Water in Arc Magmas

In collaboration with Terry Plank at Boston University and Sally Newman at California Institute of Technology we are developing new approaches for estimating the pre-eruptive H2O dissolved in arc magmas. We are combining measurments of the pre-eruptive H2O content obtained from measurments of melt inclusion composition with the results of crystallization experiments on basaltic melts under conditions of variable H2O content (up to 6 wt. %).

The technique may be used to estimate the conditions of formation from the variations in chemical composition displayed in spatially and temporally associated lavas or may be applied to the minerals that crystallized at depth and are preserved in the magma as it cools. These studies are providing a direct calibration of the pre-eruptive H2O content of Mariana and Izu-Bonin volcanics as part of the MARGINS focus on the Izu-Bonin-Mariana Arc system.