الفهرس | Only 14 pages are availabe for public view |
Abstract Following recent hydrocarbon exploration activity, this study has been carried out with the goal of defining the high-resolution biochronologic sequence stratigraphy of the Oligocene and Miocene succession in the offshore Nile Delta. Foraminiferal investigation of this succession in north Egypt, especially in the Nile Delta, shows the need for and importance of comparative studies combining the foraminiferal, calcareous nannofossils and palynological studies in order to make biostratigraphic subdivisions and to identify the Oligo-Miocene boundary.The study is based upon a detailed examination of two hundred and thirty-nine subsurface ditch cuttings and wireline logs data from three wells; Memphis-1, Habbar-1, and JH64-1R. The stratigraphic succession is represented by three formations: Tineh, Qantara and Sidi Salim which span the time interval from Early Oligocene to Late Miocene.The study resulted in the recognition of thirty-one planktonic foraminiferal species and thirty-two benthic foraminiferal species besides eight species of terrestrial palynomorphs (pollen grains and spores) and twenty-three species of dinoflagellates. These allowed to define eight planktonic foraminiferal zones and two dinoflagellate zones.The depositional regime of the area is discussed in terms of sea-level changes. The data propose that the changes from fluvial to open marine environment was controlled by sea-level changes during deposition of the studied formations. Ten 3rd order sequences are identified, six of these are Oligocene (RuSeq1, RuSeq2, RuSeq3 ChSeq4, ChSeq5, and ChSeq6), and the others are Miocene (AqSeq7, AqSeq8, BurSeq9, and TorSeq10). These sequences are measured and described in time and space for future development and modeling. The sequence boundaries and flooding surfaces were correlated with the global eustatic sea-level models.Four major breaks including Eocene-Oligocene, Lower-Upper Oligocene, Upper Oligocene-Lower Miocene and Aquitanian-Burdigalian boundaries with intraformational breaks are well defined |