1. Continental Drift
What evidence do scientists have to support the fact that the Earth’s crust is continuously moving?

2. 1500s – Abraham Ortelius
Saw that the coastlines of Africa and the Americas looked similar
Concluded they must have once fit together
Broke apart due to floods, earthquakes and volcanoes

3. 1800s – Eduard Suess
Stated that the southern continents were once a single landmass called Gondwanaland
Northern continents called Laurasia

4. 1900s – Alfred Wegener Continental Drift
Hypothesis that Earth’s continents were joined as a single landmass that broke apart about 200 million years ago (mya)
Known as Pangaea
Continents slowly moved to their present locations

5. Pangaea - All Earth

6. Evidence from Fossils
Similar fossils of several different plants and animals that once lived near each other found on widely separated continents
Land animals did not swim across ocean, so there had to be a land connection between continents

7. Evidence from Rock Formations
Similarly, rock formations are similar on distant continents
For example, rock types found in Appalachian Mountains similar to those found in Greenland and Europe

9. Climatic Evidence
Coal deposits in Antarctica indicate that the climate was much warmer in the past
Must have been located closer to the equator before it drifted

10. Flaws in Continental Drift Theory
Wegener’s theory of continental drift had some notable flaws:
Not able to explain what force was large enough to move such large pieces of earth over great distances
Not able to explain how the ocean basins were not shattered, despite solid landmasses crossing through them

11. Review Questions What does Pangaea mean in Greek?
What was Ortelius’ contribution to Continental Drift?
Who is credited with the theory of Continental Drift?
List and describe the three main evidences for Continental Drift.
What is one major flaw in the theory of Continental Drift?