Sedimentary molybdenum and uranium: Improving proxies for deoxygenation in coastal depositional environments

K. Mareike Paul; Niels A.G.M. van Helmond; Caroline P. Slomp; Sami A. Jokinen; Joonas J. Virtasalo; Helena L. Filipsson; Tom Jilbert

doi:10.1016/j.chemgeo.2022.121203

Sedimentary molybdenum and uranium: Improving proxies for deoxygenation in coastal depositional environments

K. Mareike Paul, Niels A.G.M. van Helmond, Caroline P. Slomp, Sami A. Jokinen, Joonas J. Virtasalo, Helena L. Filipsson, Tom Jilbert

Quaternary Sciences

Research output: Contribution to journal › Article › peer-review

Abstract

Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary (depositional environmental) factors impact Mo- and U-EFs. Here we investigate 18 coastal sites with varying bottom water redox conditions, which we define by means of five “redox bins”, ranging from persistently oxic to persistently euxinic, from a variety of depositional environments. Our results demonstrate that Mo- and U-EF-based redox proxies and sedimentary Mo and U contents can be used to differentiate bottom water oxygen concentration among a range of modern coastal depositional environments. This is underpinned by the contrasting EFs of Mo and U along the redox gradient, which shows a substantial difference of Mo-EFs between redox bins 3–5 (ir/regularly suboxic – ir/regularly dysoxic – persistently oxic) and of U-EFs between redox bins 1–2 (persistently euxinic – ir/regularly euxinic). Surprisingly, we observe comparatively low redox proxy potential for U in environments of mild deoxygenation (redox bins 3–5). Further, we found that secondary factors can bias Mo-and U-EFs to such an extent that EFs do not reliably reflect bottom water redox conditions. We investigate the impact of limited Mo sedimentary sequestration in sulfidic depositional environments (i.e., the “basin reservoir effect”, equilibrium with FeMoS₄), Fe/Mn-(oxy)(hydr)oxide “shuttling”, oxidative dissolution, the sulfate methane transition zone in the sediment, sedimentation rate, and the local Al background on Mo- and U-EFs.

Original language	English
Article number	121203
Journal	Chemical Geology
Volume	615
DOIs	https://doi.org/10.1016/j.chemgeo.2022.121203
Publication status	Published - 2023 Jan 5

Bibliographical note

Funding Information:
We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962 ). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education , Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190 ).

Funding Information:
We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190).

Publisher Copyright:
© 2022 The Authors

Subject classification (UKÄ)

Environmental Sciences
Geology

Free keywords

Coastal Sea
Enrichment factor
Hypoxia
Redox-sensitive
Trace metal

Access to Document

10.1016/j.chemgeo.2022.121203Licence: CC BY

3 Article

Revisiting the applicability and constraints of molybdenum - and uranium-based paleo redox proxies: comparing two contrasting sill fjords
Paul, K. M., Hermans, M., Jokinen, S. A., Brinkmann, I., Filipsson, H. L. & Jilbert, T., 2023 Dec 19, In: Biogeosciences. 20, 24, p. 5003-5028 26 p.
Research output: Contribution to journal › Article › peer-review

Open Access
Benthic Foraminiferal Mn/Ca as Low-Oxygen Proxy in Fjord Sediments
Brinkmann, I., Barras, C., Jilbert, T., Paul, K. M., Somogyi, A., Ni, S., Schweizer, M., Bernhard, J. M. & Filipsson, H. L., 2023 May, In: Global Biogeochemical Cycles. 37, 5, e2023GB007690.
Research output: Contribution to journal › Article › peer-review

Open Access
Drought recorded by Ba/Ca in coastal benthic foraminifera
Brinkmann, I., Barras, C., Jilbert, T., Næraa, T., Paul, K. M., Schweizer, M. & Filipsson, H. L., 2022 May 16, In: Biogeosciences. 19, 9, p. 2523-2535 13 p.
Research output: Contribution to journal › Article › peer-review

