CGRG Bibliography of Canadian Geomorphology
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Author : Endres, A.L.; and Bajc, A.F.
Date : 2004.
Title : Reconnaissance GPR profiling of near surface Quaternary deposits in Waterloo region, southwestern Ontario.
Publication : 49th Annual Meeting of the Geological Association and the Mineralogical Association of Canada. May 12-14, 2004. Brock University, St. Catharines, Ontario.
Issue :
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Abstract
Ground penetrating radar (GPR) profiling was conducted at 14 sites throughout the Regional Municipality of Waterloo. Most test sites were situated within the Waterloo Moraine. One site was located in the Elmira Moraine at the north end of Woolwich Township and 2 sites were situated over glaciofluvial deposits within the Grand River valley. All GPR lines were surveyed twice using both 50 MHz and 100 MHz antennae. One short transect line was also surveyed with 200 MHz antennae. Over 16 kilometres of GPR profiles have been acquired to date. Additional profiling is planned for 2004. Most of the upcoming surveying will be conducted in sand and gravel pits where calibration of the GPR signature is possible by collecting data at the tops of well exposed vertical exposures and relating the responses observed to the “unknown” test sites. The primary objective of the GPR profiling was to image the stratigraphy within the near surface deposits and infer their depositional environments. Sites were chosen on the basis of surface morphology and consisted of hummocky terrain, ridges, gently undulating terrain and plains. Profiles from areas of hummocky terrain and ridges generally displayed variably-scaled channelized systems indicative of deposition in a glaciofluvial and/or subaquatic fan environment. There is very little evidence from the GPR profiling to support an ice-contact depositional environment. Faults and chaotic bedding are infrequently observed in the profiles. Reflectors are generally flat-lying and commonly truncated along slopes and valley walls. Much of the apparent hummocky topography is therefore interpreted as erosional in origin. Channel-form reflector packages often lie at the bases of knolls and hummocks indicating incision of pre-existing deposits. Gently undulating terrain and plains generally display variable internal reflector structure. Flat-lying parallel reflectors are interpreted to represent deposition in a basinal glaciolacustrine setting. Channelized reflectors on flat plains indicate deposition in shallow braided streams or deltaic environments.
Bibliography of Canadian Geomorphology