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Energy-Dispersive X-ray Fluorescence Analysis as a Rapid Method for Identifying Tephras

Published online by Cambridge University Press:  20 January 2017

A. B. Cormie
Affiliation:
Department of Archaeology, Simon Fraser University, Burnaby, British Columbia, Canada
D. E. Nelson
Affiliation:
Department of Archaeology, Simon Fraser University, Burnaby, British Columbia, Canada

Abstract

The use of energy-dispersive X-ray fluorescence analysis (XES) for the routine identification of three tephras (Mazama, Bridge River, Mount St. Helens Yn) commonly found in archeological sites in British Columbia has been investigated. Researchers have often assumed that chemical analysis of bulk samples of glass separates would be hampered by contamination and weathering effects. Our results indicate that XES of bulk glass separates provides a very reliable method for rapidly identifying the three tephras in question, even with a very simple sample preparation. This should enable persons not skilled in geology or in tephrochronology to collect and to identify samples of these tephras. Finally, as a part of the study, similar measurements were made on the separated glass portions of these three tephras and of three others (Glacier Peak B and G, White River) from northwest North America. The results suggest that this method may provide tephrochronologists with a useful additional tool for studying tephras in other regions.

Type
Original Articles
Copyright
University of Washington

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