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A suite of drill cores undertaken on the Saqqara-Memphisfloodplain revealed an array of Late Pleistocene-Holocene sediment facies that show a complex of spatio-temporal changes in sediment related to migration of the River Nile, Nile flood variations, settlement sites and climate change. The recovered data enhance our understanding of the history of the modern River Nile and its relationship to the emergence and continuity of Egyptian civilization. The floodplain of the Saqqara-Memphis area reveals a sequence of aggradation and degradation events comprising six clearly marked sedimentary units (I-VI), overlying Late Pleistocene fluvial sand and gravel (unit I). Deposition of unit II resumed during a period of high Nile flow, rapid sea level rise and locally wet climatic conditions. As a result, the floodplain was occupied by swamps and anastomosing channels. Subsequently, the Nile changed to a more stable meandering channel system with well-developed levees and flood basins (unit III). This aggradation unit was subsequently eroded by the end of Old Kingdom (ca. 4.2 kyr cal BP). The degradation hiatus was followed by a widespread layer of alluvial silt and sand indicating very high Nile floods that coincide with historical records of very high floods during the Middle Kingdom and frequently high floods during the New Kingdom (unit IV). During the last two thousand years (units VI-VII) floods generally diminished except for several notable lows and highs. Our calculations of the long-term rate of siltation during the Middle and Late Holocene suggest an average rate of 0.235 m/century rather than the commonly cited 0.09–0.12 m per century. In addition, our study of satellite imagery of the Memphite region in the context of archaeological data combined with our own geological studies reveal that the main Nile in Neolithic and Predynastic times (ca.7.0–5.0 kyr cal BP) ran along the eastern edge of the current floodplain. A lateral branch of the Nile ran along the western edge of the floodplain. It is on the bank of this branch that the first capital of a unified Egypt was established. Our cores also reveal during the Dynastic period, the western branch shifted eastwards, while the main Nile shifted westwards. [ABSTRACT FROM AUTHOR]

We report on the sedimentology, pollen and diatom records in a 26 m long core of Holocene sediments from the Tersa area, near the centre of the Faiyum Depression (Egypt). Two radiocarbon and one OSL dates have been obtained for the core, dates range from 9545 ± 60 Cal. BP to c. 4040 BP. These correspond respectively with the Terminal Palaeolithic (Qarunian) and Neolithic Faiyum A (Faiyumian) cultures. The core is subdivided into 3 sedimentological units: unit 1 (21–26 m) is very thinly laminated, calcareous silt deposited in a deep water lake; unit 2 (9.5–21 m) is finely laminated sand, silt and carbonates formed as a lacustrine fan delta; unit 3 (9.5 m to the core top), is formed of massive silt, sandy silt and very fine grained flood plain sands. Planktonic diatom taxa, mainly Cyclostephanos, Aulacoseira, Cyclotella and Stephanodiscus spp. were abundant in units 1 & 2-a, indicating deep, open lake conditions. Magnetic minerals increased from the base of unit 2 indicating an increasing contribution of Nile alluvium. Benthic taxa such as Fragilaria, Cocconeis , Amphora and Navicula tended to increase towards the core top, from unit 2-b; 3-a to 3-b, indicative of lake shallowing and periods of low Nile floods. Unit 3-c is barren of diatoms and is compatible with terrestrial flood plain conditions. Vegetation was mainly represented by herbaceous pollen throughout most of the core and in the topmost sediment, pollen was scarce but pteridophyte (Osmundaceae) spores increased. Arboreal vegetation had low percentages in most of the record but increased in the middle section of the core (unit 2). A depositional deltaic environment was indicated throughout most of the core (sub-units 2-a & 3-a), where high abundances of Poaceae, Cyperaceae, Chenopodiaceae, Amaranthaceae, Polypodiaceae and Osmundaceae were recorded, indicating high Nile floods and fluctuating rainfall. [ABSTRACT FROM AUTHOR]

Abstract: Stable oxygen and carbon isotopes of freshwater mollusc shells from a sequence of dated palaeolake deposits in the Faiyum Depression, Egypt, provide an outline record of lake development during the Holocene. It is argued that the carbonate O18 record provides a proxy for climate change and that the isotope changes are driven by variations in monsoon precipitation in Nile headwaters and in local evaporation processes. Shells from sediments dated to ca. 10,000 to 7700cal BP had low values for oxygen and carbon isotopes indicating higher precipitation in the local area and intensified monsoonal activity, leading to higher Nile flood discharge and flooding of the entire Faiyum Depression. This was followed by a transitional period characterized by marked variability but with precipitation on average less than before. From ca. 6000 to 4300cal BP, precipitation was decreased until a dramatic reduction in Nile flood discharge occurred late in the fifth millennium BP. This reduction signalled the onset of arid conditions in the Faiyum, partly as a consequence of changes in Nile headwaters that was concomitant with declining lake levels in East Africa. Lake level decline in the Faiyum was further aggravated after 2700 BP as the Nile inflow further weaken and regulation increased. [Copyright &y& Elsevier]