The problem of the Late Miocene-Early Pliocene boundary along the Red Sea coastal area between Quseir and Mersa Alam, Egypt.

The Late Miocene- Early Pliocene succession of the Red Sea coastal area between Quseir and Mersa Alam is differentiated, from base to top, into: Abu Dabbab Evaporites and the overlying informal rock units (A), (B) and (C).

The characteristic features of Unit (A) (Lithofacies, mineralogical, chemical compositions, fossil content as well as field relations) suggest that these sediments represent the last stage of the evaporitic phase deposited during the Late Miocene.

Indo-Pacific species such as : Borelis Haueri (d, Orbigny), Borelis reicheli (Souaya), Borelis schlumbergeri (Riechel), Archaeolithothamnium sp. cf. A.erythraeum (Rothpletz), and Elphidium striatopunctatum (Fichtel&Moll) are here recovered from the bioclastic limestones of Unit (B). Furthermore, the reported species of Amphiroa, with short-long cell alternations, in the same Unit (B) indicate an Early Pliocene age. Therefore, the Late Miocene-Early Pliocene boundary lies at the top of the siliciclastic sediments directly overlying the Abu Dabbab Evaporites (unit A) and at the base of open marine bioclastic facies of Unit B.