Which of the following does NOT occur at a subduction zone?
A. The leading edges of both plates are bent downward.
B. Oceanic crust is pushed down into the mantle.
C. One oceanic plate moves into another oceanic plate.
D. One continental plate moves into an oceanic plate.
A. The leading edges of both plates are bent downward.
To determine the correct answer to this question, we need to understand what occurs at a subduction zone. A subduction zone is a tectonic plate boundary where two lithospheric plates come together, and one plate moves beneath the other and sinks into the mantle.
Let's analyze each option provided:
A. The leading edges of both plates are bent downward.
This statement is true. At a subduction zone, the leading edges of both plates involved are indeed bent downward.
B. Oceanic crust is pushed down into the mantle.
This statement is also true. In a subduction zone, oceanic crust (which is denser) is pushed down beneath the other plate and sinks into the mantle.
C. One oceanic plate moves into another oceanic plate.
This statement is true. Subduction zones often occur where two oceanic plates converge, and one plate moves beneath the other.
D. One continental plate moves into an oceanic plate.
This statement is NOT true. At a subduction zone, the denser oceanic plate typically moves beneath the less dense continental plate. It is not common for a continental plate to move into an oceanic plate at a subduction zone.
Therefore, the correct answer is option D.