Isotopic signature of dissolved iron delivered to the Southern Ocean from hydrothermal vents in the East Scotia Sea
Isotopic signature of dissolved iron delivered to the Southern Ocean from hydrothermal vents in the East Scotia Sea
复制标题
从东斯科舍海热液喷口输送到南大洋的溶解铁的同位素特征
作者：
J. Klar;R. James;D. Gibbs;A.J.M. Lough;I. Parkinson;J. Milton;Jeffrey A. Hawkes;D. Connelly
最近的研究表明，热液喷口是南大洋溶解铁（dFe）的重要来源。同位素组成（？56 Fe）的dFe在喷口流体似乎是不同的其他来源的dFe到深海，但演变？56 Fe在喷口流体和海水之间的混合过程中受到很差的约束。在这里，我们提出的演变？东斯科舍海两个地点热液流体和分散羽流中dFe的~（56）Fe。我们展示了吗？56 Fe值在浮力羽明显较低（低至？1.19‰）高于热液流体（？0.29这归因于（i）在混合的早期阶段Fe-硫化物的沉淀，和（ii）Fe（II）部分氧化成Fe（III），其中> 55%随后作为Fe-羟基氧化物沉淀。相比之下，？56 Fe签名的稳定dFe在中性浮力羽？0.3去哪0.5‰。这不能解释为继续稀释的浮力羽与背景海水，而是，我们建议，dFe的同位素分馏羽稀释过程中发生由于Fe配体络合和交换与不稳定的颗粒Fe。什么？东斯科舍海稳定热液dFe的~（56）Fe特征与背景海水明显不同，可用于量化热液dFe向海洋内部的输入。
It has recently been demonstrated that hydrothermal vents are an important source of dissolved Fe (dFe) to the Southern Ocean. The isotopic composition (?56Fe) of dFe in vent fluids appears to be distinct from other sources of dFe to the deep ocean, but the evolution of ?56Fe during mixing between vent fluids and seawater is poorly constrained. Here we present the evolution of ?56Fe for dFe in hydrothermal fluids and dispersing plumes from two sites in the East Scotia Sea. We show that ?56Fe values in the buoyant plume are distinctly lower (as low as ?1.19 ‰) than the hydrothermal fluids (?0.29 ‰), attributed to (i) precipitation of Fe-sulfides in the early stages of mixing, and (ii) partial oxidation of Fe(II) to Fe(III), > 55 % of which subsequently precipitates as Fe-oxyhydroxides. By contrast, the ?56Fe signature of stabilized dFe in the neutrally buoyant plume is ?0.3 to ?0.5 ‰. This cannot be explained by continued dilution of the buoyant plume with background seawater; rather, we suggest that isotope fractionation of dFe occurs during plume dilution due to Fe ligand complexation and exchange with labile particulate Fe. The ?56Fe signature of stabilized hydrothermal dFe in the East Scotia Sea is distinct from background seawater and may be used to quantify the hydrothermal dFe input to the ocean interior.
影响因子：
5
作者：
Cole, Catherine S.;James, Rachael H.;Hathorne, Ed C.
通讯作者：
Hathorne, Ed C.