Abstract

A wealth of information can be revealed by the chemical and isotopic compositions of archaeological artifacts (e.g., glasses, metals, pottery, etc.). Compositional data can be used to constrain provenance and trade routes for raw, finished, and recycled materials, and also to learn about ancient methods of material processing. The advent of laser-ablation inductively-coupled-plasma mass spectrometry (LA-ICPMS) several decades ago has enabled measurements of elements and isotopes in varying concentrations (~0.00001 to 10’s of %) within very small volumes (shallow pits with diameters as small as ~1 µm). The instrumentation of the Aarhus Geochemistry and Isotope Research platform (AGiR) includes a state-of-the-art laser ablation system, a quadrupole ICPMS for low-abundance trace element analyses, and a multi-collector magnetic-sector ICPMS for high-precision isotope analyses. This opens up the possibility to measure a multitude of isotopic systems and concentrations of elements from most of the periodic table in a variety of solid materials. In this presentation, I will discuss the principles, potential, and pitfalls of chemical and isotopic microanalysis by LA-ICPMS, with particular focus on methods most relevant to archaeological samples. These include protocols for measuring trace elements in glasses and metals, Sr isotopes in synthetic glasses, and Pb isotopes in silver, which we have been developing at AGiR. Time will be left for informal discussions of possible new applications of these techniques to UrbNet research initiatives.?