近日，美国犹他大学Chadlin M. Ostrander团队研究了早古生代和中古生代深海动态氧合。2025年9月5日出版的《科学-进展》杂志发表了这项最新研究成果。

早期古生代各种动物生命的辐射通常与通风良好的全球海洋有关。然而，古生代深海的氧化史仍然存在争议。

利用深海泥岩中的铊（Tl）同位素比值，研究组重建了约4.85 ~ 3.8亿年前的深海氧合历史。铊同位素可以通过其对海底锰氧化物埋藏的敏感性间接跟踪底水氧合。研究组将Tl同位素应用于一组全球泥岩，特别关注加拿大育空地区的路河组。他们的数据揭示了海水中Tl同位素比率的振荡模式，进而揭示了海洋动态通气历史。在约4.05亿至3.86亿年前确定了一个长期存在的深海氧合事件。这些短期动态叠加在整个早、中古生代的微弱的正海洋氧合趋势上。根据该数据，全球海洋底部水域的氧气持续积累发生在约3.8亿年前的某个时候。

附：英文原文

Title: Dynamic deep marine oxygenation during the Early and Middle Paleozoic

Author: Chadlin M. Ostrander, Jean Nikolas R. Clemente, Richard G. Stockey, Justin V. Strauss, Tiffani Fraser, Sune G. Nielsen, Erik A. Sperling

Issue&Volume: 2025-09-05

Abstract: The Early Paleozoic radiation of diverse animal life is commonly connected to a well-ventilated global ocean. Yet the oxygenation history of Paleozoic deep oceans remains debated. Using thallium (Tl) isotope ratios in deep-marine mudrocks, we reconstruct the history of deep marine oxygenation from ~485 to 380 million years ago. Thallium isotopes can track bottom water oxygenation indirectly through their sensitivity to seafloor Mn oxide burial. We apply Tl isotopes to a global set of mudrocks, placing a particular focus on the Road River Group of Yukon, Canada. Our data reveal an oscillatory pattern in seawater Tl isotope ratios and, in turn, a dynamic ocean ventilation history. A long-lived deep ocean oxygenation episode is identified between ~405 and 386 million years ago. These short-term dynamics are superimposed on a muted positive ocean oxygenation trend over the entire Early and Middle Paleozoic. Sustained O2 accumulation in global marine bottom waters occurred sometime after ~380 million years ago according to our dataset.

DOI: adw5878

Source: https://www.science.org/doi/10.1126/sciadv.adw5878