The Atacama Desert is an exceptionally arid plateau situated on the Pacific coast of South America, primarily within northern Chile. Its extreme dryness results from the Andes Mountains creating a rain shadow and the cooling effect of the offshore Humboldt Current, which prevents moisture from reaching the land. This hyper-aridity, making it the driest non-polar desert on Earth, preserved and concentrated vast mineral wealth over millions of years. The desert’s unique history has led to the formation of some of the world’s most significant deposits of strategic metals, industrial salts, and chemical compounds.
Strategic Metals: Copper and Molybdenum
The Atacama Desert region is globally recognized as the foremost source of copper, a metal fundamental to modern infrastructure and technology. The concentration of copper ore is tied to the Andean magmatic arc, which created massive porphyry deposits through hydrothermal activity. Chile consistently maintains its position as the world’s largest copper producer, accounting for about 24 to 28% of global mine production.
The scale of extraction is immense, centered around enormous operations like the Escondida mine, the world’s largest copper mine by output, and the historic Chuquicamata mine. These deposits are polymetallic, often containing significant quantities of molybdenum alongside the copper. Molybdenum is recovered as a byproduct during copper ore processing and is used primarily in steel alloys to increase strength and corrosion resistance.
The region’s economy is heavily reliant on the extraction of these metals, with the state-owned mining company, Codelco, operating a large portion of the reserves.
Resources of the Salt Flats: Lithium and Brines
The Atacama is home to vast salt flats, or salars, which represent another strategic resource: lithium. The Salar de Atacama holds some of the world’s highest concentrations of lithium-rich brine, positioning Chile as a major global supplier. The region forms part of the “Lithium Triangle,” spanning Chile, Argentina, and Bolivia, which contains more than half of the world’s known lithium resources.
Lithium is extracted by pumping mineral-rich brine into massive, shallow evaporation ponds. Solar energy concentrates the solution over 12 to 18 months, causing salts like potassium, magnesium, and lithium to precipitate. The resulting concentrated lithium is then processed into lithium carbonate, a key material for batteries in electric vehicles and consumer electronics.
This extraction method is highly water-intensive in an already parched environment. Extracting a single ton of lithium can require up to 500,000 gallons of water, raising environmental concerns for the local ecosystem and communities. Chile holds the world’s second-largest reserve of this element, which is increasingly sought after for the global energy transition.
Historical Legacy: Nitrates and Iodine
Before the rise of copper and lithium, the Atacama Desert’s mineral wealth was defined by extensive deposits of natural nitrates, also known as saltpeter or caliche. These water-soluble salts were preserved only because the area’s extreme aridity prevented them from washing away over millions of years. They were exploited heavily in the 19th and early 20th centuries, primarily as a source for agricultural fertilizer and explosives.
The extraction of these nitrates, which contain the world’s largest natural supply of sodium nitrate, was the basis of a massive economic boom and sparked the War of the Pacific. Today, the industry is significantly smaller, largely replaced by the synthetic nitrogen fixation process. However, the desert remains the world’s largest source of iodine, which is co-located with the nitrate deposits and continues to be mined for industrial and health applications.
Non-Extractive Potential: Solar Energy and Astronomy
Beyond its mineral deposits, the Atacama Desert offers unique environmental conditions harnessed as non-extractive resources. The region boasts the highest levels of solar irradiance on Earth, making it a prime location for large-scale solar power projects. This exceptional solar energy potential is increasingly developed to power mining operations and feed into the national grid.
The desert’s high altitude, extremely clear skies, and lack of atmospheric moisture create optimal conditions for astronomical observation. These factors have made the Atacama a global hub for astronomy, hosting major international facilities like the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Telescope (VLT).