Late-pleistocene archaeological and geoarchaeological investigations in the Mukogodo Hills and Ewaso Ng'iro Plains of Central Kenya

Abstract

Archaeological and geoarchaeological surveys of the Mukogodo Hills and Ewaso Ng'iro Plains of Kenya are reported. Seventy-one archaeological sites dating from the Middle Stone Age to the present are described. An alluvial chronology consisting of five sedimentary units dating from the late Pleistocene and Holocene epochs is presented. These data are used in attempting to reject four hypotheses about Quaternary period human adaptation in the region. Hypothesis One, that landscape changes did not affect the distribution of archaeological sites in the study area, is rejected. Sites attributable to the Later Stone Age, while found on all landforms, are more abundant in the interfluvial area between the Tol and Peleta drainages near the Mukogodo foothills. The absence of Middle Stone Age sites on the Holocene surfaces in the interfluvial areas is attributable to erosion and/or burial of Pleistocene deposits containing those sites. Hypothesis Two, that there were no significant differences in land-use patterns between the Middle and Later Stone Age in the region, is rejected. Later Stone Age sites are clustered in the Mukogodo foothills, while Middle Stone Age sites exhibit an unpatterned distribution on Late Pleistocene surfaces. This difference is interpreted as representing land use intensification in the Later Stone Age due to population growth, circumscription, or ecological factors. Later Stone Age land-use is seen as evidence of greater strategic planning or planning depth. Hypothesis Three, that the arrival of pastoralism did not contribute to erosion and degradation of the landscape, could not be rejected as no direct evidence indicates that the prehistoric introduction of pastoralism into the study area had any physical impact on the landscape. Alternate hypotheses concerning the cause of the erosion evident in the late Holocene sedimentary deposits are suggested.