Divergent Boundaries
Divergent boundaries occur where two tectonic plates move away from each other. As the plates separate, molten rock (magma) rises from the Earth's mantle to the surface, solidifying to create new crust. This process often forms mid-ocean ridges or rift valleys on land.
Convergent Boundaries
Convergent boundaries happen when two plates collide. The outcome depends on the types of plates involved. One plate may slide beneath the other in a process called subduction, leading to volcanoes. If two continental plates collide, they can crumple and form massive mountain ranges like the Himalayas.
Transform Boundaries
At a transform boundary, two plates slide horizontally past one another. No new crust is created, and no old crust is destroyed. This movement is not smooth; the plates often get stuck, building up stress that is released as an earthquake. The San Andreas Fault in California is a famous example.