What Causes Weathering of Rocks?

Water

A chemical reaction, called hydrolysis, takes place between hydrogen in rain water and the minerals in a rock. As the rock softens, it is left open to destruction by agents of mechanical weathering.

Gas

When oxygen combines with water and metallic minerals in the earth, rusting occurs. This process, a chemical reaction called oxidation, turns the earth's surface a reddish-brown color as it breaks down rock.

Ice

When water that fills cracks in rocks freezes, the ice expands. This expansion causes rocks to be pushed apart, breaking them into smaller pieces as part of the mechanical weathering process.

Plants

When a plant springs from the earth's surface, it's roots spread. As roots grow and spread they form cracks in the earth to clear room for themselves. This mechanical weathering process causes rock to break.

References

• Sciencesaurus: A Student Handbook; Great Source Education Group; 2005
• What is Weathering

Resources

• Geography for Kids