1. THIS IS NOT HOW EARTH LOOKS TODAY
WHAT IS THIS?
THIS IS NOT HOW EARTH LOOKS TODAY

2. Plate Tectonics The theory of plate tectonics was first proposed by
Alfred Wegener in Wegener noticed that the
shorelines of the continents seemed to ‘fit together’
like the pieces of a giant jig saw puzzle.
Wegener’s theory stated:
The continents were once all together in one
place forming a supercontinent, Pangea.
The continents broke apart and drifted to their
present locations.

3. Today plate tectonics and continental drift are accepted as facts.
Why? Let’s see the evidence!

4. Convection current:
Hot water rises because it’s lighter. When it reaches the top then it cools and sinks because it gets heavier.

5. What Causes Plate Motion?
Convection currents within the Earth’s mantle cause the plates floating on it to move. This movement takes millions of years.
Similar to groceries on a conveyor
belt or a raft floating on a river.
Mantle
Plates
Next >

6. The Earth’s crust is always moving!
Pangea
Pangea = Supercontinent (millions of years ago)

7. Continental Drift: The gradual movement of the continents across the earth.
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8. The speed plates move is about the speed at which your fingernails grow. (8cm per year)
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9. In 1915, The German geologist Alfred Wegener ( ) proposed continental drift. Not accepted until the 1950’s!
Copyright © 2010 Ryan P. Murphy

10. In 1915, The German geologist Alfred Wegener ( ) proposed continental drift. Not accepted until 1950’s!
“I say.” “Africa and South America fit strangely like two puzzle pieces.”
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11. The shapes match.
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12. FOSSILS!
The remains or impression of a prehistoric organism (living thing: plant, animal, footprint)

13. Same fossils found on different continents
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17. The Same rock structures on different continents
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18. What is this a fossil of?
Where would you expect to find a specimen like this on the planet?
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19. Answer! This is a fossilized tropical plant found on Antarctica.
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20. Answer! This is a fossilized tropical plant found on Antarctica.
Remember, the continents have moved and Antarctica use to be in a warmer climate.
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21. “Darn you continental Drift.”
Answer! This is a fossilized tropical plant found on Antarctica.
Remember, the continents have moved and Antarctica use to be in a warmer climate.
“Darn you continental Drift.”
“Darn you.”
Copyright © 2010 Ryan P. Murphy

23. CREATING PANGEA
Today you will be recreating Pangea using the fossil evidence.
Cut out the tectonic plates on your map and tape them on the other paper
Use the fossil evidence to help you line up the plates.

24. Current Day + or – 4mm

26. What causes continental drift and plate tectonics?
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27. Answer! Convection currents (Remember heat rises) move the plates
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28. Answer! Convection currents (Remember heat rises) move the plates
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29. Answer! Convection currents (Remember heat rises) move the plates
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30. Answer! Convection currents (Remember heat rises) move the plates
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31. Which colored arrows are incorrect based on the convection current patterns and plate movements below?
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32. Answer! The blue arrows. The plates should be moving toward each other.
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33. Answer! The blue arrows. The plates should be moving toward each other.
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34. “Oh-no!” “We are trying it again.”

35. Try Again! Which colored arrows are incorrect based on the convection current patterns and plate movements below?
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36. Answer! The purple arrows should be diverging instead of converging.
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37. Answer! The purple arrows should be diverging instead of converging.
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38. “Oh-no!” “We are trying it one more time.”

39. Try Again! Which colored arrows are incorrect based on the convection current patterns and plate movements below?
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40. Answer! The light blue arrows should be diverging instead of converging.
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41. Answer! The light blue arrows should be diverging instead of converging.
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42. “Oh-no!” “We are trying it one more time.”

43. Try Again! Which colored arrows are the only correct on in the entire group.
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44. Try Again! Which colored arrows are the only correct on in the entire group.
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45. Let's sum up everything we've learned:
1) The earth's crust is divided into many pieces called tectonic
plates which move around over long periods of time.
2) Evidence for crustal movement includes:
a) The 'fit' of the continents.
b) Correlation of rock types from opposite shores.
c) Correlation of fossils from opposite shores.
d) Age of the sea floor (youngest near mid-ocean ridges
and oldest near the continents).
e) Paleomagnetism: zones of oppositely magnetized
rock on opposite sides of the mid ocean ridge.
f) Direct satellite and GPS measurement of continental
movement.
3) The force driving the plates are convection currents (density
differences) in the earth's mantle.