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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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References

Beget, J.E.. 1981. Glacier Peak volcano: Tephrochronology, eruption history and volcanic hazards. Tephra Studies. Self, S., Sparks, R.S.J.. Reidel, Dordrecht. 449455.CrossRefGoogle Scholar
Bertin, E.P.. 1970. Principles and Practice of X-Ray Spectrometric Analysis. Plenum, New York.Google Scholar
Borchardt, G.A., Harward, M.E., Schmitt, R.A.. 1971. Correlation of volcanic ash deposits by activation analysis of glass separates. Quaternary Research 1. 247260.CrossRefGoogle Scholar
Borchardt, G.A., Thiesen, A.A.. 1971. Rapid X-ray spectrographic determination of major element homogeneity in Mazama pumice. Soil Science and Plant Analysis 2. 1116.CrossRefGoogle Scholar
Cormie, A.B.. 1981. Chemical Correlation of Volcanic Ashes for Use as Stratigraphic Markers in Archaeology. Unpublished M. A. thesis. Simon Fraser University, Burnaby, British Columbia.Google Scholar
Cormie, A.B., Huntley, D.J., Nelson, D.E.. 1982. Identifying tephras by alpha counting. Canadian Journal of Earth Sciences 19. 662665.CrossRefGoogle Scholar
Cormie, A.B., Nelson, D.E., Huntley, D.J.. 1981. X-Ray fluorescence analysis as a rapid method of identifying tephras discovered in archaeological sites. Tephra Studies. Self, S., Sparks, R.S.J.. Reidel, Dordrecht. 103107.CrossRefGoogle Scholar
Kittleman, L.R.. 1979. Tephra. Scientific American 241. 132162.CrossRefGoogle Scholar
Kunzendorf, H.. 1971. Quick determination of the average atomic number Z by X-ray scattering. Nuclear Instruments & Methods 99. 611612.CrossRefGoogle Scholar
Lerbekmo, J.F., Westgate, J.A., Smith, D.G.W., Denton, G.H.. 1975. New data on the character and history of the White River volcanic eruption, Alaska INQUA Quaternary Studies 203209.Google Scholar
Nielson, K.K.. 1977. Matrix corrections for energy dispersive X-ray fluorescence analysis of environmental samples with coherent/incoherent scattered X-rays. Analytical Chemistry 49. 641648.CrossRefGoogle ScholarPubMed
Porter, S.C.. 1978. Glacier Peak tephra in the north Cascade Range Washington: Stratigraphy distribution, and relationship to late-glacial events. Quaternary Research 10. 3041.CrossRefGoogle Scholar
Routti, J.T., Prussin, S.G.. 1969. Photopeak method for the computer analysis of gamma ray spectra from semiconductor detectors. Nuclear Instruments and Methods 72. 125142.CrossRefGoogle Scholar
Smith, R.P., Nash, W.P.. 1976. Chemical correlation of volcanic ash deposits in the Salt Lake group, Utah, Idaho and Nevada. Journal of Sedimentary Petrology 46. 930939.Google Scholar
Smith, H.W., Okazaki, R., Knowles, C.R.. 1975. Electron microprobe analysis as a test of the correlation of west Blacktail ash with Mount St. Helens pyroclastic layer T. Northwest Science 49. 209215.Google Scholar
Smith, H.W., Okazaki, R., Knowles, C.R.. 1977. Electron microprobe analysis of glass shards from tephra assigned to set W, Mount St. Helens, Washington. Quaternary Research 7. 207217.CrossRefGoogle Scholar
Smith, D.G.W., Westgate, J.A.. 1969. Electron probe technique for characterizing pyroclastic deposits. Earth and Planetary Science Letters 5. 313319.CrossRefGoogle Scholar
Westgate, J.A.. 1977. Identification and significance of late Holocene tephra from Otter Creek, southern British Columbia, and localities in west-central Alberta. Canadian Journal of Earth Sciences 14. 25932600.CrossRefGoogle Scholar
Westgate, J.A., Gorton, M.P.. 1981. Correlation Techniques in Tephra Studies. Tephra Studies. Self, S., Sparks, R.S.J.. Reidel, Dordrecht. 7394.CrossRefGoogle Scholar
Westgate, J.A., Smith, D.G.W., Tomlinson, M.. 1970. Late Quaternary tephra layers in southwestern Canada Early Man and Environments in Northwest North America The Student Press, University of Calgary, Calgary, Alberta. 1333.Google Scholar