CAREER: Petrogenesis of Hawaiian lavas, Constraints from metal stable isotopes

University Of Nevada Las Vegas, Las Vegas NV

Investigators

Abstract

This CAREER project will focus on understanding the source of the magmas that erupt in Hawaii. Hawaiian volcanism is often used as the best example of magmatism formed by the rise of a mantle plume from deep in the Earth's interior. The mantle plume hypothesis provides an elegant interpretation for many intra-plate volcanism, such as Hawaii, which has been important in shaping the Earth’s surface and its biosphere throught Earth's history. However, many aspects of mantle plumes, and even their existence, remain highly debated. In this study, the investigator sets out to use several state-of-the-art geochemical and isotopic tracers to understand the evolution of Hawaiian volcanism, and its implications for the mantle plume hypothesis. Among those proposed tracers, he will conduct the systematic analysis of several novel metal stable isotope tracers on for a set of Hawaiian samples. The PI also plans a summer education program focusing on analytical geochemistry, which complements the existing strong field-oriented research and education activities in the Geoscience Department at the University of Nevada Las Vegas (UNLV). This summer program will leverage the geochemical analytical labs inside the department to train undergraduate students with the cutting-edge geochemical analytical techniques. This summer program is research oriented and requires the participating students to complete a research project using the available analytical facilities under the supervision of their faculty mentors. The PI proposes an extensive metal stable isotope investigation, including Mg, Ca, Cr, Ti, and Fe, on well-studied lavas from six Hawaiian volcanoes. They cover the whole compositional and isotopic ranges in Hawaii, which represent a large portion of those found in global ocean island basalts. The new metal stable isotope data, together with the published geochemical data on the same lavas, will allow the PI to better understand (1) the geochemical structure of the Hawaiian plume, (2) the petrogenesis of Hawaiian lavas, and (3) their implications to the plume hypothesis. The PI is actively recruiting students into the summer research program using a variety of approaches. The diverse student body at UNLV ensures that a large proportion of the participating students will be from underrepresented groups. The proposed research and education activities are synergistic, because the PI plans to (1) use part of the proposed research as student projects of the summer program, and (2) recruit qualified and motivated students trained through this summer program to work on his proposed research. 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.