GATE-2018 (24) :Wyllie – Time average equation

1. Andesitic rock form in 

A) Continent-continent collision

B) Ocean-continent collision

C) Ocean-Ocean collision

D) Continental rift

Answer: B

Explanation:

The forces of plate tectonics are responsible for the formation of the Andes. The Nazca plate and a part of the Antarctic plate have been sub-ducting beneath the South American plate, which is a process that continues today and causes earthquakes and volcanic eruptions in the region.

Andesite is a common continental crustal rock formed above the subduction zone.This is formed due to oceanic plate melts during descent into subduction zone to produce a source of magma.

Andesite is fine grained, extrusive igneous rock. it is  rich in plagioclase feldspar minerals, it does not contain quartz and olivine.

References:

https://www.windows2universe.org/geography/andes.html

https://geology.com/rocks/andesite.shtml