Which plate sinks under a continental plate because it's more dense?

Which plate sinks under a continental plate because it's more dense?

• A. Ocean
• B. Continental
• C. Lithosphere
• D. Asthenosphere

Answer: (A)

Density differences control what happens at convergent boundaries. Oceanic crust is more dense than continental crust, so when these plates collide the oceanic lithosphere sinks beneath the continental plate. This subduction drives features like deep ocean trenches and volcanic arcs above the sinking edge. The continental plate doesn’t sink in this interaction because it is less dense. The lithosphere refers to the rigid outer shell, which includes the oceanic portion that subducts, while the asthenosphere is the weaker layer beneath it—not the sinking plate itself.

Density differences control what happens at convergent boundaries. Oceanic crust is more dense than continental crust, so when these plates collide the oceanic lithosphere sinks beneath the continental plate. This subduction drives features like deep ocean trenches and volcanic arcs above the sinking edge. The continental plate doesn’t sink in this interaction because it is less dense. The lithosphere refers to the rigid outer shell, which includes the oceanic portion that subducts, while the asthenosphere is the weaker layer beneath it—not the sinking plate itself.