Sedimentology of tunnel valley deposits

隧道谷沉积物的沉积学

• 批准号: RGPIN-2019-06568
• 负责人: Eyles, Carolyn
• 金额: $ 2.19万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754856
• 关键词: Sedimentology; tunnel; valley; deposits

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.

加拿大的城市化地区正在迅速扩大，越来越需要定位，管理和保护饮用水来源，特别是从地下水储层（含水层）中。但是，试图定位新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性沉积物的大小和位置，这些沉积物具有浓厚的冰川沉积物，可容纳地下水资源（含水层）。最近的调查表明，许多地下水含水层都托管在大型通道（隧道山谷）中的可渗透沉积物中，这些沉积物在大约20，000年前覆盖北美北美的冰盖下发展。不幸的是，对填充这些隧道山谷或其起源的沉积物的性质的理解有限。在此提案中，我寻求资金来研究阿拉斯加和安大略省南部的隧道谷沉积物的特征，以便更好地了解其沉积学记录和进化。对加拿大未来的地下水勘探和管理至关重要，对隧道谷矿床沉积学的增强理解是必不可少的。 拟议的研究将在两种环境中调查隧道谷的填充物：阿拉斯加的沿海地区，那里的新生代雅卡塔加地层均得到充分暴露，在安大略省南部，通过更新世山谷山谷可获得表面暴露和井眼数据。之所以选择这些地点，是因为两个位置都可以通过隧道谷沉积物在广泛的波浪剪裁平台上以及在世界上无与伦比的任何地方都在垂直的悬崖平台上进行特殊且可访问的曝光。 研究将采用创新的“地结”方法进行，该方法将对冰川地面的检查与沉积物的底层结合。这里提出的研究涉及卫星图像中阿拉斯加和安大略省南部的隧道谷特征的初始识别和映射；然后，这些地图将使用标准的沉积学技术来指导地面和露头的现场调查，以记录晶粒尺寸，沉积结构和单位几何形状。我们还将使用无人机（无人机/无人机）来收集在波浪切割平台和悬崖暴露中暴露的沉积物的高分辨率图像。所有这些数据将用于开发用于隧道谷系统的新沉积模型，以增强这些沉积物中地下水运动的预测。 这项研究将通过增进我们对冰川沉积物的理解及其对地下水的影响，从而极大地使加拿大受益，并有助于对地下水资源进行探索和管理。这项研究还将涉及至少6名新研究生HQP和10名本科生的培训，并且鉴于预计加拿大熟练的专业地球科学家的短缺。