Presentation on theme: "Nile behaviour and Late Palaeolithic humans in Upper Egypt Pierre M. Vermeersch, Geo-Institute, KULeuven, Belgium 2014 KONINKLIJKE VLAAMSE ACADEMIE VAN."— Presentation transcript:
Nile behaviour and Late Palaeolithic humans in Upper Egypt Pierre M. Vermeersch, Geo-Institute, KULeuven, Belgium 2014 KONINKLIJKE VLAAMSE ACADEMIE VAN BELGIË VOOR WETENSCHAPPEN EN KUNSTEN European Geosciences Union Wien 2014 The Quaternary History of the River Nile 248637
OSL & 14 C-Dates from the Upper Egyptian Nile Valley Late Palaeolithic25 - 14 ka calBP Upper Palaeolithic 40 - 25 ka BP Transition: Taramsan 40 - 60 ka BP Late Middle Stone Age60 - 70 ka BP Halfan, Safahan, Khormusan Lower Nile Valley Local Complex 70 -120 ka BP NK2, Beit Allam Late Nubian Complex 70 -100 ka BP NK1, NK3 Early Nubian Complex120 -200 ka BP Final Acheulean>250 ka BP After Wendorf, Schild, Vermeersch, Van Peer, Stokes, Bailey Out of Africa 2 ? Decreasing population density MODERN HUMANS LGM: Spectacular increase No traces of humans14 - 9 ka calBP
Makhadma 4Abu Manna Makhadma 2 Dishna Late Palaeolithic sites are situated some few meters above the present floodplain always where Nilotic clays meet local deposits. Several different cultural groups are present. Faunal remains are mainly fish. Mammalian fauna is very restricted: Bos primigenius, Hippopotamus amphibius, Alcelaphus buselaphus, Gazella dorcas, Lepus capensis. El Abadiya 3 Shore line
According to Schild & Wendorf (2010) the Late Paleolithic, Nilotic sediments in Wadi Kubbaniya seem all to be overbank; there are no channel or near-channel deposits. Phytogenetic dunes and barchans (related to southern winds ?) Wendorf & Schild 1989) were present. The Late Paleolithic Nile appears to have been a typical braided river with shallow, rapidly changing channels. It was characterized by a very great difference between its low- and high-water stages - certainly much more than the 6.5 m. The Nile waters were overloaded with sediments. A critical review of that interpration leeds us to the suggest another geomorphological model of the LGM Nile valley environments. Wadi Kubbaniya 22 ka calBP
During the period 24 000 to 14 500 calBP the regime of the Blue and the White Nile was highly seasonal and with very low flows and even periods of complete drying out for all or part of the year (Williams et al., 2000). According to Revel e.a. (2010) there was a very restricted sedimentation rate from the Nile in the Mediterranean (core MS27PT). This was coeval (24-14 ka calBP) with a reduced water content of the East African lakes. Still during that period high (up to 7 m) Nile deposits are registered in Upper Egypt. Those Nile deposits are nearly exclusively silty clays (Paulissen & Vermeersch 2000). The highest deposits are from the youngest period (~14.5 ka calBP). Sedimentation rate
To most authors (Besler 2011) an arid phase without groundwater recharge prevailed between 20 000 and 14 000 BP in NE Sahara. Draa’s have a mainly North-South direction apparently due to the trade winds. In addition to that phenomenon, the extratropical westerlies were strong and dry during the Late Pleistocene. The effect of such wind activity resulted in the accumulation of huge sand bodies into the Nile valley (Khefoug deposits). Once in the valley, the aeolian sands were trapped by the Nile cliffs and moved inside the valley to the South. The cliffs south of the Nag Hammadi-Qena bend functioned as a trap, filling the Nile valley with aeolian sand, eventually damming the very reduced river Nile flow. Dune climbing up the plateau at Nag HammadiLongtitudinal dune ingression into the Nile Valley
Armant Aeolian sand ingressing and moving South in the Nile valley of Middle Egypt. High E-W cliffs result in sand accumulation Transport of aeolian sand over the Nag’Hammadi- Armant plateau. Dune sand accumulated in the Nile valley, in sand bodies transverse to the valley.
Damming dune field Makahdma Lake Armant In Napoleon’s “Description d’Egypte” identified as “dunes” During the LGM, dunes from the Sahara invade the Nile valley. Some traces can still be observed in the present-day valley fill. A nice example, still visible, is that near Armant, where another damming could have been present (not necessarily during the same period). Such dams must be understood as large dune fields. Through seepage is minimalised as the suspension laden waters clog the pores. Vegetation along the lake shore capture the heavy clay of the lake waters, creating clay rich shores.
Wadi Kubbaniya Aswan Late Palaeolithic fish faunas along the Egyptian and Nubian Nile are always characterised by a heavy preponderance of clariid catfish. Other floodplain dwelling taxa such as tilapia, and sometimes cyprinids, can occur, but their proportions are usually minimal (Gautier & Van Neer 1989: 153; Van Neer 2004: 256). During the LGM apparently the Nile valley was often dammed, probably not always on the same places, resulting in large ephemeral lakes which were able to survive several decennia (or even centuries?). This hypothesis is corroborated by the fact that the exploited fish are mainly tilapia which typically dominate lake faunas. Gebel Silsila
All (111) 14 C dates from the Palaeo sites in the Nile valley Lake Tana, Blue Nile, is dry (Lamb H. e.a. QSR, 2007) White Nile is dry (Williams M. e.a. QSR, 2006) Highest lake level There came an end to the human presence when Blue and White Nile restarted their flow. This coincides with the Bølling.
Accumulating sand in this direction Dam failure at this position Very narrow Nile valley, strongly eroding its cliffs When White and Blue Nile were reactivated, the resulting high flows finally breached all dams.
Burial at Jebel Sabaha (15-14 ka calBP) with violent deaths Picture courtesy A. Marks
After the final dam failures around 12.5 BP (14.2 CalBP) there came apparently an end to an important period of human occupation during the LGM. During the final Tardiglacial no traces of an Egyptian population are found. Even when new groups of humans are populating the deserts, very few traces of humans are found in the Nile Valley. Late Palaeo > 12500 12500-8000 BP 8000-5300 BP 5300-3500 BP adapted from Kuper & Kröpelin, Science 2006 Lake phase Nile erosionDesert occupation Repopulation of the valley Numerous ephemeral lakes Dam failure Nile is becoming a meandering river with flood plain Elkab
Conclusions During the late Pleistocene glacial period the population of the Upper Egyptian Nile valley became very reduced, probably because the Nile was not any more a meandering river with a rich fauna and flora. During the most adverse climatic conditions of the LGM there was however a spectacular increase of the population. Indeed, during the LGM there was a huge input of aeolian sand into the Nile valley and the Nile had a very reduced flow and probably sometimes no water. Still living conditions were optimal for fishing communities, which were living at the edges of the present floodplain. The best interpretation for understanding this phenomenon is the existence at that time period of large lakes in the valley where water was dammed by aeolian sand, accumulating in the Nile valley. Such a model is corroborated by sedimentological arguments (clays and no traction load), sand accumulations transverse to the Nile valley, fish fauna typical for a lake environment, creating a optimal environment for the important population of the Nile valley during the LGM. There was an abrupt end to that population when the White and the Bleu Nile restarted there important influx of water into the Nile valley, recreating a eroding meandering river. It was apparently a catastrophic event for the humans in the valley.