The current understanding of plate tectonics is a concept and described as how the major

features of the Earth from and/or deform. The essential processes of plate tectonics are

seafloor spreading and subduction zones. These two processes operate on basic units called

plates. Key surface features such as mountain ranges form in particular tectonic settings when

these processes act on plates directly or indirectly. Plates exist as a consequence of the

specific conditions of temperature and pressure, and materials found on Earth. Plates move

around and change in size and number over geologic time."“German scientist Alfred Wegener

put forth the theory of continental drift. His theory was based on fossil evidence that showed

the existence of the same plants and animals on separate continents in differing climates.

Since they could not have crossed the ocean as living organisms, Wegener reasoned that

continents had once been joined. He theorized that over millions of years the continents had

drifted to their current locations.” (Greve, 2013, p. 9)

"Other contributors to the theory included Harry Hammond Hess, who conducted a series of

surveys of the ocean floors around the world and found a remarkable pattern that showed up a

series of trenches and ridges –"with the rocks becoming progressively older when you move

away from the ridges. From this, he developed his ideas of sea floor spreading that was

driven by underlying magma rising from the mantle and"pushing the crust outwards at ridges

where it would then be spread, and this offered a reasonable explanation for Wegener’s

findings."Subduction zones explain the ocean oor conveyor belt

mechanism, being the region in which the crust destroyed. Here

denser oceanic crust sinks beneath the light continental plate into

the upper mantle where the intense heat melts it down into an

andesitic magma. The collision produces a deep sea trench and

often a fold mountain range, and the angle at which the crust

subducts may change the characteristics of the area. For

example, the high volcanic activity to the south of Chile relative

to the north is thought to be a result of the oceanic crust

subducting at a steeper angle.“Currently, most scientists accept the theory of

plate tectonics as the explanation for the movement of plates on the earth’s surface. However,