1. Weathering, Erosion, Deposition & Landscapes
Topic 9/10
Weathering, Erosion, Deposition & Landscapes
Aim: How do rocks get weathered?

2. I. Weathering
Breakdown of rock due to physical or chemical changes. * The end product of weathering is soil.

3. II. Two types of Weathering
Physical Weathering (mechanical) changing the physical characteristics of a rock without changing its chemical composition.
Example- Plant roots, frost action, animal burrows

4. Physical Weathering Continue
Frost Action- happens only in climates with seasonal temperatures where freezing and thawing can occur.
Water seeps into cracks in the rock
Water expands when it freezes
Through freezing and thawing the cracks in the rock get larger (ex. Potholes)
Frost Action

5. Physical Weathering Continued
2. Abrasion- caused by friction between rock particles (wind, moving ice and gravity)

6. B. Chemical Weathering
Breaks down a rock by changing its chemical composition
The minerals in a rock will react with other substances to form something completely new.
Anytime you see the word acid, oxidation, rust, or lichens it’s always chemical weathering.
Example- Iron + H20 = Iron Oxide (Rust)

7. Chemical Weathering Con’t