Intellectual Merit: This research examines how ocean crust is formed at intermediate rate mid-ocean ridge spreading centers, how melts and hydrothermal systems interact in this setting, and at what scale in time and space the volcanics and hydrothermal vents relate to mantle melts beneath them. Geophysical, geological, and geochemical data will be integrated to obtain a holistic picture of the system. Major and trace element chemistry of already collected seafloor volcanic rocks from the Juan de Fuca spreading ridge, as well as corresponding radiogenic isotopes, volatile contents, and U-series elements form the core of the geochemical data set. Objectives under investigation are: testing whether layer 2A of the ocean crust forms off-axis as mantle plumbing moves during seafloor spreading and evaluating whether heterogeneities in basalts, that are erupted on the seafloor that reflect heterogeneities in magma composition and degassing, can be tied to variations in the composition and intensity of the overlying hydrothermal systems.
Broader Impacts: The work fosters collaboration between academic institutions and scientists in Washington State, California, and Oklahoma. Impacts include support of an early career scientist and support the objectives of the NSF-funded RIDGE2000 Program. Graduate and undergraduate students will be trained in state-of-the-art analytical techniques, and the work supports the set-up of a U-series analytical laboratory at Central Washington University expanding its infrastructure for research. Public outreach to K-12 teachers and their students will be carried out through the RIDGE2000 Education and Outreach Office.
