Episodic intensification of marine phosphorus burial over the last 80 million years

Abstract Marine phosphatization events cause episodic carbonate fluorapatite (CFA) precipitation on seamounts, and are commonly linked to growth hiatuses in ferromanganese (Fe-Mn) crusts. However, the full record of these events and their paleoenvironmental implications remain poorly understood, in large part due to poor age constraints. Here, we apply U-Pb dating to CFA in Fe-Mn crusts from the Western Pacific seamounts, representing the Earth’s oldest oceanic crust. These data reveal six distinct phosphatization events, which are aligned with Sr isotope records in CFA and phosphorite from both the Western Pacific and the Atlantic. This newly established CFA chronology tightens the timespan of phosphatization events and refines the age framework of Fe-Mn crusts. We subsequently utilize a multiproxy approach to demonstrate that the phosphatization events occurred coeval with the expansion of oceanic oxygen minimum zones. The Western Pacific Fe-Mn crusts thus document major perturbations in global oceanic phosphorus cycling, which appear to have been driven by climate-induced increases in primary productivity.