Andes The

Andes, The, a vast mountain system that forms the backbone of South America, and extends for 4,180 miles from Cape Pilares in the Straits of Magellan to the Isthmus of Panama. The width of the range varies from 40 to 350 miles, and its average elevation is 12,000 feet. As it passes from one country to another the chain is divided into the Andes of Patagonia, Chili, Bolivia, Peru, Ecuador, and New Granada. The loftiest peaks are: -

Aconcagua (Chilian Andes) ... 23,944

Gualatieri (Bolivian Andes) ... 22,000

Chimborazo (Ecuador) ... 20,517

Sorata (Bolivian) ... 21,290

Illimani (Bolivian) ... 21,150

Chiquibamba (Bolivian) ... 21,000

Arequipa (Peruvian) ... 18.373

Except the Himalayas, no mountains in the world can vie with these altitudes. Lofty table-lands, such as those of Assuay, Titicaca, Pasca, Quito. Bogota, and Cuzco, are a remarkable feature of the range. On the western side, owing to the steep declivity towards the neighbouring sea, there are no important rivers, but eastwards the Amazon, La Plata, Orinoko, Maddalena, and other large streams flow down from this mighty watershed. The basins of the Orinoko, Amazon, and La Plata are separated by transverse offshoots from the magistral range. These are called the "Cordilleras." The Andes are essentially volcanic, and contain some fifty active volcanoes, whilst earthquakes are of frequent occurrence along the axis of the range. The geological structure accordingly displays granite, greenstones, porphyries, and other igneous rocks, flanked here and there by metamorphic schists and palaeozoic strata, whilst the western slopes especially are covered with lava, scoriae, and other recent volcanic products. Metalliferous veins are abundant, and of every variety. The silver mines of Peru have for centuries been famous, but the mineral wealth of the range has hardly as yet been explored. Many valuable chemical deposits are also found. Some geographers regard the Andes as being an extension of the mountain system of North America, but this view is probably incorrect. Much of our knowledge of the range is due to the exertions of Humboldt, but even now comparatively little is ascertained with perfect accuracy.