What occurs when one tectonic plate is descending beneath another plate?

When one tectonic plate is descending beneath another plate, it is known as a subduction zone. This process occurs when an oceanic plate, which is generally denser, sinks beneath a lighter continental plate or another oceanic plate. The descending plate is forced into the mantle, where it begins to melt and can lead to significant geological activity.

Subduction zones are often associated with the formation of deep ocean trenches, volcanic activity, and seismic events, such as earthquakes. The intense pressure and friction generated as the plates interact contribute to powerful tectonic movements, which can lead to the development of mountain ranges or volcanic arcs along the edges of the tectonic plates.

In contrast, other options do not accurately describe this process. A sliding plate would refer to a lateral movement between plates, which is characteristic of transform boundaries, while a rift signifies the pulling apart of tectonic plates, typically leading to the formation of new oceanic crust. Finally, a collision plate implies both plates are pushing against each other horizontally without the descending action that defines subduction zones.