This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image covers 30 by 23 km (full images 30 x 37 km) in the Atacama Desert, Chile, and was acquired on April 23, 2000. The Escondida copper, gold, and silver open-pit mine is at an elevation of 3050 m, and began operations in 1990. Current capacity is 127,000 tons/day of ore; in 1999 production totaled 827,000 tons of copper, 150,000 ounces of gold, and 3.53 million ounces of silver. Primary concentrate of the ore is done on-site; the concentrate is then sent to the coast for further processing through a 170 km long, 9-inch pipe. Escondida is related geologically to three porphyry bodies intruded along the Chilean West Fissure Fault System. A high grade supergene cap overlies primary sulfide ore. The top image is a
conventional 3-2-1 (near infrared, red, green) RGB composite. The bottom image displays shortwave infrared bands 4-6-8 (1.65µm, 2.205µm, 2.33µm) in RGB, and highlights the different rock types present on the surface, as well as the changes caused by mining.
The Bingham Canyon Mine (image center) is one of the largest open-pit mines in the world, measuring over 4 kilometers wide and 1,200 meters deep. Mining first began in Bingham Canyon in the late nineteenth century, when shafts were sunk to remove gold, silver, and lead deposits that played out by the early 1900s. It would take the advent of open-pit mining in 1899 to turn the Bingham copper deposit into an economically favorable resource.