Aquisition of Equipment to Facilitate Fourier Transform Infrared Spectroscopic Study of Volatiles in Glasses and Crystals

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

The Fourier transform infrared spectroscopy laboratory in the Department of Geosciences at the University of Massachusetts houses a Bruker Vertex 70 infrared spectrometer coupled with a Hyperion 3000 microscope. The FTIR laboratory, and particularly the mapping capability of the system, has made possible research projects on the relationship between flow banding and water concentration variations in rhyolitic lavas, volatiles in the K-T Deccan basalts of India, the role of water in deformation of quartz crystals in shear zones, and water concentrations in lunar and Martian glasses and crystals, among others. This grant will fund the purchase of a heating stage that will be used to homogenize bubble-bearing melt inclusions so that accurate measurements of volatile concentrations can be obtained. In addition, the grant will fund the purchase of a cooling stage that will be used to freeze samples so that the spectral characteristics of H-O species can be examined to determine whether water occurs as part of the mineral structure or whether it occurs in fluid inclusions in the crystal. Finally, a video camera for characterizing textural characteristics of specimens, and a rotatable stage to permit collection of spectra in orientations parallel to principal crystal vibration directions are funded. This instrumentation all contributes to the analytical goal of evaluating the origin and evolution of volatiles in igneous systems. The broad significance of this project is the exploration of volcanic processes through Earth history and the role that volatile compounds play in explosive behavior and in climatic effects of volcanic eruptions. Minerals host samples of the molten material from which they crystallized. These captured samples of the parent melt are known as melt inclusions. Analyses of melt inclusions provide an evaluation of the climate-affecting gases that were dissolved in the parent melt and that were contributed to the atmosphere during volcanic eruptions. The equipment funded by this grant will be used to improve the ability of the Fourier transform infrared spectrometer in the Department of Geosciences at the University of Massachusetts to accurately measure volatile concentrations in melt inclusions and to evaluate the behavior of volatile compounds in Earth reservoirs.