Iron Isotope Fractionation of Seafloor Hydrothermal Fluids and Minerals

Seafloor hydrothermal fluids transport metals from the crust to the ocean where they can form marine mineral deposits. This project uses unique fluid and mineral samples from the Juan de Fuca Ridge acquired in collaboration with Ocean Networks Canada. The investigators will carry out cutting edge analyses on these samples to better understand how the fluids form mineral deposits on the seafloor. Laboratory experiments will be carried out at high pressures and temperatures to determine how fluids evolve after seafloor volcanic eruptions. The results are important for understanding hydrothermal mineral deposition and critical mineral formation, with relevance to mineral resources, ocean systems, and geologic processes. The project will support an early career principal investigator, will train graduate students in advanced experimental techniques and analyses, and will include a workshop on mining combined with a field trip to natural mineral formations in Minnesota. This integrated field-based and laboratory study will determine iron isotope fractionation factors and trace element partitioning coefficients between pyrite and seafloor hydrothermal fluids. Field samples are comprised of time-series hydrothermal vent fluids and co-precipitated minerals. The project will carry out iron isotope analyses on the fluids, complementary analyses on the mineral samples, and laboratory experiments to investigate the rate of pyrite recrystallization and isotopic equilibration at hydrothermal conditions. The results will have implications for processes related to hydrothermal vent fluids, massive sulfide deposits, hydrothermal plume particles, and hydrothermal ore deposits. 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: 2608685 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Guy Evans | Institution: University of Minnesota-Twin Cities, MINNEAPOLIS, MN | Award Amount: $403,841 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2608685 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2608685.html