Atmospheric oxygen regulation at low Proterozoic levels by incomplete oxidative weathering of sedimentary organic carbon.

ABSTRACT: It is unclear why atmospheric oxygen remained trapped at low levels for more than 1.5 billion years following the Paleoproterozoic Great Oxidation Event. Here, we use models for erosion, weathering and biogeochemical cycling to show that this can be explained by the tectonic recycling of previously accumulated sedimentary organic carbon, combined with the oxygen sensitivity of oxidative weathering. Our results indicate a strong negative feedback regime when atmospheric oxygen concentration is of order pO₂∼0.1 PAL (present atmospheric level), but that stability is lost at pO₂<0.01 PAL. Within these limits, the carbonate carbon isotope (δ¹³C) record becomes insensitive to changes in organic carbon burial rate, due to counterbalancing changes in the weathering

SUBMITTER: Daines SJ 

PROVIDER: S-EPMC5296660 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature