ARCHAEOLOGICAL SITES RECORD LATE HOLOCENE CLIMATE CHANGE IN THE EAST AFRICA RIFT VALLEY
Geoarchaeological study of sites provide evidence of environmental change. Dates (4.23 ± 0.27 ka) confirm that GaJj4 (Dongodien), a beach site on the Koobi Fora cuspate foreland, was the earliest site in East Africa to have domestic animals. Drying climate opened up a tsetse-free corridor between North and South Africa and falling lake levels exposed rich pasture land for domestic herds on the lake margin. This site is stratified and dates indicate that it was chosen for reoccupation (2.38 ± 20 ka). The site borders rich fishing grounds associated with nearby areas of lacustrine upwelling.
A complete buried skeleton (4.4 ± 0.28 ka), unfortunately with no grave goods, was uncovered at FwJj27. Late Holocene climate change is recorded in the palimpsest record of FwJj5 (0.90 ± 0.06 ka) in a small river valley containing a groundwater seep. Stone bowls, lithic artifacts, bone harpoons, fish bones, and domesticated cattle remains at this site located 5 km from the lake suggests a “cultural melting pot” of inhabitants. The archaeology indicates occupation by people who may have covered distances up to several km in accessing resources, but were likely drawn to an environmental refugia of a freshwater spring during times of regional aridity.