Collaborative Research: Investigating Slip Distribution over Multiple Timescales across the Central Walker Lane: Implications for the Evolution of an Active Tectonic Plate Boundary

沃克巷是横跨加利福尼亚州和内华达州边界的西北方向变形带的神秘地带，长近700公里。它的主要特征是北西向断裂，显示出右旋剪切的证据。Walker Lane的断层是在太平洋和北美板块相互滑动时相对运动的变形作用下形成的。这项研究的目的是研究沿内华达州相对狭窄的中央Walker Lane东部的一组活动断裂的断层滑动和运动的时空分布。这项研究将利用在多个时间尺度上收集的这些断层的现代地质技术，得出右向(右)断层的第一断层滑动速率。这一结果将确定右行断裂的时间，并将在第四纪(即从大约260万年到现在)产生更准确的断层滑移率。这项研究中获得的数据将有助于改进对该地区地震危险性的估计。除了研究的科学目标外，该项目将通过指导两名早期职业科学家，促进加强和多样化地球科学学术队伍；它将通过学生、教师和来自多个机构的研究人员之间的合作，促进跨学科研究项目；它将通过参与研究和以高影响力的探究为基础的课程活动，促进对下一代科学家的培训；将把这些活动传播给教学界，供他们在自己的课程中采用，以提高地球科学素养；并将通过开发讲座和在线陆地和空中视频的外联计划，提高公众的科学素养。该项目代表了不同规模和任务的教育和研究机构之间以及与国家和政府机构之间的合作和伙伴关系。主要调查人员将调查沿着一组活动的西北走向的右旋断层的断层和断层运动学的时空分布，这些断层横跨内华达州沃克巷中央相对狭窄的东部。这项研究涉及一项综合的地质填图计划，包括陆地激光扫描构造和运动学研究，40Ar/39Ar年代学，陆地宇宙成因10Be和36Cl，以及U系列测年。这项研究的动机是：目前正在进行的对Walker Lane中央当代右旋应变累积的GPS研究；对Walker Lane北部和南部更广泛形变区右旋应变释放的地质研究；以及推动变形的力随时间的拟议变化，包括边缘力(与太平洋和北美板块之间相对运动方向和速度的变化有关)和内力(由于内华达山脉最近隆起而增加的重力势能)。Walker Lane是一个右旋剪切带，容纳了叠加在盆地和山脉伸展上的太平洋-北美相对板块运动的大约25%。我们建议的跨中央Walker Lane的研究计划将产生在多个时间尺度(数百万到数千)收集的右旋断层滑移率，并对右旋断层的时间进行标记。记录沿沃克巷这部分断层的应变释放模式，将使主要调查人员能够表征沿着沃克巷这一部分断层的应变释放的空间和时间模式。将这些数据与Walker Lane其他地方正在进行的类似地质研究以及整个Walker Lane正在进行的研究相结合，将使主要调查人员能够记录Walker Lane西部和东部、邻近的盆地和山脉以及Walker Lane北部之间的应变分配幅度。检查这些数据将能够评估Walker Lane的应变模式是否与美国西部潜在驱动力的已知变化同步变化。该项目将支持U系列地质年代学技术的继续开发和应用，以确定第四纪晚期地貌和沉积物的年代。这项研究中使用的陆地宇宙成因放射性核素和U系列地质年代学相结合，将对其在大盆地晚第四纪地貌和沉积物测年中的应用进行全面评估，这将为该地区和世界未来的滑移率研究提供信息。

The Walker Lane is an enigmatic zone of northwest-trending belt of deformation that straddles the California and Nevada border and is nearly 700 kilometers long. It is primarily characterized by northwest-striking faults that show evidence of right-lateral shear. The faults of the Walker Lane have formed in response to deformation related to relative motion of the Pacific and North American tectonic plates as they slide past one another. The goal of this study is to investigate the spatial and temporal distribution of fault slip and motion along a set of active faults across the relatively narrow eastern part of the central Walker Lane in Nevada. This research will yield the first fault slip rates from right-lateral (dextral) faults using modern geologic techniques collected over multiple time scales on these faults. The results will bracket the timing of dextral faulting and will result in more accurate fault slip rates during the Quaternary (i.e., from about 2.6 million years to the present-day). The data obtained in this study will aid in developing improved estimates of seismic hazards in the region. In addition to the scientific objectives of the study, the project will contribute to strengthening and diversify the geoscience academic workforce through mentorship of two early career scientists; it will promote interdisciplinary research projects through collaborations among students, faculty, and researchers from multiple institutions; it will contribute to the training of the next generation of scientists by involvement in research and high impact inquiry-based course activities; will disseminate these activities to the teaching community for adoption in their own courses to increase geoscience literacy; and will enhance scientific literacy of the public by developing an outreach program of lectures and online land- and aerial-based videos. The project represents collaboration and partnerships between educational and research institutions of diverse scale and mission, as well as with state and governmental agencies. The principal investigators will investigate the spatial and temporal distribution of faulting and fault kinematics along a set of active northwest-striking dextral faults across the relatively narrow eastern part of the central Walker Lane, Nevada. The research involves an integrated program of geologic mapping including terrestrial laser scanning structural and kinematic studies, and geochronology using 40Ar/39Ar, terrestrial cosmogenic 10Be and 36Cl, and U-series dating. The research is motivated by: ongoing GPS studies of contemporary dextral strain accumulation in the central Walker Lane; geologic studies of dextral strain release across wider zones of deformation in the northern and southern Walker Lane; and proposed changes in the forces driving deformation over time including edge forces (related to changing directions and rates of relative motion between the Pacific and North American plates) and internal forces (increased gravitational potential energy as a consequence of recent uplift of the Sierra Nevada). The Walker Lane is a zone of dextral shear that accommodates approximately 25% of the Pacific-North American relative plate motion that is superimposed on Basin and Range extension. Our proposed research program across the central Walker Lane will yield dextral fault slip rates collected over multiple time scales (millions to thousands) and brackets on the timing of dextral faulting. Documenting the strain release patterns along faults in this part of the Walker Lane will allow the principal investigators to characterize the spatial and temporal patterns of strain release along faults in this part of the Walker Lane. Combining these data with similar geologic studies ongoing elsewhere in the Walker Lane, and studies ongoing throughout the Walker Lane will allow the principal investigators to document the magnitude of strain partitioning among the western and eastern central Walker Lane, the adjacent Basin and Range, and the northern Walker Lane. Examination of these data will allow assessment of whether patterns of strain in the Walker Lane have changed in synchrony with known changes in potential driving forces the western U.S. This project will support the continued development and application of U-series geochronological techniques for dating late Quaternary landforms and deposits. The combination of terrestrial cosmogenic radionuclide and U-series geochronology used in this study will provide a comprehensive evaluation of its application to dating late Quaternary landforms and deposits in the Great Basin that will inform future slip-rate studies in this region and worldwide.