Environmental change and archaeology:: lake evolution and human occupation in the Eastern Sahara during the Holocene

The West Nubian Palaeolake is the most large-scale hydrographic evidence in the Eastern Sahara of the early to mid-Holocene wet phase that affected northern Africa. It is the result of a significant increase in local rainfall due to the northward shift of the tropical rainfall belt. A series of fieldwork-based differential GPS (DGPS) measurements along several profiles across the West Nubian Palaeolake basin provides the first precise topographic data from this up to a 5330 km(2) large palaeolake feature. In combination with sedimentological, geochemical, and archaeological results, an almost complete picture of significant palaeoclimatic changes: and human occupation during the early to mid-Holocene for this region is presented. Different stages of palaeolake evolution ranging from non-existence of the lake through stable freshwater conditions to its extinction were identified in the period from 9400 to 3800 C-14 yr BP. These lake stages coincide with phases of intensive human inhabitation between ca. 6300 and 3500 C-14 yr BP, and include at least four settlement phases distinguishable by style of pottery. These are known from adjacent areas of the palaeolake region, emphasizing strong prehistoric cultural connections in the Eastern Sahara. During the highstands of the palaeolake in the early to mid-Holocene, the Dotted Wavy-Line pottery relates to the Early Khartoum type culture with its supra-regional distribution from the Nile Valley to the Chad, and possibly with slightly different forms even to the Atlantic coast. Later in the Holocene, Western Nubia with its large palaeolakes and migration paths along palaeowadis, such as Wadi Howar, acted as an important natural and cultural link between the Nile Valley and the Chad Basin until the region was deserted during the fourth millennium BP. (C) 2001 Elsevier Science B.V. All rights reserved.