List of longest mountain chains on Earth

The world's longest above-water mountain range is the Andes, about long. The range stretches from north to south through seven countries in South America, along the west coast of the continent: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. Aconcagua is the highest peak, at about .
This list does not include submarine mountain ranges. If submarine mountains are included, the longest is the global mid-ocean ridge system which extends for about 65,000 km(40,389 mi). 
Formation.
Mountain chains are typically formed by the process of plate tectonics. Tectonic plates slide very slowly over the Earth's mantle, a lower place of rock that is heated from the Earth's interior. Several huge sections of the earth's crust are impelled by heat currents in the mantle, producing tremendous forces that can buckle the material at the edges of the plates to form mountains. Usually one plate is forced underneath the other, and the lower plate is slowly absorbed by the mantle. Where the two plates pass one another, heated rock from the mantle can burst through the crust to form volcanoes. The movement of the plates against one another can also cause earthquakes.