法国布列塔尼大学Stefan V. Lalonde团队实现了利用La-Ce年代学测定含氧光合作用演化。2025年5月28日，《自然》杂志发表了这一成果。

关于地球上何时进化出含氧光合作用，一直存在争议。来自古代沉积物的地球化学数据表明，在大约25亿至23亿年前（Ga）的大氧化事件（GOE）之前，局部或短暂的光合O₂产生，目前表明其起源于太古代，大约3 Ga或更早。然而，早期地球的沉积记录往往受到保存问题的困扰，对氧化时间的控制不力，使古代O₂存在的地球化学替代数据受到质疑。 

研究组报告了三个不同太古代碳酸盐台地的稀土元素数据，这些台地保存在加拿大西北部苏必利尔克拉通的绿岩带中，在2.87 Ga, 2.85 Ga和2.78 Ga时通过海洋光合细菌的活性来沉积。这三个都表明，在GOE之前，O₂的产生是以铈（Ce）的显著消耗形式出现的，反映了古代海水中铈的氧化去除，就像今天发生的那样。

利用¹³⁸La-¹³⁸Ce年代学，研究组表明La/Ce分馏和Ce氧化发生在沉积时，使这些成为最古老的直接定年的Ce异常。这些结果将含氧光合作用的起源置于中太古宙或更早，并为关于地球生物和地球化学演化的长期争论带来了重要的新视角。

附：英文原文

Title: Dating the evolution of oxygenic photosynthesis using La-Ce geochronology

Author: Patry, Laureline A., Bonnand, Pierre, Boyet, Maud, Afroz, Munira, Wilmeth, Dylan T., Ramsay, Brittany, Nonnotte, Philippe, Homann, Martin, Sansjofre, Pierre, Fralick, Philip W., Lalonde, Stefan V.

Issue&Volume: 2025-05-28

Abstract: There is ongoing debate as to when oxygenic photosynthesis evolved on Earth1,2. Geochemical data from ancient sediments indicate localized or ephemeral photosynthetic O2 production before the Great Oxidation Event (GOE) approximately 2.5–2.3 billion years ago (Ga), and currently suggest Archaean origins, approximately 3Ga or earlier3,4,5,6,7,8,9. However, sedimentary records of the early Earth often suffer from preservation issues, and poor control on the timing of oxidation leaves geochemical proxy data for the ancient presence of O2 open to critique10,11,12,13. Here, we report rare Earth element data from three different Archaean carbonate platforms preserved in greenstone belts of the northwest Superior Craton (Canada), which were deposited by the activity of marine photosynthetic bacteria 2.87Ga, 2.85Ga and 2.78Ga. All three indicate O2 production before the GOE in the form of significant depletions in cerium (Ce), reflecting oxidative Ce removal from ancient seawater, as occurs today14. Using 138La-138Ce geochronology, we show that La/Ce fractionation, and thus Ce oxidation, occurred at the time of deposition, making these the oldest directly dated Ce anomalies. These results place the origin of oxygenic photosynthesis in the Mesoarchaean or earlier and bring an important new perspective on a long-standing debate regarding Earth’s biological and geochemical evolution.

DOI: 10.1038/s41586-025-09009-8

Source: https://www.nature.com/articles/s41586-025-09009-8