@article{19bbb3ee285840c28afd5bdb4d05b3ed,
title = "Lead isotopes link copper artefacts from northwestern Botswana to the Copperbelt of Katanga Province, Congo",
abstract = "Copper was highly valued in sub-Saharan Africa for jewellery and as a store of wealth, but was rarely used for tools or weapons. The Central African Copperbelt is one of the world's largest copper deposits, and is known to have been mined since at least 400–600 cal CE, but has seen very little archaeological investigation. We measured lead isotope ratios and trace element concentrations in 20 copper objects, dating between ca. 650 cal CE and ca. 1200 cal CE, from two sites in the Tsodilo Hills in northwestern Botswana. The results show unequivocally that almost all derive from Copperbelt ore deposits in Katanga Province, Democratic Republic of the Congo, at least 1050 km from Tsodilo. Our results are very similar to those recently obtained for a suite of 45 copper ingots, dated between 9th and 18th centuries cal CE, most of which are from cemeteries in the Upemba Depression, about 200 km north of the Copperbelt (Rademakers et al., 2019).",
keywords = "Botswana, Congo, Copper, Copperbelt, Lead isotopes, Provenance",
author = "Jay Stephens and David Killick and Edwin Wilmsen and James Denbow and Duncan Miller",
note = "Funding Information: We thank the Office of the President and Cabinet, Republic of Botswana, and the National Museum of Botswana for permits issued to Wilmsen to perform destructive analysis of these samples. For lead isotope measurements in Tucson, we are most grateful to Professor Joaquin Ruiz for access to his laboratory, and to Dr Mark Baker and Dr Jason Kirk for supervising JAS in the extraction and mass spectrometry of lead. Dr Mary Kay Amistadi measured the trace element concentrations. Dr Gwyneth Gordon (School of Earth and Space Exploration, Arizona State University) came to our aid by measuring lead isotopes on samples with ultra-low lead concentrations, and Dr Alyson Thibodeau (Department of Earth Sciences, Dickinson College) modified the Excel data reduction spreadsheet to make the two datasets compatible. We thank Stephanie Martin for her work in ArcGis to produce the map figures. We acknowledge with gratitude the willingness of Dr Nicolas Nikis (Mus?e Royal de l'Afrique Centrale, Tervuren) and Dr Frederik Rademakers (Earth and Environmental Sciences, Katholieke Universiteit Leuven) to share their data before publication, and for their extremely helpful comments on our data in advance of publication. We also thank three anonymous referees for their comments. Publisher Copyright: {\textcopyright} 2020 Elsevier Ltd",
year = "2020",
month = may,
doi = "10.1016/j.jas.2020.105124",
language = "English (US)",
volume = "117",
journal = "Journal of Archaeological Science",
issn = "0305-4403",
publisher = "Academic Press Inc.",
}