Great Oxidation and Lomagundi events linked by deep cycling and enhanced degassing of carbon.

ABSTRACT: For approximately the first 2 billion years of Earth history, atmospheric oxygen levels were extremely low. It wasn't until at least half a billion years after the evolution of oxygenic photosynthesis, perhaps as early as 3 billion years ago, that oxygen rose to appreciable levels during the Great Oxidation event. Shortly after, marine carbonates experienced a large positive spike in carbon isotope ratios known as the Lomagundi event. The mechanisms responsible for the Great Oxidation and Lomagundi events remain debated. Using a carbon-oxygen box model which tracks surface and interior C fluxes and reservoirs while also tracking C isotopes and atmospheric oxygen levels we demonstrate that about 2.5 billion years ago a tectonic transition resulting in increased volcanic CO₂ emiss

SUBMITTER: Eguchi J 

PROVIDER: S-EPMC6894402 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature