1. Weathering, Erosion, & Deposition
Activity 29

2. Earth Processes
Destructive- Processes that break the Earth apart.
Weathering
Constructive – processes that build up earth material
Deposition
Destructive forces are not always harmful. Constructive forces are not always helpful.

3. Weathering
The breaking apart of rocks. Wind, water, and animals are agents of weathering

4. Weathering
When water falls onto rocks, it may freeze and expand. This eventually may cause the rock to crack.
Water may also react with some chemicals in rocks, causing the rock to break down.
As rock falls from a higher location to a lower location, it may break.

5. Erosion The transportation of weathered materials.
Water cuts into rocks and forms Canyons.
One famous example is the Grand Canyon

6. Erosion
Land can slowly erode away, and when this happens, landslides can happen, roads can break apart.
Slow and steady water erosion over long periods of time cause
Lakes
Rivers
Hills
Canyons
Fertile plains

7. Erosion Effects of erosion can be slowed by: Planting vegetation
Trees
Grass
Shrubs
Creating barriers
Rock piles
Dams
Fences

8. Deposition
When erosion carries sediments from one place to another, and the sediments are left.
Deposition can cause the formation of new landforms. One example is a delta.

9. Deposition Deposition can be helpful in these ways:
Sediments add nutrients to the soil
Sediments can make new rocks
Deposition can be harmful in the following ways:
They can cover the habitat areas for fish and other animals
They can build up and fill rivers, lakes, and other wetlands

10. People and Earth’s Processes
Humans can accelerate Earth’s processes by:
Construction
Farming

11. Weathering, Erosion, or Deposition?
Whiteboard Activity

12. Weathering, Erosion, or Deposition?
Flood water pounding against a canyon wall
Weathering

13. Weathering, Erosion, or Deposition?
Rain washing away soil from a hillside
Erosion

14. Weathering, Erosion, or Deposition?
Layers of sediment forming at the bottom of the ocean
Deposition

15. Weathering, Erosion, or Deposition?
Caves being formed by acid rain dissolving underground limestone
Weathering

16. Weathering, Erosion, or Deposition?
A mudslide flowing down a steep hill
Erosion

17. Weathering, Erosion, or Deposition?
Deltas forming at the mouths of rivers
Deposition

18. Weathering, Erosion, or Deposition?
Wind blowing sand from one location or another.
Erosion

19. Weathering, Erosion, or Deposition?
Glaciers scraping across the earth’s surface
Weathering

20. Weathering, Erosion, or Deposition?
Muddy water being carried away by a fast moving river
Erosion

21. Weathering, Erosion, or Deposition?
Rocks being made smooth by tumbling across a streambed
Weathering

22. Weathering, Erosion, or Deposition?
Ponds filling up with sediment and becoming marshes
Deposition