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TitleEnvironmental geochemistry of tailings, sediments and surface waters collected from 14 historical gold mining districts in Nova Scotia
AuthorParsons, M B; LeBlanc, K W G; Hall, G E M; Sangster, A L; Vaive, J E; Pelchat, P
SourceGeological Survey of Canada, Open File 7150, 2012, 326 pages, (Open Access)
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
File formatreadme
File formatpdf; xls; rtf
ProvinceNova Scotia
NTS11D; 11E/01; 11E/02; 11E/03; 11E/04; 11E/07; 11E/08; 11F/04; 11F/05; 11F/06; 11F/11; 11F/12; 20P/15; 21A/02; 21A/03; 21A/06; 21A/07; 21A/08; 21A/09; 21A/10
AreaSeal Harbour; Goldenville; Salmon River; Mooseland; Lake Catcha; Montague; Leipsigate; Whiteburn; North Brookfield; Mount Uniacke; East Rawdon; Caribou; Cochrane Hill
Lat/Long WENS -65.5000 -61.0000 45.5000 43.7500
Subjectsenvironmental geology; geochemistry; hydrogeology; Health and Safety; tailings; tailings disposal; tailings analyses; tailings geochemistry; gold; mercury; arsenic; bacteria; environmental analysis; environmental studies; heavy metals contamination; mining methods; mining history; lake water geochemistry; stream water geochemistry; water analyses; water geochemistry; health hazards; Caribou Gold District; Cochrane Hill Gold District; East Rawdon Gold District; Goldenville Gold District; Lake Catcha Gold District; Leipsigate Gold District; Lower Seal Harbour Gold District; Montague Gold District; Mooseland Gold District; Mount Uniacke Gold District; North Brookfield Gold District; Salmon River Gold District; Upper Seal Harbour Gold District; Whiteburn Gold District; human health
Illustrationslocation maps; tables; histograms; photographs
ProgramMetals in the Environment (MITE)
ProgramEnvironmental Geoscience, Management
Released2012 10 03
AbstractFrom 1861 to the mid-1940s, stamp milling at orogenic lode gold mines in Nova Scotia generated more than 3,000,000 tonnes of tailings. Most of the mined gold was recovered using mercury (Hg) amalgamation, and an estimated 10 - 25% of the Hg used was lost to the tailings and to the atmosphere. Arsenic (As) also occurs naturally in the ore, and is present at high concentrations in the mine wastes. Tailings from these operations were generally slurried into local rivers, swamps, lakes and the ocean. Recent land-use changes (e.g. residential development, recreational activities, shellfish harvesting) in some historical mining districts are increasing the likelihood of human exposure to these tailings. This Open File Report presents the results of a multi-disciplinary investigation of the dispersion, speciation and fate of metal(loid)s in terrestrial and shallow marine environments surrounding 14 abandoned gold mines in Nova Scotia. From 2003 to 2006, samples of tailings, sediment, and water were collected at 14 former gold mines. Field studies reveal that most mine sites contain large volumes of unconfined tailings, and in several districts these have been transported significant distances (>2 km) offsite by streams and rivers. Chemical analyses of 482 tailings and sediment samples show high concentrations of As (10 mg/kg to 31 wt.%; median 2550 mg/kg) and Hg (<5 ug/kg to 350 mg/kg; median 1640 ug/kg). Arsenic is hosted in arsenopyrite and a variety of secondary phases including scorodite (FeAsO4·2H2O), amorphous Fe arsenate, and As bound to Fe oxyhydroxides. Mercury is present in elemental form, amalgam (AuxHgx), and in secondary phases. Results from this study led to the formation of a Provincial-Federal Historic Gold Mines Advisory Committee in 2005, which has evaluated the ecological and human health risks associated with gold mines throughout Nova Scotia and developed recommendations for management of these tailings sites. This Open File Report provides the most comprehensive summary available of the history, distribution, and geochemistry of tailings at gold mines throughout Nova Scotia. The geographic coordinates provided for each district can be used to quickly explore the tailings deposits via most web-based mapping services. The results can be used to help minimize the environmental impacts associated with past, present, and future gold extraction and to inform land-use decisions.