Sedimentology and stratigraphic architecture of the Cenomanian Bahariya Formation, Western Desert, Egypt

In the Western Desert of Egypt, the Cenomanian lower Bahariya Formation was deposited in marginal-marine to marine environments along a passive continental margin undergoing transgression. In the vicinity of the Khalda Ridge, the sedimentology and ichnology of thirteen cores are described.; Based on the presence of several significant stratigraphic surfaces demarcated by the Glossifungites ichnofacies, the facies of the lower Bahariya Formation are divided into four depositional stages. Stage 1 is the lowermost stage and represents deposition in a tide-influenced deltaic/estuarine setting. It contains tidal channel, brackish bay, tidal point bar, and delta front deposits that display abundant soft-sediment deformation. Stage 2 records deposition in the lower to middle shoreface. A major regressive surface is located at the base of Stage 3 and is overlain by sediment deposited in a tide-dominated estuary that represents an incised-valley fill. Stage 4 is the youngest stage and represents sediment deposited in a marine embayment subject to weak storm influence.