9614247 Garcia This is a proposal to continue work on the petrology and geochemistry of lavas from Kilauea volcano in Hawaii to improve our understanding of magmatic processes within active basaltic volcanoes. Recent work has documented large, systematic compositional variations within the historical lavas of this volcano (~200 years). The variation observed appears to be cyclic and correlated with summit explosions. The main purpose of this study will be to determine the cause of this compositional variation and to evaluate the relative importance of imputs from crustal and mantle processes. The working hypothesis is that the long-term geochemical cycle observed in Kilauea is caused by the dynamic melting of a heterogeneous plume source followed by mixing in the shallow summit magma reservoir. Inflections in the cycles occur when the summit reservoir is extensively drained during explosive events. Continuation of the study will allow the monitoring of the compositional variations in the ongoing Puu Oo eruption and the evaluation of the extent of crustal contamination in the Kilauea lavas. In addition, the proposed work will seek to provide insights into factors that may control the geochemical variation at Kilauea such as the role of explosive events, the relative effects of mantle heterogeneity and changes in the extent of partial melting and shape of melting regions.
