A Late Stone Age sequence from West Ethiopia:: The sites of K'aaba and Bel K'urk'umu (Assosa, Benishangul-Gumuz Regional State)

In this paper; the results of the test excavations in two rock shelters in the Central Ethiopian escarpment near the Sudanese border are presented. A continuous sequence of quart.: lithic industry, from the lowest levels of K'aaba (with an archaic MSA-like industry of side-scrapers, Leval-lois-discoid cores and unifacial points) to the upper levels of Bel K'urk'amu (with a LSA industry characterised by elongated flakes and end-scrapers, that still displays many archaic features such as centripetal flakes and cores) may be inferred. The escarpment's mountainous and forested areas may have acted as a refuge zone from the end of the Pleistocene, when hyper-arid conditions deterred human occupation of the Sudanese plains nearby, and may also have been a cause for the cultural archaism of the late MSA groups, a case similar to others recorded in the African continent (South Africa, Zimbabwe, Nile Valley). The arrival of Sudanese pottery in the mid-Holocene period may be explained by the onset of arid conditions that drove "aqualithic"groups and early herders towards more humid areas. The conservative character of the late prehistoric cultural sequence derived from both sites is consistent with the resilient traditional nature of the Nilo-Saharan groups that currently settle the Ethio-Sudanese borderlands.