Bossé-Demers, Thomas; Gobeil, Charles; Juhls, Bennet; Lizotte, Martine; Fritz, Michael; Bröder, Lisa; Matsuoka, Atsushi; Mareque, Santiago et Couture, Raoul-Marie 
ORCID: https://orcid.org/0000-0003-4940-3372
(2025).
Distribution of rare earth elements and their signatures from the Mackenzie River delta to the abyssal Arctic Ocean.
Continental Shelf Research
, vol. 289
.
p. 105464.
DOI: 10.1016/j.csr.2025.105464.
Résumé
The Mackenzie River is North America's largest contributor of freshwater and sediment to the Arctic Ocean. Here, we evaluate the potential of rare earth elements (REE) as tracers of its sediment sources and fate, from the river mouth to the deep Arctic Ocean. We collected sediment cores from 21 sites, from the delta to the marine shelves, slopes and basins and measured the spatial and down-core distribution of total, leached and residual REE concentrations. Our results show that the proportion of leached REE is highest in the delta. This proportion decreases with distance from the river, suggesting mixing with other sediment sources, REE loss to the residual phase, or REE scavenging via adsorption and complexation in coastal waters. Normalized REE concentrations plotted against their atomic number provide regional signatures. The leached REE signatures indicate medium REE enrichment in the Mackenzie Delta, an enrichment that diminishes with distance from the delta. We then used a similarity index (SI) to investigate the divergence amongst REE signatures, with riverine and deep marine basin values as endmembers for the calculation. Our results highlight the influence of the Mackenzie Region sediments on the Beaufort Sea margin. Overall, our findings demonstrate that REE are relevant tracers for identifying sediment sources and that tracking REE distribution from the delta to the deep Arctic Ocean offers additional insights into sediment transport mechanisms.
| Type de document: | Article |
|---|---|
| Mots-clés libres: | sediment sources; rare earth elements (REE); Beaufort Sea margin; sediment transport mechanisms; deep marine basin |
| Centre: | Centre Eau Terre Environnement |
| Date de dépôt: | 03 avr. 2025 20:03 |
| Dernière modification: | 03 avr. 2025 20:03 |
| URI: | https://espace.inrs.ca/id/eprint/16406 |
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