Bioactive Trace Metals and Their Isotopes as Paleoproductivity Proxies: An Assessment Using GEOTRACES‐Era Data

Details

Ressource 1Download: Horner et al., 21.pdf (41993.19 [Ko])
State: Public
Version: author
License: Not specified
Serval ID
serval:BIB_26503DB5F94C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Bioactive Trace Metals and Their Isotopes as Paleoproductivity Proxies: An Assessment Using GEOTRACES‐Era Data
Journal
Global Biogeochemical Cycles
Author(s)
Horner T. J., Little S. H., Conway T. M., Farmer J. R., Hertzberg J. E., Janssen D. J., Lough A. J. M., McKay J. L., Tessin A., Galer S. J. G., Jaccard S. L., Lacan F., Paytan A., Wuttig K.
ISSN
0886-6236
1944-9224
Publication state
Published
Issued date
11/2021
Peer-reviewed
Oui
Volume
35
Number
11
Language
english
Abstract
Phytoplankton productivity and export sequester climatically significant quantities
of atmospheric carbon dioxide as particulate organic carbon through a suite of processes termed
the biological pump. Constraining how the biological pump operated in the past is important for understanding past atmospheric carbon dioxide concentrations and Earth's climate history. However, reconstructing the history of the biological pump requires proxies. Due to their intimate association with biological processes, several bioactive trace metals and their isotopes are potential proxies for past phytoplankton productivity, including iron, zinc, copper, cadmium, molybdenum, barium, nickel, chromium, and silver. Here, we review the oceanic distributions, driving processes, and depositional archives for these nine metals and their isotopes based on GEOTRACES-era datasets. We offer an assessment of the overall maturity of each isotope system to serve as a proxy for diagnosing aspects
of past ocean productivity and identify priorities for future research. This assessment reveals that cadmium, barium, nickel, and chromium isotopes offer the most promise as tracers of paleoproductivity, whereas iron, zinc, copper, and molybdenum do not. Too little is known about silver to make a confident determination. Intriguingly, the trace metals that are least sensitive to productivity may be used to track other aspects of ocean chemistry, such as nutrient sources, particle scavenging, organic complexation, and ocean redox state. These complementary sensitivities suggest new opportunities for combining perspectives from multiple proxies that will ultimately enable painting a more complete picture of marine paleoproductivity, biogeochemical cycles, and Earth's climate history.
Keywords
Atmospheric Science, General Environmental Science, Environmental Chemistry, Global and Planetary Change
Open Access
Yes
Create date
23/11/2021 14:07
Last modification date
24/11/2021 7:08
Usage data