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Smithsonian National Museum of Natural History
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Chilean flags planted atop a hill blowing in the wind with sunlit sand dunes in the background.



Over the last 300 million years, dynamic forces within the Earth created huge stores of copper and other valuable metals along the ridges and foothills of Chile's Andes Mountains.

The Incas mined copper in the region as early as 500 BCE. Today Chile holds nearly one-third of the world's known supply of copper, and mining is the backbone of the nation's rapidly expanding economy.



The Geology of Chile's Copper

Chile's mineral riches lie in its enormous quantities of ore, which typically contain less than two percent copper, and, in the case of San José, small quantities of gold.

Where copper-rich minerals are located near the surface, huge open pits provide easiest access to the ore. In small “hard rock” mines like San José, miners dig a labyrinth of shafts to reach richer mineral veins.

illustration of the formation of copper due to the geological activity of tectonic plates

click image to enlarge  


1 - A hot, dense slab of oceanic rock sank beneath cooler, buoyant rock at the edge of the South American continent.

2 - As heat and pressure increased, water escaping from the oceanic slab began to melt the rocks above. Some of this molten rock, or magma, erupted to form the volcanoes of the Andes.

3 - Hot water flowing underneath some volcanoes dissolved metals from the local rocks. As this mineral-rich water rose and cooled, it fractured shallower rocks and left copper, gold, and other valuable deposits.



Buried Treasure

Over the last 300 million years, dynamic forces within the Earth created huge stores of copper and other valuable metals along the ridges and foothills of Chile's Andes Mountains.

The Incas mined copper in the region as early as 500 BCE. Today Chile holds nearly one-third of the world's known supply of copper, and mining is the backbone of the nation's rapidly expanding economy.

panoramic image of the Chuquicamata open pit mine

Chile's enormous Chuquicamata open pit mine extracts ore from the largest copper deposit on Earth. (click image to enlarge)



Where Does All the Copper Go?

Most copper is used for electric wiring, electronics, household pipe, and, when combined with other metals, bronze and brass. Also, silver–colored U.S. coins—but not pennies—consist mostly of copper.

World demand for copper is on the rise. In 1970, for example, cars contained 35 pounds of copper. Today, electronics in cars require 50 pounds or more. Even copper scrap is valuable: about one-third of all the copper used worldwide is recycled.

U.S. penny

Since 1983, “copper” pennies have been 97.5 percent zinc, with only a thin plating of copper.

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