Describe the abyssal plain.

An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 metres (9,800 ft) and 6,000 metres (20,000 ft). The creation of the abyssal plain is the result of the spreading of the seafloor (plate tectonics) and the melting of the lower oceanic crust.

Abyssal plains are deep, extremely flat features of the ocean floor. They are formed as sediments from coastal regions are transported far out to sea and settle to the ocean floor, and as materials from the water column above settle to the bottom.