1. Weathering of Rocks and Erosion and Deposition of Sediment

2. Rock Cycle

3. Weathering Mechanical Chemical Breakdown of rock
Frost and root wedging
Abrasion – the sediment does the work
Water - Ice - Wind –
Chemical
Water & Oxygen react with minerals
Depends on rock type, temperature, water

4. Mechanical Weathering
Frost Wedging
Abrasion: wind,
water and ice carry
sediment that wears
down the materials
encountered.

5. Mechanical Weathering: Exfoliation
Expansion makes cracks parallel to surface
Contraction makes cracks perpendicular to surface

6. Mechanical Weathering: Rivers
Water carries sediment in streams and rivers.
The sediment abrades the channel bottoms and sides.

7. Mechanical Weathering: Waves
Wave-cut Platforms
Coves and Headlands
Water and sediment batter the land sticking out into the ocean and wear it away.
Weaker rock is eroded more readily.
Sediment is deposited in coves
Wave Arches and Stacks

8. Mechanical Weathering: ICE
U-Shaped Valley left by a mountain glacier
Water freezes in fractures
Rocks are embedded in the moving glacier
Moving rock and ice abrade underlying material.
Evidence of glacial scour

9. Mechanical Weathering: Wind
High winds lift particles up to 1 mm
Larger particles bounce along surface
Moving particles abrade rocks into ventifacts, yardangs, arches, and hoodoos

10. Chemical Weathering
Oxygen, water, and acids react with minerals to weaken or dissolve them
Dissolution
CO2 + H2O  H2CO3 (acid)
H2CO3 + CaCO3  Ca(HCO3)2
Oxidation
4Fe + 3O2  2Fe2O3
Hydrolysis
Mg2SiO4 + 2H2O 
2Mg(OH)2 + H4SiO4
Biological activity – plants, fungi, and bacteria release acids

11. Chemical Weathering Rates increase with increased and…
Temperature
Moisture
Acidity
and…
decreased silica

12. Erosion and Transport Erosion = removal of material from a place
Transportation = the movement of eroded material
Transport by water and wind rounds and sorts the particles by size
Movement by ice and gravity does NOT sort

13. Erosion and Transport by Rivers

14. Erosion and Transport by Waves & Ocean Currents

15. Erosion and Transport by Wind

16. Erosion and Transport by Gravity
Mass Movements
Mudflows
Landslides
Creep
Rock Fall

17. Depositional Environments