Deciphering the depositional history of glaciated basins using sedimentology and geomatics

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Many urban areas in Canada and northern North America are underlain by thick (up to 200 m) successions of Quaternary-age sediment deposited under glacial and interglacial conditions.  These sediments form a rich source of information regarding environmental and climatic conditions that existed in the region over the past 120,000 years.  However, there is much debate regarding the origin of many of these sediments.  Some researchers believe that the late Quaternary record was formed by 'catastrophic' subglacial megafloods while others believe it formed through 'normal' subglacial processes operating over extended periods of time.  There is also vigorous debate regarding the severity of climatic conditions during past 'glacial' episodes and the extent of glacial lakes in the Great lakes basins.  Understanding the environmental conditions under which the Quaternary sediments formed is essential for accurate reconstruction of past climatic change and also for prediction of subsurface water and contaminant movement in aquifers found within these deposits. This proposal is for funding to examine the depositional origin of Quaternary-age sediments in the Great Lakes basins using both 'traditional' sedimentological techniques and newly developed 'geomatics' approaches that involve computer-based spatial analysis of digital databases.  Subsurface geological databases will be created for selected areas using information obtained from waterwell records, construction reports and natural exposures.  These data will be visualized as 3-D subsurface models and analyzed using GIS software. This will provide valuable information on which the depositional origin of the Quaternary deposits can be determined and will allow identification of the location and form of subsurface aquifers, important information for groundwater resource exploration, protection and remediation issues. The novelty and significance of the proposed research lies in the use of a 'hybrid' approach, combining traditional sedimentological methods of analysis with newly developed techniques for the spatial analysis of large digital databases.  This type of hybrid analysis is used in the oil and gas industry and can now be applied to investigations of Quaternary sediment stratigraphies.