Universität zu Köln

Yang, Ruiyu ORCID: 0000-0003-1692-4526, Gutjahr, Marcus ORCID: 0000-0003-2556-2619, Scholz, Florian ORCID: 0000-0001-8653-0448, Kurzweil, Florian ORCID: 0000-0002-8202-1475, Eroglu, Sümeyya and Münker, Carsten ORCID: 0000-0001-6406-559X (2025). Stable tungsten (W) isotope systematics in marine sediments: a potential paleo-proxy for deep ocean oxygenation. Earth and Planetary Science Letters, 660. pp. 1-12. Elsevier. ISSN 0012-821X

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Abstract

[Artikel-Nr.: 119346] The stable tungsten (W) isotope system has emerged as a promising paleoenvironmental indicator. However, the modern oceanic budget of W and its behavior during sedimentary burial are to date not well understood. Spe- cifically, the mechanisms governing W delivery to marine sediments and its behavior during early diagenesis remain unknown. In this study, we analyzed stable W isotopic compositions (δ186/184W) in three sediment cores from various redox environments in the Gulf of California. Additionally, we investigated δ186/184W compositions and major and trace elemental compositions in surface sediments from global ocean basins. Our findings indicate that continental margin sediments and hydrothermal precipitates lack significant authigenic W enrichment, whereas deep-ocean surface sediments exhibit notable W enrichment, primarily associated with Mn-oxides. Tungsten appears to be delivered alongside Mn but does not undergo burial under anoxic or euxinic condi- tions, unlike its geochemical counterpart, Mo. The tungsten output flux into total Mn oxides is estimated at 22.2 × 106 mol/yr. Authigenic W (excess W relative to the detrital input) exhibits heavier W isotope compositions compared to equilibrium adsorption on Mn oxides from modern seawater, averaging a δ186/184W of 0.255 ± 0.025 ‰. This is likely due to fractionation processes during continuous exchange between pore-water and the solid phase, or the recrystallization of Mn oxides during diagenesis. Finally, we propose an updated mass budget of W and its isotopes in the modern ocean suggesting that the benthic W recycling could be an important, so far underestimated source of W to the ocean. The exclusive association between W and Mn suggests that W isotopes could serve as a valuable indicator for identifying deep-ocean oxygenation in Earth’s history. To advance this idea, further comprehensive investigations into W isotopic fractionation across various Fe and Mn oxide min- erals, as well as additional downcore studies in authigenic W enriched pelagic core sites, would be essential.

Item Type:	Article
Creators:	Creators Email ORCID ORCID Put Code Yang, Ruiyu UNSPECIFIED https://orcid.org/0000-0003-1692-4526 UNSPECIFIED Gutjahr, Marcus UNSPECIFIED https://orcid.org/0000-0003-2556-2619 UNSPECIFIED Scholz, Florian UNSPECIFIED https://orcid.org/0000-0001-8653-0448 UNSPECIFIED Kurzweil, Florian UNSPECIFIED https://orcid.org/0000-0002-8202-1475 UNSPECIFIED Eroglu, Sümeyya UNSPECIFIED UNSPECIFIED UNSPECIFIED Münker, Carsten UNSPECIFIED https://orcid.org/0000-0001-6406-559X UNSPECIFIED
URN:	urn:nbn:de:hbz:38-803407
Identification Number:	10.1016/j.epsl.2025.119346
Journal or Publication Title:	Earth and Planetary Science Letters
Volume:	660
Page Range:	pp. 1-12
Number of Pages:	12
Date:	15 June 2025
Publisher:	Elsevier
ISSN:	0012-821X
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Geosciences > Institute of Geology and Mineralog
Subjects:	Earth sciences Geography and travel
Uncontrolled Keywords:	Keywords Language Stable tungsten isotopes ; Early diagenesis ; Manganese oxides ; Continental margin settings ; Manganese cycling ; Molybdenum English
['eprint_fieldname_oa_funders' not defined]:	Publikationsfonds UzK
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/80340