Which term is the deep-ocean floor made of basaltic crust?

Which term is the deep-ocean floor made of basaltic crust?

• A. Island Arc
• B. Seamount
• C. Hydrothermal Vent
• D. Ocean Basin

Answer: (D)

The deep-ocean floor is made of oceanic crust that is basaltic in composition. This basaltic crust forms at mid-ocean ridges as new magma rises and cools, creating the basaltic rock that makes up the bulk of the ocean floor. The term that best describes these large areas of the sea floor covered by this basaltic crust is the ocean basin. Other features—like island arcs (volcanic chains at subduction zones), seamounts (underwater mountains), and hydrothermal vents (hot vents along ridges)—are features or settings on the floor, not the crust type itself.

The deep-ocean floor is made of oceanic crust that is basaltic in composition. This basaltic crust forms at mid-ocean ridges as new magma rises and cools, creating the basaltic rock that makes up the bulk of the ocean floor. The term that best describes these large areas of the sea floor covered by this basaltic crust is the ocean basin. Other features—like island arcs (volcanic chains at subduction zones), seamounts (underwater mountains), and hydrothermal vents (hot vents along ridges)—are features or settings on the floor, not the crust type itself.