Image:Placas tect2 pt BR.svg

The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which float on the fluid-like (visco-elastic solid) asthenosphere. The relative fluidity of the asthenosphere allows the tectonic plates to undergo motion in different directions. Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates.

Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates.

   * 1 Synopsis on development
   * 2 Key principles
   * 3 Types of plate boundaries
         o 3.1 Transform (conservative) boundaries
         o 3.2 Divergent (constructive) boundaries
         o 3.3 Convergent (destructive) boundaries
   * 4 Driving forces of plate motion
         o 4.1 Friction
         o 4.2 Gravitation
         o 4.3 External forces
         o 4.4 Relative significance of each mechanism
   * 5 Major plates
         o 5.1 Continental drift
         o 5.2 Floating continents
         o 5.3 Plate tectonic theory
               + 5.3.1 Explanation of magnetic striping
               + 5.3.2 Subduction discovered
               + 5.3.3 Mapping with earthquakes
         o 5.4 Geological paradigm shift
   * 6 Biogeographic implications on fauna and flora
   * 7 Plate tectonics on other planets
   * 8 Metaphoric uses
   * 9 See also
   * 10 References
   * 11 External links

see below