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The carbonate compensation depth (CCD) is the depth, in the oceans, at which the rate of supply of calcium carbonates matches the rate of solvation. That is, solvation 'compensates' supply. Below the CCD solvation is faster, so that carbonate particles dissolve and the carbonate shells of animals are not preserved. Carbonate particles cannot ...
The lysocline is the depth in the ocean dependent upon the carbonate compensation depth (CCD), usually around 5 km, below which the rate of dissolution of calcite increases dramatically because of a pressure effect. While the lysocline is the upper bound of this transition zone of calcite saturation, the CCD is the lower bound of this zone.
Calcium carbonate saturation can be determined using the following equation: Ω = ([Ca 2+][CO 3 2−])/K sp. where the numerator ([Ca 2+][CO 3 2−]) denotes the concentration of calcium and carbonate ions and the denominator (K sp) refers to the mineral (solid) phase stoichiometric solubility product of calcium carbonate. [8]
Biogenic calcium carbonate is formed when marine organisms, such as coccolithophores, corals, pteropods, and other mollusks transform calcium ions and bicarbonate into shells and exoskeletons of calcite or aragonite, both forms of calcium carbonate. [57] This is the dominant sink for dissolved calcium in the ocean. [114]
Shell growth in estuaries is an aspect of marine biology that has attracted a number of scientific research studies. Many groups of marine organisms produce calcified exoskeletons, commonly known as shells, hard calcium carbonate structures which the organisms rely on for various specialized structural and defensive purposes.
Calcite, or calcium carbonate, chemical formula CaCO 3, is formed from water, H 2 O, and carbon dioxide, CO 2, dissolved in the water. The carbon dioxide provides two of the oxygen atoms in the calcite. The calcium must rob the third from the water. The isotope ratio in the calcite is therefore the same, after compensation, as the ratio in the ...
An aragonite sea contains aragonite and high-magnesium calcite as the primary inorganic calcium carbonate precipitates. The reason lies in the highly hydrated Mg 2+ divalent ion , the second most abundant cation in seawater after Na + , known to be a strong inhibitor of CaCO 3 crystallization at the nucleation stage.
The carbonate pump is sometimes referred to as the "hard tissue" component of the biological pump. [19] Some surface marine organisms, like coccolithophores, produce hard structures out of calcium carbonate, a form of particulate inorganic carbon, by fixing bicarbonate. [20] This fixation of DIC is an important part of the oceanic carbon cycle.