1. Weathering and Erosion

2. Weathering
The gradual breakdown of the materials of Earth’s crust into smaller pieces through chemical or mechanical processes.

3. Physical Weathering
Process by which rocks are broken down into smaller pieces by external conditions.
Types of Physical weathering
Frost heaving and Frost wedging
Plant roots
Friction and impact
Burrowing of animals
Temperature changes

4. Frost Wedging

5. Frost Heaving

6. Plant Roots

7. Friction and Repeated Impact
Breaks off pieces of rock, and gradually forms smooth round rocks found in stream beds or along lake shores.

8. Burrowing of Animals

9. Temperature Changes

10. Chemical Weathering
The process that breaks down rock through chemical changes.
The agents of chemical weathering
Water
Oxygen
Carbon dioxide
Living organisms
Acid rain

11. Water
Water weathers rock by dissolving the minerals

12. Oxygen
Iron contained in rock combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust

13. Carbon Dioxide CO2 dissolves in rain water and creates carbonic acid
Carbonic acid easily weathers limestone and marble

14. Living Organisms
Lichens that grow on rocks produce weak acids that chemically weather rock

15. Acid Rain
Compounds from burning coal, oil and gas react chemically with water forming acids.
Acid rain causes very rapid chemical weathering

16. Karst Topography
A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams.
Created by chemical weathering of limestone

17. Features of Karst: Sinkholes

18. Features of Karst: Caves

19. Features of Karst: Disappearing Streams

20. Erosion
The process by which water, ice, wind or gravity moves fragments of rock and soil.

21. Water Erosion Rivers, streams, and runoff
Delta-a fanlike deposit of sediment where a river enters an ocean/sea.

22. Ice Erosion
Glaciers-large long lasting mass of ice that moves due to gravity and plucks rocks and boulders and scourers valleys smooth.

23. Glaciers Creates U-Shaped valleys
Moraine-piles of rocks that form hills or ridges that are left behind/deposited once a glacier has melted or receded.
Kettles- small glacial depressions that fill with water to form small lakes

24. Wind Erosion
Winds must be 11 mph to move sediment. Dust storms can move 6,000 tons per cubic mile of air.
Loess: windblown silt and clay that produces very fertile soil (Mississippi, N. China, Argentina)

25. Mass Movements Landslides, mudslides, slump and creep
landslide clip.mpeg

26. Building Soil
Soil: A loose mixture of weathered rock, organic matter, air, and water that supports plant growth.
Humus: organic material in soil
Soil quality determines the types of vegetation that can grow.

27. Soil Factors
Parent Material: chemical composition of the original rock
Relief: steep slopes erodes faster
Organisms: decomposers help loosen soil
Climate: wet/dry, hot/cold = different soils
Time: 2.5 cubic cm per 100 years