Studies of fusion processes of natural glasses by electron magnetic resonance spectroscopy

Abstract

Electron magnetic resonance (EMR) spectra of three silicate glasses, tektite, fulgurite, and Libyan Desert glass formed by natural processes have been measured. These measurements were made to determine the nature of the natural fusion processes. One of the major trace elements, iron, was detected in the EMR spectra of samples of the three glasses. In the Libyan Desert glass, the iron was primarily Fe 3+ and randomly dispersed. In the tektite, approximately 1% of the iron was Fe 3+, the remaining 99% was Fe 2+, and both were randomly dispersed. In the fulgurite, the iron was in a metallic state and concentrated in spherical particles whose size ranged from multidomain to single domain. The results indicate that the Libyan Desert glass, in contrast to fulgurites and tektites, was fused under oxidizing conditions.