Palaeoecological studies of Late Pleistocene and Holocene deposits in the Central Sahara allowed the reconstruction of the palaeoenvironmental development of the Ténéré desert (today one of the driest places on earth) and the Tchigai and Djado plateaus in Republic of Niger. Topographical factors, geomorphologic evidence and biological remains suggest that a widespread lake country existed with perennial deep-water lakes changing in size, water level and water balance from 10 k.a BP onwards.
There was an abrupt change around 5.5 ka BP in the northern and 4.5 k.a BP in the southern part of the region. Desiccation of the now shallow permanent freshwater lakes began, coexisting with seasonal ponds of saline/alkaline waters, and finally the development of a swamp environment. The position of neolithic artifacts scattered on top of the lake sediments show that the lakes had lost much of their late Pleistocene/Early Holocene size by the time of the Neolithic settlement.
Although stratigraphic data are still rare, we have now a course idea about the chronological succession of different “cultures” in the Ténéré-region. The important stratigraphy at Adrar Bous was published 2008, which allows for the resolution of the terminal Pleistocene and Holocene assemblages into three distinct industries, each associated with moister periods and nearby lakes:
1. The first expansion of hunter and gatherers after the last glacial maximum and during the terminal Pleistocene moist phase is represented by a non-microlithic Epipaleolithic, blade-based industry with characteristic elegant shouldered points (Ounanian-points), burins, scrapers and “meches de foret”. This industry date at Adrar Bous > 7 k.a. and possible >9 k.a BP. The sites appear as short term specialized camps. Ounanian-points are wide spread in the Sahara and in North Africa. In the North, they are found in slightly older contexts (about 10000 BP) compared with the South. Their distribution in time and space therfore indicates a North to South expansion of hunters, equipped with bow and arrows, that followed the new abundance of large pray (elephant, giraffe) in the Sahara.
2. The “Kiffian” microlithic industry with geometrics but no distinct point forms, rare pottery and occasional harpoons / bone points adapted to an aquatic milieu. The “Kiffians” are suggested to represent sedentary fishers. Barbed Bone points have been found over large areas of the Sahara and are securely connected with the hunt of hippopotamus and crocodiles and fishes. Drake recently published evidence, that these people could have been Nilo-Saharan speakers, expanding over the “green Sahara” from the East to the West.
3. the Tenerian macrolithic industry with a characteristic retouched forms (axes, adzes, flat bifacial knifes, drills, scrapers and retouched blades), a variety of arrow-points and with pottery, groundstones and domestic cattle. The Tenerians are seen as mobile Cattle herders (pastoralists). At the same time, there was a continuing importance of wild fauna (antelopes, hippopotamus, rhinoceros, fish) in this context, demonstrating that there was no quick shift.
The beginnings of the Tenerian occupation has been dated to 6 k.a BP and was particularly marked about 5 k.a BP. At a first glance, it seems to be paradoxically that this complex flourished exactly at the point of a return of dry conditions to this part of the Sahara. It was therefore discussed that maybe diseases, parasites, and insects in the wet, swampy areas may have proved unattractive to humans and their animals during moister periods, but of course this is only one possible causes.
Approximately two hundred human burials were discovered on the edge of a paleolake in Niger called Gobero. Here multiple graves from Kiffian and Tenerian contextes were found. The ongoing multidisciplinar evaluation of the sklettal remains will undoubtely allow new insights in the lifestile of these groups