Stratigraphy of the Egyptian syn-rift deposits: correlations between axial and peripheral sequences of the north-western Red Sea and Gulf of Suez and their relations with tectonics and eustacy

Abstract

Dating of late Oligocene basalt in the continental early- rift deposits and micropalaeontological data (planktonic foraminifera, nanoplankton) recently obtained from Gebel el Zeit give limited but reliable correlations with the plankton-rich subsurface formations. The Burdigalian deposits equivalent to Nukhul and lower Rudeis formations appear to be rarely represented in the peripheral sequences where the sediments related to the major Langhian marine transgression generally lie unconformably either on Aquitanian evaporitic syn-rift unit or on pre-rift strata and basement morphologies. The upper pelagic marls, underlying the upper evaporitic unit at Gebel el Zeit, appear to be Serravallian in age. Thus a Middle Miocene age is proposed for most of the marine pre-evaporite strata of the western rift margin. Because of limited biostratigraphic correlations, subdivisions of the informal group stratigraphy are retained for general description of regional stratigraphy.