1. Aim: How do Continents Drift?

2. Do Now: Using yesterday’s notes and your knowledge from past topics, which layer of the Earth do you think has undergone the most change and why? List the process that caused the layer you named to change.

3. I. Alfred Wegener and Continental Drift - Wegner’s continental drift theory stated that the continents had once been joined to form a super-continent called Pangaea (all land)

4. Breakup of Pangaea

5. II. Evidence for Continental Drift 1.The Continental Puzzle The continents look as if they were pieces of a giant jigsaw puzzle

6. 2. Matching Fossils - Several of the same fossil organisms (plants and animals) found on different landmass.

7. 3. Rock Types and Structures - Mountain belts that end at one coastline reappear on coastlines across the ocean.

8. 4. Ancient Climates - Matching glacial striations and similar till are found on several continents.

11. III. Rejecting a Hypothesis - Most scientists rejected Wegner’s hypothesis because he could not explain how the continents moved. - Wegner could not explain the mechanism that made the continents move.

12. IV. A New Theory Emerges Plate Tectonics – theory that the Earth’s surface is composed of ~ 12 large, rigid plates that diverge and converge, carrying the continents. (uses Wegner’s evidence)

13. Closure Will the continents come back together and form a single landmass? - YES – but not for a very long time (about 300 million years).

14. Review book: Page 99-102 # 3-5, 9 and 11