1. Continental Drift Theory
Created by Kesler Science – More 5E lessons at KeslerScience.com
Presented by Kesler Science

2. Essential Questions: Who is Alfred Wegener
What is the historical evidence that supports the Continental Drift Theory?
What causes the movement of the continents?

3. Continental Drift Theory
Staple notes on page 53
Meet Alfred Wegener (1880 – 1930)
Proposed the Continental Drift Theory - The idea that Earth’s continents moved apart from a single large continent called Pangaea
Despite a large body of compelling fossil and rock evidence, his theory was rejected by most other scientists.
He could not explain “how” the continents moved.
It was only in the1960s that the Continental Drift Theory finally became accepted and became part of the Theory of Plate Tectonics.
© KeslerScience.com

4. Continental Drift Theory
Pangaea
Was a super continent
Began to break apart about 175 million years ago
There were probably other supercontinents before Pangaea.
The Earth’s continents have been continually breaking apart and coming together.
© KeslerScience.com

5. Continental Drift Theory
Laurasia and Gondwanaland
Gondwanaland separated from Laurasia between million years ago.
This roughly formed the northern and southern hemispheres.
© KeslerScience.com

6. Continental Drift Theory
Wegner’s Supporting Evidence
Fossil evidence
Continental Fit
Glacial evidence
Landforms & Rock Layers
© KeslerScience.com

7. Continental Drift Theory
Fossil Evidence
Fossils of the same species were found on separate continents and nowhere else.
These plants and animals would have had to evolve independently or swim the distances.
Fossils found didn’t fit the climate. (Palm tree leaf fossils were found in Alaska.)
© KeslerScience.com

8. Continental Drift Theory
Continental Fit
The continents, particularly South America and Africa, fit together like puzzle pieces.
This was another piece of evidence that the continents were once joined.
© KeslerScience.com

9. Continental Drift Theory
Glacial Evidence
Glacial deposits formed 300 mya are found in Antarctica, Africa, South America, India and Australia.
Striations (scratches on rocks) show the ice flowing from the glaciers came from a single point.
Evidence of glaciers is found in warm climates today.
© KeslerScience.com

10. Continental Drift Theory
Landforms and Rock Layers
The Appalachian Mountain matched well with those on the British Isles as well as other places.
Similar types of rocks and similar ages of rocks were found on these three continents and other places.
The coal fields in North America and Europe match up.
© KeslerScience.com

11. Quick Action – Continental Drift Theory
The Great Debate
As a scientist how would you feel if years of your research was discounted, unnoticed, or completely rejected? That has happened to many of our great scientists over the decades. Years after their death many of those theories became accepted.
Two students from the class will be chosen to debate the Theory of Continental Drift. Spend a few minutes with your group prepping your arguments. Debaters will “take the stage” and try to convince the other of their position. We will vote on who won the debate.
© KeslerScience.com

12. Check for Understanding
Can you…
Identify Alfred Wegener and his contributions to the Continental Drift Theory?
Explain the historical evidence that supports the Continental Drift Theory?
Describe the process that moves the continents.
Clear up any confusion and answer questions.
© KeslerScience.com