Acta Petrologica et Mineralogica

The environmental changes in the Ediacaran epigenetic system of the Earth are closely linked to the evolution of organisms. However, there is still ongoing debate surrounding their interaction. This study focuses on the carbonate sedimentary sequences of the Ediacaran Doushantuo Formation in the Jiulongwan section of the Three Gorges Region, South China. The rare earth elements information was extracted from the carbonate phase using dilute acetic acid distribution leaching. The obtained data was then utilized to construct the evolution curve of Ce anomalies, which underwent a process involving of reduction/manganization-strong oxidation-suboxidation-strong oxidation-weak oxidation/reduction. Two significant negative Ce anomalies were observed, indicating the occurrence of two significant oxygenation stages during the prolonged oxidation process of the Ediacaran Doushantuo shallow water. These two oxygenation events align with the periodic oxidation of deep water at 632 Ma and 580 Ma, respectively. Moreover, Ce negative anomalies were also found in contemporaneous sedimentary sequences in Australia, suggesting that global oxygenation events occurred in the Ediacaran Doushantuo ocean. The fossil record of the Doushantuo Formation in the Yangtze Plateform reveals that the duration of Doushantuo ocean oxidation corresponds to the production strata of major fossil groups. This finding supports the understanding that marine oxidation facilitated the origin and evolution of Ediacaran Doushantuo metazoans.

Jiulongwan section; Ce/Ce^*; Doushantuo Formaion; Ediacaran; the Yangtze Plateform