PLATE TECTONICS

Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium).

3 TYPES OF PLATE BOUNDARIES

CONVERGENT PLATE BOUNDARY

In plate tectonics, a convergent boundary, also known as a destructive plate boundary (because of subduction), is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.

DIVERGENT PLATE BOUNDARY

In plate tectonics, a divergent boundary or divergentplate boundary (also known as a constructive boundaryor an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other.

TRANSFORM PLATE BOUNDARY

A transform fault or transform boundary (also known as a conservative plate boundary, since these faults neither create nor destroy lithosphere), is a type of fault whose relative motion is predominantly horizontal, in either a sinistral (left lateral) or dextral (right lateral) direction.