| Abstract: | The Shurmai rockshelter (GnJm1) is located in the semiarid Mukogodo Hills region of north central Kenya. The rockshelter cavity is formed in Precambrian granite gneiss. The site contains a stratified sequence of sediments and archaeological materials that date from the end of the African Middle Stone Age (at or before ca. 45,000 yr B.P.) to modern times. The stratigraphic sequence at the Shurmai rockshelter is described and the principal noncultural formation processes responsible for its creation are reconstructed. Extant rockshelter sediments consist predominately of coarse angular rubble produced by rock fall, and additional sands and gravels produced by granular disintegration, slopewash, debris flow activity, and, to a lesser extent, human activity. The more identifiable aspects of the geologic history of the shelter include a number of episodes of rock fall deposition, in situ rock fall weathering, and erosional truncation. The reconstruction of the formation processes active at the Shurmai Rockshelter is used to illustrate how such geoarchaeological analysis clarifies understanding of prehistoric human occupation in rockshelter contexts in general, and in granitic terrane in particular. © 1999 John Wiley & Sons, Inc. |
