West African copper alloys used in West Africa from the middle of the first millennium A.D. was the focus of research using lead isotope analysis. Work was concentrated on samples from the earlier part of the tradition, using samples from Marandet, Igbo Ukwu, Ife and Benin. Inspection of the lead isotope ratios from the analysis of the objects from these sites reveal distinct and well-separated groupings, indicating that a variety of ore sources was used in their production. Data for samples from Igbo Ukwu, Ife and Marandet each reveal exploitation of two main sources. Benin, which according to the historical documents traded with several different parts of Europe, primarily shows one single, very compact source.
Frank Willett, SCMRE Research Collaborator and Research Fellow at the Hunterian Museum, Glasgow, Scotland assisted in the project, sampling objects at the National Museum of Natural History and the National Museum of African Art. Additional samples were obtained from objects from the ancient city of Jenne in Mali; these objects are held by the Virginia Museum of Fine Arts. Samples of objects from Lower Nigeria, including the areas of the Forcados River, Andoni Creeks and from the Apapa Hoard were also obtained from the British Museum.