FN Archimer Export Format
PT J
TI Iron Isotopes Reveal a Benthic Iron Shuttle in the Palaeoproterozoic Zaonega Formation: Basinal Restriction, Euxinia, and the Effect on Global Palaeoredox Proxies
BT 
AF Mänd, Kaarel
   Lalonde, Stefan
   Paiste, Kärt
   Thoby, Marie
   Lumiste, Kaarel
   Robbins, Leslie J.
   Kreitsmann, Timmu
   Romashkin, Alexander E.
   Kirsimäe, Kalle
   Lepland, Aivo
   Konhauser, Kurt O.
AS 1:1,2;2:3;3:1,4;4:3;5:1;6:5;7:6;8:7;9:1;10:1,8,9,10;11:2;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;
C1 Department of Geology, University of Tartu, 50411 Tartu, Estonia
   Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada
   CNRS-UMR 6538 Laboratoire Géosciences Océan, European Institute for Marine Studies, Technopôle Brest-Iroise, 29280 Plouzané, France
   Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
   Department of Geology, University of Regina, Regina, SK S4S 0A2, Canada
   Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
   Institute of Geology, Karelian Research Centre, Russian Academy of Sciences, 185610 Petrozavodsk, Russia
   CAGE—Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway
   Geological Survey of Norway, 7491 Trondheim, Norway
   Tallinn University of Technology, Institute of Geology, 19086 Tallinn, Estonia
C2 UNIV TARTU, ESTONIA
   UNIV ALBERTA, CANADA
   CNRS, FRANCE
   UNIV WASHINGTON, USA
   UNIV REGINA, CANADA
   UNIV BREMEN, GERMANY
   RUSSIAN ACAD SCI, RUSSIA
   UNIV ARCTIC UIT NORWAY, NORWAY
   GEOL SURVEY NORWAY, NORWAY
   UNIV TECH TALLIN, ESTONIA
UM LGO
IN DOAJ
IF 2.818
TC 4
UR https://archimer.ifremer.fr/doc/00688/79959/82885.pdf
   https://archimer.ifremer.fr/doc/00688/79959/82886.zip
LA English
DT Article
DE ;isotope geochemistry;redox stratification;benthic Fe shuttle;dissimilatory iron reduction
AB 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 
PY 2021
PD APR
SO Minerals
SN 2075-163X
PU MDPI AG
VL 11
IS 4
UT 000643328800001
DI 10.3390/min11040368
ID 79959
ER

EF