Collaborative Research: Investigating Initiation and History of the Aleutian Arc and Composition and Significance of North Pacific Seafloor via Dredge Samples from the R/V Sonne

俯冲是塑造地球物理和化学演化的基本构造过程，具有许多重要的潜在人类影响，包括地震和火山灾害以及作为俯冲岩浆作用共同产物的矿产资源。因此，与俯冲有关的过程是地球科学界广泛关注和广泛研究的主题。尽管对阿拉斯加-阿留申俯冲系统进行了近一个世纪的研究，但仍有几个关键问题没有得到解答，包括俯冲带是如何以及何时形成的，以及俯冲的太平洋板块在多大程度上促进了阿拉斯加-阿留申火山之下产生的岩浆。该项目将使一组来自南卡罗来纳大学和威斯康星大学麦迪逊分校的美国科学家能够准确地确定阿留申火山弧形成的时间，并对进入和喷发这一活跃火山弧的产物进行表征。这是一项合作努力，涉及来自德国、俄罗斯和美国的研究生和本科生、博士后以及研究人员。这个项目的所有数据都将向公众开放。该项目有两个广泛相关的主题：1)限制阿留申弧俯冲开始和早期演化的时间，2)确定阿留申弧和堪察加弧俯冲输入的特征，并将它们与控制弧岩浆形成的过程联系起来。作为德国-俄罗斯白令项目的一部分，对德国R/V Sonne探险队SO249样品的分析将限制阿留申弧形成的时间和早期弧产物的地球化学。该项目还将获得毗邻阿留申弧西部的北太平洋海底样品的地球化学数据，包括北部帝王海山以东和以西的地点。这项研究将有助于更好地了解俯冲输入和火山输出之间的地球化学联系，并将为阿留申群岛和堪察加群岛提供新的限制条件并显著改进弧岩浆成因模型。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Subduction is a fundamental tectonic process that shapes the Earth's physical and chemical evolution and has many important potential human impacts, including seismic and volcanic hazards, as well as mineral resources, which are common products of subduction magmatism. As a result, subduction-related processes are the subject of broad public interest and widespread investigation in the geosciences. Despite almost a century of research on the Alaska-Aleutian subduction system, several key questions remain unanswered including how and when the subduction zone was formed and to what extent the subducting Pacific plate contributes to the creation of magma generated beneath Alaska-Aleutian volcanoes. This project will allow a group of U.S. scientists from the University of South Carolina and the University of Wisconsin-Madison to precisely determine the timing of Aleutian arc formation and to characterize the products that are entering and have erupted from this active volcanic arc. This is a collaborative effort involving graduate and undergraduate students, post-docs, and researchers from Germany, Russia and the United States. All data from this project will be made available to the public. The project has two broadly related themes: 1) Constraining the timing of subduction initiation and early evolution of the Aleutian arc, and 2) Characterizing subduction inputs to both the Aleutian and Kamchatka arcs and relating them to the processes controlling arc magma formation. Analyses of samples from Expedition SO249 of the German R/V Sonne as part of the German-Russian BERING project will provide constraints on the timing of Aleutian arc formation and the geochemistry of the early arc products. The project will also obtain geochemical data for north Pacific seafloor samples adjacent to the western Aleutian arc, including sites both east and west of the northern Emperor seamounts. This study will help better understand geochemical linkages between subduction input and volcanic output, and will provide new constraints and significantly improve models of arc magma genesis for the Aleutians and Kamchatka.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.