Volcanos of the western margin of the Andes dominate the left half of this scene. Many of these volcanos reach above 5000 meters, and the tallest among them are snowcapped. The linear chains of volcanos trending north-south that occur here and throughout the Andes are the result of plate tectonic processes. As the heavier Pacific plate moves eastward, it is forced under the stationary, lighter South American plate. Deep underground, the Pacific plate begins melting. The hot material then rises and forms mountains and volcanic landforms at the surface. At the same time, the mechanical crunching together of these plates pushes up the regional area. Together, these processes often produce unique geologic deposits.
One such deposit is seen in the right portion of this photograph. Chuquicamata, the largest open-pit copper mine in the world, is the white and tan area (right center) just west of the volcanos in the lower (2850 meters), arid Atacama Desert. Copper from Chuquicamata is transported by rail southwest to the port city of Antofagasta. Approximately 30,000 people work in the remote region around the mine. The white dry lake in the bottom left of the scene is covered in part by a brown deposit that is likely the result of weathering of volcanic deposits of varying composition.
April 1991, image STS-37-153-101.