Mahmoud Faris

Integrated biostratigraphy of two Upper Maastrichtian – Palaeocene successions in north-central Sinai, Egypt

Integration of the calcareous nannofossil and planktonic foraminiferal biostratigraphies has been performed for theUpper Maastrichtian – Palaeocene successions at Gebel Umm Khushayb and west El-Hassana sections (north-centralSinai, Egypt). The studied successions include the uppermost part of the Sudr, Dakhla, and their lateral coeval Beida Formation. Biostratigraphic analysis has allowed recognition from Zone CF2 to Zone P4in terms of planktonic foraminifera and from Zone CC26c to Zone NP7/8 in terms of calcareous nannofossils. Maastrichtian/Palaeogene (K/Pg) boundary is characterized by an erosional surface that marks a hiatus between theSudr/Dakhla or Sudr/Beida formation boundaries, as confi rmed by the absence of the planktonic foraminiferal CF1to P1a zones and their equivalent nannofossil zones (top part of CC26c to lowest part of Zone NP3). Selandian (Da/Se) boundary lies in the upper part of the Dakhla Formation within the top of nannofossil Zone NP4,and within planktonic foraminiferal Zone P3b, similar to that of the Global Standard Stratotype-section and Point(GSSP) of the D/S boundary which has recently been chosen at the Zumaia section, northern Spain. was observed across the Selandian/Thanetian boundary as indicated by a lithological change and a very condensedZone NP6, corresponding to the Dakhla and Tarawan formation boundary in the west El-Hassana section.

Plankton stratigraphy of the Early and Middle Miocene Kareem and Rudeis Formations in the central part of the Gulf of Suez, Egypt

The planktonic foraminifera and nannofossils of three wells in the Gulf of Suez penetrating the Early to Middle Miocene Upper Rudeis and Kareem Formations are attributed (from top to base) to the Middle Miocene Globorotalia peripheroronda Partial Range Zone (M6), the earliest Middle Miocene Praeorbulina sicana–Orbulina suturalis Interval Zone (M5), subdivided into the Praeorbulina glomerosa s. strict.–O. suturalis Interval Subzone (M5b) and the P. sicana–P. glomerosa s. str. Interval Subzone (M5a) and the Early Miocene Globigerinoides bisphericus Partial Range Subzone (M4b). The appearance of O. suturalis at the base of Subzone M5b represents the final stage of evolution of the Globigerinoides trilobus–Praeorbulina–Orbulina Lineage. In addition, the calcareous nannoplankton assemblages indicate the Sphenolithus heteromorphus Zone (NN5) and the Helicosphaera ampliaperta Zone (NN4). These biozones are well correlatable with those established by El-Heiny and Martini (1981, Geol Mediterr. Tome, VIII(2): 101–108) from the southwestern flank of the Gulf of Suez.

Bio- and Sequence Stratigraphy of Upper Cretaceous – Palaeogene rocks, East Bahariya Concession, Western Desert, Egypt

This work deals with the plankton stratigraphy of the subsurface Upper Cretaceous-Palaeogene succession of theEast 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 dividedinto 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 thoseof CATUNEANUet al., 2006); 4 System tracts of Turonianage, 2 System tracts of Campanian-Maastrichtian ageand 4 System tracts of Eocene age.

Quantitative calcareous nannofossil biostratigraphy of the subsurface Pliocene sequence, north-east Nile Delta, Egypt

Detailed quantitative calcareous nannofossil biostratigraphy was carried out on a subsurface lower–upper Pliocene succession (Kafr El Sheikh Formation) in three offshore wells (Ras El Barr-1, Bougaz-1 and Bougaz East-1), north-east Nile Delta area, Egypt. The standard zonations are easily applied in these sediments and additional biohorizons have been adopted in this study. For early to late Pliocene interval, the following five bioevents are considered reliable: last occurrences (LOs) of Discoaster surculus, D. tamalis, Reticulofenestra pseudoumbilicus and Amaurolithus tricorniculatus and first occurrence of D. asymmetricus. The LO of R. pseudoumbilicus was used to detect the early/late Pliocene boundary in the three studied wells. In Bougaz-1-Well, the LO of D. intercalcaris was used to approximate the Miocene/Pliocene boundary. The calcareous nannofossils are moderate to good preserved. Lower–upper Pliocene sediments are dominated by small-sized reticulofenestrids (R. minuta), Pseudoemiliania lacunosa, Helicosphaera carteri and H. kamptneri. Large size (>7 μm) R. pseudoumbilicus is recorded. Discoaster species is rarely represented. No nannofossils were found in the top part of the Kafr El Sheikh and the overlying Wastani Formations.

