Divergent Plate Boundary: Divergent Plate Boundary is a plate that is being pulled apart and the seafloor spreads. It forms at the mid-ocean Ridge. (Mid-Atlantic Ridge. When a divergent boundary occurs beneath oceanic lithosphere the rising convention current below lifts the lithosphere producing a Mid-Ocean Ridge. A type of stress is Tension.
As the plates separate along the boundary, the block between the faults cracks and drops down into soft, plastic interior. A divergent boundary crosses the land, the rift valleys which form are typically 30 to 50 kilometers wide.
Convergent Boundary: Convergent Boundary is a plate that slides underneath another plate. 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.
When continental and oceanic plates collide the thinner and more dense oceanic plate is overridden by the thicker and less dense continental plate. When a convergent boundary occurs between two oceanic plates one of those plates will subduct beneath the other. The Cascade Mountain Range is a line of volcanoes above the melting oceanic plate. The Andes Mountain Range of western South America is another example of a convergent boundary between an oceanic and continental plate. Here the Nazca Plate is subducting beneath the South American plate.
Transform Boundary: Transform Boundary is a plate that moves pass each other. Transform boundaries are places where plates slide sideways past each other. At transform boundaries lithosphere is neither created nor destroyed. Many transform boundaries are found on the sea floor, where they connect segments of diverging mid-ocean ridges. California's San Andreas fault is a transform boundary.