Start: Feb 24, 2014 04:00 PM
Location: Room 612, Institute of Archaeology
Ernst Pernicka (Curt-Englehorn Centre for Archaeometry, Mannheim & University of Heidelberg) will give the sixth seminar in the Term II Institute Research Seminar series on Isotopes in Archaeology on 24 February.
It has long been recognized that it should be possible to use some form of geochemical fingerprinting to trace archaeological metal objects to their geological source or, at least, to their production site. The basic ideas were already formulated in the nineteenth century and first applications on archaeological metal finds were attempted. Since the advent of instrumental methods for chemical analysis large programs of analysis of prehistoric metal objects have been undertaken.
However, the relationship between metal ores and metal objects is much more complicated than originally assumed. Although the chemical composition can be used to some extent for provenance studies, the application of lead isotope abundance ratios in this field has provided a major breakthrough since around 1970. The application of isotope geochemistry is neither confined to metal objects nor to lead isotope abundance ratios. In some applications covering copper, silver, lead and tin from various periods the possibilities and limitations of lead isotope ratios in metals will be discussed.
New isotope systems have been introduced in the last two decades including isotope ratios of copper, tin and osmium. The possibility of using zinc isotope ratios has at least been discussed. While the copper isotope system may provide limited information concerning the provenance of copper, the isotope ratios of tin have already proven to be invaluable to tackle the old question of tin provenance in the Bronze Age. Furthermore, osmium isotope ratios may eventually be useful for provenance studies of gold but the major application is for iron objects which have eluded attempts to relate them to specific ore sources so far. Another application may be the detection of large-scale smelting in general by deposition of osmium in peats and other environmental sinks.
Last but not least radioactive isotope systems have been developed for dating of metals. 210Pb can be used to determine, if any base metal or silver was produced within the last hundred years and thus provides a very significant test of authenticity. The radioactive decay of uranium and thorium produces helium that can be stored in gold metal. It is released on heating above 800°C so that this U/Th-He method in principle allows the absolute dating of gold objects. Applications of both methods will be presented.
The seminar will take place at 4pm in Room 612 at the Institute and will be followed by a reception in the Staff Common Room (Room 609).
Any enquiries about the seminar series may be directed to Ian Freestone.
Institute Research Seminar Programme | Isotopes in Archaeology
- 13 January: Tracing Visitors to our Shores (Jane Evans, NERC Isotope Facility)
- 20 January: Stable Isotopes, Climate Change and Early Hominin Palaeoecology (Philip Hopley, Birkbeck)
- 27 January: House and home at Çatalhöyük: Stable carbon and nitrogen isotope evidence from people and their animals (Jessica Pearson, University of Liverpool)
- 3 February: The origin and spread of glass making: the isotopic evidence (Patrick Degryse, University of Leuven)
- 10 February: Plant stable isotope analysis: new insights into farming practice and diet (Amy Bogaard, University of Oxford)
- 24 February: Isotope Archaeometallurgy (Ernst Pernicka, Curt-Englehorn Centre for Archaeometry, Mannheim & University of Heidelberg)
- 3 March: Milking the Residues: Molecular and Isotopic Signatures from Human Prehistory (Richard Evershed, University of Bristol)
- 10 March: Hunter-gatherer cuisine: recent advances in chemical and isotopic analysis of early pottery (Oliver Craig, University of York)
- 17 March: Stable light isotopes offer new perspectives on early hominin dietary ecology (Julia Lee-Thorp, University of Oxford)
- 24 March: Loaves or fishes? Reconstructing individual 5000-year-old dietary histories for the children of Shetland's first farmers (Janet Montgomery, University of Durham)