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

摘要/ abstract摘要：Langmuir/Michael(0751844/0752256)：本研究探讨了弧后火山作用的深层机制，以及这些构造背景下火山链如何随时间变化，以及它们与俯冲沟距离的影响。将分析西太平洋劳盆地东北部岩石的全套地球化学数据，以分析主要元素和微量元素，以及各种挥发性物质（如H2O和CO2）的含量以及放射性成因同位素：Sr、Pb和Nd。数据将用于测试含水量是否随距离海沟的远近而有系统的变化，并确定弧后火山活动如何受到缺乏火山锋的影响。地球化学数据还将用于检查路易斯维尔岭火山链的俯冲作用是否有助于区域火山作用。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美国国家科学基金会资助的位于南部劳盆地的RIDGE 2000主要研究地点的结果进行比较。更广泛的影响：这项工作的更广泛的影响包括：两个机构之间的合作，其中一个是在EPSCoR州（俄克拉何马州），学生和博士后的教育和培训，国际合作，以及在伍兹霍尔海洋研究所使用nsf资助的多用户离子探测设备。还将进一步向K-8学龄儿童提供服务。

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.