Late Quaternary Environments in the Nile Basin
The Late Quaternary history of the Nile has been reconstructed using well-dated sedimentary, stable isotope and fossil records and associated archaeological remains. The White Nile flows over the bed of an ancient lake dating to ~ 400 ka (Marine Isotope Stage 11). High flood levels in the White Nile since that time appear to coincide with times of sapropel accumulation in the eastern Mediterranean. During times of aridity, the most recent phase being roughly coeval with the Last Glacial Maximum, the large lakes in Uganda either dried out or were too low to provide flow into the White Nile, which became a highly seasonal river, as did the main Nile.
The sediments of Lake Albert, from where the White Nile starts its long journey to the Mediterranean, preserve critical evidence on the discharge history of this river. The lake's sedimentary record confirms the coincidence between overflow of Lake Victoria and reestablishment of flow in the White Nile north of Khartoum at ~14.5 ka and also shows a lake low-stand at ~ 4.2 ka that, by cutting off flow to the White Nile, may have contributed to the fall of Egypt's Old Kingdom. The modern hydrological regime in the Nile was thus re-established at ~14.5 ka, with strengthening of the summer monsoon and overflow from Lake Victoria. A modest number of calibrated radiocarbon ages on White Nile gastropod shells indicate that White Nile levels were high around 14.7–13.1 ka, 9.7–9.0, 7.9–7.6, 6.3 and 3.2–2.8 ka. The Blue Nile and main Nile flood records, albeit less complete, accord with those of the White Nile. Preliminary OSL ages obtained by us from the upper 2 m of dunes west of the White Nile and main Nile show discrete phases of Holocene dune activity that seem to correlate with at least three of six significant periods of rapid global climatic change during 9–8, 6–5, 4.2–3.8, 1.2–1.0 and 0.6–0.15 ka, the first five of which coincided with polar cooling and tropical aridity. The intervals in between were wetter in the tropics and, allowing for dating errors, tally reasonably well with the intervals of high White Nile floods identified here.
KeywordsClay Quartz Dust Sedimentation Geochemistry
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- Butzer, K. W., 1980. Pleistocene history of the Nile Valley in Egypt and Lower Nubia. In M. A. J. Williams & H. Faure (eds), The Sahara and the Nile: Quaternary Environments and Prehistoric Occupation in Northern Africa. Balkema, Rotterdam, pp. 253–280.Google Scholar
- Hurni, H., 1982. Climate and the Dynamics of Altitudinal Belts from the Last Cold Period to the Present Day, Simen Mountains-Ethiopia, Volume 2. Geographica Bernensia, G13, University of Berne, Berne, Switzerland.Google Scholar
- Lamb, H. F., R. Bates, M. H. Marshall, M. Umer, S. J. Davies & H. H. Toland, 2007. Pleistocene desiccation of Lake Tana, source of the Blue Nile. Quaternary International 167–168, 226.Google Scholar
- Pik, R., B. Marty, J. Carignan & J. Lave, 2003. Stability of the Upper Nile drainage network (Ethiopia) deduced from (U-Th)/He thermochronometry: implications for uplift and erosion of the Afar plume dome. Earth and Planetary Science Letters 6813: 1–17.Google Scholar
- Sylvestre, F., F. Gasse, M. Williams, F. Chalie, A. Vincens & D. Williamson, 2007. Late Quaternary climates in Africa, South America and Australia. Quaternary International 167–168: 409.Google Scholar
- Talbot, M. R., M. L. Filippi, M. B. Jensen & J.-J. Tiercelin, 2007. An abrupt change in the African Monsoon at the end of the Youger Dryas. Geochemistry Geophysics Geosystems 8, Q03005. DOI 10. 1029/2006GC001465.Google Scholar
- Welsby, D. A., M. G. Macklin & J. C. Woodward, 2002. Human responses to Holocene environmental changes in the northern Dongola reach of the Nile, Sudan. In R. Friedman (ed), Egypt and Nubia: Gifts of the Desert. British Museum Press, London, pp. 28–38.Google Scholar
- Williams, M. A. J., (in press). Late Pleistocene and Holocene environments in the Nile basin. Global and Planetary Change.Google Scholar
- Williams, M. A. J. & D. A. Adamson (eds), 1982. A Land Between Two Niles: Quaternary Geology and Biology of the Central Sudan. Balkema, Rotterdam, 246 pp.Google Scholar
- Williams, M. A. J. & H. Faure (eds), 1980. The Sahara and the Nile: Quaternary environments and prehistoric occupation in northern Africa. Balkema, Rotterdam, 607 pp.Google Scholar
- Williams, M. A. J., A. H. Medani, J. A. Talent & R. A. Mawson, 1974. A note on Upper Quaternary sub-fossil mollusca west of Jebel Aulia. Sudan Notes and Records 54: 168–172.Google Scholar
- Williams, M. A. J., D. Dunkerley, P. De Deckker, P. Kershaw & J. Chappell, 1998. Quaternary Environments (Second Edition). Arnold, London, 329 pp.Google Scholar
- Woodward, J. C., M. G. Macklin & D. Welsby, 2001. The Holocene fluvial sedimentary record and alluvial geoarchaeology in the Nile Valley of northern Sudan. In D. R. Maddy, M. G. Macklin & J. C. Woodward (eds), River Basin Sediment Systems: Archives of Environmental Change. Balkema, Rotterdam, pp. 327–355.Google Scholar
- Woodward, J. C., M. G. Macklin, M. D. Krom & M. A. J. Williams, 2007. The Nile: Evolution, Quaternary river environments and material fluxes. In A. Gupta (ed), Large Rivers: Geomorphology and Management. Wiley, New York, pp. 261–292.Google Scholar