Open Access

1 Finished

Tracing past bottom water oxygenation in the sea: a microanalytical approach to improve calcium carbonate based proxies (TOPICaL)
Filipsson, H. (PI), Brinkmann, I. (Research student), Bernhard, J. M. (Researcher), Barras, C. (Researcher), Schweizer, M. (Researcher) & Geslin, E. (Researcher)
Swedish Research Council
2017/12/01 → 2022/12/31
Project: Dissertation

Cite this

@article{c14e2620c4f84bb09fc3491e41076eef,

title = "Sedimentary molybdenum and uranium: Improving proxies for deoxygenation in coastal depositional environments",

abstract = "Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary (depositional environmental) factors impact Mo- and U-EFs. Here we investigate 18 coastal sites with varying bottom water redox conditions, which we define by means of five “redox bins”, ranging from persistently oxic to persistently euxinic, from a variety of depositional environments. Our results demonstrate that Mo- and U-EF-based redox proxies and sedimentary Mo and U contents can be used to differentiate bottom water oxygen concentration among a range of modern coastal depositional environments. This is underpinned by the contrasting EFs of Mo and U along the redox gradient, which shows a substantial difference of Mo-EFs between redox bins 3–5 (ir/regularly suboxic – ir/regularly dysoxic – persistently oxic) and of U-EFs between redox bins 1–2 (persistently euxinic – ir/regularly euxinic). Surprisingly, we observe comparatively low redox proxy potential for U in environments of mild deoxygenation (redox bins 3–5). Further, we found that secondary factors can bias Mo-and U-EFs to such an extent that EFs do not reliably reflect bottom water redox conditions. We investigate the impact of limited Mo sedimentary sequestration in sulfidic depositional environments (i.e., the “basin reservoir effect”, equilibrium with FeMoS4), Fe/Mn-(oxy)(hydr)oxide “shuttling”, oxidative dissolution, the sulfate methane transition zone in the sediment, sedimentation rate, and the local Al background on Mo- and U-EFs.",

keywords = "Coastal Sea, Enrichment factor, Hypoxia, Redox-sensitive, Trace metal",

author = "Paul, {K. Mareike} and {van Helmond}, {Niels A.G.M.} and Slomp, {Caroline P.} and Jokinen, {Sami A.} and Virtasalo, {Joonas J.} and Filipsson, {Helena L.} and Tom Jilbert",

note = "Funding Information: We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962 ). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education , Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190 ). Funding Information: We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190). Publisher Copyright: {\textcopyright} 2022 The Authors",

year = "2023",

month = jan,

day = "5",

doi = "10.1016/j.chemgeo.2022.121203",

language = "English",

volume = "615",

journal = "Chemical Geology",

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T1 - Sedimentary molybdenum and uranium

T2 - Improving proxies for deoxygenation in coastal depositional environments

AU - Paul, K. Mareike

AU - van Helmond, Niels A.G.M.

AU - Slomp, Caroline P.

AU - Jokinen, Sami A.

AU - Virtasalo, Joonas J.

AU - Filipsson, Helena L.

AU - Jilbert, Tom

N1 - Funding Information: We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962 ). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education , Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190 ). Funding Information: We thank the captain, crew, and scientific participants on board R/V Skagerrak (2019) and R/V Pelagia (2019) for their assistance with the field work campaigns. We acknowledge the staff of the Kristineberg Marine Research Station and the Royal Netherlands Institute for Sea Research (NIOZ) for their support during the field campaigns. The GeoLab, especially Helen de Waard, Coen Mulder, Natasja Welters, and Arnold van Dijk are acknowledged for analytical assistance at Utrecht University. We thank Heini Ali-Kovero for analytical assistance at the University of Helsinki. We also thank Martijn Hermans and Ricardo Correia for helping with making figures, computing in R, and providing feedback. This research was funded by the Academy of Finland (grant numbers 1319956 and 1345962). Additional funding was provided by the Netherlands Organisation for Scientific Research (NWO; Vici-grant number 865.13.005), and the European Research Council (ERC Synergy Marix grant number 854088). This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW). HLF acknowledges support by the Swedish Research Council VR (grant number 2017-04190). Publisher Copyright: © 2022 The Authors

