9614754 Rhodes The primary aim of this project is to provide insights into the processes of magma generation within the Hawaiian mantle plume using the geochemical and isotopic composition of samples from Mauna Loa, a volcano with one of the best-documented prehistoric eruptive geochronologies. This goal will be achieved by completing the geochemical database on a group of samples from Mauna Loa that have been previously analysed with 14C. The intent of this proposal is to utilize this unique record to provide detailed documentation of both long- and short-term geochemical variations in Mauna Loa's eruptive history. This information will allow the determination of periods of cyclical activity in the eruptive record where the magma supply rate appears to have changed dramatically. Samples from critical periods, selected on the basis of XRF data, will be analysed for additional trace elements by INAA, and for Sr and Pb isotopic compositions. The results of this work will be used to evaluate long-term geochemical and isotopic trends from the perspectives seen in the short-term data, and to provide answers to questions of the nature and evolution of the plume source over time.
