Physical Weathering Physical weathering breaks rocks into smaller pieces but does not alter their chemical compositions. – Examples- Abrasion caused by.

Physical Weathering

• Physical weathering breaks rocks into smaller pieces but does not alter their chemical compositions.– Examples- Abrasion caused by particles in wind or

water.– Frost wedging- when water seeps into the crack of

a rock and freezes.– Plants- roots of plants can act as wedges as they

grow into the cracks of rocks.

Chemical Weathering

• Chemical weathering causes rocks to weaken, decompose, dissolve, or change chemical composition. – Carbon dioxide- carbon dioxide mixes with

rainwater. This mixes with the calcite in limestone and results in caves.

– Water- water mixes with minerals and is then transported to other locations.

– Acid Rain- rain with an acidic pH that causes rock and metal to erode.

Erosion

• Erosion is the removal and transport of weathered and nonweathered material by gravity, running water, wind, waves, ice, and underground water.

Deposition (Erosion)

• Deposition is how sediment moves by erosion, is dropped, and comes to rest. This is how canyons and deltas are formed.

Glacier Erosion

• Glaciers exert force on rock. As they move they carve into the surface of rock making “U” shaped valleys. Some material becomes embedded in the glacier along the way and is deposited elsewhere.

Wind Erosion

• Wind carries small particles and causes rock to erode. It is similar to sandblasting.

Gravity (Erosion)

• Gravity causes pieces of rock to move downhill. This is also call mass movement. Landslides and mudflows are examples of mass movement.

Humans Cause Erosion

• Deforestation speeds up erosion by removing plant life and established root systems to hold soil in place.