1. Weathering and Erosion

2. Student Expectation
Analyze the effects of weathering, erosion, and deposition on the environment in ecoregions of Texas.

3. Weathering
The breakdown of the materials of Earth’s crust into smaller and smaller pieces.

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

5. Ice Wedging

6. Frost Heaving

7. Plant Roots

8. Friction and Repeated Impact

9. Burrowing of Animals

10. Temperature Changes

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

12. Water
Water weathers rock by dissolving it

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

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

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

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

17. Features of Karst: Sinkholes

18. Features of Karst: Caves

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

20. Water Erosion
Rivers, streams, and runoff

21. Ice Erosion
Glaciers

22. Wind Erosion

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

24. Deposition
The dropping of sediment when an agent of erosion, such as gravity, a glacier, wind, or water, loses its energy
Horizontal sorting – the sediments that were once carried down the stream are dropped off from largest to smallest.
Graded bedding – the smallest sediments are also dropped to the bottom last

25. Horizontal Sorting

26. Graded Bedding

27. Deltas form as a result