The theory of plate tectonics states that the Earth's crust is divided into plates that move over the mantle. There are three types of boundaries where plates meet: divergent boundaries where plates pull apart and new crust is formed; convergent boundaries where plates push together resulting in subduction zones, volcanoes, or mountain building; and transform boundaries where plates slide past one another causing earthquakes. Convection currents in the mantle are believed to drive the motion of tectonic plates.

1. Theory of Plate
Tectonics

3. The crust (rocky and
rigid) is divided into
“plates” that move over the
mantle (that is plastic
like).

4. Boundary Fault Plate Creates
(o=ocean &
Direction c=continental)

5. Boundary Fault Plate Creates
(o=ocean &
Direction c=continental)
Divergent Normal Pull or Moving Seafloor Spreading
Apart (O vs. O)
Or Valley (C vs. C)

7. Boundary Fault Plate Creates
(o=ocean &
Direction c=continental)
Divergent Normal Pull or Moving Seafloor Spreading
Apart (O vs. O)
Or Valley (C vs. C)

8. Boundary Fault Plate Creates
Direction (o=ocean &
c=continental)
Divergent Normal Pull or Moving Seafloor Spreading
Apart (O vs. O)
Or Valley (C vs. C)
Convergent Reverse Move Together Subduction Zone/
Trench / Volcanoe
(C vs. O)
Mountain (C vs. C)

9. Oceanic-Continental Convergence

10. Boundary Fault Plate Creates
Direction (o=ocean &
c=continental)
Divergent Normal Pull or Moving Seafloor Spreading
Apart (O vs. O)
Or Valley (C vs. C)
Convergent Reverse Move Together Subduction Zone/
Trench / Volcanoe
(C vs. O)
Mountain (C vs. C)

11. Boundary Fault Plate Creates
Direction (o=ocean &
c=continental)
Divergent Normal Pull or Moving Seafloor Spreading
Apart (O vs. O)
Or Valley (C vs. C)
Convergent Reverse Move Together Subduction Zone/
Trench / Volcanoe
(C vs. O)
Mountain (C vs. C)
Transform Strike-Slip Slide Alongside Earthquake and
One Another Faultline

14.  Scientist believe convection currents
move the plates by the hot material in
the mantle rising and as it cools it
carries the plates along with it until it
sinks and starts the process all over
again.

18. Previously scientists knew
plates were moving, but new
methods use lasers and
satellites to measure precise
movements.