Crystallization and Vesiculation of Hawaiian Basalts

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The P.I.s propose a series of crystallization experiments on Mauna Loa basalt compositions with the goals of (1) quantifying relationships between magmatic undercooling, cooling rate and crystallization rates of all phases in 1984 Mauna Loa basalt, (2) repeating the experiments on a more magnesian composition, (3) extending the experiments to include variations in temperature, and (4) calibrating a glass geothermometer for Mauna Loa basalt compositions. These experiments will be complemented by a detailed textural study of a series of near-vent samples collected during the 1984 eruption of Mauna Loa. Finally, the P.I.s propose a related study on near-surface vesiculation in Hawaiian basalt using samples from the current eruption of Kilauea Volcano to (1) determine rates of lava degassing, (2) study mechanisms of bubble coalescence, (3) document post-emplacement modifications to original bubble size distributions, and (4) use textural measurements of pumiceous products of fire fountaining episodes to constrain proposed models of fire fountain formation. By combining textural and chemical studies of experimental and well- documented natural samples we can substantially advance our understanding of these processes in Hawaiian basalts.