A ~60 Myr periodicity is common to marine-87Sr/86Sr, fossil biodiversity, and large-scale sedimentation: what does the periodicity reflect?

TL;DR

This study identifies a ~60 million-year cycle in marine geochemistry, biodiversity, and sedimentation, suggesting a common underlying Earth or solar system process influencing these phenomena.

Contribution

It reveals a significant periodicity in marine 87Sr/86Sr, biodiversity, and sedimentation, proposing a unified Earth or solar system process as the cause.

Findings

Marine 87Sr/86Sr shows a 59.3 Myr cycle.

Biodiversity exhibits a 62 Myr cycle, out of phase with Sr record.

Sedimentary carbonate packages cycle every 58 Myr.

Abstract

We find that the marine 87Sr/86Sr record shows a significant periodicity of 59.3 \pm 3 Myr. The 87Sr/86Sr record is 171{\deg} \pm 12{\deg}out of phase with a 62 (\pm 3) Myr periodicity previously reported in the record of marine-animal diversity. These periodicities are close to 58 (\pm 4) Myr cycles found for the number of gap-bounded sedimentary carbonate packages of North America We propose that these periodicities reflect the operation of a periodic "pulse of the Earth" in large-scale, Earth processes. These may be linked to mantle or plate-tectonic events, possibly uplift, which affects Earth's climate and oceans, and so the geochemistry, sedimentation, and biodiversity of the marine realm. Alternately, they may be linked to oscillation of the solar system normal to the plane of the galaxy.