The andes mountains running along the western edge of south america were formed by collisions between the south american plate and the

The Andes mountains running along the western edge of south america were formed by collisions between the south american plate which is continental and the nazca plate which is oceanic. The collision reasons the continental crust to clasp and form fold mountains which are then scattered with volcanoes produced by melting of nazca plate as it is enforced down into the earth’s mantle.