A tectonically driven 60 million-year biogeochemical redox cycle paces marine biodiversity

The fossil record shows a prominent 60 million-year biodiversity cycle during the Phanerozoic Eon, the origin of which is still unknown. Here we use time-series analysis and correlation of empirical and model datasets of Earth’s interior and surficial processes to demonstrate that this cycle is a pervasive feature in marine animal genus-level diversity data that dominates in the Paleozoic Era. Our results suggest that extinctions are likely the primary driver of this observed cyclicity. We detected a correlatable 60 million-year cyclicity in global tectonics, and in marine 87Sr/86Sr and δ34S isotopes, all of which are dominant in the Paleozoic. We conclude that continental weathering driven by global tectonic degassing and building of continental arcs may have in turn controlled paleo-seawater redox cycling during the Paleozoic when oceans were likely less saturated with respect to oxygen. In particular, we suggest that the 60 million-year fluctuations in biotic diversity are responses of shallow marine habitats to the combined effects of continental weathering and redox cycling, under global tectonic control. A 60 million-year cyclic fluctuation in biotic extinction and diversity in the Phanerozoic suggests a response to biogeochemical redox cycling in shallow marine habitats paced by global tectonic processes, according to time-series analysis and correlation of empirical and model datasets of Earth’s interior and surficial processes.