1. Warm-up for Today Put your Erosion article summary in the Turn-In Bin.
Clear your desk. All you need is your agenda and a pen/cil.

2. Soil Formation and Composition
Section 7-2

3. Dirt Excrement Filthy or soiling substance Something worthless
Synonyms: filth, dust, grime, muck

4. Soil
The loose upper layer of the Earth’s crust in which plants can grow

5. We do NOT say “Dirt”,
We say “SOIL” !!!

6. Where does soil come from?
Weathered Rock
other stuff
Soil

7. Bedrock The solid rock in Earth’s crust
When exposed at the surface, it weathers into smaller and smaller pieces to become soil

8. Bedrock weathers to Rock Particles

10. What is the “other stuff?”
Humus
Air
Water

11. Humus The organic part of soil Formed from decomposed organisms
dark-colored
Rich in nutrients

12. Loam Loam is the BEST kind of soil.
Loam has a good balance of air and water, and holds LOTS of nutrients.
Loam contains equal parts of
Sand (drainage)
Silt
Clay (holds water)

16. O = litter A = topsoil B = subsoil C = parent material bedrock
Soil Horizons
O = litter
A = topsoil
B = subsoil
C = parent material
bedrock

17. Life Science RE:visited
The Weatherers
The Defecators
The Decomposed
The Decomposers
The Aerators

18. What is the relationship between weathering and soil?
Let’s Review!
What is the relationship between weathering and soil?

19. What different materials make up soil?
Let’s Review!
What different materials make up soil?

20. What is the best kind of soil?
Let’s Review!
What is the best kind of soil?

21. How do plants and animals affect soil?
Let’s Review!
How do plants and animals affect soil?

22. Bedrock weathers to Rock Particles

23. `
DEPOSITION

24. Material added to land Sediment stops moving (erosion)
depostion
Material added to land
Sediment stops moving (erosion)
Organic stuff deposited

35. Loess