1. Continental drift

2. You will be able to Describe the hypothesis of continental drift
Identify evidence supporting continental drift.

3. Alfred Wegener
Realized that the fact that the continents appeared to “fit” was not just a coincidence.
He proposed the hypothesis of continental drift.
Continental drift: the slow movement of the continents to their current space.

4. Pangaea: the name of the large land mass, that contains all the continents.
All continents were together as one large one and they broke apart about 200 million years ago.

6. EVIDENCE

7. Fossil clues
Hypothesis: If the continents were originally together and then separated, then there would be Fossil clues to support the idea.
Reptile Mesosaurus
found in South America and Africa
even though they are swimming reptiles, they only like fresh water.

8. Widespread plant clues
Hypothesis: If the continents were originally together and then separated, then there would be some kind of plant that is found all over that would support the idea.
Glossopteris
Found in Africa, Australia, India, South America, and Antarctica.

9. Climate clues
Hypothesis: If the continents were originally together and then separated, then there would be climate clues to support the idea.
Fossils of warm weather plants were found in island in the Arctic Ocean.
Glacial deposits and rock surfaces scoured and polished by glaciers. Found in South America, Africa, India and Australia.

10. Rock clues
Hypothesis: If the continents were originally together and then separated, the places (continents) where they would have been touching (continent to continent), then they would share the similar rock type in those areas.
Parts of the Appalachian mountains (easter US) are similar to the mountain range in Green Land and Western Europe.
Rocks in Easter South American and Western Africa will also be similar.

12. How did they drift? Wegener explanation.
Lower density continental crust had to plow though higher density.
After his death there was new evidence that supported his hypothesis.
The main reason why more things were found is because technology improved and the idea of sea floor spreading appeared.
Sea floor spreading is the explanation on how the continents could have moved.