1. Continental Drift Lecture Notes

2. Background: Continental Drift (Movimiento continental) Idea proposed by Alfred Wegener in 1912 that continents are moving very slowly, parallel to Earth’s surface But how/why do they move?

3. CONTINENTAL DRIFT IN DOUBT Why didn’t people believe in continental drift?  People couldn’t image how the earth could be millions of years old  People couldn’t image a force great enough to move the continents Why didn’t people believe in continental drift?  People couldn’t image how the earth could be millions of years old  People couldn’t image a force great enough to move the continents

4. Argumentation! How did Wegener convince other’s that his theory was true? – Claim: The continents move around on the surface of the Earth. – Evidence: ?? – Reasoning: ??

5. Evidence #1 APPARENT FIT OF THE CONTINENTS (Continents fit together like puzzle pieces)

6. Mesosaurus was incapable of swimming across a large ocean. FOSSIL CORRELATION (same fossils, different continents) Evidence #2

7. ROCK AND MOUNTAIN CORRELATION (same rocks and mountain structures, different continents) ROCK AND MOUNTAIN CORRELATION (same rocks and mountain structures, different continents) Evidence #3

8. ROCK AND MOUNTAIN CORRELATION (same rocks and mountain structures, different continents) ROCK AND MOUNTAIN CORRELATION (same rocks and mountain structures, different continents) Evidence #3  Existing mountain ranges separated by vast oceans contain rocks of identical mineral content.  A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles.  Existing mountain ranges separated by vast oceans contain rocks of identical mineral content.  A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles.

9. (same glacial scars, different continents) (glaciers in now tropical regions, coal in now non-tropical regions) Evidence #4 PALEOCLIMATE DATA

10. Argumentation! How did Wegener convince other’s that his theory was true? – Claim: The continents move around on the surface of the Earth. – Evidence: Shape, Fossils, Rocks, Paleoclimate – Reasoning: ?? Discuss with your partner: What is the reasoning?