Describe the types of rocks and explain their formation process.

Types of Rocks
 

The Earth's crust is made up of various types of rocks, which are classified into three main categories:
 

1. Igneous Rocks
 

• These rocks are formed by the cooling and solidification of magma.

• They are primary rocks, from which other types of rocks are formed.

• Types of Igneous Rocks:

  • Extrusive Igneous Rocks:

    • Formed by the cooling of lava on the Earth's surface.

    • Example: Basalt (found in the Deccan Plateau).

  • Intrusive Igneous Rocks:

    • Formed by the cooling of magma beneath the Earth's surface.

    • Example: Granite
       

2. Sedimentary Rocks
 

• Formed by the compression and hardening of sediments carried by wind, water, or ice.

• These rocks often contain fossils.

• Examples: Sandstone, Limestone
   

3. Metamorphic Rocks
 

• These are formed when igneous or sedimentary rocks undergo changes due to high temperature and pressure.

• Examples:

  • Limestone → Marble

  • Clay particles → Slate
     

Conclusion
 

• The formation of rocks is a cyclical process, known as the Rock Cycle.

• These rocks shape the Earth's surface and are important sources of various minerals.