Organic geochemistry of the Cenomanian-Turonian sequence in the Bakr area,Gulf of Suez, Egypt

The Cenomanian-Turonian transgression has been studied in a 220 m cored sec tion using common source rock data, elemental data and conventional biomark er parameters. Differences in the type of organic matter found in these reg ressive and transgressive offshore: marine sediments have been documented a nd assessed within a sequence stratigraphic framework. The interval of maxi mum flooding of the Cretaceous seaway shoreline is delineated by discontinu ities in the total organic carbon content and Hydrogen Index. The overall t ransgressive event is also accompanied by (a) an increase in the concentrat ions of elements such as thorium, vanadium, potassium, barium, sodium ... e tc., (b) changes in the relative concentrations and the characteristics of the biomarker parameters and (c) changes in the characteristic features of the kerogen. All of these data are consistent with a simultaneous decrease in terrigenous organic matter and increase in marine algal input.