Major to trace element imaging and analysis of iron age glasses using stage scanning in the analytical dual beam microscope (tandem) Show others and affiliations
2022 (English) In: Heritage Science, E-ISSN 2050-7445, Vol. 10, article id 90Article in journal (Refereed) Published
Abstract [en]
Dark and clear silicate glasses formed during an iron age vitrification event ≈ 1500 years ago at the Broborg hillfort near Uppsala, Sweden have been analyzed using a scanning electron microscope equipped with a micro-X-ray fluorescence (μXRF) spectrometer. Correlated µXRF and electron beam-induced energy dispersive spectrometry (EDS) X-ray maps were collected via stage-scanning at constant velocity. This coupled procedure represents a new approach for the cultural heritage community to conduct analytical studies of archaeometric specimens composed of metal, ceramic, or mixed inorganic/organic materials, where major and trace element compositions are registered in space for areas up to the centimeter-length scale at micrometer-scale resolution. Overview images were used to select areas for EDS beam scan maps correlated with multispectral cathodoluminescence (CL) imaging and co-located quantitative EDS and μXRF point analysis. Fe, Ca, Mg, Ti, P, Mn, Zr, Zn, and Y are enriched in the dark glass, while Si, Al, K, Na, Ba, Sr, Rb, and Ga are enriched in the clear glass. Unmelted material is comprised predominately of quartz (SiO2) along with trace apatite (Ca5(PO4)3[Cl,OH]) and zircon (ZrSiO4). Multivariate statistical analysis was used to measure the area fractions of high variance components while lower variance components represented phase mixtures. Differences between calculated melt viscosities for the glass compositions are consistent with field and laboratory observations. Coupled large area EDS and μXRF imaging shows significant promise for informed selection of higher spatial resolution and higher sensitivity follow-up studies, e.g., those performed using synchrotron analysis.
Place, publisher, year, edition, pages Springer, 2022. Vol. 10, article id 90
Keywords [en]
Hillfort, μXRF, SEM, EDS, X-ray microanalysis, Cathodoluminescence, Quantitative, Vitrifcation, Silicate glass, Spectrometry
National Category
Manufacturing, Surface and Joining Technology
Research subject Waste Science and Technology
Identifiers URN: urn:nbn:se:ltu:diva-91692 DOI: 10.1186/s40494-022-00707-4 ISI: 000811763200001 Scopus ID: 2-s2.0-85129962293 OAI: oai:DiVA.org:ltu-91692 DiVA, id: diva2:1673711
Note Validerad;2022;Nivå 2;2022-06-21 (sofila);
Funder: the Smithsonian Institution; the National Institute of Standards and Technology; the United States Department of Energy (US DOE) Office of Environmental Management, International Programs; the US DOE Waste Treatment and Immobilization Plant Project
2022-06-212022-06-212023-10-11 Bibliographically approved