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TitreBaseline geochemistry and controls on mine drainage composition in the Bridge River Mining District, British Columbia
AuteurParsons, M B; Little, M E; Desbarats, A J; Percival, J B; LeBlanc, K W G; Vaive, J E; Pelchat, P
SourceCommission géologique du Canada, Dossier public 6435, 2013, 269 pages, (Accès ouvert)
ÉditeurRessources naturelles Canada
Documentdossier public
Mediaen ligne; numérique
Formatspdf; xls; rtf
SNRC92J/10; 92J/15; 92O/02
Lat/Long OENS-122.9333 -122.5000 51.0667 50.7250
Sujetsanalyse environnementales; etudes de l'environnement; effets sur l'environnement; or; antimoine; mercure; tungstène; minéralisation; échantillons de sédiment de cours d'eau; géochimie des sédiments de cours d'eau; géochimie de l'eau de cours d'eau; géochimie du sol; échantillons de sol; géochimie des résidus; résidus; exhaure des mines acides; drainage; contamination des métaux lourds; pollution; substances polluantes; biogéochimie; levés biochimiques; levés géochimiques; Mine Bralorne ; Mine King ; Mine Pioneer ; géochimie; minéralogie; géologie des dépôts meubles/géomorphologie; géologie de l'environnement; Santé et sécurité; Cénozoïque; Quaternaire
Illustrationslocation maps; photographs; tables; plots; hydrographs
Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre)
ProgrammeOutils d'adaptation et d'impacts sur l'environnement pour les mines de métaux, Géosciences environnementales
Diffusé2013 01 14
Résumé(disponible en anglais seulement)
Without appropriate environmental management controls and regulatory oversight, the mining and milling of gold (Au) can result in significant risks to the environment and human health. Orogenic lode Au deposits, hosted mainly by quartz-carbonate veins, occur in deformed greenstone and metasedimentary terranes around the world. These deposits are the main source of Au in Canada, and are presently a key focus for exploration and development. This Open File Report summarizes results from a three-year environmental geochemistry and mineralogy study of past-producing Au deposits in the Bridge River Mining District in British Columbia. From 2006 to 2008, samples of stream water, sediment, waste rock, tailings, and mine drainage were collected from the Bridge River District, including the Bralorne, King, and Pioneer Au mines near Bralorne, BC. Together, these three mines represent the largest historical Au producer in the Canadian Cordillera (> 4.15 M oz. between 1932 and 1971). Samples were also collected from several nearby antimony (Sb) and mercury (Hg) deposits, which may represent the epizonal portions of the Bralorne-Pioneer hydrothermal system. Baseline concentrations of As, Sb, and Hg in stream sediments from the Bridge River District range from 0.6-168 mg/kg, 0.1-8.3 mg/kg, and 9-1010 µg/kg, respectively. The distribution of these elements is strongly controlled by the original pattern of hydrothermal mineralization within the district. Historical tailings and sediments from underground mine workings have much higher concentrations of As (7.4-137,000 mg/kg; median, 3300 mg/kg), Sb (0.3-707 mg/kg; median, 12.6 mg/kg), and Hg (49->100,000 µg/kg; median, 1200 µg/kg). The highest Hg concentrations occur in tailings at former mill sites where Hg was used for Au amalgamation, and in stream sediments at an abandoned Hg mine. Baseline concentrations of As, Sb, and Hg in filtered stream waters throughout the district ranged from 0.1-4.5 µg/L, 0.03-0.43 µg/L, and 0.6-4.1 ng/L, respectively. Dissolved concentrations of As and Sb were typically much higher in waters draining from mine workings, whereas Hg concentrations were relatively low (<12 ng/L) in all waters sampled. Drainage from the main portal of the Bralorne Mine contains high concentrations of As (2250-2560 µg/L) derived from the flooded mine workings, and this study provides new information on the key processes controlling the composition of this mine effluent. The results of this research can be used to better understand the environmental characteristics of orogenic lode Au deposits, and help to minimize the environmental impacts associated with Au extraction.