Human Mobility and Land-use Patterns During the Holocene: Lithic Analysis of Holocene Sites From Koobi Fora, Northern Kenya

Abstract

The Holocene period recorded a global climate variability phenomenon. The manifestation of these changes varied greatly across the globe. In Turkana Basin, northern Kenya, evidence of this climatic variability is preserved both in the terrestrial landscapes and lacustrine sediments. The lake Turkana experienced lake-level changes, where it was highest in the early Holocene and declined in the mid-Holocene. It is obvious that these changes affected the Holocene populations and influenced their behaviour, especially mobility. This study analysed obsidian stone tools as a proxy to understand the extent of the mobility of these communities across the Holocene landscape in the east Turkana basin. This study was carried out on laboratory artefacts to investigate the effect of climate change on Holocene populations and how they culturally responded to the drastically changing environments. Specifically, mobility and land use by different Holocene populations were examined. The project aimed at establishing the distances between raw material resources and the sites where the artefacts were recovered and compared the results to those obtained from cortex ratio analyses, another novel method in understanding mobility established in the last decade that was used in this study. The cortical ratio analyses showed extremely low ratios, ranging from 0.046 to 0.086, which indicates that the artifacts were found farther from their place of manufacture. Only 6 core fragments were found across 5 archaeological sites. This supports the claim that the tools were used and reused for prolonged periods of time and came from far-off locations. For early Holocene populations, the distances between sites and sources varied between 38km and 162km versus between 26 km and 235 km for mid-Holocene populations. It was evident that climatic change influenced Holocene populations' land use patterns and mobility. The early Holocene populations relied on resources from the East Turkana Basin with reliance on one source by all the sites (Surgei) as well as other two sources. On the other hand, populations during the mid-Holocene were more mobile as resources became more limited and unpredictable and the habitats dried up and explored resources outside the east Turkana Basin. This led to increased movements and longer distances and often returns to original locations where vegetation had regenerated at locations likely used as livestock enclosures. More samples are needed from different locations to understand intra-site source variations, more surveys and samples are required for archaeological sites to increase sample size to draw accurate conclusions and it is vital to assert the chronology of FxJj 108 to comprehend various dynamics across time.