Geo-archaeological and geometrically corrected reconstruction of the 1.84 Ma FLK Zinj paleolandscape at Olduvai Gorge, Tanzania

Abstract

A geomorphological, sedimentological, stratigraphic, and geometric study of 30 trenches excavated around FLK Zinj (Bed I, Olduvai Gorge) has enabled the partial reconstruction of the paleolandscape surrounding this site for a radius of ∼1000 m. This is the largest sample of geological and archaeological information yet available to reconstruct the topography, ecology, and geomorphology of the Zinj paleosurface and the hominin activities preserved within it. Contrary to previous interpretations, which place FLK Zinj on an isolated and narrow peninsula, it appears that the site was located on the edge of an elevated platform traceable for hundreds of meters. Hominins created FLK Zinj (and other sites, such as the recently discovered PTK and AMK) within the wooded habitats of this platform rather than the more open and grassy environments situated on lower portions of the lacustrine floodplain. Input areas, probably in the form of alluvial fans, existed to the south, following a North-South direction. These input areas are partially responsible for changes in the type sequence. Restricted erosion documented on the wooded platform was mostly caused by runoff processes. An archaeological study of the excavated trenches reveals a sharp contrast in fossil and stone tool density between FLK Zinj and the surrounding landscape, further supporting the contention that the site may have acted as a “central place” where repeated carcass transport, butchery, and consumption took place. Taphonomic studies indicate that at this stage of human evolution, hominins had primary access to carcasses and were not dependent on other carnivores for obtaining meat.