QUATERNARY CHANGES IN THE EGYPTIAN SHORELINE OF THE NORTHWESTERN RED-SEA AND GULF OF SUEZ

On the NW, Egyptian, shoreline of the Red Sea, remarkably preserved Pl eistocene-Holocene marine (reefs, beaches, mangrove swamps, gypsum-sal inas) and non marine (alluvial fans and wadi terraces) deposits are lo cated within a complex Neogene rift frame. The Early and Middle Pleist ocene reefs are uplifted to a maximum of 40 m, subsequent movement bei ng limited to a few metres (except on the S Gulf of Suez shores) which suggests a decreasing tectonic activity of the northern part of the r ift. A new series of radiometric dates and precise levelling have demo nstrated a short-lived, low stand of relative sea level during the Las t Interglacial high stand (5e). At that time, flooding of the Isthmus of Suez has enabled exchanges between Mediterranean and Indian Ocean f aunas and the biogeographic limit was temporarily located in the South ern Gulf of Suez, thus explaining the Late Quaternary introduction of Potamides conicus into the Indian Ocean subprovince.