1. The Theory of Continental Drift
Drifting Continents
The Theory of Continental Drift

2. Alfred Wegener German scientist – 1910
Curious about relationship of continents
Wegener’s Hypothesis – All the continents were once joined together as a single landmass and have since drifted apart.
Pangaea – Wegener’s name for the supercontinent; means “all lands"; existed 300 million years ago

3. Continental Drift
Wegener’s idea that the continents slowly moved over Earth’s surface to their present locations

4. Wegener’s Evidence
LANDFORMS
FOSSILS
3. CLIMATE

5. Evidence from Landforms
The shapes of the continents
Folded mountain ranges in South America and Africa that matched up
Coal fields in North America and Europe that matched up
The Himalaya Mtn. range that formed when India collided with Asia

6. Evidence from Fossils
Fossil – any trace of an ancient organism that has been preserved in rock
Glossopteris fossils found on widely separated landmasses (Africa, S.A., Austr., India, Antarct.); seeds too large to be carried by wind or birds; too fragile to be carried by ocean waves
Mesasauras fossils – freshwater reptile, found in S.A. and Africa only

7. Evidence from Climate
Tropical plant fossils found in the harsh polar climate of Spitsbergen
Glacier scratches in rocks of warm climate areas of South Africa, S.A., India, Austr.
Coal beds found in polar climate of Antarctica ? ? ?

8. Scientists Reject Wegener’s Theory
Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents.

9. Drifting Continents Define: Pangaea, continental drift, fossil
Describe Wegener’s theory of continental drift
List the 3 main categories of evidence used by Wegener to support his theory
Give one example from each of the 3 categories of evidence
What was important about the seed of the Glossopteris?
Why did scientists reject Wegener's theory?