Canadian copper ore grades since the late 1800’s have been declining steadily from around 4.5% copper to under 0.5% of the metal content in the rock. Also displayed is the available tonnes of copper remaining to be mined. Figures for the “metal stock” have only become available since 1977.
Ore Grade: Percentage of the rock mined that is actually copper.
Copper Remaining: workable reserves of copper ore known to exist in Canada.