RUI: Collaborative Research: Early Cenozoic basin development in the southwestern US: a record of extensional collapse following subduction of an oceanic plateau?

俯冲带是地球上构造活动最活跃的地区之一。下行板块角度的变化可以控制上覆陆壳的火山作用、断层作用和盆地发育。暴露于加州南部莫哈韦沙漠的Maniobra组和Goler组为晚白垩世至始新世（约8000 - 5000万年前）与低角度俯冲有关的上覆大陆板块上伸展盆地的发育提供了证据。这项研究将测试的假设，晚白垩世的扩展导致的Maniobra和Goler盆地的发展，同时介绍了50多名本科生和2名硕士生的盆地分析技术。位于莫哈韦沙漠的野外基地距离洛杉矶不到3小时车程，为培养下一代地球科学家提供了天然实验室。来自西班牙裔服务机构的学生将学习现代地质技术，如地质测绘，地质年代学，古地磁学和热年代学，这些技术可以应用于他们的研究生和研究生职业生涯。这项研究的分析数据将在社区数据库上提供，拟议的研究结果将用于构建一个公开的在线学习模块。最近的构造模型的西南部美国科迪勒拉调用俯冲的海洋高原，共轭沙茨基隆起，作为驱动器的板扁平化，俯冲侵蚀和弧停止在晚白垩世至始新世的时间。俯冲和随后的高原通道可能促进了伸展和相关的区域古地理变化，如盆地发育和地块旋转。本研究的目标是Goler和Maniobra组，这是唯一的晚白垩世至始新世盆地地层位于沿着解释俯冲路径。这项研究将测试的假设，重力崩溃后，高原俯冲是广泛的整个莫哈韦地区在晚白垩世至新生代早期，并导致超拆离盆地的发展和剥露的残余俯冲复合体。这项研究将结合磁性地层学、碎屑锆石物源分析、基底和碎屑热年代学，对地层和构造关系进行新的测绘。这些数据将限制盆地形成的时间和持续时间，并能够评估盆地发展的不同构造模型。从晚白垩世到始新世Goler和Maniobra地层的新盆地分析结果将提供高原俯冲过程和相关地表变形之间的关键联系，并将突出构造演化的复杂性，沿着高度分段的边缘随着时间的推移。该奖项反映了NSF的法定使命，并已被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Subduction zones represent some of the most tectonically active regions on earth. Changes in the angle of the downgoing plate can control volcanism, faulting, and basin development in the overlying continental crust. The Maniobra and Goler Formations, exposed in the Mojave Desert in southern California, provide evidence for the development of extensional basins on the overriding continental plate related to low-angle subduction in Late Cretaceous to Eocene time (~80-50 million years ago). This research will test the hypothesis that Late Cretaceous extension resulted in the development of the Maniobra and Goler Basins, while simultaneously introducing more than 50 undergraduate and 2 Masters students to the techniques of basin analysis. The field sites in the Mojave Desert, located within 3 hours of Los Angeles, provide a natural laboratory to train the next generation of geoscientists. Students from a Hispanic-serving institution will learn modern geologic techniques, such as geologic mapping, geochronology, paleomagnetism, and thermochronology, that can be applied to their graduate and post-graduate careers. Analytical data from this research will be made available on community databases, and results of the proposed research will be used to construct a publicly-available online learning module.Recent tectonic models of the southwestern US Cordillera have invoked the subduction of an oceanic plateau, the conjugate Shatsky Rise, as a driver of slab flattening, subduction erosion and arc cessation in Late Cretaceous to Eocene time. Subduction, and subsequent passage of the plateau, likely promoted extension and associated regional paleogeographic changes, such as basin development and block rotations. This study targets the Goler and Maniobra Formations, which are the only Late Cretaceous to Eocene basinal strata located along the interpreted subduction pathway. This research will test the hypothesis that gravitational collapse in the wake of plateau subduction was widespread across the Mojave region in the Late Cretaceous to early Cenozoic and led to the development of supra-detachment basins and the exhumation of relict subduction complexes. This research will incorporate new mapping of stratigraphic and structural relationships, combined with magnetostratigraphy, detrital zircon provenance analysis, and basement and detrital thermochronology. This data will constrain the timing and duration of basin formation and enable the evaluation of different tectonic models of basin development. New basin analysis results from the Late Cretaceous to Eocene Goler and Maniobra Formations will provide a crucial link between plateau subduction processes and related surface deformation and will highlight the complexity of tectonic evolution along a highly segmented margin over time.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.