Knowra Pelagic sediment Pelagic sediment Pelagic sediment is fine-grained material that settles and accumulates on the deep ocean floor, far from land. It consists chiefly of microscopic biological remains and slowly falling particles.
Calcareous ooze : Deep-sea sediment containing abundant microscopic calcium carbonate shells and skeletal fragments. Shells of planktonic organisms supply carbonate where seawater preserves them.
Sedimentation : The process by which particles settle from suspension and accumulate as sediment. Pelagic deposits form through the slow, continuous settling of particles through seawater.
Ocean drilling : The recovery of cores and samples from beneath the ocean floor using drilling systems. Drilled pelagic sediment cores provide long sequences of past ocean conditions.
Biological pump : The transport of carbon from surface waters to the deep ocean by sinking organic matter. Pelagic deposits receive part of the carbon exported downward by marine life.
Siliceous ooze : Deep-sea sediment rich in the silica shells of organisms such as diatoms and radiolarians. Siliceous plankton remains dominate where carbonate dissolves or biological silica production is high.
Carbonate compensation depth : The ocean depth below which calcium carbonate dissolves faster than it accumulates. It helps explain why calcareous ooze gives way to carbonate-poor sediment at depth.
Paleoclimatology : The study of past climates using evidence preserved in natural archives. Pelagic layers preserve signals of ancient temperature, ice volume, and productivity.
Carbon sequestration : The capture and long-term storage of carbon in reservoirs such as oceans, soils, and rocks. Burial of organic matter in marine sediment can remove carbon from active circulation.
Red clay : Fine, reddish deep-sea sediment dominated by windblown dust, volcanic material, and slowly accumulating particles. It represents pelagic deposits with little biogenic material and extremely slow accumulation.
Silica cycle : The movement of dissolved and particulate silica through Earth’s oceans, organisms, and sediments. Silica recycling controls the supply and preservation of siliceous skeletal material.
Show all 23