Deep-ocean basins - This includes parts of the oceans where deep water prevails. Deep ocean basins cover the greatest portion of the Earth's surface. Oceanic (mid-ocean) ridges - nearly 12,000 miles of mountain belts run through ocean basins and are associated with divergent plate boundaries (spreading centers).

What is a deep water basin?

Deep-ocean basins cover the greatest portion of the Earth's surface. Geographic features associated with deep-ocean basins include trenches, abyssal plains, ocean ridges and rises, and submarine mountainous regions.

What are deep ocean basins made of?

Ocean basins are formed geologically of oceanic (basalt) crust, in contrast to continental (granite) crust that forms the Earth's major land masses.