Consider the following differences about Intrusive and extrusive igneous rocks:
1. While Intrusive rocks have larger crystals, extrusive rocks have smaller crystals
2. While Intrusive rocks are result of fast cooling of magma, extrusive rocks are result of slow cooling of magma
Which of the above statements is/are correct?
Magma that solidifies below the Earth’s surface and remains surrounded by older, pre-existing rock is called intrusive igneous rock. Because intrusive rocks cool slowly, they develop large mineral crystals that are visible to the eye. If the magma reaches the surface and emerges as lava, it forms extrusive igneous rock. Extrusive igneous rocks cool very rapidly on the land surface or ocean bottom and thus show crystals of only microscopic size.
This question is a part of GKToday's Integrated IAS General Studies Module