Pliocene History of South Saharan/Sahelian Aridity: Record of Freshwater Diatoms (Genus Melosira) and Opal Phytoliths, ODP Sites 662 and 664

  • Edward M. Pokras
Part of the NATO ASI Series book series (ASIC, volume 282)


The record of windblown, siliceous microfossils transported from North Africa to the tropical Atlantic provides evidence for times of increased aridity and intensified eolian transport during the Pliocene. Data from ODP Sites 662 and 664, which record climatic changes in the southern Sahara and Sahel, are presented here. These results indicate that cyclical aridification of North Africa began at least 3.8 Ma ago. The data are also consistent with an increase in the severity of arid events approximately 2.3–2.5 Ma ago, although such a change cannot be proved solely on the basis of data presented here.


Ocean Drill Program Freshwater Diatom Hole 664D Hole 662A Siliceous Microfossil 
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Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • Edward M. Pokras
    • 1
  1. 1.Lamont-Doherty Geological Observatory of Columbia UniversityPalisadesUSA

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