Next Article in Journal
Bromine Isotope Variations in Magmatic and Hydrothermal Sodalite and Tugtupite and the Estimation of Br Isotope Fractionation between Melt and Sodalite
Previous Article in Journal
Chemical Analysis of Thermoluminescent Colorless Topaz Crystal Using Laser-Induced Breakdown Spectroscopy
Previous Article in Special Issue
Iron and Carbon Isotope Constraints on the Formation Pathway of Iron-Rich Carbonates within the Dagushan Iron Formation, North China Craton
Open AccessFeature PaperArticle

Iron Isotopes Reveal a Benthic Iron Shuttle in the Palaeoproterozoic Zaonega Formation: Basinal Restriction, Euxinia, and the Effect on Global Palaeoredox Proxies

1
Department of Geology, University of Tartu, 50411 Tartu, Estonia
2
Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada
3
CNRS-UMR 6538 Laboratoire Géosciences Océan, European Institute for Marine Studies, Technopôle Brest-Iroise, 29280 Plouzané, France
4
Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
5
Department of Geology, University of Regina, Regina, SK S4S 0A2, Canada
6
Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
7
Institute of Geology, Karelian Research Centre, Russian Academy of Sciences, 185610 Petrozavodsk, Russia
8
CAGE—Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway
9
Geological Survey of Norway, 7491 Trondheim, Norway
10
Tallinn University of Technology, Institute of Geology, 19086 Tallinn, Estonia
*
Author to whom correspondence should be addressed.
Academic Editor: Stefan Peiffer
Minerals 2021, 11(4), 368; https://doi.org/10.3390/min11040368
Received: 28 February 2021 / Revised: 20 March 2021 / Accepted: 27 March 2021 / Published: 31 March 2021
(This article belongs to the Special Issue Copper and Other Metallic Isotope Systems)
The Zaonega Formation in northwest Russia (~2.0 billion years old) is amongst the most complete successions that record the middle of the Palaeoproterozoic era. As such, geochemical data from the formation have played a central role in framing the debate over redox dynamics in the aftermath of the Great Oxidation Event (GOE). However, uncertainty over local redox conditions and the degree of hydrographic restriction in the formation has led to contradictory interpretations regarding global oxygen (O2) fugacity. Here, we provide new iron (Fe) isotope data together with major and trace element concentrations to constrain the local physiochemical conditions. The Zaonega Formation sediments show authigenic Fe accumulation (Fe/Al ≫ 1 wt.%/wt.%) and δ56Fe ranging from −0.58‰ to +0.60‰. Many of the data fall on a negative Fe/Al versus δ56Fe trend, diagnostic of a benthic Fe shuttle, which implies that Zaonega Formation rocks formed in a redox-stratified and semi-restricted basin. However, basin restriction did not coincide with diminished trace metal enrichment, likely due to episodes of deep-water exchange with metal-rich oxygenated seawater, as evidenced by simultaneous authigenic Fe(III) precipitation. If so, the Onega Basin maintained a connection that allowed its sediments to record signals of global ocean chemistry despite significant basinal effects. View Full-Text
Keywords: isotope geochemistry; redox stratification; benthic Fe shuttle; dissimilatory iron reduction isotope geochemistry; redox stratification; benthic Fe shuttle; dissimilatory iron reduction
Show Figures

Figure 1

MDPI and ACS Style

Mänd, K.; Lalonde, S.V.; Paiste, K.; Thoby, M.; Lumiste, K.; Robbins, L.J.; Kreitsmann, T.; Romashkin, A.E.; Kirsimäe, K.; Lepland, A.; Konhauser, K.O. Iron Isotopes Reveal a Benthic Iron Shuttle in the Palaeoproterozoic Zaonega Formation: Basinal Restriction, Euxinia, and the Effect on Global Palaeoredox Proxies. Minerals 2021, 11, 368. https://doi.org/10.3390/min11040368

AMA Style

Mänd K, Lalonde SV, Paiste K, Thoby M, Lumiste K, Robbins LJ, Kreitsmann T, Romashkin AE, Kirsimäe K, Lepland A, Konhauser KO. Iron Isotopes Reveal a Benthic Iron Shuttle in the Palaeoproterozoic Zaonega Formation: Basinal Restriction, Euxinia, and the Effect on Global Palaeoredox Proxies. Minerals. 2021; 11(4):368. https://doi.org/10.3390/min11040368

Chicago/Turabian Style

Mänd, Kaarel; Lalonde, Stefan V.; Paiste, Kärt; Thoby, Marie; Lumiste, Kaarel; Robbins, Leslie J.; Kreitsmann, Timmu; Romashkin, Alexander E.; Kirsimäe, Kalle; Lepland, Aivo; Konhauser, Kurt O. 2021. "Iron Isotopes Reveal a Benthic Iron Shuttle in the Palaeoproterozoic Zaonega Formation: Basinal Restriction, Euxinia, and the Effect on Global Palaeoredox Proxies" Minerals 11, no. 4: 368. https://doi.org/10.3390/min11040368

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop