1. Plate Tectonics
The theory that explains how large pieces of the Earth’s outermost layer, called tectonic plates, move and change shape.

2. Plate Tectonic Boundaries
Plate Boundary: Place where two tectonic plates meet (Like the seams on a puzzle that is put together)
All tectonic plates share boundaries with other tectonic plates.
There are 3 types of plate boundaries.
The type of boundary depends on how the two plates interact.

3. 3 Types of Boundaries
Convergent
Divergent
Transform

4. Convergent boundary: the boundary formed by the collision of two lithospheric plates

5. 1. Continental - Continental
When continental plates collide, they buckle and thicken, which pushes the continental crust upward. (Remember c, c)

6. Continental - Continental
Before collision
After collision

7. Results: Mountain building

8. 2. Continental- Oceanic Collision
When a plate with oceanic crust collides with a plate with continental crust, the denser oceanic crust sinks (subducts) into the asthenosphere.

9. Result: Trenches, Volcanoes

10. 3. Oceanic- Oceanic Collisions
When two tectonic plates with oceanic lithosphere collide, one of the plates with oceanic lithosphere is subducted, or sinks, under the other plate.

11. Result: Trenches, Under water volcanoes or island formation

12. Divergent Boundary
The boundary between two tectonic plates that are moving away from each other

13. Oceanic Separation RESULT:
Oceanic Separation = mid-ocean ridge (new seafloor)
Two oceanic plates separate from each other. As they move apart, magma rises to fill the gap.

14. Result: Continental Separation Continental Separation = rift valley
Two continental plates separate from each other. As they move apart, magma rises to fill the gap.

15. Transform Boundary
When plates are sliding past each other horizontally
(Remember translations in math class = sliding shapes)

16. Continental or Oceanic Plates Slide
As two plates slide past each other, their irregular edges grind and jerk.

17. Result: Earthquakes

19. Remember: Lithospheric plates are moved by convection currents within the asthenosphere. Lithospheric plates move apart when magma rises.

20. 1. Volcanic islands 2. Subduction zone
3. Mid-ocean ridge 4. Magma
5. Oceanic crust Trench