EVERYDAY SCIENCE

Detailed explanation-1: -Deep in the crust, magma cools slowly. Slow cooling gives crystals a chance to grow. Intrusive igneous rocks have relatively large crystals that are easy to see. Intrusive igneous rocks are also called plutonic.

Detailed explanation-2: -If magma cools slowly, deep within the crust, the resulting rock is called intrusive or plutonic. The slow cooling process allows crystals to grow large, giving the intrusive igneous rock a coarse-grained or phaneritic texture.

Detailed explanation-3: -Intrusive (plutonic) rocks form when magma solidifies within the crust below the surface. It usually cools slowly and produces large crystals. Extrusive (volcanic) rocks form when magma erupts onto the surface of the Earth as lava flows, and usually cools quickly producing small crystals.

Detailed explanation-4: -Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. Great globs of molten rock rise toward the surface.

Detailed explanation-5: -When magma cools, crystals form because the solution is super-saturated with respect to some minerals. If the magma cools quickly, the crystals do not have much time to form, so they are very small. If the magma cools slowly, then the crystals have enough time to grow and become large.