Plate Tectonics

Topic: Compare and contrast the topographical features at divergent and convergent plate margins.

Divergent and convergent plate margins are two of the three major types of plate boundaries that are recognized by geologists in the study of plate tectonics, which describes the movement of plates, due to convection currents in the mantle, which constitute the Earth’s lithosphere and the resultant landform changes. The movement of plates has profoundly affected the geologic and biologic history of the planet and it is the interaction of plates at their boundaries which accounts for most of the Earth’s volcanic eruptions and earthquakes, as well as the formation and evolution of its mountain systems (Jordan, 2012, 40).

Topographical features formed at these margins have some similarities but differ greatly due to the varying type of movements displayed at each margin as well as the type of plates involved; oceanic or continental.

Divergent plate margins are characterized by the moving apart of two plates. These margins are also called spreading ridges or spreading zones because the newly formed plates move away from the ridge axis as further material up wells. Most divergent boundaries are located along the crests of ocean ridges and can be thought of as constructive plate margins because this is where new ocean floor is generated (Jordan, 2012, 40). Whereas new crust is formed at divergent plate margins older crust must be destroyed and recycled in order for the entire surface area of Earth to remain the same. Such plate destruction occurs at convergent plate margins, where two plates collide and the leading edge of one plate is subducted beneath the margin of the other plate and is eventually incorporated into the asthenosphere (Jordan, 2012, 44). There are three types of collision that occur at these margins: oceanic-oceanic, oceanic-continental and continental-continental. Convergent plate margins produce more varied features because of the three possible...