Earth Science Rocks! Warm up October 9

1. Earth Science Rocks!Warm up October 9 Question: Why do you think caring & principled might be good learner profile terms for your new unit on soil?

2. Earth Science Rocks! • MYP Unit Question: How does land change? • Area of Interaction: Environment • Learner Profile: Caring and Principled

3. Earth Science Rocks! • Standard: Investigate the scientific view of how the Earth’s surface is formed. • Learning target: Today I am learning about soil because human survival depends on it.

4. Activating strategy Soil analyzer

5. Soil… What is it?

6. Soil Formation • Soil • How does soil form? • Loose weathered material on Earth’s surface where plants can grow • Soil forms as rock is broken down by weathering and mixes with other materials

7. Bedrock • Solid layer of rock beneath the soil

8. What is the composition of soil? • Soil is a mixture of rock particles, minerals, decayed organic material (humus), air, and water

9. Why is humus good? • Makes spaces for air and water • Rich in nitrogen and minerals that plants need to grow

10. Organisms in the soil • Living things make space for air and water in soil • Decomposers break down the remains of dead organisms into smaller pieces and digest them with chemicals.

11. What is a soil’s texture • Soil texture depends upon size of individual particles • Gravel – 2mm or larger • Sand – less than 2 mm • Silt - less than 1/16 mm • Clay – less than 1/256 mm

12. Clay soils • Dense, heavy texture • Hold a lot of water • Not much space for air

13. Sandy soils • Water drains quickly • Lots of space for air • Nutrients wash out of the soil

14. Loam • Soil with equal parts clay, sand and silt • Crumbly texture that holds both air and water

15. Soil horizon • A layer of soil that differs in color and texture from the layers above or below it.

16. Mrs. McIntire standing by a soil profile at Red Top Mountain.

21. Soil horizons • A horizon – top soil – crumbly, dark brown soil that is a mixture of clay, humus, and other minerals • B horizon – sub soil – usually clay and other particles washed down from A horizon, little humus • C horizon – partly weathered rock

23. How do horizons form?

24. How do the horizons form? • Bedrock weathers and forms C horizon • A horizon develops from C horizon when plants add organic material to soil and rocks mechanically and chemically weather • B horizon develops when rainwater washes clay and minerals from A horizon into B horizon.