1. Chapter 5 Lesson 1 Weathering and Erosion
Earth Science Unit 1
Chapter 5
Lesson 1
Weathering and Erosion

2. Start-Up Work
Pick up a Supplemental Packet from the Lab Table by the door
Answer the following questions in your packet (pg 2):
Have you ever tripped over a crack in the sidewalk? Why are sidewalks designed with spaces between the sections and why do they raise and buckle?
Objectives:
Identify and discuss several processes of mechanical weathering
Discuss the results of basic mechanical weathering processes
Observe the process and effects of mechanical weathering

3. Let’s see the results!
Class trip to the Freezer to retrieve straws from yesterday!
Answer the Questions:
What happened to the clay?
What do you think will happen when the water in the cracks of rocks freeze?

4. Weathering
Defined: breaking down of rocks into smaller pieces by chemical or physical processes

5. Mechanical Weathering
Aka Physical Weathering- the breaking down of rocks by physical processes
No chemical processes are involved
Most is caused by temperature extremes
Other causes include ice, water, and activities of living things

6. Ice Wedging
When water in cracks of rocks expands, it creates a bigger crack

7. Extreme Climates
Desert- changes in temperature causes the surface layer of the rocks to fracture from the under layers
When this process occurs in granite or other hard rocks it is called exfoliation

8. Water
Waves hitting a rock shoreline creates steep cliffs called sea cliffs

9. Living Things Trees can sink their roots into rocks splitting them
Animals- expose rocks to the processes
Mollusks can bore holes into rocks!

10. Bring it all together!
Answer the questions in your text books on page 90.
Write the answers in your supplemental packet
After completed- read lesson 2 if you do not finish, it is homework!