| Titre | A mercury and trace element geochemical record across Oceanic Anoxic Event 1b in Arctic Canada |
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| Auteur | Galloway, J M ;
Grasby, S E; Wang, F; Hadlari, T; Dewing, K; Bodin, S; Sanei, H |
| Source | Palaeogeography, Palaeoclimatology, Palaeoecology vol. 617, 111490, 2023 p. 1-14, https://doi.org/10.1016/j.palaeo.2023.111490 |
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| Année | 2023 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20220383 |
| Éditeur | Elsevier |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.palaeo.2023.111490 |
| Media | papier; numérique; en ligne |
| Formats | pdf |
| Province | Nunavut |
| SNRC | 38G; 48H; 48G; 58H; 58G; 68H; 68G; 78H; 78G; 88H; 88G; 98H; 39; 49; 59; 69; 79; 89; 99; 29 |
| Lat/Long OENS | -160.0000 -40.0000 80.0000 75.0000 |
| Sujets | océanographie; mercure; climat arctique; géologie de l'arctique; paléoclimatologie; Bassin de Sverdrup ; géochimie |
| Illustrations | cartes de localisation; échelles stratigraphiques; graphiques |
| Programme | GEM-GéoNord : La géocartographie de l'énergie et des minéraux Modèles tectoniques - îles de l'arctique de l'ouest |
| Diffusé | 2023 03 10 |
| Résumé | (disponible en anglais seulement)
A geochemical record from a continuous Arctic marine succession of the upper Aptian to upper Albian Christopher Formation exposed at Glacier Fiord on Axel
Heiberg Island, Canada, reveals the characteristic carbon isotopic excursions associated with the early Albian cluster of sub-events that comprise Oceanic Anoxic Event 1b (OAE 1b). Concentrations of redox-sensitive elements in the Christopher
Formation indicate that conditions ranged from oxic to anoxic, with anoxic conditions during deposition of the Kilian sub-level, and suboxic conditions during deposition of the Jacob and Paquier sub-levels of OAE 1b. Mercury is elevated above
siliciclastic background at several horizons in the succession, including prior to, and following, the Jacob, Kilian, and Paquier sub-levels. Sulphides, rather than organic matter, appear to be the most important host phase for Hg in the Christopher
Formation, particularly in the mid to upper Albian part of the succession following OAE 1b. A lack of enrichment of most redox sensitive trace elements, and their relationship to detrital indicators Al, Ti, and Li, combined with other indicators of
overall ventilated conditions during deposition of the Christopher Formation, suggests a terrigenous source of Hg rather than fixation of Hg by S in an anoxic or euxinic setting. Although volcanic activity associated with the HALIP could have
released gaseous Hg to the atmosphere and the surrounding landscape, another potential source of Hg, S, and other metal(loid)s to the basin is mineralization associated with salt diapirism that may have been exhumed by the Albian. A change in clay
mineral content (K/ Al ratios) in strata overlying the Paquier sub-level indicates a change in continental weathering that may be associated with a widespread increase in humidity and warmer climate conditions at this time, that would have increased
the input of detrital metal(loid)s (As, Cu, Hg, Ni, Pb, S) into the Sverdrup Basin. We suggest that Hg input into restricted marine basins can be predominantly detrital, and that there are no unequivocal atmospheric-sourced Hg anomalies associated
with the Jacob, Kilian, or Paquier sub-levels of OAE 1b at Glacier Fiord. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cet article présente un enregistrement d'éléments traces et de mercure de la Formation de Christopher Aptien-Albien et de l'événement anoxique
océanique 1b dans le bassin de Sverdrup de l'Arctique canadien. Nous suggérons que l'apport de Hg dans les bassins marins restreints peut être principalement détritique et qu'il n'y a pas d'anomalies sans équivoque de Hg d'origine atmosphérique
associées aux sous-niveaux Jacob, Kilian ou Paquier de l'OAE 1b dans l'Arctique canadien. |
| GEOSCAN ID | 331078 |
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