Abyssal fan

[2][3][4] Abyssal (or submarine) fans are formed from turbidity currents.

A dense slurry of muds and sands speeds towards the foot of the slope, until the current slows.

The decreasing current, having a reduced ability to transport sediments, deposits the grains it carries, thus creating a submarine fan.

The slurry continues to slow as it is moved towards the continental rise until it reaches the ocean bed.

Thus results a series of graded sediments of sand, silt and mud, which are known as turbidites, as described by the Bouma sequence.