CALCIUM-CARBONATE PRESERVATION IN THE OCEAN
CALCIUM-CARBONATE PRESERVATION IN THE OCEAN
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DOI：
10.1098/rsta.1990.0054
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发表时间：
1990-06-19
期刊：
影响因子：
5
通讯作者：
ARCHER, D
中科院分区：
文献类型：
--
作者：
EMERSON, SR;ARCHER, D
最近在沉积物-水界面上的微电极pH和o2测量表明，caco3溶解动力学比实验室值慢得多，并且支持沉积物表面附近有机物降解的溶解响应。受这些结果的启发，我们报告了一项建模练习，该模型表明，使用比实验室测量值小10到100倍的溶解速率常数，最容易再现赤道大西洋和印度洋中碳酸钙保存的模式。该模型表明，随着沉积物中有机物的降解，40%或更多的颗粒caco3雨在方解石饱和层溶解，并且这种效应对测量范围内溶解速率常数的选择不敏感。这意味着沉积物的溶解通量比以前认为的要大，深海中碳酸钙的保存应该强烈依赖于颗粒有机碳与碳酸钙雨的比例。
Recent microelectrode pH and O2measurements across the sediment-water interface suggest CaCO3dissolution kinetics substantially slower than laboratory values and support a dissolution response to organic matter degradation near the sediment surface. We report a modelling exercise, motivated by these results, that indicates the pattern of calcium carbonate preservation in the equatorial Atlantic and Indian oceans is most readily reproduced using a dissolution rate constant 10 to 100 times smaller than those measured in the laboratory. The model suggests that 40% or more of the particulate CaCO3rain dissolves at the calcite saturation horizon in response to organic matter degradation within the sediments, and that this effect is insensitive to the choice of dissolution rate constant in ranges measured. Implications are that the dissolution flux from the sediments is greater than previously thought, and that calcium carbonate preservation in the deep sea should be strongly dependent on the particulate organic carbon to calcium carbonate rain ratio.