Collaborative Research: Geochemical investigations of newly discovered back-arc spreading centers in the northeastern Lau Basin

摘要-0751844/0752256(朗缪尔/迈克尔)学术价值：这项研究探索了弧后火山作用的深层机制，以及这些构造环境中的火山链如何随着时间的推移而变化，以及它们与俯冲海沟的距离是如何影响的。将对西太平洋刘盆地东北部岩石的全套地球化学数据进行常量和微量元素分析，以及各种挥发性物质(如H2O和CO2)的含量以及放射性同位素：锶、铅和钕的含量。数据将被用来测试水分含量是否随着距离海沟的距离而有系统地变化，并确定弧后火山活动如何受到缺乏火山前锋的影响。地球化学数据也将被用来研究路易斯维尔岭火山链的俯冲是否对区域火山活动起到了促进作用。将对数据进行建模，以确定熔融和岩浆源过程。这项工作的结果将与南边刘盆地NSF资助的Ridge 2000主要研究地点的结果进行比较和对比。广泛的影响：工作的更广泛影响包括：两个机构之间的合作，其中一个处于EPSCoR状态(俄克拉荷马州)，学生和博士后的教育和培训，国际合作，以及伍兹霍尔海洋研究所NSF资助的多用户离子探测器设施的使用。还将向K-8学童开展更多的外联活动。

ABSTRACT-0751844/0752256 (Langmuir/Michael)Intellectual Merit: This research explores the deep-seated mechanisms that underlie back-arc volcanism and how volcanic chains in these tectonic settings change over time and are influenced by their distance from a subduction trench. A full suite of geochemical data from rocks in the northeastern Lau Basin in the western Pacific Ocean will be analyzed for major and trace elements as well as for the content of various volatile species such as H2O and CO2 and the radiogenic isotopes: Sr, Pb, and Nd. Data will be used to test whether there are systematic variations in water content with distance from the trench and determine how back-arc volcanism is affected by the lack of a volcanic front. Geochemical data will also be used to examine whether subduction of the Louisville Ridge volcanic chain is contributing to regional volcanism. Data will be modeled to determine melting and magmatic source processes. Results of the work will be compared and contrasted to those from the major NSF-funded RIDGE 2000 study site in the Lau Basin to the South.Broader Impacts: Broader impacts of the work include: collaboration between two institutions, one of which is in an EPSCoR state (Oklahoma), education and training of students and a postdoc, international collaboration, and the use of an NSF-funded multi-user ion probe facility at the Woods Hole Oceanographic Institution. Additional outreach to K-8 school children will also be undertaken.