GEOLOGY

Detailed explanation-1: -The Andes were formed by tectonic activity whereby earth is uplifted as one plate (oceanic crust) subducts under another plate (continental crust). To get such a high mountain chain in a subduction zone setting is unusual which adds to the importance of trying to figure out when and how it happened.

Detailed explanation-2: -The Andes Mountains are part of the Southern Cordillera formed from subduction zone volcanism at the convergent boundary of the Nazca plate and the South American plate.

Detailed explanation-3: -Fold mountains are generally formed between 40-50 million years ago, which is geologically-speaking, young. They are often high with steep faces. Examples of fold mountains include The Himalayas, The Andes, The Rockies and The Alps.

Detailed explanation-4: -The Cascadia Subduction Zone, extending from northern California through western Oregon and Washington to southern British Columbia, is a type of convergent plate boundary. Two parallel mountain ranges have been forming as a result of the Juan de Fuca Plate subducting beneath the edge of North America.

Detailed explanation-5: -ANDESITE is a medium gray, fine-grained rock of volcanic origin, named after the Andes Mountains, but is abundant in all volcanic regions associated with subduction zones (where crust is sinking and partially remelting-example: volcanos associated with the Pacific “Ring of Fire").