Photo: Excavations at Locality 1, Kapedo Tuffs, 2006.
Silali is the largest volcano in the Kenya's Rift Valley, with an eruptive history that began hundreds of thousands of years ago, forming the base of the Suguta Valley, a very arid portion of the Rift. The Kapedo Tuffs are ancient volcanic ash deposits erupted from Silali between 135,000-123,000 years ago, exposed in places along the flanks of the volcano. Shallow stream deposits within the Kapedo Tuffs preserve Middle Stone Age (MSA) archaeological sites; the sparse density of which suggest ephemeral occupation of the area potentially linked to the limited availability of water. Comparison of archaeological material from the Kapedo Tuffs with material from the adjacent Turkana and Baringo basins demonstrates the powerful effects that stone raw material type and availability can have on artifact size and the presence of retouch, important factors in the definition of lithic industries and measures of human behavioral variability.
Photo: Test excavations,, 2006 with Mathew Eregae Macharwas, Bernard Kanyenze Ngeneo. Silali in background.
Tryon, Christian; Roach, Neil, & Amelia Logan
2008 The Middle Stone Age of the northern Kenyan Rift: age and context of new archaeological sites from the Kapedo Tuffs. Journal of Human Evolution 55:652-664. pdf
Neil Roach, The George Washington University
M. Amelia V. Logan, Smithsonian Institution