近日，bet36体育在线:地质大学（武汉）陈中强团队研究了埃迪卡拉纪中期的周期性海洋氧合事件。该研究于2026年1月6日发表在《自然—地球科学》杂志上。

埃迪卡拉纪加斯基尔冰期（5.7978亿至5.7944亿年前）是新元古代的最后一次重大气候事件，但同时期的海洋氧化还原条件尚不清楚。

研究组对澳大利亚西北部伊根组冰期至冰消期序列（相当于加斯基尔冰期序列）中的海洋碳酸盐样品进行了碳-铀-硫同位素（δ13Ccarb–δ238Ucarb–δ34SCAS）和元素分析。负的δ13Ccarb和正的δ238Ucarb偏移，结合δ34SCAS和铈异常剖面，揭示了一次广泛的海洋氧化事件。加斯基尔海洋氧化事件是埃迪卡拉纪中期三次此类短暂事件中的一次，这些事件大约相隔500万年。

研究组使用一个磷、氧和碳耦合生物地球化学循环模型，证明这些周期性的海洋氧化事件、相关的δ238Ucarb变化以及部分δ13Ccarb变化可以用地球系统中的自持振荡来解释。有机碳埋藏通量的增加可能与当时真核生物的进化有关，这可能使地球系统从稳定的缺氧海洋状态转变为不稳定的振荡状态。随后有机碳埋藏通量的进一步增加可能使系统转变为稳定的、类似现代的氧化海洋状态。

附：英文原文

Title: Periodic ocean oxygenation events during the mid-Ediacaran

Author: Li, Zi-Heng, Chen, Zhong-Qiang, Daines, Stuart J., Zhang, Feifei, Lenton, Timothy M.

Issue&Volume: 2026-01-06

Abstract: The Ediacaran Gaskiers Glaciation (579.78–579.44 million years ago) is the last major climatic event of the Neoproterozoic, but the contemporaneous ocean redox conditions remain unclear. Here we conducted carbon–uranium–sulfur isotopic (δ13Ccarb–δ238Ucarb–δ34SCAS) and elemental analyses on marine carbonate samples from the glacial-to-deglacial succession (equivalent to the Gaskiers Glaciation successions) of the Egan Formation in northwestern Australia. Negative δ13Ccarb and positive δ238Ucarb excursions paired with δ34SCAS and cerium anomaly profiles reveal an extensive ocean oxygenation event. The Gaskiers ocean oxygenation event is the middle of three such transient mid-Ediacaran events, occurring roughly 5 million years apart. Using a model for the coupled biogeochemical cycles of phosphorus, oxygen and carbon, we show that these periodic ocean oxygenation events, associated δ238Ucarb variations and part of the δ13Ccarb variation can be explained by a self-sustaining oscillation in the Earth system. An increase in the organic carbon burial flux plausibly linked to eukaryote evolution at the time could have tipped the Earth system from a stable anoxic ocean regime to an unstable oscillatory regime. A later further increase in organic carbon burial flux could have tipped the system into a stable, modern-like oxic ocean regime.

DOI: 10.1038/s41561-025-01883-1

Source: https://www.nature.com/articles/s41561-025-01883-1