Sediment distribution

Clays & Silts

Small, light particles like clays and silts re suspended in water & carried by the currents until they settle out of the water. They are found in deep ocean, low energy environments. Mud is the most common sediment on the deep-ocean floor.

Sand

Larger particles such as sands are found closer to shore, on margins of continents. They are brought to margins by by rivers. Sand requires high energy to transport, more than the average wave has (that's why there's actually sand on the beach). Some sand makes it to deep ocean through submarine canyons.

Where are sediments the thickest?

Sediments are thinnest along spreading centers, as the crust there is new and hasn't had a long time for sediment to accumulate. Sediments are thickest in trenches — accumulations there may approach 10 kilometers, depending on how old the subducting crust is.

The ocean basins comprise about 78% of the ocean area, but only contain 13% of the sediments. Still, as the list below shows, sediment accumulations can still be fairly thick.

• Pacific Ocean—About 600 meters or less
• Atlantic Ocean—From 500 to 1000 meters thick

Rates Of Deposition

In the quite waters of deep ocean, clays and silts will accumulate at a rate of 0.5-1.0cm/1000 yrs. These rates are slow, yet 200 m.y. of sediment accumulation can create very thick layers.