Final answer:
Volcanoes form when two tectonic plates collide and one plate is forced beneath the other, creating a subduction zone. The friction and pressure caused by the collision and subduction leads to the melting of rock, which then rises to the surface as magma. When the magma erupts onto the Earth's surface, it forms a volcano.
Step-by-step explanation:
Volcanoes form when two tectonic plates collide. The Earth's crust is composed of several large pieces called tectonic plates. When these plates collide, one plate is forced beneath the other, creating a subduction zone. The friction and pressure caused by the collision and subduction leads to the melting of rock, which then rises to the surface as magma. When the magma erupts onto the Earth's surface, it forms a volcano.
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