Closing the geologic carbon cycle.

ABSTRACT: Estimates of sedimentary organic carbon burial fluxes based on inventory and isotope mass balance methods have been divergent. A new calculation of the isotope mass balance using a revised assessment of the inputs to the ocean-atmosphere system resolves the apparent discrepancy. Inputs include weathering of carbonate and old kerogen, geogenic methane oxidation, and volcanic and metamorphic degassing. Volcanic and metamorphic degassing comprise ≈23% of the total C input. Inputs from isotopically light OCpetro and CH_4-geo drive the mean δ¹³C of the input to =-8.0 ± 1.9‰, notably lower than the commonly assumed volcanic degassing value. The isotope mass balance model yields a modern burial flux =15.9 ± 6.6 Tmol y^-1. The impact of the mid-Miocene

SUBMITTER: Derry LA 

PROVIDER: S-EPMC11494303 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature