Collaborative Research: New Constraints on the Geodynamics of the Lake Bonneville Basin

这个项目的重要性部分是基于地球动力学研究中这种机会的稀缺性。邦纳维尔湖是更新世晚期地球上最大的洪积湖之一，拥有最著名的湖泊历史之一，拥有多个已知年龄的海岸线，现在被任何规模相当的洪积湖盆地的最佳地形数据集所覆盖。这些因素的汇合，以及建模和分析的进展，将有助于更好地了解均衡反弹和伴随的地壳变形的过程和速率。这项研究将为其他区域和其他大陆的湖盆的地球动力学研究提供一个模板。 除了开发新的见解，将被使用的Bonneville盆地的地球动力学的粘度模型和其他更好地约束和理解地震周期，这项研究的结果对其他学科，如地质年代学的影响。这项工作的结果也可能有助于地热能勘探，更好地限制高热流异常的尺寸，这可能是由超高的海岸线区域不符合其加载历史。该项目还将对研究生进行跨学科培训，并通过大盆地古环境数据库网站（www.dri.edu/gbped）向广大受众进行宣传和传播。除了向该数据库添加研究产生的新出版物外，该项目还将开发一个在线教育模块，突出Bonneville盆地有据可查的环境和地球动力学历史。该模块将是一个更大的努力，以教育感兴趣的观众在大盆地的第四纪历史的各个方面的一部分。邦纳维尔湖盆地已成为地球动力学研究的首要例子之一，因为在1890年引入的粘弹性基板上的弹性板的等值线模型。从那时起，该盆地一直是许多研究的主题，详细阐述了均衡反弹的时间，幅度和过程，以及地壳和上地幔对邦纳维尔湖施加的巨大负荷的反应。该项目的目标是采用密度更高的海岸线高程测量、更精确的载荷历史、回弹信号的地理信息系统空间分析以及模拟地球均衡响应的全三维有限元模型。自上一次关于盆地反弹的主要出版物以来，在湖泊级年表（加载历史）、建模复杂性、三维分析、地形数据以及定义由多个离散岸线记录的反弹几何形状的能力方面都有了重大改进。这些改进的结合将导致一个更好的约束三维地球模型记录岩石圈强度和粘度结构的横向变化。这项工作的地质年代学结果可能会限制海岸线的发展速度，也可能会导致宇宙成因表面暴露测年的校准生产率的修订。

The significance of this project is based, in part, on the rarity of this type of opportunity in geodynamic research. Lake Bonneville was one of the largest pluvial lakes on the planet during the late Pleistocene, has one of the best known lake-level histories, possesses multiple shorelines of known ages, and is now covered by the best topographic data set for any pluvial lake basin of comparable size. The convergence of these factors, as well as advances in modeling and analysis, will facilitate greater understanding of the processes and rates of isostatic rebound and accompanying crustal deformation. This study will provide a template for what is possible for geodynamic studies in lacustrine basins located in other regions and on other continents. In addition to developing new insights on the geodynamics of the Bonneville basin that will be used by geophysicists and others to better constrain viscosity models and understand the earthquake cycle, the results of this research have implications for other disciplines such as geochronology. Results from this work may also assist in geothermal energy exploration by better constraining the dimensions of high heat flow anomalies, which may be expressed by regions of super-elevated shorelines not consistent with their loading history. This project will also result in the interdisciplinary training of graduate students and be highlighted and disseminated to a broad audience through the Great Basin Paleoenvironmental Database website (www.dri.edu/gbped). In addition to adding to this database with new publications resulting from the research, the project will develop an online educational module highlighting the Bonneville basin's well documented environmental and geodynamic history. This module will be part of a larger effort to educate interested viewers on various aspects of the Quaternary history of the Great Basin.The Lake Bonneville basin has become one of the premier examples of geodynamic research since the isostasy model of an elastic plate overlying a visco-elastic substrate was introduced in 1890. Since that time, the basin has been the subject of numerous studies elaborating on the timing, magnitude, and processes of isostatic rebound and the response of the crust and upper mantle to the enormous loads imposed by Lake Bonneville. The goal of this project is to employ much higher density shoreline elevation measurements, a more refined loading history, geographic information system spatial analysis of the rebound signal, and a fully three-dimensional finite-element model for simulating the isostatic response of the Earth. Since the last major publication on the rebound of the basin, significant improvements have been made to the lake-level chronology (loading history), modeling sophistication, three-dimensional analysis, topographic data, and the ability to define the geometry of rebound recorded by multiple, discrete shorelines. The combination of these improvements will lead to a much better constrained three-dimensional Earth model documenting lateral variations in lithospheric strength and viscosity structure. Geochronology results from the work may provide constraints on rates of shoreline development and also may lead to revision of calibrated production rates for cosmogenic surface exposure dating.