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TitreA test of the stability of Cd, Cu, Hg, Pb and Zn profiles over two decades in lake sediments near the Flin Flon Smelter, Manitoba, Canada
AuteurPercival, J B; Outridge, P M
SourceScience of the Total Environment vol. 454-455, 2013 p. 307-318,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110265
Documentpublication en série
Mediaen ligne; numérique
ProvinceManitoba; Saskatchewan
SNRC63K/12; 63K/13; 63L/09; 63L/10; 63L/15; 63L/16; 63M/01; 63M/02; 63M/07; 63M/08; 63N/04; 63N/05
Lat/Long OENS-103.0000 -101.5000 55.5000 54.5000
Sujetssediments lacustres; métaux; géochimie du cadmium; géochimie du cuivre; géochimie du mercure; géochimie du plomb; géochimie du zinc; fonderies; analyses géochimiques; carottes de sediments lacustres; analyses minéralogiques; géochimie des éléments en trace; diagenèse; Bouclier Précambrien; géochimie; minéralogie; Précambrien; Protérozoïque
Illustrationslocation sketch map; geochemical concentration charts
ProgrammeGestionnaire de programme, Géoscience de l'environnement
Résumé(disponible en anglais seulement)
Lake sediments are valuable archives of atmospheric metal deposition, but the stability of some element profiles may possibly be affected by diagenetic changes over time. In this extensive case study, the stability of sedimentary Cd, Cu, Hg, Pb and Zn profiles was assessed in dated sediment cores that were collected in 2004 from four smelter-affected lakes near Flin Flon, Manitoba, which had previously been cored in 1985. Metal profiles determined in 1985 were in most cases clearly reproduced in the corresponding sediment layers in 2004, although small-scale spatial heterogeneity in metal distribution complicated the temporal comparisons. Pre-smelter (i.e. pre-1930) increases in metal profiles were likely the result of long-range atmospheric metal pollution, coupled with particle mixing at the 1930s sediment surface. However, the close agreement between key inflection points in the metal profiles sampled two decades apart suggests that metals in most of the lakes, and Hg and Zn in the most contaminated lake (Meridian), were stable once the sediments were buried below the surface mixed layer. Cadmium, Cu and Pb profiles in Meridian Lake did not agree as well between studies, showing evidence of upward remobilization over time. Profiles of redox-indicator elements (Fe, Mn, Mo and U) suggested that the rate of Mn oxyhydroxide recycling within sediment was more rapid in Meridian Lake, which may have caused the Cd, Cu and Pb redistribution.