1. Do First Questions: On Moday write Labor Day for both sides
On Tuesday write SLO Testing for both sides
On Wednesday write Test for both sides
Today:
Draw and label the diagram of the mechanical layers of the earth

2. Agenda Retake Policy Plate Tectonic Guided Notes
Self-Directed Plate Practice

3. Test Corrections
If your overall grade is a 75 or less then you can complete a test corrections afterschool or in the morning
If you scored a 55 or higher, the test corrections will get you to a 70
If you scored less than a 55, you must do an hour of remediation with me before you can do test corrections

4. What are Tectonic Plates?
Tectonic plates are pieces of Earth's crust and uppermost mantle, together called the lithosphere.

5. Evidence of Tectonic Plates
Continental Drift Theory
1. Coastline Matching
2. Fossil Evidence
3. Rock types and structures
Theory of Plate Tectonics
4. Mid Atlantic Ridge
5. Age of Sea floor
6. Paleomagnetism

6. Alfred Wegner
He was a German researcher who proposed the continental drift theory
The continental drift theory states that the continents had once been joined to form a single supercontinent named Pangea 200 million years ago
He was the first to propose the continents could move

8. Wegener
Watch the short clip and answer why Wegner’s idea was not supported

9. 1. Coastline Matching
Continents fit together like a puzzle

10. If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.
If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle…..the shape of Africa and South America are a good example.
This is because they DID used to fit together!
The Earth as we see it today was not always like it is now. Land masses have pulled apart and joined together by the process we call Plate Tectonics….

12. 2. Fossil Evidence Same fossils were found on different continents.
The fossils were of organisms that could not cross oceans.

13. 3. Rock Types and Structures
Several mountain belts end at one coastline, reappear on a landmass across the ocean.

14. 3. Rock Types and Structures
Evidence of glaciers has been found in areas with high temperatures

15. So far Wegener is supported
But was he right?

16. He was only partially correct.
Continental drift was replaced with the theory of plate tectonics because the lithosphere “plates” were moving not the continents.

17. 4. Mid - Atlantic Ridge
The Mid Atlantic ridge is mostly underwater and spews lava which when hardened produces new rock.
The new rock pushes away old rock
The new rock is new lithosphere.

19. 5. Age of the Sea Floor
The age of the crust near ridges is younger than the crust near the continents bordering the ridges

20. 6. Paleomagnetism
Paleomagnetism is the natural magnetism in rock bodies.
This permanent magnetization acquired by rock can be used to determine the location of the magnetic poles at the time the rock became magnetized
Normal polarity—when rocks show the same magnetism as the present magnetism field
Reverse polarity—when rocks show the opposite magnetism as the present magnetism field

21. The alternating polarity shows that new lithosphere has been formed over time

22. Theory of Plate Tectonics
All the evidence shows:
The Earth is creating new lithosphere “plates”
The lithosphere “plates” have moved over time
The lithosphere “plates” are still moving

23. Self Directed Plate Practice
Answer the questions
Cut and paste the continents together to show Wegner’s theory
Make sure to label the continents

25. DYL
1. Why is the term plate tectonics more correct than using continental drift?
2. How did the age of sea floor support the idea of plate tectonics?
3. What is paleomagnetism?