What geological process occurs when two of the earth's crustal plates collide?

The process that occurs when two of the earth's crustal plates collide is known as subduction. Subduction happens when one tectonic plate is forced beneath another in a convergent boundary scenario. This process can lead to the formation of mountain ranges, earthquakes, and volcanic activity as the subducted plate melts and interacts with the mantle.

In the context of plate tectonics, when two plates collide, one plate may slide underneath the other, creating a subduction zone. This interaction is critical in shaping the Earth’s geology and can also lead to the recycling of materials back into the Earth's mantle. Understanding subduction is essential for comprehending how various geological features are formed, particularly in regions known for their seismic activity.