Collaborative Research: Investigating Iron Isotope Fractionation during Partial Melting

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

One of the main goals in earth science research is to determine the chemical composition of the Earth and its primary units. For years, studies have tried to use isotopic and chemical mass balance calculations to better constrain major fundamental issues such as the structure of mantle convection and determination of the light elements in the core. Much work has focused on chemical partitioning experiments at a large range of both pressures and temperatures but not on the effect of the stable isotopic fractionation that results from these processes. With this project, the team aims to create new interdisciplinary research at the interface of stable isotope geochemistry and experimental petrology. A graduate and undergraduate student will be engaged and trained in a range of experimental and analytical techniques. This project is highly interdisciplinary and will be of use to petrologists, geochemists, geodynamicists, planetary scientists, cosmochemists and astronomers. Isotope fractionation will exist between phases with distinct bonding environments, and separation of elements between reservoirs manifests this fractionation. Experiments at high pressure and temperature can reveal equilibrium isotopic fractionation factors that cannot be directly measured in planetary materials, and, when combined with isotopic ratios found in natural materials, provide constraints on the formation conditions of those materials. These researchers will focus on the equilibrium stable isotopic fractionation of iron due to partial melting of the mantle. They aim to understand if and how partial melting of the mantle leaves an isotopic fingerprint on mantle rocks. During the course of this project, a new module will be developed to be part of the Center for Earth and Environmental Science curriculum. It will focus on mantle melting and magma production, which are relevant to volcanic eruptions and environmental hazards. 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.