Significant contribution of subseafloor microparticles to the global manganese budget
Significant contribution of subseafloor microparticles to the global manganese budget
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DOI：
10.1038/s41467-019-08347-2
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发表时间：
2019-02
影响因子：
16.6
通讯作者：
G. Uramoto;Y. Morono;N. Tomioka;S. Wakaki;R. Nakada;Rota Wagai;K. Uesugi;A. Takeuchi;M. Hoshino;Yoshio Suzuki;F. Shiraishi;S. Mitsunobu;H. Suga;Y. Takeichi;Y. Takahashi;F. Inagaki
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作者：
G. Uramoto;Y. Morono;N. Tomioka;S. Wakaki;R. Nakada;Rota Wagai;K. Uesugi;A. Takeuchi;M. Hoshino;Yoshio Suzuki;F. Shiraishi;S. Mitsunobu;H. Suga;Y. Takeichi;Y. Takahashi;F. Inagaki
铁锰矿物广泛分布于海底下沉积物和大洋深海平原的海底。评估其输入、形成和保存对于了解全球海洋锰循环和相关微量元素具有重要意义。然而，埋藏在海底下沉积物中的铁锰矿物的范围仍不清楚。在这里，我们发现，丰富的（108- 109个粒子cm−3）微米尺度的铁锰矿物颗粒（Mn微粒）被发现在从海底到基底以上的~ 1亿年的沉积物的南太平洋环流（SPG）的含氧远洋粘土。三维微观结构，和主要和微量元素成分分析表明，这些锰微粒由结晶不良的铁锰氧化物沉淀从底层水。根据我们的研究结果，我们推断，1.5-8.8 × 1028锰微粒，占1.28-7.62 Tt的锰，是全球存在于含氧海底沉积物。这一估计数至少比海底结核和结壳的锰总量大两个数量级。因此，海底锰微粒对全球锰收支有重大贡献。
Ferromanganese minerals are widely distributed in subseafloor sediments and on the seafloor in oceanic abyssal plains. Assessing their input, formation and preservation is important for understanding the global marine manganese cycle and associated trace elements. However, the extent of ferromanganese minerals buried in subseafloor sediments remains unclear. Here we show that abundant (108–109particles cm−3) micrometer-scale ferromanganese mineral particles (Mn-microparticles) are found in the oxic pelagic clays of the South Pacific Gyre (SPG) from the seafloor to the ~100 million-year-old sediments above the basement. Three-dimensional micro-texture, and major and trace element compositional analyses revealed that these Mn-microparticles consist of poorly crystalline ferromanganese oxides precipitating from bottom water. Based on our findings, we extrapolate that 1.5–8.8 × 1028Mn-microparticles, accounting for 1.28–7.62 Tt of manganese, are globally present in oxic subseafloor sediments. This estimate is at least two orders of magnitude larger than the manganese budget for nodules and crusts on the seafloor. Subseafloor Mn-microparticles thus contribute significantly to the global manganese budget.