Assessing the copper-based metal diversity in the late 19th century in the Congo Basin using pXRF analysis

At the end of the 19th century, copper and brass were used in a large part of the Congo Basin to make ornaments and prestige objects. The main region of copper production in Central Africa exploited before the 20th century were the Copperbelt (S-E DRC) and the Niari Basin (South Rep. of Congo). However, while these areas would have provided a significant part of the copper consumed at the time, it is not excluded that other deposits supplied the Congo Basin. Furthermore, in the last decades of the 19th century, imported brass seems to have overshadowed local production of unalloyed copper. While the onset of colonial occupation seems to have played a role in this mass import, the chronology of these changes and the role of other brass suppliers, such as the Swahili trade in the east of the region, is still unclear. In addition to literature review and archival works, this talk will investigate whether portable X-ray fluorescence (pXRF) analysis can help to investigate the origin of the metal and pattern of trade and consumption in the Congo Basin at the end of the 19th century. It will be based on the analyses of a hundred copper-based objects originating from the region along the Congo River and some of its tributaries and curated at the Royal Museum for Central Africa. Key questions are, among others, whether other copper deposits than the Niari Basin and Copperbelt supplied the Congo Basin and to what extent imported brass overshadowed local copper production.