1. Major Geological Events
Caused by
Plate Tectonics

2. Take out Plate Tectonics Map
Plate Boundary Notes
Today we will be discussing and recording the following in your Science Journals:
Type of Boundary
Direction of plate movement
Types of plates involved
Land features formed
Take out Plate Tectonics Map

3. Draw table (landscape/sideways) in Science Journal
Type of Boundary
Direction of plate movement
Types of plates involved
Land features formed
Divergent
Convergent
Transform

4. Types of Boundaries (Direction of Plate Movement)
Divergent  
Plates move apart
Convergent 
Plates come together
Transform
Plates slide horizontally
past each other

5. Divergent Structures (Land Features Formed)
New crust is formed as plates pull apart
Land features include:
Mid-Ocean Ridges
Ex. - Mid-Atlantic Ridge
Rift Valleys
Ex. - African Rift Valley
Earthquakes

6. Mid-Atlantic Ridge

7. Mid–Ocean Ridge (Location of Sea Floor Spreading)
The mid-ocean ridge (shown in red) winds its way between the continents much like the seam on a baseball.

9. Sea Floor Spreading (Mid-Ocean Ridge)
Younger
Older
Older
Divergent Structure
Types of Plates Involved: Oceanic

10. Rift Valley Divergent Structure Types of Plates Involved: Continental
Mid-Ocean Ridge when on oceanic crust
Rift Valley when on land
Types of Plates Involved: Continental
Divergent Structure

11. African Rift Valley

12. Convergent Boundaries (Land Features Formed)
Crust is destroyed and recycled back into the mantle
Three types of convergent collisions
Features include:
Trenches – Mariana Trench
Volcanic Arc (Volcanic Mountains) – Andes mountains
Mountain Ranges – (Folded Mountains)-Himalayan Mountains
Earthquakes

13. Mariana Trench
The Mariana Trench is part of a global network of deep troughs that cut across the ocean floor. They form when two oceanic tectonic plates collide. At the collision point, one of the plates dives beneath the other into the Earth’s mantle, creating an ocean trench.

14. Types of Plates Involved: Oceanic to Continental

15. Types of Plates Involved: Continental - Continental

16. Convergent Boundary: Andes Mountains

17. Subduction Result of convergent boundary
A more dense plate slides under a less dense plate and sinks into the mantle.
Features include:
Oceanic-Oceanic = Trenches
Oceanic-Continental = Volcanic Mountain Ranges
Continental-Continental – Folded Mountain Ranges

18. Subduction Examples

19. Oceanic-Oceanic convergence
Convergent Boundary
Oceanic-Oceanic
Land Features – Trench and Island Arc
Oceanic-Oceanic convergence

20. Oceanic-Continental convergence
Convergent Boundary
Oceanic-Continental
Land Features – Trench and Volcanic Arc (Volcanic Mountains)
Oceanic-Continental convergence

21. Continental-Continental convergence
Convergent Boundary
Continental-Continental
Land Features – Folded Mountains
Continental-Continental convergence

22. Mountain Ranges

23. Transform Fault Structures
Land Features
Crust is neither destroyed nor created
Features include:
Earthquakes
Fault line – San Andreas Fault
Types of Plates
Can occur between:
Oceanic -Oceanic plates
Oceanic-Continental plates

24. Transform Boundary
Land Feature – Fault Line

25. Transform Boundary San Andreas Fault Line

26. Transform Boundary Continental-Continental Land Features – Fault Line
Aerial view of San Andreas Fault in the Carrizo Plain, self-made, Nov 16, 2007, I. Kluft,

28. Earthquakes – All Boundaries
Compare map to your Plate Tectonics Map. What do you notice? Are earthquakes random around the Earth? Do you think record keeping of earthquakes has helped scientists develop the Plate Tectonics Theory?!

29. Volcanoes
Compare to your Plate Tectonics Map. Do volcanoes occur in random places? Are volcanoes found on all plate boundaries?

30. The Ring of Fire
About 90% of the world's earthquakes and 80% of the world's largest earthquakes occur along the Ring of Fire.

31. Mountain Ranges
What do mountains tell you about the location of plate boundaries? What type of plate boundary do the Himalayan Mountains have? The Andes Mountains? What land feature do you see at the Andes and not at the Himalayas?

32. Putting It All Together

33. Plate Boundaries

34. Plate Movement

36. The upper cookie is the lithosphere, the creamy filling the asthenosphere, and the lower cookie the lower mantle.
Carefully remove the upper cookie with a “twisting” motion.
Slide the upper cookie over the creamy filling to simulate motion of a rigid lithospheric plate over the softer asthenosphere.
Next, break the upper cookie in half. As you do so, listen to the sound it makes. What does that sound represent? An earthquake.
It takes cold, brittle lithosphere to make earthquakes – earthquakes do not occur in the soft, flowing asthenosphere.