RUI: Collaborative Research: Testing models for the Late Jurassic Nevadan Orogeny: Age, provenance, and structural evolution of the Galice and Mariposa basins, OR and CA

拟议的研究将增进对俄勒冈州南部和加利福尼亚州北部北美大陆边缘在收缩变形的关键时期之前和期间的发展的理解。在此期间（晚侏罗纪），造山活动分别封闭了克拉马斯山脉西部和塞拉山脉西部的加利斯和马里波萨沉积盆地。盆地沉积物来源、沉积年龄以及变质作用和变形程度的详细信息可能会在造山事件之前和期间提供最佳的地质记录。该项目为本科生和研究生水平的学生提供了关键的教育优势，需要整合一系列无法​​在课堂上复制的学科知识和技能。该项目将招收研究生和本科生中的女性和代表性不足的少数族裔学生，这些学生将全面参与研究，而不是观察员。通过这项研究进行的体验式学习将提供技能发展和培训，这些技能发展和培训将直接转化为 STEM 劳动力。此外，强调这项研究和关键兴趣领域的现场指南将通过林业服务区和 NSF Flyover Country® 应用程序广泛传播，从而提高公众的科学素养。人们对金矿开采和岩石开采历史的持续兴趣增加了公众参与的可能性。克拉马斯山脉和塞拉西部省份的上侏罗统加利斯和马里波萨地层长期以来一直被认为是了解美国科迪勒拉大陆边缘中生代历史的基础。晚侏罗世内华达造山运动的两种相反的构造模型对加利斯和马里波萨沉积的构造环境和年龄有不同的解释。第一个模型援引了洋内盆地中马里波萨组的成因，该盆地沿着相反倾斜的俯冲带逐渐闭合，而年龄相当的加利斯组则代表了原产于北美西缘的弧间盆地。在第二个模型中，这两个地层都出现在沿北美西部边缘向东倾斜的长期俯冲带上方的拉张盆地内。由于这些地层构成晚侏罗世内华达变形期间变形的最年轻的岩石，因此沉积年龄、沉积物来源以及变形运动学和类型的详细信息对于为所提出的构造模型提供信息并评估其可行性至关重要。对每个盆地进行的全面综合分析，包括岩相特征、碎屑锆石 U-Pb 年龄和 Hf 分析、重矿物分析、沉积结构解释、变质程度评估以及变形时间和运动学分析，将为修改和完善对晚侏罗世大陆边缘的理解提供一个强有力的框架。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识和技能进行评估，被认为值得支持。更广泛的影响审查标准。

The proposed research will improve the understanding of the development of the North American continental margin in southern Oregon and northern California just prior to and during a critical and poorly understood period of contractional deformation. During this time (the Latest Jurrassic), mountain building closed the Galice and Mariposa sedimentary basins in the western Klamath and Sierra mountains, respectively. Details of the basins’ sediment sources, depositional ages, and extent of metamorphism and deformation may provide the best geologic record just prior to and during the mountain-building event. The project provides key educational benefits for students at the undergraduate and graduate level, requiring integration of a range of disciplinary knowledge and skills that cannot be duplicated in a classroom. The project will recruit women and underrepresented minority students at graduate and undergraduate levels, and these students will be full participants in the research, not observers. The experiential learning through this research will provide skill development and training that will translate directly to the STEM workforce. In addition, field guides highlighting this research and key areas of interest will be broadly disseminated through Forest Service districts and the NSF Flyover Country® app, improving public scientific literacy. The ongoing interest in gold mining and the mining history of the rocks that form the focus of this research increase the likelihood of public engagement.The Upper Jurassic Galice and Mariposa Formations in the Klamath Mountains and western Sierran provinces have long been considered fundamental to understanding the mid-Mesozoic history of the U.S. Cordilleran continental margin. Two opposing tectonic models for the Late Jurassic Nevadan orogeny variously interpret the tectonic setting and age of Galice and Mariposa deposition. The first model invokes the genesis of the Mariposa Formation in an intra-oceanic basin that progressively closed along oppositely dipping subduction zones, while the age-equivalent Galice Formation represents an inter-arc basin native to the western margin of North America. In the second model, both formations occur within transtensional basins above an east-dipping, long-lived subduction zone along the western North American margin. Because these strata constitute the youngest rocks deformed during the Late Jurassic Nevadan deformation, details of depositional age, sediment provenance, and the kinematics and style of deformation are critical to informing the proposed tectonic models and assessing their viability. This comprehensive and integrated analysis of each of these basins that includes petrofacies characterization, detrital zircon U-Pb age and Hf analysis, heavy mineral analysis, interpretation of sedimentary structures, assessment of the degree of metamorphism, and analysis of the timing and kinematics of deformation, will provide a robust framework for modification and refinement of the understanding of the Late Jurassic continental margin.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.