Atmospheric oxygen levels control the oxidative side of key biogeochemical cycles and place limits on the development of high‐energy metabolisms. Understanding Earth's oxygenation is thus critical to developing a clearer picture of Earth's long‐term evolution. However, there is currently vigorous debate about even basic aspects of the timing and pattern of the rise of oxygen. Chemical weathering in the terrestrial environment occurs in contact with the atmosphere, making paleosols potentially ideal archives to track the history of atmospheric O₂ levels. Here we present stable chromium isotope data from multiple paleosols that offer snapshots of Earth surface conditions over the last three billion years. The results indicate a secular shift in the oxidative capacity of Earth's surface in the Neoproterozoic and suggest low atmospheric oxygen levels (<1% PAL pO₂) through the majority of Earth's history. The paleosol record also shows that localized Cr oxidation may have begun as early as the Archean, but efficient, modern‐like transport of hexavalent Cr under an O₂‐rich atmosphere did not become common until the Neoproterozoic.

中文翻译：

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Cr氧化还原循环演化的古土壤记录，以及新元古代期间大气中氧气增加的证据。

大气中的氧气水平控制着关键生物地球化学循环的氧化侧，并限制了高能代谢的发展。因此，了解地球的含氧量对于更清晰地了解地球的长期演变至关重要。然而，目前对于氧上升的时间和方式的甚至基本方面都存在激烈的争论。地球环境中的化学风化与大气接触，使古土壤成为追踪大气O ₂历史的潜在理想档案水平。在这里，我们提供了来自多种古土壤的稳定铬同位素数据，这些数据提供了过去30亿年地球表面状况的快照。结果表明，在新元古代，地球表面的氧化能力发生了长期变化，并表明在整个地球历史上，大气中的氧气含量都很低（<1％PAL p O ₂）。古土壤记录还表明，早在太古宙时代，局部铬的氧化就可能开始，但是直到新元古代，在富含O _2的气氛下有效，现代的六价铬运输才开始普遍。