Accurate Measurements of Low Z Elements in Sediments and Archaeological Ceramics Using Portable X-ray Fluorescence (PXRF)
This study seeks to demonstrate the ability of portable X-ray fluorescence (PXRF) to estimate concentrations of K, Ca, and Fe in sediments and archaeological ceramics under controlled conditions. After a discussion of the potential confounding factors in PXRF use, a protocol which attempts to address these issues through repeated measurement, calibration, and re-sampling is detailed. Data generated using this protocol are then tested for accuracy and repeatability. PXRF is argued to be able to produce accurate estimates of K provided the suggested protocol is used, and able to produce repeatable estimates of K and Ca under these same conditions. Other experimental conditions tested failed to produce accurate and repeatable results. Fe results are found to be problematic given the calibration standards used here.
KeywordsPXRF Geochemistry Sediments Ceramics
Significant assistance in statistics, calibration, and R software was provided by UW statisticians Soyoung Ryu, Paul Sampson, and Jonathan Gruhl. Sediment samples used for this study were collected during fieldwork supported by National Science Foundation DDIG #0731529. PXRF units and equipment used for this study were purchased with funds awarded by University of Washington STF Award #2008-068-1. Access to field sites in Peru was graciously given by Dr. Santiago Uceda (Universidad Nacional de Trujillo) and by Mr. Francisco Burga (Agroindustrias San Simon S.A.). Ceramic samples and ICP-MS data were made available by Dr. James Feathers (University of Washington). Jim also deserves thanks along with Dr. Donald Grayson (UW) and two anonymous reviewers for providing insightful comments on drafts.
- Aitken, M. J. (1985). Thermoluminescence dating. London: Academic.Google Scholar
- Buhrke, V. E., Jenkins, R., & Smith, D. K. (Eds.). (1998). A practical guide for the preparation of specimens for X-ray fluorescence and X-ray diffraction analysis. New York: Wiley.Google Scholar
- Davis, L. G. (2011). Return to Cooper’s ferry site: studying cultural chronology, geoecology, and foragers in context. Idaho Archaeologist, 34, 1–4.Google Scholar
- Lachance, G. R., & Claisse, F. (1995). Quantitative X-ray fluorescence analysis. Chichester, UK: Wiley.Google Scholar
- Liritzis, I., & Zacharias, N. (2010). Portable XRF of archaeological artifacts: Current research, potentials and limitations. In M. S. Shackley (Ed.), X-ray fluorescence spectrometry (XRF) in geoarchaeology (pp. 109–142). New York: Springer.Google Scholar
- Schuenemeyer, J. H., & Drew, L. J. (2011). Statistics for earth and environmental scientists. Hoboken, NJ: Wiley.Google Scholar
- Shackley, M. S. (2010). Is there reliability and validity in portable X-ray fluorescence spectrometry (PXRF)? The SAA Archaeological Record, 10(5), 17–20.Google Scholar