Deciphering the depositional history of glaciated basins using sedimentology and geomatics

加拿大和北美北部的许多城市地区都是在冰期和间冰期条件下沉积的第四纪厚（高达200米）沉积层。这些沉积物形成了有关该地区过去12万年存在的环境和气候条件的丰富信息来源。然而，关于这些沉积物的来源存在很多争论。一些研究人员认为，晚第四纪记录是由“灾难性的”冰下特大洪水形成的，而另一些人则认为它是通过长时间的“正常”冰下过程形成的。关于过去“冰川”时期气候条件的严重程度和五大湖盆地冰川湖的范围，也存在激烈的争论。了解第四纪沉积物形成的环境条件对于准确重建过去的气候变化以及预测这些沉积物中发现的含水层中的地下水和污染物运动至关重要。这项提议是为了资助研究大湖盆地第四纪沉积物的沉积起源，使用“传统的”沉积学技术和新开发的“地理信息学”方法，其中包括基于计算机的数字数据库空间分析。将利用从水井记录、施工报告和自然暴露中获得的信息，为选定地区建立地下地质数据库。这些数据将被可视化为三维地下模型，并使用GIS软件进行分析。这将提供宝贵的资料，使第四纪沉积物的沉积来源得以确定，并可查明地下含水层的位置和形式，这是地下水资源勘探、保护和补救问题的重要资料。该研究的新颖性和意义在于使用了一种“混合”方法，将传统的沉积学分析方法与新开发的大型数字数据库空间分析技术相结合。这种类型的混合分析用于石油和天然气工业，现在可以应用于第四纪沉积地层的研究。

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.