Did phosphorus derived from the weathering of large igneous provinces fertilize the Neoproterozoic ocean?

Abstract Primary productivity and organic carbon burial rates in the Precambrian were highly sensitive to fluxes of phosphorus (P) from the weathering of continental crust. Large igneous provinces (LIPs)—containing substantial P and highly susceptible to chemical weathering—occurred regularly during the breakup of the Rodinia supercontinent, and flood basalts probably covered 3.7–7.4 × 10 6 km 2 at a time when a low‐latitude continental configuration expedited weathering. Assuming chemical weathering liberated much of the P contained in the flood basalts, an estimated 1–4 × 10 17 mol of biologically available P entered the ocean from LIPs between 900 and 500 Ma. Especially, voluminous LIP magmatism began at ∼850 Ma and culminated with the Franklin Province at 720 Ma, after which an estimated bioavailable P flux from flood basalts of 1–5 × 10 9 mol/yr may have been sustained for millions of years, elevating primary production and organic carbon burial rates. P enrichment of LIP magmas prior to eruption could have contributed to efficient reactive P delivery to the ocean: liquid‐crystal fractionation beneath thick cratonic lithosphere and the incorporation of metasomatic P potentially enriched Neoproterozoic LIP magmas more than anytime previously. Thus, a unique convergence of tectonic conditions—supercontinent breakup, voluminous mafic volcanism containing abundant P, and a low‐latitude continental configuration—may have facilitated an unprecedented flux of bioavailable P to the ocean that was capable of triggering oxidation of the ocean‐atmosphere system and enabling accelerated biologic diversification.