Lead isotopic compositions link copper axes from Kietrz (Poland, 3500–3350 BC) to Slovak and Balkan copper mines

Chemical and lead isotope analyses aided by metallographic examination of copper axes found at the Late Neolithic settlement of Kietrz in southwestern Poland provide new evidence for the origin of copper and metal trade routes in the region. Our results indicate that metal used for the axes could be sourced from copper mines in modern Slovakia, Bulgaria and perhaps Serbia. The evidence from this study confirms that the Funnel Beaker people from Poland became parties to a metal trading network that connected much of continental Europe in the mid-4th millennium bce and provides a better understanding of how these contacts provided the background for the technological and socio-economic developments of the Baden era.