Chemical Cycling at the Ocean Margin: The Sedimentary Source

关于沉积物之间微量金属循环的工作正在进行中 和水在加州的大陆边缘。 通量 营养物质和微量金属是通过使用USC 自由飞行器底部着陆器，并通过计算孔隙中的梯度 毫米尺度的沉积物的沃茨。 一个令人惊讶的结果， 最初的工作是， 来自沉积物的金属似乎来自充分充氧的沃茨， 而不是来自最小含氧带深度范围内的沉积物。 此外，高通量与高氧气速率有关 消耗、碳氧化和碳酸钙溶解。 因此，新的工作正在解决金属之间的联系， 碳循环。 年沉积物通量的测量 蒙特利湾正在与正在进行的沉积物测量进行比较 捕获碳通量（由查韦斯），以确定是否在季节性 碳信号由金属的矿化速率反映。 还正在对来自以下物质的通量进行详细研究： 模拟孔隙水剖面，与海底的剖面进行比较 腔室，这往往会给出更高的通量值。 的差异 表明在绒毛层中的快速成岩反应， 沉积物表面，或由底栖动物灌溉;可能性是 正在调查

Work is in progress on the cycling of trace metals between sediment and water in the continental margin of California. Fluxes of nutrients and trace metals are being determined by using the USC free vehicle bottom lander and by calculation of gradients in pore waters of sediments on a millimeter scale. A surprising result of the initial work is that the highest rate of remineralization of metals from the sediment appears to be from well oxygenated waters, not from sediments in the depth range of the oxygen minimum zone. Moreover the high fluxes are linked with high rates of oxygen consumption, carbon oxidation, and calcium carbonate dissolution. consequently, new work is addressing the association between metal and carbon cycling. Measurements of fluxes out of the sediments in Monterey Bay are being compared to ongoing measurements of sediment trap carbon fluxes (by Chavez) to determine whether seasonality in the carbon signal is reflected by remineralization rates of metals. A detailed study is also being made of fluxes derived from modelling pore water profiles, compared to those from the benthic chambers, which tend to give higher flux values. The discrepancy suggests rapid diagenetic reactions in the fluff layer at the sediment surface, or irrigation by infauna; the possibilities are being investigated.