1. Plate Tectonics
Movement of the Crust

2. Convergent Boundaries
Plates Move Toward Each Other
Three Types of Convergent Boundaries
Oceanic-to-Continental
Oceanic-to-Oceanic
Continental-to- Continental

3. Oceanic-to-Continental Convergent Boundaries
More dense oceanic crust subducts under the less dense continental crust.
Characteristics include:
- Trenches at subduction zone
- Volcanoes
- Deep Earthquakes

7. Andes Mountains in South America

8. Oceanic-to-Oceanic Convergent Boundaries
An older, cooler, and more dense oceanic plate subducts under another oceanic plate
Characteristics include:
- Volcanic Activity
- Earthquakes
- Trenches

11. Continental-to-Continental Convergent Boundary
Two continental crust plates collide.
Since continental material is equally dense, movement is mostly upward.
Characteristics include:
- Tall mountains
- Earthquakes

12. Continental-to-Continental Convergent Boundary

13. Collision of India and Asia

14. Himalaya Mountains

15. Other Characteristics of the Plate Tectonics Theory
Volcanoes and Earthquakes are concentrated along Plate boundaries
An example is the “Ring of fire” around the Pacific Ocean

17. Earthquakes are Also Concentrated Along Plate Boundaries

19. Hot Spots!
An EXCEPTION to volcanoes and earthquakes occurring along plate boundaries are hot spots
These occur where magma rises to the surface away from a plate boundary.
An example is the Hawaiian Islands.

21. Plate Moves over Hot Spot, Creating an Island Chain

22. Map of Island Chain Created by the Hawaiian Hot Spot

23. What Causes the Plates to Move?
The cause of tectonic (lithospheric) plate movement is convection currents in the plastic-like mantle, or the Asthenosphere

26. Plate Boundary Summary