1. Plate Tectonics
Evolution of the Earth

2. Catalyst: How are these words and pictures related?
Are there any groups that fit together?
What do you think our next unit will be about?
What do you already know about these things?

3. Tectonic Plates
Our first evidence of tectonic motion is based on similar fossils and
rock types on opposing sides of the ocean

4. Tectonic Plates

5. Tectonic Plates Today plate boundaries are determined by examining
the location of volcanoes and earthquakes.
Volcanoes result from the friction (heat) of the plates
motion.
Earthquakes occur where plate rub against one another

6. Tectonic Plates
Volcanoes

7. Tectonic Plates

8. Tectonic Plates

9. Tectonic Plates

10. Tectonic Plates

11. Tectonic Plates Another source of evidence is based on seafloor ages
which get younger
as we approach
sea floor ridges

12. Tectonic Plates Oceanic plates: basalt
Dark (black) and dense rock type composed of silicates, iron and magnesium
Continental plates: granite and andesite
Light colored (pink, white and gray) and low density rock type composed almost entirely of silicates.

13. Plate tectonics Start from1:11 Start from :56 to 1:50
Brain Pop
Plate tectonics
Start from1:11
Start from :56 to 1:50

14. What are the different plate boundaries?
Convergent boundaries
Divergent boundaries
Transform boundaries
Today we are learning about CONVERGENT!

15. Plate Boundaries Convergent – plates move toward one another
Divergent – plates move away from each other
Transform – plate moves sideways from each other

16. Convergent Plate Types
Oceanic- Oceanic
Oceanic-Continental
Continental-Continental
The only difference between the two type of plates is the rock composition and the density.

17. Oceanic- Oceanic & Continental- Oceanic
Both happen because of subduction: when one tectonic plate moves under another.
This causes volcanoes to occur
Which plate type is more dense?
Oceanic-Continental:
Oceanic plates will always go under continental plates because of density!
Oceanic-Oceanic:
Same density
oldest plate will subdue, or go under

18. Continental-Continental
Plates have the same density…
NO subduction!!
Plates crash into each other–
Lithosphere folds like wrinkles
Mountains are formed

19. Exit Ticket
Plate Tectonics

20. Plate Boundaries

21. Convergent Plates

22. Convergent Plates

23. Convergent Plates

24. Convergent Plates
The only subduction zone
in the Atlantic

25. Convergent Plates Black arrows show subduction zones and
the direction of plate movement

26. Convergent Plates Looking at the depth of earthquakes shows
that angle that the
plate is being subducted

27. The Big Picture

28. Where are we going? We appear to be headed for another
super continent as North America,
South America, Asia and Australia converge in the
ever shrinking Pacific Ocean