Collaborative Research: An integrated mantle to surface study of the causes and consequences of high topography in the Northern US Cordillera

最近的理论进展表明，发生在地球地幔深处的过程可能对地球表面的地形产生重大影响。由于一个地区的地形历史可以影响气候和生物进化，了解地幔在塑造景观中的作用对于了解地球作为一个系统至关重要。地幔和地表过程联系研究的一个主要障碍是，很少有地方存在过去的地幔和地表事件的时间历史可以很好地约束。内陆西北部，其中包括黄石热点的研究通过，提供了一个独特的机会来研究地幔动力学在山脉隆起和景观演化中的作用。该项目的重点是在俄勒冈州和爱达荷州的现场，被设计为一个综合的地幔表面的研究，量化的区域侵蚀历史和该地区下的上地幔的结构。 这项工作的结果将激励广义模型，将不同的地幔过程和地形响应的隆起模式的范围。因此，我们的发现，虽然具体到我们的现场，可能有助于阐明地幔和表面的相互作用在地球仪。该项目将支持来自不同合作研究机构的三名研究生和三名主要研究人员。该项目还通过与俄勒冈州东部的两个组织建立伙伴关系，将学术科学家和研究生与公共教育工作者和科学传播者联合起来：Wallowa资源，一个从事教育推广，环境行动，可再生能源计划和Wallowology的组织，这是该地区唯一的自然历史博物馆。地幔动力学在推动隆起和景观演化中的作用是一个关键的，但人们对其了解甚少。地球动力学和地貌学研究方面。该项目将探索美国西北部崎岖多山的内陆地区的黄石羽状痕迹以北的地幔驱动的造山隆起和景观演化。没有其他地方有一个大陆经历了这样一个最近和深刻的相互作用与地幔柱，使该地区的理想候选人的岩石圈尺度的地幔动力学的反应检查。指导我们的调查是岩石圈和景观的黄石羽响应的四个可检验的假设：（1）隆起和侵蚀后，岩石圈损失通过分层，（2）隆起和侵蚀后，岩石圈损失通过滴状瑞利-泰勒对流，（3）隆起和侵蚀后，平坦的浮动黄石羽，和（4）侵蚀驱动的断层引起的排水重组。我们将在俄勒冈州东北部和爱达荷州中部的地震、地质和景观研究的坚实基础上再接再厉。这项有针对性的研究将通过地质和地貌实地观测、低温热年代学、碎屑宇宙成因放射性核素得出的侵蚀率和地幔层析成像，通过地球动力学和景观演变建模，解决区域景观演变及其与成像地幔结构的关系。该研究将生成模型，将地幔动力学与隆起和景观发展联系起来，受到我们研究区域数据的约束，并适用于整个地球历史的其他位置。这项工作将有助于完善板块构造理论，提供一个强大的研究板内变形无关板块边界力。此外，我们预计这项研究将提供最清晰的测量的重要性，地壳下地幔变形的景观演化，一个关键的主题，研究从安第斯山脉西藏。

Recent theoretical advances suggest processes occurring deep within Earth's mantle can have significant impacts on topography at Earth's surface. As topographic history of a region can influence the climate and biologic evolution, understanding the role of the mantle in shaping the landscape is paramount to understanding the Earth as a system. A major barrier to the study of mantle and surface process linkages is that few locations exist where time histories of past mantle and surface events can be well constrained. The inland northwest, which includes the well-studied passage of the Yellowstone hotspot, offers a unique opportunity to examine the role mantle dynamics play in mountain uplift and landscape evolution. This project, which focuses on field sites in Oregon and Idaho, is designed as an integrated mantle to surface study that quantifies the regional erosion history and the structure of the upper mantle beneath this region. Results from this work will motivate generalized models incorporating different mantle processes and the topographic response to a range in uplift patterns. As a result, our findings, while specific to our field sites, may help shed light on mantle and surface interactions around the globe. The project will support three graduate students and three Primary Investigators from separate collaborating research institutions. The project also unites academic scientists and research students with public educators and science communicators through a partnership with two eastern Oregon organizations: Wallowa Resources, an organization that engages in educational outreach, environmental action, and renewable energy programs and Wallowology, the only natural history museum in this region.The role of mantle dynamics in driving uplift and landscape evolution is a critical and poorly understood facet of geodynamics and geomorphology research. This project will explore mantle driven epeiorogenic uplift and landscape evolution north of the Yellowstone plume track in the rugged and mountainous Inland Northwest of the United States. Nowhere else has a continent experienced such a recent and profound interaction with a mantle plume, making this area the ideal candidate for the examination of lithosphere-scale responses to mantle dynamics. Guiding our investigation are four testable hypotheses of lithospheric and landscape responses to the Yellowstone plume: (1) uplift and erosion following lithospheric loss through delamination, (2) uplift and erosion following lithospheric loss through drip-like Rayleigh-Taylor convection, (3) uplift and erosion following flattening of the buoyant Yellowstone plume, and (4) erosion driven by faulting induced drainage reorganization. We will build on a strong foundation of prior seismic, geologic and landscape studies across northeastern Oregon and central Idaho. This targeted study will resolve regional landscape evolution and its relation to imaged mantle structure via the integration of geologic and geomorphic field observations, low-temperature thermochronology, and detrital cosmogenic radionuclide derived erosion rates and mantle tomography through geodynamic and landscape evolution modeling. The research will generate models that relate mantle dynamics to uplift and landscape development, constrained by data from our study area and applicable to other locations throughout earth history. This work will help to refine plate-tectonics theory by providing a robust study of intraplate deformation not related to plate boundary forces. Furthermore, we anticipate this study will give the clearest-yet measure of the importance of sub-crustal mantle deformation on landscape evolution, a critical topic in studies from the Andes to Tibet.