Cenomanian–turonian stable isotope signatures and depositional sequences in northeast Egypt and central Jordan

Abstract

Lithostratigraphic, biostratigraphic and microfacies studies of two Cenomanian-Turonian shallow-marine, siliciclastic-carbonate successions at Gebel Ekma plateau (southwestern Sinai, Egypt) and Wadi Karak section (central Jordan) are calibrated with δ13C-, profiles to reveal relative sea-level changes within a sequence stratigraphic framework. The study provides significantly enhanced stratigraphic resolution and key sections for regional correlation. Lithofacies are dominated by well-developed peritidal to subtidal facies associations indicating deposition in a rimmed carbonate shelf setting. Biostratigraphic analysis indicates the presence of 6 ammonite zones, 3 calcareous nannofossil zones and 3 planktonic foraminiferal zones within the Cenomanian to Turonian succession. Six, third-order depositional sequences, bounded by correlatable sequence boundaries can be traced across the African-Arabian platform. Comparison with δ13C records in deeper water pelagic sequences help to improve the resolution of the boundaries of each depositional sequence. Recognition of time gaps at the sequence boundaries on the platform, recorded in different parts of African-Arabian platform, is attributed to local tectonic activity, associated with the change from passive to active margins, which are overprinted by the global eustatic signature.