Revisiting Elevated δ13C Values of Sediment on Modern Carbonate Platforms

Autor: Elizabeth J. Trower, Brianna M. Hibner, Tyler A. Lincoln, Jacqueline E. Dodd, Cedric J. Hagen, Marjorie D. Cantine, Maya L. Gomes
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Geophysical Research Letters, Vol 51, Iss 15, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 1944-8007
0094-8276
DOI: 10.1029/2023GL107703
Popis: Abstract The measured carbon isotopic compositions of carbonate sediments (δ13Ccarb) on modern platforms are commonly 13C‐enriched compared to predicted values for minerals forming in isotopic equilibrium with the dissolved inorganic carbon (DIC) of modern seawater. This offset undermines the assumption that δ13Ccarb values of analogous facies in the rock record are an accurate archive of information about Earth's global carbon cycle. We present a new data set of the diurnal variation in carbonate chemistry and seawater δ13CDIC values on a modern carbonate platform. These data demonstrate that δ13Ccarb values on modern platforms are broadly representative of seawater, but only after accounting for the recent decrease in the δ13C value of atmospheric CO2 and shallow seawater DIC due to anthropogenic carbon release, a phenomenon commonly referred to as the 13C Suess effect. These findings highlight an important, yet overlooked, aspect of some modern carbonate systems, which must inform their use as ancient analogs.
Databáze: Directory of Open Access Journals
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