What are igneous rocks and how are they formed give examples?

Igneous rocks and how they are formed

Igneous rocks are one of the three main types of rocks (along with sedimentary and metamorphic). They are formed through the cooling and solidification of molten rock material, which may occur below Earth's surface as magma or on the surface as lava.

How Are Igneous Rocks Formed?

• Formation Process:
  • Magma (molten rock beneath the Earth's surface) or lava (molten rock that reaches the surface) begins to cool and solidify.
  • If cooling occurs deep within the Earth, the resulting rocks are called intrusive (plutonic) igneous rocks. These cool slowly, allowing larger crystals to form.
  • If cooling occurs on or near the surface, usually after a volcanic eruption, the rocks are extrusive (volcanic) igneous rocks. These cool quickly, resulting in smaller crystals or a glassy texture.

Types of Igneous Rocks:

• Intrusive (Plutonic): Formed from magma that cools slowly beneath the Earth's surface. These rocks tend to have large, visible crystals.
• Extrusive (Volcanic): Formed from lava that cools quickly on or near Earth's surface, leading to fine-grained or glassy textures.

Examples of Igneous Rocks