Abstract Phosphorus availability limits marine productivity and influences ocean oxygenation, yet the mechanisms driving phosphorus enrichment in Ediacaran oceans remain uncertain. Here we present petrographic and geochemical data from phosphorites of the Ediacaran Doushantuo Formation at the Longxi section, South China. Elevated uranium to thorium ratios, positive europium anomalies, and preserved volcanic glass indicate a substantial contribution from volcanic and hydrothermal activity in addition to continental sources. We propose a conceptual depositional model involving three stages: hydrothermal phosphorus delivery and precipitation under reducing conditions, dolomitization-associated apatite formation during early diagenesis, and microbially mediated phosphogenesis linked to progressive oxygenation. Our results suggest that episodic volcanic and hydrothermal phosphorus inputs enhanced marine productivity and contributed to increasing ocean oxygen levels, highlighting a dynamic coupling between palaeoenvironment and biogeochemical cycles during the Ediacaran.
Han et al. (Wed,) studied this question.