What type of rock are the Andes made of?

The Andes mountains are composed primarily of igneous and sedimentary rocks. The igneous rocks were formed from the cooling of magma from volcanic eruptions, while the sedimentary rocks were created by the accumulation and cementation of sediments such as sand, clay, and gravel. The collision and subduction of the Nazca Plate under the South American Plate has resulted in the formation of volcanoes and the uplift of the Andes Mountains, which are composed primarily of igneous and metamorphic rocks.