Synchronous Marine and Terrestrial Carbon Cycle Perturbation in the High Arctic During the PETM

Authors

Ying Cui, Montclair State UniversityFollow
Aaron F. Diefendorf, University of Cincinnati
Lee R. Kump, Pennsylvania State University
Shijun Jiang, Hohai University
Katherine H. Freeman, Pennsylvania State University

Document Type

Article

Publication Date

4-1-2021

Journal / Book Title

Paleoceanography and Paleoclimatology

Abstract

The Paleocene-Eocene Thermal Maximum (PETM; 56 Ma) is considered to be one of the best analogs for future climate change. The carbon isotope composition (δ¹³C) of n-alkanes derived from leaf waxes of terrestrial plants and marine algae can provide important insights into the carbon cycle perturbation during the PETM. Here, we present new organic geochemical data and compound-specific δ¹³C data from sediments recovered from an early Cenozoic basin-margin succession from Spitsbergen. These samples represent one of the most expanded PETM sites and provide new insights into the high Arctic response to the PETM. Our results reveal a synchronous ∼−6.5‰ carbon isotope excursion (CIE) in short-chain n-alkanes (nC19; marine algae/bacteria) with a ∼−5‰ CIE in long-chain n-alkanes (nC29 and nC31; plant waxes) during the peak of the PETM. Although δ¹³Cn-alkanes values were potentially affected via a modest thermal effect (1‰–2‰), the relative changes in the δ¹³Cn-alkanes remain robust. A simple carbon cycle modeling suggests peak carbon emission rate could be ∼3 times faster than previously suggested using δ¹³CTOC records. The CIE magnitude of both δ¹³C n-C19 and δ¹³Cn-C29 can be explained by the elevated influence of ¹³C-depleted respired CO2 in the water column and increased water availability on land, elevated pCO2 in the atmosphere, and changes in vegetation type during the PETM. The synchronous decline in δ¹³C of both leaf waxes and marine algae/bacteria argues against a significant contribution to the sedimentary organic carbon pool from the weathering delivery of fossil n-alkanes in the Arctic region.

Comments

© 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

DOI

10.1029/2020PA003942

Journal ISSN / Book ISBN

85104984761 (Scopus)

MSU Digital Commons Citation

Cui, Ying; Diefendorf, Aaron F.; Kump, Lee R.; Jiang, Shijun; and Freeman, Katherine H., "Synchronous Marine and Terrestrial Carbon Cycle Perturbation in the High Arctic During the PETM" (2021). Department of Earth and Environmental Studies Faculty Scholarship and Creative Works. 749.
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/749

Published Citation

Cui, Y., Diefendorf, A. F., Kump, L. R., Jiang, S., & Freeman, K. H. (2021). Synchronous marine and terrestrial carbon cycle perturbation in the high arctic during the PETM. Paleoceanography and Paleoclimatology, 36(4), e2020PA003942.