Stable Isotopic Constraints on Benthic Carbonate Dissolution

本项目将测定深海孔隙水中溶解无机碳（DIC）的浓度和碳同位素组成（d13C），以直接测量沉积物中有机碳氧化与CaCO3溶解的比例。这些数据将被用来验证一个假设，即底栖有机物氧化驱动了底水覆盖的沉积物中CaCO3的溶解，而底水相对于方解石来说是过饱和的。这些研究将在两个单独资助的邮轮上进行，重点是底栖动物的碳循环。这一合作将克服现有孔隙水d13C数据的局限性；同时，d13C的结果将通过提供底栖CaCO3溶解速率和垂直分布的独立估计，为这些研究做出有价值的贡献。

This project will determine the concentration and carbon isotopic composition (d13C) of dissolved inorganic carbon (DIC) in deep-sea pore water, in order to provide a direct measure of the ratio of organic carbon oxidation to CaCO3 dissolution in the sediments. These data will be used to test the hypothesis that benthic organic matter oxidation drives CaCO3 dissolution in sediments overlain by bottom water which is supersaturated with respect to calcite. These study will be carried out in two separately-funded cruises which are focused on the benthic carbon cycle. This collaborative effort will enable limitations in the existing pore water d13C data to be overcome; at the same time, the d13C results will make a valuable contribution to these studies, by providing independent estimates of the rate and vertical distribution of benthic CaCO3 dissolution.