Origin of the Columbia River Basalts and Uplift of the Wallowa Mountains

黄石公园的热点大约始于16.5英里。前与洪水有关的玄武岩喷发集中在俄勒冈州东北部。这一事件的起源尚不清楚，其对岩石圈的整体影响也不清楚。这项研究将有助于我们了解黄石热区是如何开始的，以及大陆岩石圈内的过程。一些观测结果似乎与羽流假说不符：没有喷发前的隆起，岩浆裂解发生在一个700公里长的狭窄地带，岩浆活动的主要焦点发生在远离当前黄石热点的轨道上。这是一个特别适合进行这项研究的地点；在非洲大陆内部，没有其他地方有如此大的、暴露良好的、年轻的和可接近的大陆生长区域。调查人员将在瓦洛瓦地区部署25个远程地震站，与美国阵列部署相协调，以成像俄勒冈州东北部及其附近地区的基本地壳和上地幔结构。这是最大的玄武岩喷发发生的地区，也是见证了一次显著的隆起事件的地区，该事件创造了以瓦洛瓦岩体为中心的靶眼浮雕模式。地震调查将增加一套有重点的地球动力学模型，以检验一系列假设，以在现实流变行为的约束下实施质量和热量守恒以及力平衡。这项提议的研究计划旨在改进用于理解地球过程的方法，方法是使用地球动力学计算机模型将假设和一系列观测定量地联系起来，并通过研究嵌入国家岩石圈尺度分辨率阵列(USArray)内的地壳尺度分辨率远程地震阵列的区域。这个项目将通过合作，参与不同的学科，并将一系列发现整合到一致的结果中，为未来的学生和博士后做好准备。

The Yellowstone hotspot initiated about 16.5 m.y. ago with a flood basalt eruption concentrated in NE Oregon. The origin of this event is not clear, nor is its overall effect on the lithosphere. This study will help us to understand how the Yellowstone hotspot began and the processes within the continental lithospheric. Several observations seem inconsistent with the plume hypothesis: there was no pre-eruptive uplift, magmatic fissuring occurred from a narrow but 700 km-long zone, and the main focus of magmatism occurred far off of the current Yellowstone hotspot track. This is a particularly suitable location for this study; nowhere else is there such a large, well-exposed, young and accessible area of continental growth interior to the continent. The investigators will deploy 25-station teleseismic stations coordinated with the USArray deployment in the Wallowa area to image basic crustal and upper mantle structure in NE Oregon and nearby regions. This is the region from which the greatest basalt eruption occurred, and it is that which witnessed a remarkable uplift event that created a bull's eye pattern of relief with the Wallowa pluton at its center. The seismic investigation will be augmented with a focused set of geodynamic models to test a range of hypotheses in a manner that enforces mass and heat conservation and force balance under the constraints of realistic rheologic behavior.The research plan of this proposal is designed to improve on the methods used to understand Earth processes by using geodynamic computer models to quantitatively relate hypotheses and a range of observations, and by studying a region with a teleseismic array of crustal-scale resolution embedded within a national array (USArray) of lithospheric-scale resolution. This project will prepare students and post-docs for the future through collaborations, participation in a diverse set of disciplines, and integration of the range of findings into consistent results.