Collaborative Research: Volatiles (H2) and CO2) in Mariana and Izu Arc Magmas

California Institute Of Technology, Pasadena CA

Investigators

Abstract

Recommended project is for a study of the volatile flux in the Izu-Bonin-Mariana (IBM) arc system. Water and CO2 analyses will be done using the Fourier Transform Infrared Spectrometry (FTIR) method on glassy inclusions from olivines, laser-ablation, inductively-coupled plasma mass spectrometry (LA-ICPMS) trace element analysis on these same inclusions, and also will do experimental phase equilibrium studies with IBM basalts at pressures ranging from 100-800 megapascals in water saturated and undersaturated conditions. This work is very important for understanding mass balances in arc systems, addressing key unknowns in volatile flux budgets. The samples to be used are already well characterized. The research will address the relative role of decompression versus flux melting for these samples, determine key phase equilibria relationships under hydrous conditions, and develop melt geohygrometers to estimate water contents in IBM lava compositions.