Deep-Sea Sedimentation

Taking Clay Samples

Much of the seafloor of the deep ocean is covered by sediment. Some of these sediments, such as hydrogenous sediment nodules, can only be found in this region because they form thousands of feet below the ocean's surface. Biogenous sediments from plankton and other life forms are found throughout the ocean, but they dominate the deep ocean because there are not many other types of sediment found in the deep waters. These sediments eventually form oozes that are either calcareous or siliceous.

Biogenous sediments are also found along the continental margin, but only in relatively small amounts in comparison with the terrigenous sediments that are dumped here in large amounts from the continents. Some of this terrigenous sediment makes its way to the deep ocean as a result of turbidity currents and other bulk emplacement forces powered by gravity. Once they reach the bottom of the deep ocean, however, gravity can no longer move these sediments and, over time, they turn into clay.