Chang Liao, Hoogakker Babette A A, Heslop David, Zhao Xiang, Roberts Andrew P, De Deckker Patrick, Xue Pengfei, Pei Zhaowen, Zeng Fan, Huang Rong, Huang Baoqi, Wang Shishun, Berndt Thomas A, Leng Melanie, Stuut Jan-Berend W, Harrison Richard J
Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, 100871, Beijing, China.
Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, 266071, Qingdao, China.
Nat Commun. 2023 Aug 10;14(1):4841. doi: 10.1038/s41467-023-40452-1.
Reconstructions of ocean oxygenation are critical for understanding the role of respired carbon storage in regulating atmospheric CO. Independent sediment redox proxies are essential to assess such reconstructions. Here, we present a long magnetofossil record from the eastern Indian Ocean in which we observe coeval magnetic hardening and enrichment of larger, more elongated, and less oxidized magnetofossils during glacials compared to interglacials over the last ~900 ka. Our multi-proxy records of redox-sensitive magnetofossils, trace element concentrations, and benthic foraminiferal ΔδC consistently suggest a recurrence of lower O in the glacial Indian Ocean over the last 21 marine isotope stages, as has been reported for the Atlantic and Pacific across the last glaciation. Consistent multi-proxy documentation of this repeated oxygen decline strongly supports the hypothesis that increased Indian Ocean glacial carbon storage played a significant role in atmospheric CO cycling and climate change over recent glacial/interglacial timescales.
海洋氧合作用的重建对于理解呼吸碳储存在调节大气CO方面的作用至关重要。独立的沉积物氧化还原指标对于评估此类重建至关重要。在这里，我们展示了一份来自印度洋东部的长磁化石记录，在其中我们观察到，在过去约90万年的时间里，与间冰期相比，冰川期期间较大、更长且氧化程度更低的磁化石出现了同时期的磁性硬化和富集现象。我们对氧化还原敏感的磁化石、微量元素浓度和底栖有孔虫ΔδC的多指标记录一致表明，在过去21个海洋同位素阶段，冰川期印度洋的O含量较低的情况反复出现，正如过去冰川期大西洋和太平洋所报道的那样。对这种反复出现的氧气下降的一致多指标记录有力地支持了这样一种假设，即在最近的冰川/间冰期时间尺度上，印度洋冰川期碳储存增加在大气CO循环和气候变化中发挥了重要作用。
