Andean natural region
The Andes mountains form the most populated region of Colombia and contain the majority of the country's urban centers. They were also the location of the most significant pre-Columbian indigenous settlements. Beyond the Colombian Massif in the south-western departments of Cauca and Nariño, the Colombian Andes divide into three branches known as "cordilleras" (from the Spanish for "mountain range"): the West Andes run adjacent to the Pacific coast and is home to the city of Cali. The Central Andes run up the center of the country between the Cauca and Magdalena river valleys (to the west and east respectively) and includes the cities of Medellín, Manizales and Pereira. The East Andes extend northeast towards the Guajira Peninsula, and includes the cities of Bogotá, Bucaramanga and Cúcuta.
Andes
The Andes Mountains host large ore and salt deposits and some of their eastern fold and thrust belt acts as traps for commercially exploitable amounts of hydrocarbons. In the forelands of the Atacama desert some of the largest porphyry copper mineralizations occurs making Chile and Peru the first and second largest exporters of copper in the world. Porphyry copper in the western slopes of the Andes has been generated by hydrothermal fluids (mostly water) during the cooling of plutons or volcanic systems. The porphyry mineralization further benefited from the dry climate that let them largely out of the disturbing actions of meteoric water. The dry climate in the central western Andes has also led to the creation of extensive saltpeter deposits which were extensively mined until the invention of synthetic nitrates. Yet another result of the dry climate are the salars of Atacama and Uyuni, the first one being the largest source of lithium today and the second the world's largest reserve of the element. Early Mesozoic and Neogene plutonism in Bolivia's Cordillera Central created the Bolivian tin belt as well as the famous, now depleted, deposits of Cerro Rico de Potosí.