Spectroscopic FTIR imaging of water and carbon in geologic samples: an example from the Izu-Bonin arc and implications for models of silicic crustal growth

Abstract

An important advance in the FTIR technique in the past decade has been the advent of spectroscopic imaging, which allows a map of the volatile species of interest to be constructed from 4096 simultaneously collected spectra, each of which has a sensitivity approaching larger analyses using conventional FTIR techniques. Here, we introduce the technique and apply it to the analysis of volcanic glasses and melt inclusions from the Izu-Bonin arc to test models for silicic crustal growth, such as differentiation of basaltic material or from melting of pre-existing andesitic lower crust.