1. Theory of Continental Drift

2. James Hutton 1785 Uniformitarianism
He is known as the father of geology

3. Uniformitarianism The present is the key to the past
The geological forces and processes of today are the same as those from the past.
These forces are very slow and methodical.

4. Alfred Wegener 1915 Continental Drift

5. Evidence for continental drift
Matching
Coastlines
(jigsaw puzzle)
Becomes more of a match when you use the
continental shelves.

6. Matching folded mountain Ranges (Atlas, Appalachians, and Scandinavian
Highlands)

7. Matching glacial
deposits and
erosional features

8. Salt beds found in Texas and Germany
Salt beds found in Texas and Germany. These are only created in dry tropical areas.

9. Coal deposits found in USA
Coal deposits found in USA. Coal is created in environments similar to the Everglades.

10. Matching Fossils
Plants and animals found on distant lands

11. Lystrosaurus found on Africa, South America, India, & Antarctica

12. Evidence for continental drift
Matching coastlines
Matching folded mountains
Matching glacier deposits
Salt beds in Texas and Germany
Coal beds in West Virginia
Matching fossils

13. Pangaea A Greek word meaning “All-lands”
Split apart approximately 200 million years ago (MYBP)

14. 1915 maps by Wegener of Pangaea

15. Continental drift
Theory that continents drift on the surface of the Earth
No mechanism proposed
No one believed this was possible

16. 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

17. 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

19. Topography of ocean floor

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

21. Recurring patterns in oceans

22. Plate Tectonics
Combining Hutton theory, Wegener’s evidence, Glomar Challenger’s data, and the following world map the present theory of Plate Tectonics came into being
Video plates over time

23. Earthquake and Volcano Distribution
Weekly quakes map

24. Unexpected consequence of continental drift