Final answer:
A subduction zone is a region where two tectonic plates collide and one plate is forced beneath the other, sinking into the mantle. This process occurs at convergent plate boundaries.
Step-by-step explanation:
A subduction zone is a region where two tectonic plates collide and one plate is forced beneath the other, sinking into the mantle. This process occurs at convergent plate boundaries. Subduction zones are marked by ocean trenches, such as the deep Japan trench along the coast of Asia.
The subducted plate is forced down into regions of high pressure and temperature, eventually melting several hundred kilometers below the surface. This melting material is recycled into a downward-flowing convection current, maintaining the balance between the material that rises along rift zones.
The amount of crust destroyed at subduction zones is approximately equal to the amount formed at rift zones.