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Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor.These particles either have their origins in soil and rocks and have been transported from the land to the sea, mainly by rivers but also by dust carried by wind and by the flow of glaciers into the sea, or they are biogenic deposits from marine organisms or from ...
The two primary types of ooze are siliceous, which is composed primarily of silica (SiO 2), and calcareous or carbonate, which is mostly calcium carbonate (CaCO 3). [1] In an area in which biogenous is the dominant sediment type, the composition of microorganisms in that location determines to which category it is classified.
Kerogen is a complex mixture of organic chemical compounds that make up the most abundant fraction of organic matter in sedimentary rocks. [12] As kerogen is a mixture of organic materials, it is not defined by a single chemical formula. Its chemical composition varies substantially between and even within sedimentary formations.
Sedimentary organic matter includes the organic carbon component of sediments and sedimentary rocks. The organic matter is usually a component of sedimentary material even if it is present in low abundance (usually lower than 1%). Petroleum (or oil) and natural gas are particular examples of sedimentary organic matter.
The marine carbon cycle is a central to the global carbon cycle and contains both inorganic carbon (carbon not associated with a living thing, such as carbon dioxide) and organic carbon (carbon that is, or has been, incorporated into a living thing). Part of the marine carbon cycle transforms carbon between non-living and living matter.
The first step in the biological pump is the synthesis of both organic and inorganic carbon compounds by phytoplankton in the uppermost, sunlit layers of the ocean. [13] Organic compounds in the form of sugars, carbohydrates, lipids, and proteins are synthesized during the process of photosynthesis: CO 2 + H 2 O + light → CH 2 O + O 2
Sediments are commonly studied with a box corer or a sediment trap, and older sediments may be recovered by scientific drilling. Autonomous Underwater Vehicle (AUV) Advanced analytical equipment such as mass spectrometers and chromatographs are applied to detect trace elements, isotopes, and organic compounds.
Southern Ocean sediments are a major sink for biogenic silica (50-75% of the oceanic total of 4.5 × 10 14 g SiO 2 yr −1; DeMaster, 1981), but only a minor sink for organic carbon (<1% of the oceanic 2 × 10 14 g of organic C yr −1). These relatively high rates of biogenic silica accumulation in the Southern Ocean sediments (predominantly ...