PY - 2023/1/5

Y1 - 2023/1/5

N2 - Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary (depositional environmental) factors impact Mo- and U-EFs. Here we investigate 18 coastal sites with varying bottom water redox conditions, which we define by means of five “redox bins”, ranging from persistently oxic to persistently euxinic, from a variety of depositional environments. Our results demonstrate that Mo- and U-EF-based redox proxies and sedimentary Mo and U contents can be used to differentiate bottom water oxygen concentration among a range of modern coastal depositional environments. This is underpinned by the contrasting EFs of Mo and U along the redox gradient, which shows a substantial difference of Mo-EFs between redox bins 3–5 (ir/regularly suboxic – ir/regularly dysoxic – persistently oxic) and of U-EFs between redox bins 1–2 (persistently euxinic – ir/regularly euxinic). Surprisingly, we observe comparatively low redox proxy potential for U in environments of mild deoxygenation (redox bins 3–5). Further, we found that secondary factors can bias Mo-and U-EFs to such an extent that EFs do not reliably reflect bottom water redox conditions. We investigate the impact of limited Mo sedimentary sequestration in sulfidic depositional environments (i.e., the “basin reservoir effect”, equilibrium with FeMoS4), Fe/Mn-(oxy)(hydr)oxide “shuttling”, oxidative dissolution, the sulfate methane transition zone in the sediment, sedimentation rate, and the local Al background on Mo- and U-EFs.

AB - Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary (depositional environmental) factors impact Mo- and U-EFs. Here we investigate 18 coastal sites with varying bottom water redox conditions, which we define by means of five “redox bins”, ranging from persistently oxic to persistently euxinic, from a variety of depositional environments. Our results demonstrate that Mo- and U-EF-based redox proxies and sedimentary Mo and U contents can be used to differentiate bottom water oxygen concentration among a range of modern coastal depositional environments. This is underpinned by the contrasting EFs of Mo and U along the redox gradient, which shows a substantial difference of Mo-EFs between redox bins 3–5 (ir/regularly suboxic – ir/regularly dysoxic – persistently oxic) and of U-EFs between redox bins 1–2 (persistently euxinic – ir/regularly euxinic). Surprisingly, we observe comparatively low redox proxy potential for U in environments of mild deoxygenation (redox bins 3–5). Further, we found that secondary factors can bias Mo-and U-EFs to such an extent that EFs do not reliably reflect bottom water redox conditions. We investigate the impact of limited Mo sedimentary sequestration in sulfidic depositional environments (i.e., the “basin reservoir effect”, equilibrium with FeMoS4), Fe/Mn-(oxy)(hydr)oxide “shuttling”, oxidative dissolution, the sulfate methane transition zone in the sediment, sedimentation rate, and the local Al background on Mo- and U-EFs.

KW - Coastal Sea

KW - Enrichment factor

KW - Hypoxia

KW - Redox-sensitive

KW - Trace metal

U2 - 10.1016/j.chemgeo.2022.121203

DO - 10.1016/j.chemgeo.2022.121203

M3 - Article

AN - SCOPUS:85142181809

SN - 0009-2541

VL - 615

JO - Chemical Geology

JF - Chemical Geology

M1 - 121203

ER -

Sedimentary molybdenum and uranium: Improving proxies for deoxygenation in coastal depositional environments

Abstract

Bibliographical note

Subject classification (UKÄ)

Free keywords

Access to Document

Fingerprint

Research output

Revisiting the applicability and constraints of molybdenum - and uranium-based paleo redox proxies: comparing two contrasting sill fjords

Benthic Foraminiferal Mn/Ca as Low-Oxygen Proxy in Fjord Sediments

Drought recorded by Ba/Ca in coastal benthic foraminifera

Projects

Tracing past bottom water oxygenation in the sea: a microanalytical approach to improve calcium carbonate based proxies (TOPICaL)

Cite this