1. Plate Tectonics
Liz LaRosa for use with my 5th Grade Science Class

2. Plate Tectonics Greek – “tektonikos” of a builder
Pieces of the lithosphere that move around
Each plate has a name
Fit together like jigsaw puzzles
Float on top of mantle similar to ice cubes in a bowl of water

3. Tectonic Plates

4. Pangea? Famous Scientist: Alfred Wegener- German Meteorologist
He proposed that the Continents were once a single land mass that drifted apart over time.
He called this single land mass supercontinent Pangea,
Greek for “all Earth”
Wegner proposed this in 1912, but it wasn’t considered to be sufficient evidence in itself. He analyzed either side of the Atlantic Ocean for rock type, geological structures, and fossils.

5. Evidence of Pangea
1. Puzzle-like fit of the continents.

6. Evidence of Pangea
2. Fossils of the same plants and animals are found on different continents.

7. Evidence of Pangea
3. Climate Clues.

8. Evidence of Pangea
4. Rock clues.

9. Problems with Wegner’s Theory
Wegner couldn’t explain how, when, or why Continental Drift took place.

10. Sea Floor Spreading

11. Sea Floor Spreading
Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins
Magma rises to the surface and solidifies and new crust forms
Older Crust is pushed
farther away from the ridge

12. How Plates Move

13. Different Types of Boundaries

14. Divergent Boundary – Arabian and African Plates
Arabian Plate
Red Sea
African Plate

15. Divergent Boundary – Iceland

16. Divergent Boundary - Oceanic

17. Divergent Boundary - Continental

18. Convergent Boundary – Indian and Eurasian Plates
Indian Plate

19. Convergent Boundary – Oceanic & Continental
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20. Convergent Boundary – Oceanic & Oceanic
Note – plates are reversed
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21. Convergent Boundaries - Continental
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22. Transform Boundary – San Andreas Fault

23. Review Name the 3 main layers of the Earth What is a tectonic plate?
What was Pangea?
What is Sea-Floor spreading?
Name the three different types of plate boundaries and one location on Earth for each one