Oxygenation and Alkalinity Drive the Lacustrine Nitrogen Isotope Record Throughout the Past 3.2 Billion Years.

ABSTRACT: The widespread, stepwise oxygenation of Earth's atmosphere in the Precambrian led to a transformation of the global carbon (C) and nitrogen (N) cycles. While the temporal evolution of these nutrient cycles has been studied extensively in marine environments, lacustrine environments are understudied. This study first examines how water column oxygen conditions impact sedimentary carbon (δ¹³C_org) and nitrogen (δ¹⁵N) isotope signals in modern lakes. Subsequently, we use these patterns to interpret past changes in the geological record of lacustrine δ¹⁵N during atmospheric oxygenation. The compiled modern lake sediment dataset reveals average (± standard deviation) δ¹⁵N values of +2.9‰ ± 3.2‰ and δ¹³C_org values of -25

SUBMITTER: Velazquez D 

PROVIDER: S-EPMC12444620 | biostudies-literature | 2025 Sep-Oct

REPOSITORIES: biostudies-literature