The Oudierin Drainage Archaeological Project: New Perspectives on the Saloum Delta Shell Middens (Senegal)

Archaeological research on the Saloum Delta (Senegal) shell middens has had relative highs and lows since the first half of the twentieth century, but they are one of the most investigated regional clusters in West Africa. Research has been structured along three main thematic axes: mortuary archaeology (investigating burial mounds); taphonomy (assessing the rhythm and speed of shell midden formation); and ethnoarchaeology (contributing to the construction actualistic references). The Oudierin Drainage Archaeological Project was designed to shift perspective from single sites to the "region"-in this case, the Bolon Oudierin drainage-by investigating the long-term dynamics of the local shellfish economy via fine-tuned "motorboat" and pedestrian surveys, detailed site-mapping and recording, and excavation at two key sites. The research reported here presents new details on the structure of large shell middens, including detailed stratigraphic sections, activity areas, and material culture. The analysis of shell size variations along the stratigraphic column of the largest midden allows for modeling the reasons for the punctuated nature of shell middens formation-relatively short periods of exploitation followed by longer periods of abandonment. Finally, it is shown that shellfish exploitation started some 10,000 years ago during the early Holocene, much earlier than the formation of the Saloum Delta as known today. The formation of cemeteries with burial mounds occurred early in the second millennium (AD 1000-1300), supporting the Diorom-Boumak sequence.