Ahmed Ibrahim Abd El Naby

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.

Tectono-sedimentary evolution of active extensional basins controlling the deposition of the Middle Miocene Kareem Formation, southwestern Gulf of Suez, Egypt

Tectono-sedimentary evolution of the Gulf of Suez active extensional basin affected the deposition of the syn-rift Middle Miocene (Langhian) Kareem Formation. Six interpreted tectono-sedimentary models and lithofacies distribution maps are based mainly on facies interpretation and log data from ten wells. They revealed the paleogeography during six system tracts of the two third-order depositional sequences of this formation. Differential fault block movement resulted in the presence of deep basins beside high-relief areas and consequent sudden thickness and facies changes. The interpretation of depositional settings and the structural evolution during the six system tracts of the two depositional sequences is based on interpretations of earlier tectonics, the interaction between sedimentation and tectonism, subsidence rates, and abrupt thickness as well as facies changes along the individual fault blocks.

What is Nummulites depressus Kenawy 1978? Evolution of Nummulites fabianii group in the Middle Eocene of Egypt

New species Nummulites vetustufabianiin. sp. is described from the El Hamra Formation, Gara El Hamra section Bahariya Oasis Western Desert. The biometrical measurements include maximum and minimum diameter of the successive radii and heights of whorls, length/height ratio, number of chambers and the marginal cord thickness of each whorl for the megalospheric generation as well as the diameter of proloculus were elaborated to differentiate between some allied granulated species such as Nummulites depressus, Nummulites decrouezae, Nummulites cuvillieri and N. vetustufabianiin. sp.Nummulites fabianii group has lateral distribution for the entire Tethys basin, hence such biometrical studies are needed to emphasise the polyphyletic nature of the group.

Biometric analysis of Nummulites bahariyaensisn. sp. (Nummulites partschi group) from the Bartonian of Bahariya Oasis, Egypt

Nummulites bahariyaensisn. sp., typical of Nummulites partschi group, Nummulites gizehensis subgroup, is biometrically studied, described and photographed through both generations from El-Hamra Formation, Garra El Hamra, northern plateau of Bahariya Oasis, Western Desert of Egypt. From the biometric analysis, N. bahariyaensis is phylogenetically parallel to Nummulites lyelli, both of Bartonian age based on the presence of Nummulites decrouezae and Nummulites aff. pulchellus which were dated as Bartonian from Gebel Mokattam, the species which is equated with those from Naalon stratigraphic section, Fayum, by Morsi et al. (2003). Nummulites bahariyaensis could be compared with Nummulites champollioni as both are thick in the microspheric generation. However, the phylogeny of the present new species should be searched on. The described species spans SBZ 17 of the Shallow Benthic Zones of Serra-Kiel et al. (1998, Bull Soc Geol France 169(2):281–299), which denotes an Early Bartonian ( = Biarritzian sensu Hottinger and Schaub 1960, Eclogae Geol Helv 53: 453–479). At Garra El Hamra, El-Hamra Formation with N. bahariyaensis unconformably overlies the Qazzun Formation (Late Ypresian) emphasising that the Lutetian and the top part of Ypresian possibly are missing.http://zoobank.org/22549148-0BD6-4097-A22C-01CA614B5CE1

New Middle Eocene Nummulites from Kait Bey, Gebel Mokattam, Egypt

Nummulites paucispira and Nummulites kaitbeyi are newly erected from the Upper Building Stone Member (Bartonian) of the Mokattam Formation at Kait Bey, Gebel Mokattam, Greater Cairo, Egypt both belong to Nummulites partschi group. N. paucispira and N. kaitbeyi are different in their ontogenetic growth stages; N. paucispira has a step of coiling from tight to lax, contrary to N. kaitbeyi. The regression line of both species indicates that both are distinct and they belong to different lineages. Detailed investigations of the new species N. paucispira n. sp. and N. kaitbeyi n. sp. of N. partschi group and their ontogenetic growth stages are discussed. This study is of considerable importance for distinguishing paleoecological events of Bartonian stage and for tracing the phylogenetic trends for the entire Tethys basin.

Biostratigraphy and seismic data analysis to detect the sequence stratigraphic depositional environment of the Miocene succession: Gulf of Suez (Egypt)

This work comprises a study of the sequence stratigraphy, seismic-facies analysis, biostratigraphy and depositional environments of the northern part of the Gulf of Suez, Egypt, using a set of 24 3D seismic profiles, composite logs and sonic logs from ten wells. The syn-rift formations in the studied ten wells are described lithologically and interpreted based on investigating two seismic profiles. Biostratigraphically, the Miocene fossils are identified to correlate the five planktonic foraminiferal biozones in the examined boreholes (RB-A1, RB-B1, RB-B3, EE85-2 and RB-C1). The sequence stratigraphic analysis suggests that the Miocene succession can be subdivided into two major third order depositional sequences (S1 and S2) separated by the three major sequence boundaries (DSB1, DSB2 and DSB3).