Upper Cretaceous to Lower Eocene calcareous nannofossil biostratigraphy from Malaqet and Mundassah sections western flank of the Northern Oman Mountains

This work is the first attempt to undertake a biostratigraphic study on calcareous nannofossil assemblages of the exposed Upper Cretaceous to Lower Eocene rocks at the Malaqet and Mundassah sections, NW Oman. The Upper Cretaceous to Lower Eocene rocks belong to the Simsima Formation and the Muthaymimah Formation. Specimens of calcareous nannofossils identified during this study have been ascribed to 67 different species. The Cretaceous/Palaeocene boundary can be placed in correspondence with the unconformity between the mentioned formations. The presence of a big hiatus in this area is suggested by the absence of the latest Maastrichtian Micula prinsii nannofossil Zone, and the Palaeocene NP1 and NP2 nannofossil Zones. In the two study sections, the Danian/Selandian boundary is placed at the level of the first occurrence (FO) of Fasciculithus tympaniformis (base of NP5 Zone). At Jabal Mundassah, the Selandian/Thanetian boundary is positioned at the FO of Discoaster mohleri, which is used to define the base of NP7/8 Zone. Unfortunately, a major hiatus is detected at the Selandian/Thanetian boundary at the Jabal Malaqet section as indicated by the absence of NP6 and NP7/8 Zones. The Paleocene/Eocene boundary is placed at the base of Subzone NP9b at Jabal Mundassah, whereas at Jabal Malaqet the Paleocene/Eocene boundary interval is missing and a major hiatus is testified by the absence of the NP9b Subzone and NP10 Zone. This work is the first attempt to undertake a biostratigraphic study on calcareous nannofossil assemblages of the exposed Upper Cretaceous to Lower Eocene rocks at the Malaqet and Mundassah sections, NW Oman. The Upper Cretaceous to Lower Eocene rocks belong to the Simsima Formation and the Muthaymimah Formation. Specimens of calcareous nannofossils identified during this study have been ascribed to 67 different species. The Cretaceous/Palaeocene boundary can be placed in correspondence with the unconformity between the mentioned formations. The presence of a big hiatus in this area is suggested by the absence of the latest Maastrichtian Micula prinsii nannofossil Zone, and the Palaeocene NP1 and NP2 nannofossil Zones. In the two study sections, the Danian/Selandian boundary is placed at the level of the first occurrence (FO) of Fasciculithus tympaniformis (base of NP5 Zone). At Jabal Mundassah, the Selandian/Thanetian boundary is positioned at the FO of Discoaster mohleri, which is used to define the base of NP7/8 Zone. Unfortunately, a major hiatus is detected at the Selandian/Thanetian boundary at the Jabal Malaqet section as indicated by the absence of NP6 and NP7/8 Zones. The Paleocene/Eocene boundary is placed at the base of Subzone NP9b at Jabal Mundassah, whereas at Jabal Malaqet the Paleocene/Eocene boundary interval is missing and a major hiatus is testified by the absence of the NP9b Subzone and NP10 Zone.

Calcareous nannofossil biostratigraphy of the Paleocene at the Misheiti section, East Central Sinai, Egypt

Integration of calcareous nannofossil data, δ13C and δ18O values, and carbonate contents of the lower Paleocene–upper Paleocene sequence that crops out at the Misheiti section, East Central Sinai, Egypt, were used to denote the Danian/Selandian (D/S) and Selandian/Thanetian (S/T) stage boundaries. The study interval belongs to the Dakhla and Tarawan formations. Four calcareous nannofossil zones (NP4, NP5, NP6, and NP7/8) were recognized. The base of the Selandian Stage is tentatively placed at the lowest occurrences (LOs) of taxa ascribable to the second radiation of fasciculiths (i.e., Lithoptychius janii). This level is marked by a sudden drop of δ13C and δ18O values and carbonate content. No distinctive lithological changes were observed across the D/S boundary at the study section. A hiatus at the NP5/NP6 zonal boundary is indicated by the condensation of zones NP5 and NP6.The base of the Thanetian is placed at the base of Zone NP7/8 at the lithological change observed in correspondence to the boundary between the Dakhla and Tarawan formations. The δ13C and δ18O values abruptly decrease slightly above the base of Zone NP7/8. No consistent variations in the carbonate contents were recorded within Zone NP6 or across the NP6/NP7/8 zonal boundary.

Calcareous nannofossil biostratigraphy of the marine Oligocene and Miocene succession in some wells in Northern Egypt

Twelve calcareous nannofossil biozones of Late Oligocene-Late Miocene in Northern Egypt were defined and correlated with their corresponding biozones in Egypt and other parts of the world. These are arranged from the top to base as Zone NN12, Zone NN11, Zone NN10, Zone NN8, Zone NN7, Zone NN6 Zone NN5, NN4, Zone NN3, Zone NN2 Zone NP25 and Zone NP24. In the present study (Boughaz-1 Well), the Late Miocene unconformably overlies the Middle Miocene. This unconformity surface is recognized by the missing of calcareous nannofossil zones NN7 to NN9. While, in North Sinai (Malha-1 Well), the Early/Middle Miocene boundary cannot be recognized, where the Middle Miocene unconformably overlies the topmost Oligocene, and it is defined by the missing calcareous nannofossil zones NN1 to NN4.