Plate Tectonics

There are 3 types of plate boundaries;

1. Convergent Boundaries

   • Two plates collide to form mountains or a subduction zone.

2. Divergent Boundaries

   • Two plates are moving in opposite directions as in a mid-ocean ridge.

1. Transform Boundaries

   Two plates are sliding past each other as in the San Andreas fault of California. A transform boundary is like a tear in the Earth's crust. These plates move very slowly across the surface of the Earth as though they were on a conveyor belt. The convection currents in the much hotter mantle continually move the plates about 1/2 to 4 inches per year.

   

The Earth is producing "new" crust where two plates are diverging or spreading apart. This occurs in the middle of our great oceans. The mid-ocean ridges are the longest continually running mountain range in the world. These ridges are connected and are about 40,000 miles long!!