MODELING THE CALCITE LYSOCLINE
MODELING THE CALCITE LYSOCLINE
复制标题
DOI：
10.1029/91jc01812
复制
发表时间：
1991-09-15
影响因子：
3.6
通讯作者：
ARCHER, D
中科院分区：
文献类型：
--
作者：
ARCHER, D
利用方解石与沉积物孔隙水接触溶解的数值模型，预测了深海方解石溶跃层的深度和形状。模型结果进行了比较，从13个地区在大西洋，太平洋和印度洋的溶跃层数据。模型溶跃层的形状是敏感的方解石溶解速率常数，方解石，有机碳，和耐火材料率，和缺氧与缺氧的有机碳降解的沉积物中的速率。该模型能够再现所观察到的溶跃层，在沉积物陷阱和方解石积累数据的约束下，使用方解石溶解速率常数为30-100%d-1，有机碳与方解石雨率的摩尔比为0.5-1.0，初始CaCO 3分数为90%（不包括有机碳）。该速率常数与Archer等人[1989]给出的微电极结果一致。该模型预测，30-50%的方解石雨到海底的饱和层溶解响应有机碳呼吸，与以前的建模研究一致。有机-无机碳雨率的最佳拟合值的范围来自模型对沉积物中缺氧碳降解率和耐火材料雨率的不确定性的敏感性，而不是来自数据的分散。从赤道大西洋西部的溶跃层数据是异常的，其余的数据，这种异常可能是由高利率的耐火材料沉积从亚马逊河。
A numerical model of calcite dissolution in contact with sediment pore water is used to predict the depth and shape of the calcite lysocline in the deep sea. Model results are compared with lysocline data from 13 regions in the Atlantic, Pacific, and Indian Oceans. The model lysocline shape is sensitive to the calcite dissolution rate constant, the calcite, organic carbon, and refractory material rates, and the rates of oxic versus anoxic organic carbon degradation in the sediment. The model is able to reproduce the observed lysocline, Within the constraints of the sediment trap and calcite accumulation data, using a calcite dissolution rate constant of 30-100%d-1, a molar ratio of organic carbon to calcite rain rates of 0.5-1.0, and an initial CaCO3 fraction of 90% (excluding organic carbon). This rate constant is consistent with microelectrode results presented by Archer et al. [1989]. The model predicts that 30-50% of the calcite rain to the sea floor at the saturation horizon dissolves in response to organic carbon respiration, consistent with previous modeling studies. The range in the best fit value of the organic-inorganic carbon rain rates arises from model sensitivity to uncertainty in the rate of anoxic carbon degradation in the sediment and in the rain rate of refractory material, rather than from scatter in the data. Lysocline data from the western equatorial Atlantic are anomalous to the rest of the data; this anomaly may be explained by high rates of refractory material sedimentation from the Amazon River.