Late Ordovician climate change and extinctions driven by elevated volcanic nutrient supply

The Late Ordovician (~459–444 million years ago) was characterized by global cooling, glaciation and severe mass extinction. These events may have been driven increased delivery of the nutrient phosphorus (P) to ocean associated increases in marine productivity, but it is not clear why this occurred two pulses identified geological record. We link both cooling phases—and extinction—to volcanic eruptions through deposition nutrient-rich ash weathering terrestrially emplaced lava. then reconstruct influence P on system coupling an estimate bioavailable phosphate supply (derived from a depletion model) biogeochemical model. Our model compares content sediments before after alteration determine factors, we find good agreement with observed carbon isotope reconstructed temperature shifts. Hence, massive volcanism can drive substantial million-year timescales due long-term deposits, offsetting transient warming greenhouse gas emission eruptions. Such longer-term potential for eutrophication be important other volcanism-driven events. Increased volcanism-related helps explain widespread eutrophication-driven extinctions, as shown incorporating records.