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TitleSedimentology and Hydrogeology of the Paris and Galt Moraines
AuthorRussell, H A J; Bajc, A F; Sharpe, D R; Cummings, D I
SourceIAH-CNC 2015 Waterloo, abstracts; 2015.
Alt SeriesEarth Sciences Sector, Contribution Series 20150063
MeetingIAH-CNC 2015 Waterloo; Waterloo; CA; October 27-30, 2015
NTS40P/08; 40P/09
AreaBrantford; Cambridge; Guelph
Lat/Long WENS-80.5000 -80.0000 43.7500 43.2500
Subjectsstratigraphy; sedimentology; hydrogeology; glacial deposits; moraines; aquifers; groundwater; lithology; sands; clays; silts; gravels; depositional models; depositional environment; stratigraphic analyses; stratigraphic correlations; pits; cores; boreholes; modelling; Paris Moraine; Galt Moraine; St. George Aquifer; Grand River; Blue Spring Creek; Quaternary
Illustrationsgeological sketch maps; stratigraphic correlations
ProgramAquifer Assessment & support to mapping, Groundwater Geoscience
AbstractThe Paris and Galt moraines extend from near Lake Erie, 130 km north towards the Caledon area, are up to 11 km wide, and have a relief of 30 m. They evolve from two distinct ridges in the south to a broad, hummocky terrain with multiple ridges and secondary landscape elements (kettle depressions, eskers, subaerial fans, channels) in the north. These geomorphic changes are mirrored by changes in sediment type, thickness, and stratigraphy. Continuous cores reveal that the moraine consists of a succession of intercalated sand, gravel and diamicton units. Depending on the geographic location, a variety of different units can underlie the moraine, including older tills, lacustrine mud, or glacifluvial sand and gravel. Locally, the lower contact is cryptic where the moraine overlies sedimentologically similar deposits. Outcrop data suggest northern and southern parts of the moraine are different. Within the southern glacilacustrine basin, large foresets of >10 m height occur at the base of one pit exposure. By contrast, horizontally stratified outwash gravel is common in northern pits. A stoney, sandy silt diamicton, (Wentworth Till), covers large parts of the moraine, is massive to stratified, and is locally inter-bedded with sand and gravel. Where overlain by gravel, its upper contact can be loaded, suggesting it was water-saturated and thus prone to deformation during gravel deposition. Glacifluvial deposits are present in front of and locally underneath the moraine. The moraine strata are interpreted to have been deposited during a pause in the overall retreat of the Erie-Ontario ice margin with a highly variable meltwater flux both spatially and temporally. The narrow, southern moraine ridges may represent more rapid retreat within a glacial lake basin given the scale of foresets and confining lacustrine sediment. The northern, broader hummocky terrain is interpreted to have been deposited in a terrestrial environment based on the bedding character of the glacifluvial sand and gravel.
Of the numerous moraines present within the Grand River watershed, the Paris-Galt moraines represent one of the three most hydrogeologicaly significant moraines, along with the Waterloo and Orangeville. The hummocky terrain of the moraine likely contributes to enhanced infiltration and recharge; a number of local aquifers occur within the moraine sediments (e.g. St George Aquifer); and the porous substrate of the moraine enhances groundwater contribution to baseflow of the Grand River.
Summary(Plain Language Summary, not published)
Documents sedimentology of the Paris and Galt moraines and places the aquifer potential of the moraines in this geological context.