1. Theory of Continental Drift

2. Alfred Wegener 1915 Continental Drift

3. Evidence for continental drift
Matching
Coastlines
(jigsaw puzzle)

4. Matching folded Mountain ranges
(Atlas, Appalachians, and Scandinavian Highlands)

5. Matching glacier
deposits

6. Matching Fossils (Lystrosaurus)

7. Evidence for continental drift
Matching coastlines
Matching folded mountains
Matching glacier deposits
Matching fossils

8. Pangaea A Greek word meaning “All-lands”
Split apart approximately 200 MYBP

9. 1915 maps by Wegener of Pangaea

10. Continental drift
Theory that continents drift on the surface of the Earth
No mechanism proposed
No one believed this was possible
Do you think continents can float ?

11. Glomar Challenger
1960’s this ship took core samples of ocean floor rocks as it crossed the Atlantic Ocean
A map was produced from this data showing the rock types and ages
From this map a new theory was developed to explain Wegener’s evidence

12. Ocean floor rock ages
Get older symmetrically away from ridges, the oldest rocks have to be 200,000,000 years old
Theory: sea floor splits apart and rocks move away from each other
Process: Seafloor spreading
Seafloor spreading provides clues to mechanism driving continental drift

13. Topography of ocean floor

14. Does sea floor spreading explain everything ?
If the Atlantic Ocean is spreading, doesn’t that mean some place is being squeezed together

15. Recurring patterns in oceans

16. Plate Tectonics
Combining Wegener’s evidence, Glomar Challenger’s data, and the following world map the present theory of Plate Tectonics came into being
Video about plate movements over time

17. Earthquake and Volcano Distribution
Weekly quakes map