GEOSCAN, résultats de la recherche


Titre3-D sediment mapping on the Niagara Peninsula
TéléchargerTéléchargement (publication entière)
LicenceVeuillez noter que la Licence du gouvernement ouvert - Canada remplace toutes les licences antérieures.
AuteurBurt, A K
SourceRegional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house; par Russell, H A J; Ford, D; Priebe, E H; Commission géologique du Canada, Dossier public 8212, 2017 p. 5, (Accès ouvert)
ÉditeurRessources naturelles Canada
RéunionOntario Geological Survey and Geological Survey of Canada groundwater geoscience open house; Guelph; CA; mars 1-2, 2017
Documentdossier public
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Russell, H A J; Ford, D; Priebe, E H; (2017). Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house, Commission géologique du Canada, Dossier public 8212
SNRC30L/13; 30L/14; 30L/15; 30M/02; 30M/03; 30M/04; 30M/06
Lat/Long OENS -80.0000 -78.7500 43.5833 42.7500
Sujetsétablissement de modèles; eau souterraine; aquifères; ressources en eau souterraine; gestion des ressources; levés géophysiques; levés gravimétriques, sol; levés de reflexion sismiques; diagraphie géophysique; trous de mine; échantillons carrotés; puits d'observation; épaisseur de la couverture meuble; topographie du substratum rocheux; distribution des sédiments; dépôts glaciaires; topographie glaciaire; drumlins; moraines; dépôts glaciolacustres; dépôt deltaïque; cônes alluviaux; épandage fluvio glaciaire; sediments de contact glaciaire; dépôts glaciaires; dépôts fluvioglaciaires; lacs proglaciaires; dépôts postglaciaires; dépôts éoliens; dépôts fluviaux; silts; argiles; sables; graviers; antécédents géologiques; glaciation; Wisconsinien; mouvement de la glace; déglaciation; retrait de la glace; vallées enfouies; Till de Catfish Creek ; Till de Wentworth ; Till d'Halton ; géologie des dépôts meubles/géomorphologie; hydrogéologie; géophysique; Phanérozoïque; Cénozoïque; Quaternaire
ProgrammeGéoscience des eaux souterraines, Aquifer Assessment & support to mapping
Diffusé2017 02 22
Résumé(disponible en anglais seulement)
In 2013, the Ontario Geological Survey (OGS) initiated a 3D sediment mapping project encompassing the Niagara Peninsula. As with other sediment mapping projects, the goals are to reconstruct the Quaternary history of the area, build a 3D model of Quaternary deposits that form regional-scale aquifers and aquitards, and to define the internal characteristics of each sediment package. This study represents a multi-agency collaborative effort: a regional ground gravity survey (6828 stations covering 3920 km2) and sediment logging of hand auger cores, natural sediment exposures, and 95 continuously cored boreholes have been completed by the OGS; the Geological Survey of Canada has completed shallow seismic reflection surveys (48.1 km) and downhole geophysical logging (14 wells); and 28 monitoring wells have been installed and sampled by conservation authority and municipal partners.
This presentation will focus on the results of the 2014-2016 OGS drilling program. The bedrock surface is characterised by southward-dipping strata forming 2 prominent escarpments. Ordovician shale lies below the Niagara Escarpment, Silurian dolostone, shale and gypsum between escarpments and Devonian limestone and cherty limestone above the Onondaga Escarpment. The surface is incised by buried and partially buried bedrock valleys that range from broad and shallow to narrow and deep. Drift thickness is largely controlled by bedrock topography; the thickest sediments are found within the bedrock valleys while the thinnest sediments are found at the escarpments. Drumlins, moraines, deltas and fans form locally thicker sediment accumulations.
In the western part of the area there is a thick older drift package of diamicton, glaciolacustrine silt and clay and sand to gravelly sand that can be correlated with the main Late Wisconsin Catfish Creek Till aquitard, late glacial Port Stanley Till aquitard, Grand River outwash aquifer and Wentworth Till aquitard from adjacent 3D sediment mapping areas. The central and eastern portions of the study area are dominated by younger sediments. Coarse-textured ice-contact stratified drift, glaciofluvial sand and gravel and glaciolacustrine sand that forms the Whittlesey aquifer was deposited during and after ice retreat. Thick glaciolacustrine silt and clay was then deposited in a series of proglacial lakes that ponded against the retreating ice front. In the northern and eastern portions of the area these fine-textured glaciolacustrine deposits are separated into lower and upper Whittlesey aquitards by a 'sandwich' of sandy aquifers and muddy Halton Till, diamicton and glaciolacustrine sediments (Halton aquitard) deposited during the late glacial ice advance out of the Lake Ontario basin. The uppermost unit is typically a thin aquifer composed of post-glacial to modern shoreline, aeolian and river sediments. This high-resolution stratigraphy forms the framework for interpreting monitoring well data collected by conservation authorities and municipalities.
The results of the extensive drilling program mean that the physical properties of aquifer and aquitard sediments can now be defined across the region. This information, as well as seismic velocities obtained by downhole geophysical logging, will allow verification of seismic time sections into depth sections. It is anticipated that combining the results of drilling and geophysics will provide the best possible definition of buried valley geometry and fill; an important objective of the project. The long-term impact of this study will be to provide conservation authority and municipal partners with an improved water resource decision making tool.