the abyssal plain is the broad, flat part of the deep-ocean basin, and supports much life. depth about 4,000 meters deep.
it is in the ocean Ah, the more SPECIFIC answer!. The Abyssal plain is the Flat SEAFLOOR!
It is mountan area
an abyssal plain is a flat or very gently sloped area of the ocean floor
That are form due to the crust melting.