card, 1990; Jackson and Sutcliffe, 1990; Williams, 1990; Corfu, 1993; Heather et al., 1995; Jackson and Cruden, 1995). The metallogenic history of the Superior province has been described in detail by Franklin and Thorpe (1982) and Poulsen et al. (1992). The Abitibi subprovince (94,000 km2) is the largest of the greenstone belts. It contains the major gold and base metal mining camps in Canada (Fig. 2), with production and reserves totaling more than 480 Mt of massive sulfide and 4,700 t of Au. Metal production in the western portion of the Abitibi greenstone belt is dominated by the Timmins region, which historically has accounted for 37 percent of the total gold production