Systemic Analyses of Radiocarbon Ages of Coexisting Planktonic Foraminifera

Authors

Jörg Lippold, Heidelberg University
Julia Gottschalk, Kiel University
Jean Lynch-Stieglitz, Georgia Institute of Technology
Matthew W. Schmidt, Old Dominion UniversityFollow
Sönke Szidat, University of Bern
Andre Bahr, Heidelberg University

ORCID

0000-0001-6362-7845 (Schmidt)

Document Type

Article

Publication Date

2023

DOI

10.1017/RDC.2023.69

Publication Title

Radiocarbon

Volume

65

Issue

4

Pages

876-898

Abstract

We compare radiocarbon (¹⁴C) ages of coexisting planktonic foraminifera species from sediment cores VM12-107 and KNR166-2-26JPC from the Equatorial Atlantic Ocean for three time periods (Holocene, Heinrich Stadial 1, last glacial maximum). We find a maximum inter-species difference of 1200 ¹⁴C yr. On average, the ¹⁴C ages deviate by ∼300 yr between Globigerinoides ruber and other species. In most cases, this exceeds the analytical uncertainty range of the measurements and thus renders the choice of species for generating age models as important as sample weight. While modern stratified water-column profiles imply an increase in ¹⁴C ages with water depth, we observe an expected parallel increase of ¹⁴C ages and δ¹⁸O only at VM12-107. The mismatch between ¹⁴C ages and δ¹⁸O at KNR166-2-26JPC likely results from the effects of bioturbation and the hydrographic setting. The largest difference in ¹⁴C ages between mixed-layer versus thermocline-calcifying planktonic foraminifera are observed during Heinrich Stadial 1 despite a decrease in upper-ocean stratification at that time. This difference is likely the result of inconsistent increases in ¹⁴C reservoir ages during times of reduced overturning circulation masking the potential of ¹⁴C ages of coexisting planktonic foraminifera to reflect the density stratification of the water column.

Rights

© The Authors, 2023.

This is an Open access article, distributed under the terms of the Creative Commons Attribution 4.0 International Licence, which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.

Original Publication Citation

Lippold, J., Gottschalk, J., Lynch-Stieglitz, J., Schmidt, M. W., Szidat, S., & Bahr, A. (2023). Systematic analyses of radiocarbon ages of coexisting planktonic foraminifera. Radiocarbon, 65(4), 876-898. https://doi.org/10.1017/RDC.2023.69

Repository Citation

Lippold, Jörg; Gottschalk, Julia; Lynch-Stieglitz, Jean; Schmidt, Matthew W.; Szidat, Sönke; and Bahr, Andre, "Systemic Analyses of Radiocarbon Ages of Coexisting Planktonic Foraminifera" (2023). OES Faculty Publications. 490.
https://digitalcommons.odu.edu/oeas_fac_pubs/490