Tracing Melt Formation at the Tonga-Lau Island Arc

Volcanic arcs can produce large eruptions. However, there are many unknowns about how the magma at volcanic arcs is formed. In particular, it is unclear whether these silicic magmas form deep in the mantle or shallow in the crust. This study will analyze trace elements using cutting edge techniques to explore the conditions of melt formation. The results will be important for understanding the causes of catastrophic explosive arc eruptions. The project will support an undergraduate student and will produce outreach materials on volcanic eruptions for the general public. This study will integrate olivine trace element data, melt inclusion data, and Chromian-spinel inclusion data to explore conditions of melt formation in the mantle wedge. Cutting-edge techniques will integrate mapping with major and trace element analysis of magmatic olivines. The project will test two hypotheses: 1) Arc olivine trace elements allow for a deeper look into mantle wedge processes than possible by bulk rock compositions. 2) The Tonga-Lau olivine trace element patterns ground-truth hydrous partial peridotite melting. The study leverages existing samples and international collaborations. 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. NSF Award ID: 2554162 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Susanne Straub | Institution: Columbia University, NEW YORK, NY | Award Amount: $262,699 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2554162 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2554162.html