OCE-PRF: Melt Inclusions as Windows into Melt Generation and Crystallization Beneath Off-Axis Seamounts at Mid-Ocean Ridges

在这个项目中，研究人员将通过分析胡安德富卡海脊附近离轴海山的熔岩流的组成来探索洋壳的演化。洋壳是在大洋中脊扩张中心的轴线上形成的，随后被离轴火山作用所改变。大洋中脊玄武岩在中轴上喷发的成分通常相对均匀，而离轴海山喷发的成分范围很广，表明这些火山建筑物下存在一个复杂的熔体生成、堆积和结晶系统。研究人员将使用对几个海山喷发的熔岩中的熔体包裹体和相关玻璃(包括主要、微量和挥发性元素)的地球化学分析，从地球化学的角度确定离轴海山下从熔体生成到海底喷发的岩浆管道系统。结果将与正在进行的对邻近山脊段熔体包裹体的研究相结合，这将提供轴上和轴外深部岩浆系统之间的直接对比。因此，调查员将能够系统地评估熔体的生成、堆积和离轴海山下的结晶深度。更广泛的影响包括赞助代表不足的群体中的一名本科生作为暑期实习生参与研究项目，以及研究生指导。该项目的研究成果将在新贝德福德海洋探险中心举行的“家庭科学之夜”上向公众展示，以激励年轻科学家。数据和解释将在国际会议上提出。一旦公布，所有产生的数据将通过并入PetDB(www.petdb.org)向科学界提供。该项目得到美国国家科学基金会海洋科学博士后研究奖学金(OCE PRF)计划的支持，旨在支持早期职业科学家的创新研究，并增加美国海洋科学劳动力和研究社区的多样性。在海洋科学和可持续发展基金的支持下，该项目将使有前途的早期职业研究人员能够从事与海洋科学有关的独立研究事业，并扩大未被充分代表的群体在海洋科学领域的参与。

In this project, the investigator will explore the evolution of oceanic crust by analyzing the composition of the lava flows from off-axis seamounts near the Juan de Fuca Ridge. Oceanic crust is created at the axis of mid-ocean ridge spreading centers and is subsequently modified by off-axis volcanism. While mid-ocean ridge basalts erupted on-axis are typically relatively uniform in composition, off-axis seamounts erupt a wide range of compositions suggesting a complex system of melt generation, accumulation, and crystallization beneath these volcanic edifices. The investigator will use geochemical analyses of melt inclusions and associated glasses (including major, trace, and volatile elements) from lavas erupted at several seamounts to geochemically define the magmatic plumbing system beneath off-axis seamounts from melt generation to eruption on the seafloor. Results will be integrated with an ongoing study of melt inclusions at the adjacent ridge segment, which will provide a direct comparison between on- and off-axis magmatic systems at depth. Thus, the investigator will be able to systematically assess melt generation, accumulation, and the depth of crystallization beneath off-axis seamounts. The broader impacts include sponsoring an undergraduate student from an under-represented group to work on the research project as a summer intern, and graduate student mentorship. Findings from this project will be presented to the general public in an effort to inspire young scientists at "family science nights" at the New Bedford Ocean Explorium. Data and interpretations will be presented at international conferences. Once published, all data produced will be made available to the scientific community though incorporation into PetDB (www.petdb.org). This project is supported under the NSF Ocean Sciences Postdoctoral Research Fellowship (OCE PRF) program, with goals to support novel research by early career scientists and increase the diversity of the U.S. ocean sciences workforce and research community. With OCE-PRF support, this project will enable a promising early career researcher to establish themselves in an independent research career related to ocean sciences and broaden participation of under-represented groups in the ocean sciences.