1. Objective 5 October 2012
Describe the theory of continental drift.
Intro
Did the Earth always look like this?

2. Continental Drift

3. Who? What? Where? When? Alfred Wegener Theory of Continental Drift
German scientist who developed the Theory of Continental Drift in 1912
The theory that states that the continents once formed a single landmass, broke up, and drifted to their present locations.

4. Restless Continents

5. Restless Continents Evidence of Continental Drift
Same fossils found on opposite continents
Same rock types found on opposite continents
Warm climate plant fossils on cold climate continents

6. Restless Continents Pangaea
All continents were once joined as a single, giant super- continent
Greek for “all Earth”
Existed 245 MYA

7. Restless Continents

8. Restless Continents Sea-Floor spreading
The process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies
Occurs at mid-ocean ridges (underwater mountain chains)
CRT Question

9. Restless Continents Magnetic Reversals Proof of Sea-floor Spreading
Magnetic North and South poles switch positions
Recorded when molten rock solidifies

10. Restless Continents
Summary: Alfred Wegener developed continental drift hypothesis explaining that continents once formed Pangaea and then moved to their current positions. This occurs due to sea-floor spreading and that is proved by records of magnetic reversals solidified in new ocean rock.

11. Objective: 5 October 2012
Describe the theory of continental drift.
Outro
If Sea-Floor Spreading continues, what will the Earth look like in another 250 MY? Describe it or draw a picture!

12. Restless Continents
When scientists proposed the Theory of Continental Drift, there were many skeptics. Which discovery confirmed that the continents move on plates?
Deep-sea currents
Earthquake formation
Spreading of the sea floor
Sedimentary rocks
Interim 2