1. Tectonic Plate
Boundaries
Ag Earth Science
Mr. Silva

2. Objective
• Students will be able to identify three
different plate boundaries, explain what
type of stress is acting on them, and tell
what landscape features are created at each
boundary.

3. Three Plate Boundaries
• Divergent Plate Boundaries
• aka. Spreading Centers
• Convergent Plate Boundaries
• aka. Subduction Zones
• Transform Boundaries
• aka. Transform Faults

4. Divergent Plate
Boundaries

7. Divergent Plate
Boundaries
• Pull Apart
• Tension
• Create new rock (Lithosphere)
• Occur under water (Oceanic Crust)
• Occur on land (Continental Crust)

8. Mid Atlantic Ridge

9. Continental Rifting

10. African Rift Valley
Example of Continental Rifting

11. Convergent Plate
Boundaries

14. Convergent Plate
Boundaries
• Push together “plates collide”
• Compression
• Destroy/Recycle rock (lithosphere)

17. Convergent Plate
Boundaries
• Three Possible Collisions
• Oceanic-Continental Collision
• Oceanic-Oceanic Collision
• Continental-Continental Collision

18. Oceanic-Continental
Collision continental
• Denser oceanic crust dives under
crust
• Oceanic crust is then recycled by melting back
into the mantle
• This massive collision creates deep ocean
trenches, an accretionary wedge, a forearc basin,
and a volcanic arc.
• Exactly like the
California landscape.

19. California’s Profile

20. Oceanic-Oceanic
Collision
• One oceanic plate will subduct under another
• Creates deep ocean trenches
• Creates volcanic island arcs
• Example: the Aleutian
Islands in Alaska or
Japan

21. Aleutian Islands are aa
Aleutian Islands are
Volcanic Island Arc
Volcanic Island Arc

22. Continental-Continental
Collision
• This occurs when continental crust is riding
on a subducting plate and then smashes
into another continent

24. Transform Fault
Boundaries

25. In the simplest form, plates slide past each other

29. In Review