Bio- and sequence stratigraphy of Upper Cretaceous - Palaeogene rocks, East Bahariya concession, Western Desert, Egypt

Abstract

This work deals with the plankton stratigraphy of the subsurface Upper Cretaceous-Palaeogene succession of the East Bahariya Concession based on planktonic foraminifera and calcareous nannofossils. The examination of the cuttings from five wells: AQSA-1X, KARMA-E-1X, KARMA-3X, KARMA-NW-1X and KARMA-NW-5X is biostratigraphically evaluated. It is possible to identify the planktonic foraminifera as well as the calcareous nannofossil biozones. The analyses of calcareous nannofossils revealed the presence of several hiatuses. Information obtained from well data such as seismic facies analysis for the studied area has enabled classification of the Upper Cretaceous- Palaeogene succession into five major 2nd order depositional sequences, separated by four major depositional sequence boundaries (SB1, SB2, SB3 and SB4). The Upper Cretaceous-Palaeogene succession in the East Bahariya is divided into 17 systems tracts. These systems tracts are: 7 System tracts of probable Cenomanian age, (the sequence stratigraphic framework as well as the cycles and system tracts of the Cenomanian Bahariya Formation match well with those of CATUNEANU et al., 2006); 4 System tracts of Turonian age, 2 System tracts of Campanian-Maastrichtian age and 4 System tracts of Eocene age.