Elevated Phosphorus Concentrations in Shallow Oceans as a Trigger for the 1.57‐Ga Oxygenation Event

作者：Baozeng Xie, Zihu Zhang, Chao Li, Matthew S. Dodd, Xiaoying Shi, Qing Shi, Chao Li, Longfei Sun, Lei Xu, Xinqiang Wang, Dongjie Tang · 发表于：Geophysical Research Letters · 年份：2024 · DOI：10.1029/2024gl111586 · 被引用次数：9 · 研究领域：Paleontology and Stratigraphy of Fossils、Geochemistry and Elemental Analysis、Geology and Paleoclimatology Research

Abstract Enhanced continental phosphorus (P) input into the oceans has been proposed as a potential trigger for the 1.57 Ga oxygenation event; however, uncertainty remains due to the absence of direct evidence for seawater P concentrations. Here, we investigate shallow marine carbonate rocks of the Gaoyuzhuang Formation in the North China Platform, using the carbonate‐associated phosphate (CAP) proxy to directly reconstruct seawater P levels at that time. Two significant CAP/(Ca + Mg) increases correspond with rises in I/(Ca + Mg) during the oxygenation event suggesting that elevated seawater P concentrations were important in triggering the oxygenation event. Furthermore, a concurrent positive shift in ε Nd (t) values from −12.3 to −0.9 suggests that a transition in weathering source rocks from intermediate to mafic lithologies significantly contributed to the elevated P fluxes to the oceans during the oxygenation event. This study provides new insights into assessing seawater P levels and their role in the mid‐Proterozoic oxygenation events.