When oceanic or continental plates slip past each other in contrasting directions or shift in the same direction, but at distinct speeds, a transform fault boundary is established. No new crust is produced or subducted, and no volcanoes form, but earthquakes occur along the fault.
The transform fault boundaries link spreading centers and subduction zones, which are the other aspects that comprise the earth’s plates. Continental plates usually do not subduct underneath oceanic plates because of how thick and resilient they are.
Instead, continental plates typically bend, crack, and crumple, creating folds: thick creases and mountain ranges like the Andes, Swiss Alps, and the Himalayas. Rocks stuck within the collision zone change because of the intense heat and squeezing. Continental plates have greater density, sometimes reaching lower than the mantle.