Which feature corresponds to a small sediment-covered inactive volcano or intrusion of molten rock less than 200 meters high, thought to be associated with seafloor spreading?

Which feature corresponds to a small sediment-covered inactive volcano or intrusion of molten rock less than 200 meters high, thought to be associated with seafloor spreading?

• A. Abyssal Plain
• B. Abyssal Hill
• C. Continental Margin
• D. Fracture Zone

Answer: (B)

The feature being described are small, sediment-covered elevations on the deep ocean floor formed in the context of seafloor spreading. These are abyssal hills: tiny volcanic mounds or intrusive bodies that rise only a few hundred meters above the surrounding abyssal plain and are typically buried under sediment. They occur as the ocean crust pulls apart at mid-ocean ridges and blocks tilt and fault, creating numerous small hills rather than broad flat plains. This fits the description of a small, low-height, inactive volcanic or intrusive feature linked to spreading. In contrast, the abyssal plain is the broad, flat, sediment-covered expanse of the deep ocean floor; continental margins are the edges where land meets the sea; and fracture zones are long linear transform faults that offset ridge segments, not individual small hills.

The feature being described are small, sediment-covered elevations on the deep ocean floor formed in the context of seafloor spreading. These are abyssal hills: tiny volcanic mounds or intrusive bodies that rise only a few hundred meters above the surrounding abyssal plain and are typically buried under sediment. They occur as the ocean crust pulls apart at mid-ocean ridges and blocks tilt and fault, creating numerous small hills rather than broad flat plains. This fits the description of a small, low-height, inactive volcanic or intrusive feature linked to spreading.

In contrast, the abyssal plain is the broad, flat, sediment-covered expanse of the deep ocean floor; continental margins are the edges where land meets the sea; and fracture zones are long linear transform faults that offset ridge segments, not individual small hills.