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TitreDetermination of mercury biogeochemical fluxes in the remote Mackenzie River Basin, northwest Canada, using speciation of sulfur and organic carbon
AuteurCarrie, J C; Stern, G S; Sanei, H S; MacDonald, R W M; Wang, F W
SourceApplied Geochemistry vol. 27, issue 4, 2012 p. 815-824,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110413
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceYukon; Territoires du Nord-Ouest
SNRC95O; 95N; 96B; 96C; 85F; 106H; 106I; 106L; 106M
Lat/Long OENS-136.0000 -116.0000 68.0000 60.0000
Sujetsmercure; soufre; carbone organique; biogéochimie; biote; effets sur l'environnement
Illustrationslocation maps; histograms; graphs; tables
ProgrammeEcosystems Risk Mitigation, Géosciences environnementales
Résumé(disponible en anglais seulement)
The Mackenzie River Basin (MRB) in NW Canada is one of the least human-impacted large watersheds in the world. The western and eastern sub-basins of the MRB are also marked by contrasting geology, geomorphology, hydrology, and biology. These remarkable differences in a remote river basin provide a unique opportunity to probe the biogeochemical processes governing the sources, transport, and bioavailability of Hg at the terrestrial-marine interface and ultimately in the Arctic Ocean. Based on a large dataset of the concentration and speciation of Hg, S and organic matter in surface sediments across the MRB, a source-apportioned budget was constructed for Hg in the MRB. The results indicate that the Hg flux in the basin originates primarily from the weathering of sulfide minerals in the western mountainous sub-basin (\'0278% of the total), followed by the erosion of coal deposits along the mainstream of the Mackenzie
River (\'0210%), with the remainder split between atmospheric inputs and organic matter-bound Hg (6% and 5%, respectively). Although the Hg flux from the eastern peatland sub-basin only accounts for \'0210% of the total riverine Hg flux, Hg in this region correlates strongly with labile organic matter, and will likely have a much stronger influence on local biota.