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TitreChemical and isotopic evidence of fragmented recharge areas for the carbonate aquifers of the Niagara Escarpment
TéléchargerTéléchargement (publication entière)
AuteurPriebe, E H; Frape, S K; Jackson, R E; Rudolph, D L; Burt, A K
SourceRegional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario geoscientists open house; par Russell, H A J; Ford, D; Priebe, E H; Holysh, S; Commission géologique du Canada, Dossier public 8363, 2018 p. 34, https://doi.org/10.4095/306568
Année2018
ÉditeurRessources naturelles Canada
RéunionRegional-Scale Groundwater Geoscience in Southern Ontario: Open House; Guelph; CA; février 28 - mars 1, 2018
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/306568
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Russell, H A J; Ford, D; Priebe, E H; Holysh, S; (2018). Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario geoscientists open house, Commission géologique du Canada, Dossier public 8363
Formatspdf
ProvinceOntario
SNRC30M/05; 40P/08NE; 30M/12; 30M/11NW; 30M/13; 30M/14; 30M/15NW; 30M/15NE; 30M/16NW; 30M/16NE; 31C/04SW; 31C/04NW; 31D/01; 31D/02; 31D/03; 31D/04; 31D/06; 40P/09SE; 40P/09NE; 40P/16SE; 40P/16NE
Lat/Long OENS -80.2500 -77.5000 44.5000 43.2500
Sujetseau souterraine; aquifères; ressources en eau souterraine; estimation des ressources; régimes des eaux souterraines; géochimie des eaux souterraines; géologie du substratum rocheux; lithologie; roches sédimentaires; carbonates; dolomites; topographie karstique; dépôts glaciaires; etudes isotopiques; analyses géochimiques; épaisseur de la couverture meuble; tritium; rapports strontium-strontium; géochimie du calcium; sulfate; pyrite; hydrogéochimie; Bassin de Michigan ; Till de Newmarket ; Till d'Halton ; Moraine d'Oak Ridges ; Approvisionnement en eau; hydrogéologie; géochimie; géologie régional; géologie des dépôts meubles/géomorphologie; Phanérozoïque; Paléozoïque; Silurien
Consultation
Endroit
 
Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre)
 
ProgrammeAquifer Assessment & support to mapping, Géoscience des eaux souterraines
Diffusé2018 02 16
Résumé(disponible en anglais seulement)
The Early Silurian carbonate bedrock formations of the Michigan basin, southern Ontario, contain significant quantities of high-quality groundwater resources and provide the sole drinking water source to many large municipalities and private residences. This investigation represents the first attempt to characterize these carbonate groundwater resources in their entirety. Although the bedrock formations are relatively flat-lying and regionally extensive, suggesting ease of characterization, the systems are complex due to the influence of glacial sediment cover on recharge and the effect of karst on groundwater residence times. Recharge timing and controls are investigated with several isotopic and geochemical indicators of recent recharge in groundwater, within the context of the sedimentary geology and sediment thickness of the study area. Spatial trends of tritium, and SF6 in groundwater, interpreted as representing recent recharge (< 50 years), corroborate with aerobic redox chemistry in the carbonate groundwater systems underlying areas of thin or permeable sediment cover. Groundwater chemical evolution beyond recharge areas is assessed with general chemistry, the redox profile and an investigation of water-rock interaction. A comparison of strontium isotope ratios (87Sr/86Sr) in bedrock and groundwater shows that long residence times are required for the isotopic signature of the rock to imprint on the groundwater. Increasing Sr to Ca ratios along the groundwater flow path are likely resulting from incongruent dissolution of dolomite and the precipitation of calcite with evolution. Sulphur isotopic composition of sulphate (delta-34SSO4 and delta-18OSO4) in groundwater shows isotopic evidence of pyrite oxidation in recharge areas, and a Silurian sulphur isotopic signature in areas of thick and low permeability sediments, well downgradient of identified recharge areas. For this investigation, isotopic and hydrochemical tools have provided many essential lines of evidence, supporting the development of a conceptual model of recharge and groundwater evolution in this complex setting with many geological controls at play.
GEOSCAN ID306568