Which is caused by the difference in density of oceanic and continental plates?
Subduction.
The difference in density between oceanic and continental plates is known to cause a geological phenomenon called subduction. Subduction occurs when one tectonic plate, typically an oceanic plate, is forced beneath another plate, usually a continental plate. This process is driven by the varying densities of the plates involved.
To understand why subduction occurs, we need to consider the composition and density of oceanic and continental plates. Oceanic plates are primarily made up of basaltic rocks, which are denser than the rocks found in continental plates. Continental plates consist mainly of granitic rocks, which are less dense.
When an oceanic plate collides with a continental plate at a convergent plate boundary, the denser oceanic plate sinks beneath the less dense continental plate. The downward movement of the oceanic plate is facilitated by its greater density.
This subduction process can lead to the formation of various geologic features, including volcanic arcs, deep ocean trenches, and mountain ranges. The melting of the subducted oceanic plate in the underlying mantle can also generate magma, which eventually rises to the surface, resulting in volcanic activity.
In summary, the difference in density between oceanic and continental plates causes subduction, where the denser oceanic plate sinks beneath the less dense continental plate at convergent plate boundaries.