Proterozoic oxygen rise linked to shifting balance between seafloor and terrestrial weathering.

ABSTRACT: A shift toward higher atmospheric oxygen concentration during the late Proterozoic has been inferred from multiple indirect proxies and is seen by many as a prerequisite for the emergence of complex animal life. However, the mechanisms controlling the level of oxygen throughout the Proterozoic and its eventual rise remain uncertain. Here we use a simple biogeochemical model to show that the balance between long-term carbon removal fluxes via terrestrial silicate weathering and ocean crust alteration plays a key role in determining atmospheric oxygen concentration. This balance may be shifted by changes in terrestrial weatherability or in the generation rate of oceanic crust. As a result, the terrestrial chemical weathering flux may be permanently altered--contrasting with the conventional

SUBMITTER: Mills B 

PROVIDER: S-EPMC4078816 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature