Which type of material becomes molten rock at subduction zones?

light plates

heavy plates

continental crust

new oceanic crust

The correct answer is C.

Subduction zones are convergent (moving) boundaries between two of the earth's tectonic plates. One of the plates is the oceanic crust. The plates are pieces of crust that slowly move towards each other across the planet's surface. This happens over a period of million years.

When two tectonic plates meet, subduction areas develop. A continental crust converges with an oceanic crust. The oceanic crust is heavier than the continental so it bends and moves downward towards the upper mantle.

The edge of the continental crust gets soaked and begins to melt, moving deeper into the earth. This creates molten rock that accumulates in the magma chamber (large pool of liquid rock beneath the surface of the earth). The molten rock (magma) is under such great pressure that it can fracture the rock around it and move upward. If it reaches the surface, a volcanic eruption takes place.