Which boundary is defined by plates moving apart, forming new ocean crust?

Which boundary is defined by plates moving apart, forming new ocean crust?

• A. Crust
• B. Density
• C. Core
• D. Divergent Plate Boundary

Answer: (D)

When two tectonic plates move away from each other, magma rises to fill the gap and then solidifies, creating new oceanic crust. This repeating process at spreading centers, like mid-ocean ridges, defines a divergent plate boundary. The other terms describe things that aren’t boundaries—crust is a layer, density is a property, and the core is the planet’s center—so they don’t capture the idea of plates pulling apart and new crust forming.

When two tectonic plates move away from each other, magma rises to fill the gap and then solidifies, creating new oceanic crust. This repeating process at spreading centers, like mid-ocean ridges, defines a divergent plate boundary. The other terms describe things that aren’t boundaries—crust is a layer, density is a property, and the core is the planet’s center—so they don’t capture the idea of plates pulling apart and new crust forming.