Nutrient Cycles during the Permian-Triassic transition (NUC)

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Anthropogenic ocean warming is expected to result in increased ocean stratification and a decline in dissolved O2 in the ocean interior with implications for nutrient cycling, primary productivity, carbon cycling and marine habitats. The Permian–Triassic (P-T) time interval can be seen as an extreme case analogue to the modern climate change. It not only witnessed the most catastrophic mass extinction of the Phanerozoic, but was accompanied by 8 to 10° C low latitudinal warming and extensive global ocean anoxia. The project aims to reconstruct the effect of global warming on nutrient cycles and primary productivity in latest Permian to Early Triassic oceans and to document whether these changes may have had an impact on faunal extinction/recovery. Nitrogen, phosphorus and silicon cycles will be studied by combining geochemical proxy reconstruction with state-of the art Earth System modeling. We will test the hypotheses that (i) Early Triassic productivity was not limited by phosphate, (ii) ammonium was a main form of nutrient-N in Early Triassic oceans, and, (iii) higher ocean temperatures caused the Early Triassic chert gap. While the generated proxy records will represent the conditions in specific parts of the oceans, global biogeochemical modeling will provide a global view on nutrient distribution and availability with a relatively high spatial resolution. The proxy records as well as spatiotemporal nutrient reconstructions will be used by other Tersane 2.0 projects to test whether altered nutrient levels impacted on the extinction risk of organism, the body size of specific organisms or resulted in latitudinal extinction patterns during the P-T crisis.