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.
