Young seabed at the active spreading center of an ocean, boundary between diverging plates; often called a mid-ocean ridge, though less than 60% of the length exists at mid-ocean.

Young seabed at the active spreading center of an ocean, boundary between diverging plates; often called a mid-ocean ridge, though less than 60% of the length exists at mid-ocean.

• A. Passive Margin
• B. Seamount
• C. Oceanic Ridge
• D. Shelf Break

Answer: (C)

At divergent plate boundaries, magma rises and creates new oceanic crust, pushing the plates apart. This process builds an underwater mountain range known as an oceanic ridge, or mid-ocean ridge, where the seabed is youngest because new crust forms there. As you move away from the ridge, the crust gets progressively older, which is why the spreading center is associated with the freshest seabed. This feature is not a passive margin, which is a tectonically quiet edge of a continent; nor is it a seamount, which is an isolated underwater volcano; nor a shelf break, which marks the edge of the continental shelf.

At divergent plate boundaries, magma rises and creates new oceanic crust, pushing the plates apart. This process builds an underwater mountain range known as an oceanic ridge, or mid-ocean ridge, where the seabed is youngest because new crust forms there. As you move away from the ridge, the crust gets progressively older, which is why the spreading center is associated with the freshest seabed.

This feature is not a passive margin, which is a tectonically quiet edge of a continent; nor is it a seamount, which is an isolated underwater volcano; nor a shelf break, which marks the edge of the continental shelf.