Lead isotopes and archaeometallurgy

Abstract

This special issue presents several studies applying leadisotope analysis (LIA) to address archaeological questionsin the field of ancient mining and metallurgy. They werepresented during an international workshop, held inFribourg (Switzerland), June 19–20, 2008, organised incollaboration between the Geosciences Department of theUniversity of Fribourg and the Laboratory of PrehistoricArchaeology and Human Peopling (Department of Anthro-pology and Ecology) of the University of Geneva with thefinancial support of the Swiss National Science Foundation.Dr. F. Cattin and Dr. B. Guenette-Beck were in charge ofthe scientific organization. More than 30 scientists fromBelgium, France, Germany, Italy and Switzerland attendedthe sessions with the seven key lectures dedicated todifferent aspects of actual research in the field of LIA.Over the last few years, several studies of archaeologicalartefacts using lead isotope analysis have shown a renewedinterest in this technique. The workshop aimed to bringtogether experienced senior researchers and young scien-tists active in the field to promote contacts and discussions.The idea was to address research questions on four generalpoints:1. Analytical considerations: possibilities, advantages andshortcomings of various methods like TIMS, ICP-MSand LA-ICP-MSSince the first application of Pb isotopic data inarchaeology, its acquisition has relied on different analyticalmethods. From this concern, it is legitimate to ask if onelead isotope analysis is equivalent to another lead isotopeanalysis. First of all, thermal ionisation mass spectrometry(TIMS) was the only method used in Pb isotope measure-ment until the introduction of high precision multi-collectorinductively coupled plasma mass spectrometer, as detailedin the LIA historical perspective of Stos-Gale and Gale. Themore recent development of mass spectrometry with laserablation reduced the sample size and therefore widenednew perspectives of applications, with the opportunity toinvestigate small or precious artefacts and micro-scalesampling in a heterogeneous matrix. The methodologicalpaper of Villa discusses the protocols of all thesetechniques, with a focus on the one processed at theLaboratory of Isotope Geology at the University of Berne(Switzerland). What comes out of this contribution is thataccuracy should concentrate our full attention whenacquiring new data and that precision, whatever high ornot, may allow distinction between what needs to bedifferentiated regarding specific archaeological questions.