Boundary processes and neodymium cycling along the Pacific margin of West Antarctica
Boundary processes and neodymium cycling along the Pacific margin of West Antarctica
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南极洲西部太平洋边缘的边界过程和钕循环
DOI：
10.1016/j.gca.2022.04.012
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发表时间：
2022
影响因子：
5
通讯作者：
Wang R
中科院分区：
文献类型：
--
作者：
Wang R
钕同位素在现代海洋和古海洋学研究中已被用作水团来源的示踪剂，但钕的海洋循环尚未完全确定。最近的研究强调了海水-沉积物界面附近发生的过程在改变底层沃茨Nd同位素组成方面的重要性。两个主要的观测过程“边界交换”和“底栖通量”被认为在确定水体组成方面起着重要作用，然而，需要更多的研究来限制其化学机制以及这些过程在多大程度上确定深水沃茨的组成。南极大陆边缘是研究这些过程的重要场所，因为舌状源沃茨控制着南大洋并覆盖全球深海。这项研究首次测量和比较南极洲边缘沿着的海水、孔隙水和沉积物数据，以审查潜在边界过程的性质。我们发现，一个类似于边界交换的过程似乎是发生在孔隙水，修改孔隙水化学的Nd同位素比值转移到更多的放射性值，而不显着增加溶解Nd的浓度。我们推测，这种转变的结果，从部分溶解的放射性碎屑颗粒，如蒙皂石，角闪石和/或火山玻璃，而重新清除保持低钕浓度。我们推断存在的底栖通量的孔隙沃茨深沃茨通过检查孔隙沃茨的化学梯度，并表明它是低得多的南极边缘相比，其他研究。底栖通量似乎是略高沿着南极半岛比在别林斯高晋海由于部分降解的有机质和相关的溶解铁锰氢氧化物。两者合计，边界过程并没有显着改变南极边缘海水的Nd同位素组成，因为虽然孔隙水有一个改变的Nd同位素组成的Nd浓度低，这些孔隙水相比，其他设置。
Neodymium (Nd) isotopes have been utilized as a tracer of water mass source in the modern ocean and in palaeoceanographic studies, though the oceanic cycling of Nd is not yet fully constrained. Recent studies have highlighted the importance of processes that occur near the seawater – sediment interface in altering the Nd isotopic composition of bottom waters. The two major observed processes “boundary exchange” and “benthic flux” have been suggested as playing an important role in setting water mass compositions, however, more studies are needed to constrain their chemical mechanism and the extent to which these processes set the composition of deep waters. The Antarctic continental margin is an important place to study these processes because Antarctic-sourced waters dominate the Southern Ocean and ventilate the global deep ocean. This study is the first to measure and compare seawater, porewater and sediment data from along the margin of Antarctica to examine the nature of potential boundary processes. We show that a process similar to boundary exchange seems to be occurring within porewaters, modifying porewater chemistry by shifting its Nd isotopic ratios to more radiogenic values without significantly increasing the concentration of dissolved Nd. We hypothesize that this shift results from partial dissolution of radiogenic detrital particles, such as smectite, amphibole and/or volcanic glass, while re-scavenging maintains low Nd concentrations. We infer the existence of benthic flux of porewaters to deep waters by examining chemical gradients in porewaters and show that it is much lower on the Antarctic margin compared to other studies. Benthic flux appears to be slightly higher along the Antarctic Peninsula than in the Bellingshausen Sea due to partial degradation of organic matter and associated dissolution of Fe-Mn oxyhydroxides. Taken together, boundary processes do not significantly change the Nd isotopic composition of Antarctic margin seawater because while the porewaters have an altered Nd isotopic composition the Nd concentration of these porewaters is low compared to other settings.
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DOI：
10.1016/j.dsr.2019.103135
发表时间：
2019-12
期刊：
--
影响因子：
--
作者：
Shuzhuang Wu;G. Kuhn;B. Diekmann;L. Lembke‐Jene;R. Tiedemann;Xufeng Zheng;Sophie Ehrhardt;H. Arz;F. Lamy
通讯作者：
Shuzhuang Wu;G. Kuhn;B. Diekmann;L. Lembke‐Jene;R. Tiedemann;Xufeng Zheng;Sophie Ehrhardt;H. Arz;F. Lamy
从南大洋沉积物中有效提取过去海水中的 Pb 和 Nd 同位素特征
影响因子：
3.5
作者：
Huang Huang;M. Gutjahr;G. Kuhn;E. Hathorne;A. Eisenhauer
通讯作者：
A. Eisenhauer
南极半岛太平洋边缘沉积物漂移区海底流态十个月观测
影响因子：
1.6
作者：
A. Camerlenghi;A. Crise;C. Pudsey;E. Accerboni;R. Laterza;M. Rebesco
通讯作者：
M. Rebesco
TAG Plume：重新审视热液钕对海水的贡献
影响因子：
3.7
作者：
T. Stichel;K. Pahnke;B. Duggan;S. Goldstein;A. E. Hartman;Ronja Paffrath;H. Scher
通讯作者：
H. Scher
影响因子：
1.6
作者：
Fretzdorff, S;Smellie, JL
通讯作者：
Smellie, JL