Authors

Kassandra M. Costa, Woods Hole Oceanographic Institution
Christopher T. Hayes, University of Southern Mississippi
Robert F. Anderson, Lamont-Doherty Earth Observatory
Frank J. Pavia, Lamont-Doherty Earth Observatory
Alexandra Bausch, Lamont-Doherty Earth Observatory
Feifei Deng, University of Oxford
Jean Claude Dutay, Universite de Versailles Saint-Quentin-en-Yvelines
Walter Geibert, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
Christoph Heinze, Universitetet i Bergen
Gideon Henderson, University of Oxford
Claude Hillaire-Marcel, Université du Québec à Montréal
Sharon Hoffmann, The University of North Carolina Wilmington
Samuel L. Jaccard, University of Bern
Allison W. Jacobel, Brown University
Stephanie S. Kienast, Dalhousie University
Lauren Kipp, Lamont-Doherty Earth Observatory
Paul Lerner, Columbia University in the City of New York
Jörg Lippold, Universität Heidelberg
David Lund, University of Connecticut Avery Point Campus
Franco Marcantonio, Texas A&M University
David McGee, Massachusetts Institute of Technology
Jerry F. McManus, Lamont-Doherty Earth Observatory
Figen Mekik, Grand Valley State University
Jennifer L. Middleton, Lamont-Doherty Earth Observatory
Lise Missiaen, University of New South Wales (UNSW) Australia
Christelle Not, The University of Hong Kong
Sylvain Pichat, Laboratoire de Géologie de Lyon : Terre, Planètes, Environnement
Laura F. Robinson, University of Bristol
George H. Rowland, University of Bristol
Matthieu Roy-Barman, Universite de Versailles Saint-Quentin-en-Yvelines
Alessandro Tagliabue, University of Liverpool
Adi Torfstein, Hebrew University of Jerusalem
Gisela Winckler, Lamont-Doherty Earth Observatory
Yuxin Zhou, Lamont-Doherty Earth Observatory

Document Type

Article

Publication Date

2-1-2020

Department

Marine Science

School

Ocean Science and Engineering

Abstract

230Th normalization is a valuable paleoceanographic tool for reconstructing high‐resolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, the nuances of 230Th systematics, with regard to particle type, particle size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records of 230Th from across the global ocean at two time slices, the late Holocene (0–5,000 years ago, or 0–5 ka) and the Last Glacial Maximum (18.5–23.5 ka), and investigated the spatial structure of 230Th‐normalized mass fluxes. On a global scale, sedimentary mass fluxes were significantly higher during the Last Glacial Maximum (1.79–2.17 g/cm2kyr, 95% confidence) relative to the Holocene (1.48–1.68 g/cm2kyr, 95% confidence). We then examined the potential confounding influences of boundary scavenging, nepheloid layers, hydrothermal scavenging, size‐dependent sediment fractionation, and carbonate dissolution on the efficacy of 230Th as a constant flux proxy. Anomalous 230Th behavior is sometimes observed proximal to hydrothermal ridges and in continental margins where high particle fluxes and steep continental slopes can lead to the combined effects of boundary scavenging and nepheloid interference. Notwithstanding these limitations, we found that 230Th normalization is a robust tool for determining sediment mass accumulation rates in the majority of pelagic marine settings (>1,000 m water depth).

Comments

© 2020, "230Th Normalization: New Insights on an Essential Tool for Quantifying Sedimentary Fluxes in the Modern and Quaternary Ocean, Paleoceanography, Vol. 35, 10.1029/2019PA003820. To view the published open abstract, go to https://doi.org/10.1029/2019PA003820.

Publication Title

Paleoceanography and Paleoclimatology

Volume

35

Issue

2

Find in your library

Share

COinS