Andes form on west coast of south america.how are these mountains formed?

Question

The Andes are a moutain range forming on the west coast of South America.Explain how these mountains are being formed?

Answer 1

The formation of the Andes extends into the Paleozoic Era, when terrane accretion was the dominant process. It was during the Cretaceous Period that the Andes began to take their present form, by the uplifting, faulting and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. Tectonic forces along the subduction zone along the entire west coast of South America where the Nazca Plate and a part of the Antarctic Plate are sliding beneath the South American Plate continue to produce an ongoing orogenic event resulting in minor to major earthquakes and volcanic eruptions to this day.

Answer 2

They form when oceanic crust (which is dense and cold) meets continental crust which is much lighter. When they meet the oceanic crust sinks (usually ) beneath the lighter continental crust - a process called subduction. As it sinks it gets hot and eventually melts and this allows the less dense silica rich minerals in it to rise up as magma eventually forming volcanoes. Check out the Andes for volcanoes on Google Earth they're stuffed with them. So a lot of the Andes are due to volcanic action (past or present).
Banging together two such plates also produces a lot of folding faulting and uplift of other rock formations so this too contributes to the mountain building.

Answer 3

Thanks to help of my friends, I found out this. The Andes Mountains have been formed by one of the crustal plates of the Pacific Ocean floor pushing slowly against the American continental plate. This pressure has caused the sedimentary rocks to bend and fold up into long ridges, called "sierras." Where the sedimentary rocks cracked, molten granite and igneous rocks erupted from below as volcanoes, caused by the oceanic plate melting from the friction and exploding to the surface