Mechanical Weathering

Animal Actions

• Some animals that can cause this type of weathering are...
• Gophers, moles, prairie dogs, and some insects can loosen the soil.
• Animal Actions is when a animal such as a mole burrows into the ground.
• causing the ground to loosen and break apart rocks in the soil.

Freezing and Thawing

• When water freezes in a crack in a rock, it expands and makes the crack 
• bigger. The process of frost wedging also widens cracks in sidewalks and 
• causes potholes in streets.
• As shown in the picture behind,  water has seeped into the crack that was 
• more than likely only and in. but when it froze it expanded the crack.

Plant Growth

• Plant roots enter cracks in rocks.  As roots grow, they force the cracks
• apart.  Over time, the roots of even small plants can pry apart cracked roc
• As shown in the picture behind,  the tree has grown onto and over and prob.
• in the house but is still getting its nutrients.  Also weathering the house
• and dirt around it.  Along with minerals.

Release of Pressure

• As erosion removes material from the surface of a mass of rock, pressure on
• the rock is reduced.  This release of pressure causes the outside of the 
• rock to crack and flake off like the layers of an onion.

Abrasion

• Sand and other rock particles that are carried by wind, water, or ice. Can 
• wear away exposed rock surfaces like sandpaper on wood.

Now you know more about...

Animal Actions

Freezing and Thawing

Plant Growth

Release of Pressure

Abrasion