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Mineralogy and geochemistry of Late Pleistocene-Holocene lacustrine sediments in the Faiyum Depression, Egypt: implication on palaeoclimate

  • Mohamed A. Hamdan,
  • Rounaq H. Badawy,
  • Refaat A. Osman,
  • Fekri A. Hassan,
  • Roger J. Flower,
  • Mohamed S. Mabrouk,
  • Adel M. Afify

摘要

The geochemical and mineralogical investigations conducted on a core retrieved from a paleolake in Faiyum Depression, Egypt, reveal a variation in two precipitation patterns; these are the Ethiopian African Monsoon (EAM) at the Nile Headwaters and the Mediterranean winter rains. The heavy mineral assemblage, and the geochemical characteristics, exhibit significant shifts in clastic input to the paleolake. These variations suggest shifting in the sources of sediment, with an East African origin during the African Humid Period (AHP) and in the Late Holocene, and a White Nile source during the Late Pleistocene and Middle Holocene. Geochemical data is additionally utilized in the determination of variations in the properties of the paleo-water (paleo-salinity and paleo-productivity). The paleo-water of Faiyum Lake exhibited characteristics of a substantial freshwater body during the Early to Mid-Holocene. During the subsequent period, there was a sudden drop in the lake level, accompanied by a subsequent rise in salinity due to hydrological modifications.