USGS professional paper · 1929 · 110 citations · 0 references
AgricultureAgricultural EconomicsEarth SciencesEconomic GeologyMetallurgyProduction EconomicsHeavy Metal ContaminationMetal Commodity MarketsCopper Ore Deposits
The copper district of Keweenaw Point, in the northern peninsula of Michigan, is the second largest producer of copper in the world. The output of the district since 1845 has been more than 7,500,000,000 pounds and showed a rather steady and consistent increase from the beginning of production to the end of the World War in 1918, since which there has been a marked decrease.