Sedimentology of tunnel valley deposits

加拿大的城市化地区正在迅速扩大，人们越来越需要定位、管理和保护饮用水水源，特别是地下水库(含水层)的水源。然而，试图寻找新的地下水来源的水文地质学家面临的一个主要问题是确定可渗透沉积物单元的大小和位置，这些可渗透沉积物单元在厚厚的冰川沉积物序列中承载着地下水资源(含水层)。最近的调查表明，许多地下水含水层赋存于可渗透的沉积物中，这些沉积物沉积在大约20,000年前覆盖北美北部的冰盖下发育的大型渠道(隧道山谷)中。不幸的是，人们对充填这些隧道山谷的沉积物的性质或其来源的了解有限。在这项提议中，我寻求资金来调查阿拉斯加和安大略省南部隧道谷沉积物的特征，目的是更好地了解它们的沉积学记录和演化。加强对隧道谷地沉积物沉积学的了解对于加拿大未来的地下水勘探和管理是至关重要的。拟议的研究将在两个背景下调查隧道山谷的充填情况：阿拉斯加沿海地区，晚新生代Yakataga组暴露良好，安大略省南部，那里有更新世隧道山谷沉积的地表暴露和钻孔数据。之所以选择这些地点，是因为这两个地点都提供了特殊的、可访问的暴露，通过广泛的波浪切割平台上的隧道山谷沉积物和垂直悬崖段，其规模是世界上任何地方都无法比拟的。将使用一种创新的“土地系统”办法进行研究，将冰川地貌的检查与冰川地貌下的沉积物结合起来。这里提出的研究包括从卫星图像初步识别和绘制阿拉斯加和安大略省南部地点的隧道山谷特征；然后这些地图将指导使用标准沉积学技术对地貌和露头进行实地调查，这些技术记录了粒度、沉积结构和单元几何形状。我们还将使用无人驾驶飞行器(无人机/无人机)收集在波浪切割平台和悬崖曝光中暴露的沉积物的高分辨率图像。所有这些数据将被用来开发新的隧道山谷系统沉积模型，以加强对这些沉积物中地下水运动的预测。这项研究将增进我们对冰川沉积物及其对地下水运动的影响的了解，从而使加拿大受益匪浅，并将有助于地下水资源的勘探和管理。这项研究还将涉及对至少6名新毕业的HQP和10名本科生的培训，鉴于加拿大预计缺乏熟练的专业地球科学家，这项研究具有重要意义。

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.