Late Paleozoic oxygenation of marine environments supported by dolomite U-Pb dating.

ABSTRACT: Understanding causal relationships between evolution and ocean oxygenation hinges on reliable reconstructions of marine oxygen levels, typically from redox-sensitive geochemical proxies. Here, we develop a proxy, using dolomite U-Pb geochronology, to reconstruct seawater U/Pb ratios. Dolomite samples consistently give U-Pb dates and initial ²⁰⁷Pb/²⁰⁶Pb ratios lower than expected from their stratigraphic ages. These observations are explained by resetting of the U-Pb system long after deposition; the magnitude of deviations from expected initial ²⁰⁷Pb/²⁰⁶Pb are a function of the redox-sensitive U/Pb ratios during deposition. Reconstructed initial U/Pb ratios increased notably in the late-Paleozoic, reflecting an increase in oxygenation of marine e

SUBMITTER: Ben-Israel M 

PROVIDER: S-EPMC10991507 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature