Geomorphic Development and Neotectonic Deformation of Paleolake Coasts in the Eastern Great Basin

该项目将(1)重建大盆地东部晚更新世海岸过程和海岸年代学的区域格局，(2)在具有相对良好约束年龄的选定海岸线上测量300至400个垂直控制点，(3)将这些测量海岸线用作长基线倾斜仪，以重建区域和局部均衡和地震构造形变；(4)对这些数据进行模拟，以约束地球的力学/流变性。最近对博纳维尔湖及其附近两个古湖盆的海岸年代学和岸线形态计量学的研究表明，晚更新世海岸线的变形主要是由博纳维尔湖施加的载荷造成的，但可能包括对大陆冰盖施加的载荷的远场响应。这项研究将极大地扩展现有的数据集，以包括大盆地东部16个古湖盆地最后一个深湖旋回的海侵、最大阶段和海退海岸线的变形。海岸年代学和海岸地貌的研究将与使用电子测距经纬仪的垂直控制测量相结合，以确定湖后变形的空间和时间维度。在月球和行星研究所，观测到的偏转(海岸线倾斜)将被模拟为层状弹性/粘弹性地球对小湖泊、更大的博纳维尔湖以及更大但更远的劳伦蒂德和科迪勒兰冰盖施加的载荷的反应。

This project will (1) reconstruct regional patterns of late Pleistocene coastal processes and coastal chronology in the eastern Great Basin, (2) survey 300 to 400 vertical control points on selected shorelines having relatively well constrained ages, (3) use those surveryed shorelines as long-baseline tiltmeters to reconstruct regional and local isostatic and seismotectonic deformation; (4) and model those data to constrain the mechanical/rheological properties of the earth. Recent studies of coastal chronology and shoreline morphometry in the basins of Lake Bonneville and two nearby paleolakes indicate that deformation of late Pleistocene shorelines resulted mainly from loads imposed by Lake Bonneville, but probably included far-field responses to loads imposed by continental ice sheets. This study will vastly expand the existing data set, to include the deformation of transgressive, maximum-stage, and regressive shorelines of the last deep-lake cycle in 16 paleolake basins in the eastern Great Basin. Studies of coastal chronology and coastal geomorphology will be combined with vertical control surveying using an electronic distance measuring theodolite to define the spatial and temporal dimensions of post-lacustrine deformation. At the Lunar and Planetary Institute, the observed deflections (shoreline tilt) will be modelled as the response of a layered elastic/visco-elastic earth to loads imposed by the small lakes, the much larger Lake Bonneville, and the still more massive but more distant Laurentide and Cordilleran ice sheets.