The Archaeology of Aduma Middle Stone Age Sites in the Awash Valley, Ethiopia.

Abstract

The Aduma region of the Middle Awash Valley, Ethiopia, contains multiple surfaceand in situ Middle Stone Age (MSA) occurrences that include lithics and spatiallyassociated faunal and hominid remains. While one Aduma site may, on the basisof lithic comparison, be assigned to an early phase of the MSA, both absolute datesand lithic typology indicate that the remainder represent a significantly later stageof this industrial tradition, likely dating to ca. 80,000 to 100,000 years ago.Assemblages were deposited on an aggrading alluvially dominated landscapewhich included riverine and floodplain environments. Chronological changes inlandform and raw material availability within the geographically limited Adumaregion provided a dynamic context that required behavioral flexibility to adaptsuccessfully. Analysis of ten assemblages from eight sites provides the basis forcharacterizing the Aduma sequence, setting it into broader sub-Saharan contextand reconstructing aspects of hominid subsistence strategy and lithic economy.The Aduma lithic assemblages constitute a regional variant within the MSAcharacterized by a distinctive range of point, scraper and core types. Most strikingare the small “microlithic” size of multiple types all produced by MSA technologiesand the increasing emphasis on smaller tools over time, which suggests a processsimilar to yet independent from that which culminated in the appearance of theLate Stone Age. Faunal remains indicate use of multiple habitats with a strong andconsistent reliance on riverine resources including large easily predated fish.Based on cranial remains, the Aduma hominids fall within the range of anatomi-cally modern humans. Intersite comparison reveals a scheduling of subsistenceand manufacturing behaviors typical of some ethnographically known hunter andgatherer groups. As raw material availability changed over time, lithic manufac-turing and utilization patterns varied in an economically rational manner to max-imize efficiently the use of scarce and valuable stone types.