Sedimentology of tunnel valley deposits

加拿大的城市化地区正在迅速扩大，越来越需要确定、管理和保护饮用水源，特别是来自地下水库（含水层）的饮用水源。然而，水文地质学家在寻找新的地下水来源时面临的一个主要问题是确定在厚厚的冰川沉积物序列中承载地下水资源（含水层）的渗透性沉积物单元的大小和位置。最近的调查表明，许多地下水含水层都是在大约2万年前覆盖北美北部的冰盖下形成的大通道（隧道谷）中沉积的可渗透沉积物中。不幸的是，人们对填充这些隧道山谷的沉积物的性质及其起源的了解有限。在这项提案中，我寻求资助，以调查阿拉斯加和南安大略隧道山谷沉积物的特征，以便更好地了解它们的沉积记录和演化。加强对隧道谷沉积物沉积学的了解对加拿大未来的地下水勘探和管理至关重要。

The urbanized regions of Canada are rapidly expanding and there is a growing need to locate, manage and protect sources of drinking water, particularly from groundwater reservoirs (aquifers). However, a major problem facing hydrogeologists trying to locate new sources of groundwater is determining the size and location of units of permeable sediments that host groundwater resources (aquifers) in thick successions of glacial sediment. Recent investigations have shown that many groundwater aquifers are hosted in permeable sediments deposited in large channels (tunnel valleys) that developed beneath the ice sheets that covered northern North America approximately 20,000 years ago. Unfortunately, there is limited understanding of the nature of the sediments infilling these tunnel valleys or their origin. In this proposal I seek funding to investigate the characteristics of tunnel valley sediments in Alaska and Southern Ontario with the aim of better understanding their sedimentological record and evolution. Enhanced understanding of the sedimentology of tunnel valley deposits is essential for future groundwater exploration and management in Canada. The proposed research will investigate the infills of tunnel valleys in two settings: the coastal region of Alaska where the late Cenozoic Yakataga Formation is well exposed, and in southern Ontario where surface exposures and borehole data through Pleistocene tunnel valley deposits are available. These sites were chosen because both locations provide exceptional, and accessible, exposures through tunnel valley deposits on extensive wave cut platforms and in vertical cliff sections on a scale unmatched anywhere in the world. Research will be conducted using an innovative landsystems' approach that integrates examination of glacial landforms with the sediments underlying them. The research proposed here involves initial identification and mapping of tunnel valley features at sites in Alaska and Southern Ontario from satellite imagery; these maps will then guide field investigations of landforms and outcrops using standard sedimentological techniques that document grain size, sedimentary structures, and unit geometries. We will also use an unmanned aerial vehicle (UAV/drone) to collect high resolution imagery of sediment exposed on wave cut platforms and in cliff exposures. All of these data will be used to develop new depositional models for tunnel valley systems that will enhance the prediction of groundwater movement in these deposits. This research will greatly benefit Canada by enhancing our understanding of glacial sediments and their influence on the movement of groundwater, and will aid in the exploration for, and management of, groundwater resources. This research will also involve the training of at least 6 new graduate HQP's and 10 undergraduates and is significant given the anticipated shortage of skilled professional geoscientists in Canada.