Summary

Copper was a highly prized material in sub-Saharan Africa at the time of the Sahelian kingdoms of Ancient Ghana and Mali. In certain regions, especially those where gold was mined, it was exchanged for gold at rates that would be considered unfair by present-day standards. Together with salt, it was one of the main commodities of the trans-Saharan trade that contributed to the enrichment of these sub-Saharan kingdoms. Salt was the most highly prized product in sub-Saharan Africa. However, it did not leave any direct archaeological trace, whereas copper remains in the archaeological records. Copper may be combined with other metals to form alloys with diverse mechanical and aesthetic properties. Determining the absence or presence or the ubiquity of some of these alloys in time and space and mapping this data has been done for other contexts. Thanks to a significant set of meaningful compositional analyses of archaeological copper-based objects and remains, such undertaking may be done for West African sites dating between the 8th and the 14th centuries ce. The archaeometric data check must take into account additional data, such as the nature of the site (e.g., habitat or sealed context), the dating, the nature of the copper-based material, and the quality of the metal (analytical data), as well as precise references about the source documentation. When the cartographic material is combined with archaeological evidence relating to the places where the metal was processed and consumed, or with written sources referring to historical events or changes in the trade routes, a picture can be drawn of the use, transformation, and circulation of copper and copper alloys over the course of six centuries Studies of what happened with regard to copper and copper alloys contribute to the construction of a finer history of the West African Sahel at the time of the kingdoms of Ghana and Mali. This research considers fluctuation in the value of copper and copper alloys, the increased exploitation of local copper deposits, the importance of secondary production loci, such as the workshops of Tegdaoust where local processing (or dilution!) of brass imported from the north took place, the wealth of copper-based objects in certain sites testifying to a modification of the trans-Saharan routes, and the development of new trading ports.