1. The Theory of Continental Drift

2. Homework:
Complete puzzle and “position” Paper (1 full pg).
Due Monday, March 3

3. Continental Drift Theory
Proposed by Alfred Wegener in 1912
250 million years ago, all of the continents were combined into one super-continent called “Pangaea”
The continents gradually drifted apart to where they are today

4. Video Link
Alfred Wegener clip

5. Evidence of Continental Drift
Puzzle Pieces
Continents look like they could be part of a giant jigsaw puzzle
Continental shelves
of Africa and South America fit together almost perfectly

6. Distribution of Fossils
The Fossil Record
Glossopteris remains found in SA, Australia, Asia, and Africa, & Antarctica
Fossils of deciduous trees found near North Pole
Coal formation in many parts of the world, but needed to be swampy marshes with lots of rain near the equator

7. The Evidence
Fossil Evidence

8. The Evidence
Fossil Evidence

9. Sequence of Rock Types The Rock Record
Rocks in Argentina identical to ones in Africa
Diamond rich rocks in South Africa match rocks in Brazil
Coal beds in NA, Britain, and Belgium same
Red sandstone same in NA, Greenland, Britain, Norway

10. The Evidence
Mountain Ranges

11. Ancient Climates
Tropical plant remains (coal deposits) found in Antarctica
Glaciation in Africa, South America, India, and Australia during the same time

12. The Evidence
Climatic Evidence
Glacial evidence

13. Theory of Continental Drift
Vocabulary
Continental shelf – part of a continent that extends under shallow water from the ocean’s edge to the steeper sea floor slope.
Pangaea- all land
Panthalassa – all seas
Theory of Continental Drift – continents were once one landmass that broke apart and moved to present locations.

14. Evidence of Continental Drift1. 2. 3. 4.

15. Evidence of Continental Drift
1. Puzzle Pieces – continents fit together like a giant puzzle – esp. SA and Africa
2. Fossil Record – the same plants, trees, and animals and coal beds occur in different continents
3. Rock Record – same sequence of rock occurs on different continents, same mountain ranges occur on different continents
4. Climate – same glaciation marks on different continents, fossil indicate tropical climates where now cold.

16. Pangaea