Physical Processes

Weathering is the break down of rocks...

Name two types of weathering

• Chemical Weathering

• Hydraulic Action

• Exfoliation

• Deposition

• Freeze-thaw weathering

• Onion-skin weathering

• Biological weathering

• Chemical weathering

Water collects in a crack in a rock. Water freezes and expands by 10% forcing the crack to widen. Ice melts and water seeps deeper into the crack. Repeated freezing and thawing causes the rock to break up.

• Biological Weathering

• Chemical Weathering

• Freeze-Thaw Weathering

• Onion-skin weathering

• Freeze-thaw weathering

• Onion-skin weathering

• Biological weathiner

• Chemical weathering

Plant seeds blow into cracks in a rock. The crack gives the seed moisture and shelter. A plant begins to grow. As its roots develop, they break up the rock.

• Freeze-thaw weathering

• Onion-skin weathering

• Biological weathering

• Chemical weathering

Why does chemical weathering occur?

• Chemicals get thrown down the drains causing the rock underground to break down.

• Rainwater is slightly warm, which means that when its wet statues and rocks melt in the rain.

• Normal rainwater is weakly acidic. The acid in the rain attacks the rock.

• The repeated freezing and thawing of water in a crack in a rock forces it apart.

• Freeze-thaw weathering

• Onion-skin weathering

• Biological weathering

• Chemical weathering

Where in the world is exfoliation most efficient?

• Antarctica

• Desert climates

• The mid-latitudes (e.g. the UK)

• Tropical Rainforest