Mechanical weathering

Kids learn about examples of mechanical weathering and conduct an experiment with seeds and plaster in this cool geology science fair project idea.

A short explanation of mechanical weathering.

Weathering is the wearing down or breaking of rocks while they are in place. Weathering can be biological, chemical or physical.

Chemical weathering occurs when rocks are weakened and broken down through chemical reactions. This process involves a chemical change, which actually alters the rock's or mineral’s chemical composition. Chemical weathering is more common in wet, humid areas than in dry ones, because moisture is an important component of many types of chemical weathering.

Mechanical weathering refers to physical processes that break down the structure of rocks. It differs from chemical weathering, by which rocks are broken down by reactions among chemicals inside and outside the rock. You can observe mechanical weathering's effects nearly anywhere: In addition to producing some of the most impressive rock formations on Earth, mechanical weathering is responsible for the cracked and smoothed rocks you see in your daily life.

frost wedging - a type of disintegration in which jointed rock is forced apart by the expansion of water as it freezes in fractures.

Mechanical Weathering / Frost Action Photo by Natalie Region

"This is an example of frost wedging that occurred at my house. Due to this example of mechanical weathering, there are numerous large cracks in my driveway. "- Photo and caption by Makenzie Smith

Can you name the types of physical weathering processes that you see on the pictures? Can you name the types of mechanical weathering processes that you see on the pictures? wind abrasion water abrasion glacial abrasion frost wedging exfoliation thermal expansion root wedging salt crystallization Biological Activity/Root Wedging