This project is a detailed geochemical and isotopic study of high MgO basalts from the Azores archipelago, aimed at elucidating the origins of heterogeneous mantle sources. This study utilizes 187Os, 186Os and Hf isotopes to address several significant regional questions including: 1) What is the origin of the predominant Azores plume?; 2) What are the origins of the Azores enriched mantle components, and where do they reside?; and 3) Does the Azores plume rise from the core-mantle boundary, and is there evidence for core-mantle interaction? Understanding the origin of mantle heterogeneity in the Azores, including the nature of potential recycled materials, the location within the mantle of the enriched sources, and the depth of origin of the plume, all have important implications for our larger understanding of crustal recycling processes, scales of mixing and mantle heterogeneity, and the nature of convective regimes within the Earth's interior. This project will involve one Ph.D. student, one M.S. student, and 1-3 undergraduate students over the 3 year duration of the grant. The graduate and undergraduate students will gain extensive training in state-of-the-art geochemical lab techniques, and will share their results and experiences through participation in K-12 and community outreach programs associated with Miami University's Limper Geology Museum.
