Question
What are metamorphic rocks? Describe the types of metamorphic rock and how are they formed.
Solution
A metamorphic rock is a type of rock which has been changed by extreme heat and pressure.
The types of metamorphic rocks depend upon the original rocks that were subjected to metamorphism. Metamorphic rocks are classified into two major types:
(i)foliated rocks
(ii)non-foliated rocks
Formation of metamorphic rocks : These rocks are formed due to thermal metamorphism.
It is of two types :
(i)Contact metamorphism: In contact metamorphism the rocks come into the contact with hot magma and lava and the rock material is recrystallized under high pressure and temperature.
(ii)Regional metamorphism: In regional metamorphism, rocks under go recrystallization due to deformation caused by tectonic shearing together with high temperature or pressure or both.
