| Title | Mercury and other trace metals in the seasonal snowpack across the subarctic taiga-tundra ecotone, Northwest Territories, Canada |
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| Author | Zdanowicz, C ;
Zheng, J; Klimenko, E; Outridge, P M |
| Source | Applied Geochemistry vol. 82, 2017 p. 63-78, https://doi.org/10.1016/j.apgeochem.2017.04.011 |
| Year | 2017 |
| Alt Series | Natural Resources Canada, Contribution Series 20170120 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html; docx (Microsoft® Word®); xlsx (Microsoft® Excel®) |
| Province | Northwest Territories |
| NTS | 75K/05; 75K/12; 75K/13; 75L/05; 75L/06; 75L/07; 75L/08; 75L/09; 75L/10; 75L/11; 75L/12; 75L/13; 75L/14; 75L/15; 75L/16; 75M; 75N/04; 75N/05; 75N/12; 75N/13; 76C/04; 76C/05; 76C/12; 76C/13; 76D; 76E/01;
76E/02; 76E/03; 76E/04; 76E/05; 76E/06; 76E/07; 76E/08; 76E/09; 76E/10; 76E/11; 76E/12; 85I/05; 85I/06; 85I/07; 85I/08; 85I/09; 85I/10; 85I/11; 85I/12; 85I/13; 85I/14; 85I/15; 85I/16; 85P; 86A; 86H/01; 86H/02; 86H/03; 86H/04; 86H/05; 86H/06; 86H/07;
86H/08; 86H/09; 86H/10; 86H/11; 86H/12 |
| Area | Lutselk'e; Tibbit Lake; Tibbitt-Contwoyto Winter Road; Lac de Gras; Yamba Lake; MacKay Lake; Matthews Lake; Snap Lake; Great Slave Lake |
| Lat/Long WENS | -113.9000 -109.9000 65.6000 62.3000 |
| Subjects | environmental geology; geochemistry; surficial geology/geomorphology; mining; metals; gold; diamond; environmental impacts; snow geochemistry; mercury geochemistry; metals; trace metals; soil
geochemistry; sediment dispersal; dispersal patterns; atmospheric geochemistry; source areas; ecosystems; climatology; hydrologic environment; arsenic geochemistry; lead geochemistry; zinc geochemistry; geochemical dispersion; Shield Taiga; Low
Arctic Tundra; snowpacks |
| Illustrations | location maps; photographs; tables; geochemical plots; geoscientific sketch maps; frequency distribution diagrams |
| Program | Environmental Geoscience
Management |
| Released | 2017 05 06 |
| Abstract | In Canada's Northwest Territories, mining for base metals and diamonds are vital economic activities which carry risks of adverse environmental impacts. To gather baseline geochemical data against which
the impact of future mining activities may be measured, a survey of trace metal concentrations in snow was carried out in 2012 along a 285-km stretch of winter mining road crossing the taiga-tundra ecotone between latitudes 62.8 and 65.5\'01 N. The
distribution of 17 elements, including mercury (Hg), was measured and mapped. Results indicate that road traffic along the winter road has only a modest impact on the metal content of the nearby tundra-taiga snowpack, and that this impact is largely
due to the mobilization of soil dust and associated elements. However, some enrichment of As, Pb, Sr and Zn in snow was detected near former gold mine sites, likely reflecting the windborne dispersion of contaminated soils. The Hg concentrations in
snow across the study area were generally low (<=3.01 ng L(-1)), and did not covary with any other metals, which suggests atmospheric deposition from distant/diffuse sources. An analysis of air back-trajectories pointed to the most likely distant
(>103 km) anthropogenic source regions being eastern Asia or Russia. Using Hg data from the present survey and another source, in combination with gridded maps of snowpack water equivalent, we calculated the potential flux of atmospherically-derived
Hg that could be released by spring snowmelt into the Mackenzie River to be in the order of ~195e404 kg a(-1), which may represent a substantial fraction of the estimated total Hg discharge to the Beaufort Sea. |
| Summary | (Plain Language Summary, not published)
In NW Territories, mining for base metals and diamonds are activities. To gather baseline geochemical data to evaluate the impact of future mining
activities, a survey of trace metal concentrations in snow was carried out in 2012 along a 285-km stretch of winter mining road between latitudes 62.8 and 65.5° N. The distribution of 17 elements, including mercury (Hg), was studied. Results indicate
that road traffic along the winter road has only a modest impact on the metal content of the nearby tundra-taiga snowpack, largely due to the mobilization of soil dust and associated elements. However, some enrichment of arsenic, lead, strontium and
zinc in snow was detected near former gold mine sites, reflecting the windborne dispersion of contaminated soils. The Hg concentrations in snow were generally low (= 3.01 ng L-1), and did not relate with any other metals. This suggests that
atmospheric deposition of Hg was from distant sources, likely distant source regions in Asia or Russia. |
| GEOSCAN ID | 304210 |
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